Database: MEDLINE <: biomedical, nursing & dental literature, 1966 - Oct 2000.> Search Strategy (You Saved Citations 1-143 From Set 53): ----------------------------------------------------------------------------- 1 exp Tooth demineralization/ 22653 2 demineralization.mp. 1622 3 caries.mp. 15310 4 caires.mp. 1 5 craies.mp. 0 6 careis.mp. 4 7 carise.mp. 0 8 (teeth adj3 cavit:).mp. 422 9 (tooth adj3 cavit:).mp. 217 10 (dental adj3 cavit:).mp. 276 11 (dentin adj3 cavit:).mp. 255 12 (enamel adj3 cavit:).mp. 182 13 (teeth adj3 decay:).mp. 375 14 (tooth adj3 decay:).mp. 322 15 (dental adj3 decay:).mp. 250 16 (dentin adj3 decay:).mp. 12 17 (enamel adj3 decay:).mp. 20 18 (active adj decay).mp. 9 19 (rampant adj3 decay:).mp. 14 20 (recurrent adj3 decay:).mp. 30 21 (white adj spot:).mp. 510 22 carious.mp. 2082 23 cariology.ti,ab. 56 24 (non-cavitated adj3 lesion:).mp. 15 25 (noncavitated adj3 lesion:).mp. 2 26 Tooth remineralization/ 479 27 (dental adj3 fissure:).mp. 99 28 (tooth adj3 fissure:).mp. 50 29 (teeth adj3 fissure:).mp. 98 30 caries-free.mp. 605 31 cariesfree.mp. 17 32 Cariogenic agents/ 728 33 precavit:.mp. 8 34 (filled adj3 teeth).mp. 511 35 (filled adj3 tooth).mp. 117 36 (oral adj fissure:).mp. 6 37 (tooth adj3 remineraliz:).mp. 28 38 (teeth adj3 remineraliz:).mp. 24 39 dft.mp. 413 40 dfs.mp. 1261 41 dmf:.mp. 6402 42 cariogeni:.mp. 1787 43 or/1-42 32291 44 Dental leakage/ 1854 45 (mineral adj loss).mp. 409 46 or/43-45 34030 47 exp Ultrasonics/ 30250 48 Ultrasonography/ 30205 49 ultrason:.mp. 105960 50 ultrasound:.mp. 49937 51 (acoustic adj3 microscop:).mp. 167 52 or/47-51 127619 53 46 and 52 143 54 from 53 keep 1-143 143 *************************** <1> UI - 20327486 AU - Eisenburger M AU - Hughes J AU - West NX AU - Jandt KD AU - Addy M IN - Department of Prosthetic Dentistry, Medical University of Hanover, Hanover, Germany. TI - Ultrasonication as a method to study enamel demineralisation during acid erosion. SO - Caries Research 2000 Jul-Aug;34(4):289-94 AB - The aim of this study was to use ultrasonication as a method to measure subsurface demineralisation of enamel. Polished human enamel samples with surface profiles within +/-0.3 microm were divided into 6 groups of 10 specimens. The groups of specimens were exposed to 0. 3% citric acid (pH 3.2) for 30 min, 1, 2, 3 or 4 h. The depths of the resulting lesions were measured using a profilometer. A control group was stored in water for 4 h. Ultrasonication in water was performed on the specimen groups for 5, 30, 120, 240 and 480 s with profilometric measurements at each time point. The depth of the erosion increased linearly with the exposure time. Most of the additional loss of enamel occurred with the 5-second ultrasonication. The 30-min and 1-hour erosion lesions were further deepened by approximately 1 microm with 5 s of ultrasonication. The 2-, 3- and 4-hour lesions were deepened by 2-4 microm with 5 s of ultrasonication. There were no changes in the control group. It is concluded that ultrasonication removed softened enamel from the surface of the eroded enamel. Ultrasonication together with accurate measurement of lesion depth by profilometry offers a useful method for studying the depth of enamel softening associated with erosion. <2> UI - 20317427 AU - Banerjee A AU - Watson TF AU - Kidd EA IN - Division of Conservative Dentistry, Guy's, King's and St. Thomas' Dental Institute, KCL, London. avijit.banerjee@kcl.ac.uk TI - Dentine caries excavation: a review of current clinical techniques. [Review] [62 refs] SO - British Dental Journal 2000 May 13;188(9):476-82 AB - Since the invention and application of rotary instruments, the operative treatment of carious lesions has often resulted in considerable removal of tooth structure. More recently, newer techniques for removal of carious dentine have been developed in an attempt to minimise this excessive tissue loss. The following article reviews and discusses some of the techniques available to excavate demineralised dentine clinically. These methods can be classified as mechanical and non-mechanical, rotary and non-rotary and include: dental handpieces/burs, manual excavators, air-abrasion, air-polishing, ultrasonication, sono-abrasion, chemo-mechanical methods, lasers and enzymes. The advantages and disadvantages of each technique are discussed. [References: 62] <3> UI - 20237501 AU - Banerjee A AU - Kidd EA AU - Watson TF IN - Division of Conservative Dentistry, Guy's, King's and St. Thomas' Dental Institute, KCL, London, UK. avijit.banerjee@kcl.ac.uk TI - In vitro evaluation of five alternative methods of carious dentine excavation. SO - Caries Research 2000 Mar-Apr;34(2):144-50 AB - This in-vitro, split-tooth study aimed to evaluate the efficiency (time taken) and effectiveness (quantity of dentine removed) of four techniques of carious dentine excavation (bur, air-abrasion, sono-abrasion and Carisolv gel) compared to conventional hand excavation. Eighty freshly extracted human molars were assigned to four experimental groups (n = 20), sectioned longitudinally through occlusal lesions and pre-excavation colour photomicrographs obtained. Using the natural autofluorescence of carious dentine (detected using confocal laser scanning microscopy) as an objective and reproducible guide, carious dentine removal was assessed in each half of the split tooth sample, comparing hand excavation to the test method. The time taken to reach a cavity floor that was hard to a dental probe was noted and final colour photomicrographs were taken. From the results, it was concluded that bur excavation was quickest but overprepared cavities relative to the autofluorescent signature, whereas Carisolv excavation was slowest but removed adequate quantities of tissue. Sono-abrasion tended to underprepare whereas air-abrasion was more comparable to hand excavation in both the time and amounts of dentine removed. Conventional hand excavation appeared to offer the best combination of efficiency and effectiveness for carious dentine excavation within the parameters used in this study. <4> UI - 20221859 AU - Aqrabawi J IN - Faculty of Dental Medicine, University of Jordan, Amman, Jordan. TI - Sealing ability of amalgam, super EBA cement, and MTA when used as retrograde filling materials. SO - British Dental Journal 2000 Mar 11;188(5):266-8 AB - OBJECTIVE: To compare apical microleakage of MTA following reverse retrograde root filling with that following amalgam and EBA retrofilling. DESIGN: Prospective random control trial. SETTING: It was conducted at the University of Jordan in 1998. MATERIALS AND METHODS: The root canals of 79 extracted teeth were instrumented and obturated with vertically condensed gutta-percha. Each tooth was apically resected and the apex was prepared ultrasonically to 3 mm depth and the root surface isolated with nail varnish. Teeth were divided randomly into three groups of 25 teeth each. First group was retrofilled with amalgam, second group with EBA and the third group with MTA. Following immersion in 1% methylene blue dye for 72 hours, the roots were sectioned and the depth of dye penetration was evaluated by a stereomicroscope at x10 magnification. INTERVENTIONS: Super EBA is a reinforced zinc oxide cement based on a mixture of 32% eugenol and 68% ethoxy benzoic acid (EBA). MTA is a mineral trioxide aggregate cement (MTA) based on a mixture of sterile water. MAIN OUTCOME MEASURES: The sealing effectiveness of the retrograde filling materials used in this study was determined by their ability to inhibit dye penetration. RESULTS: 56% of the group filled with amalgam and 20% of the group filled with EBA showed dye leakage beyond the retrofilling material whereas the MTA group showed none, two samples from MTA group were eliminated because of their fractured roots. The chi-squared test revealed a statistically significant difference among all three groups (P < 0.05). CONCLUSION: MTA cement provides a better seal than amalgam and EBA cement when used as retrograde filling, but the extrapolation of this result into a clinical practice may be questionable. <5> UI - 20131017 AU - Reppel R AU - Goldbecher C AU - Schubert J IN - Klinik und Poliklinik fur Mund-, Kiefer- und Gesichtschirurgie, Martin-Luther-Universitat Halle-Wittenberg, Halle, Deutschland. TI - [The preparation of retrocavities in apicoectomies]. [German] SO - Mund-, Kiefer- und Gesichtschirurgie 2000 Jan;4(1):30-4 AB - The purpose of this in vitro and in vivo study was to compare the quality of retrograde cavities and retrofilling using various retrograde techniques (microhead, ultrasonic). The quality was evaluated on the basis of dye penetration, macroscopic control, and both light microscopic and scanning electron microscopic examination. A total of 40 extracted teeth with a single canal were analyzed. The clinical result was evaluated in 25 patients with root-filled teeth and the indication of apicoectomy. Statistical analysis indicated that the seal was significantly better with ultrasonically prepared cavities than with microhead preparation. Retrofillings prepared ultrasonically also showed significantly fewer peripheral fissures. The scanning electron microscopic examination, however, demonstrated peripheral fissures in all filled teeth. Furthermore, the cavities prepared ultrasonically had a smoother surface and a lower smear layer. This preparation produced a more pleasing final result. The advantages of better accessibility during the preparation, namely, more precise preparation of the retrofilling and only minor substance loss were confirmed clinically. Using the ultrasonic equipment, absolutely sterile working conditions are present. <6> UI - 20174115 AU - Banerjee A AU - Kidd EA AU - Watson TF IN - Division of Conservative Dentistry, Guy's, King's and St. Thomas' Dental Institute, Guy's Dental Hospital, London, UK. avijit.banerjee@kcl.ac.uk TI - Scanning electron microscopic observations of human dentine after mechanical caries excavation. SO - Journal of Dentistry 2000 Mar;28(3):179-86 AB - OBJECTIVES: The structural integrity and surface characteristics of dentine remaining after caries excavation may be relevant to the subsequent bonding of adhesive restorative materials to the prepared cavity. This in vitro investigation aimed to analyse the different surface characteristics of the dentine cavity floor created after preparation using five different mechanical and chemo-mechanical methods of excavation: hand excavation, slow-speed bur, sono-abrasion, air-abrasion and Carisolv gel. METHODS: Ten cavities were prepared using each excavation method in extracted teeth with occlusal carious lesions. Epoxy resin replicas of the 50 cavities were manufactured from silicone impressions and then analysed using secondary electron scanning electron microscopy (SEM) to ascertain the surface characteristics of the dentine at the cavity floor. RESULTS AND CONCLUSIONS: Results from the 50 cavities examined suggested that each alternative excavation technique produced a different and characteristic dentine surface. Carisolv gel was the only method examined that consistently removed the smear layer during excavation to leave exposed dentine tubules at the end of cavity preparation. <7> UI - 20107077 AU - Fukuizumi T AU - Inoue H AU - Tsujisawa T AU - Uchiyama C IN - Department of Oral Microbiology, Kyushu Dental College, Kokura-kita, Kitakyushu, Fukuoka 803-8580, Japan. izumi@kyu-dent.ac.jp TI - Streptococcus sobrinus antigens that react to salivary antibodies induced by tonsillar application of formalin-killed S. sobrinus in rabbits. SO - Infection & Immunity 2000 Feb;68(2):725-31 AB - We previously found that tonsillar application of antigen induces a strong antibody response to Streptococcus sobrinus in saliva and blood plasma. Rabbits immunized against S. sobrinus by tonsillar application were highly resistant to experimental dental caries triggered by oral inoculation of living S. sobrinus organisms with sucrose. In the present study, we examined the reaction of S. sobrinus antigens to the antibodies induced by the tonsillar application of S. sobrinus AHT-k in rabbits and compared them to those antibodies induced by intramuscular injection. In an enzyme-linked immunosorbent assay using ultrasonic fragments from mutans group streptococci, the saliva and blood plasma selectively reacted to S. sobrinus AHT-k (serotype g) and serologically related streptococci (serotypes a, d, and h) in the sixth week after tonsillar application, whereas the blood plasma in the sixth week after intramuscular injection reacted to the unrelated streptococci (serotypes b, c, e, and f) in addition to the aforementioned streptococci. The antibody reactivity induced after tonsillar application was not lost after treatment of the antigen with heat or proteinase digestion, whereas these treatments resulted in a 70% decrease of the antibody reactivity induced by intramuscular injection. The inhibition by haptenic sugars and the decrease in immunoreactivity by heat treatment and proteinase digestion suggested that 80% of the antibodies induced by tonsillar application reacted to saccharides. These saccharide antigens appeared to be involved in a specific reaction with S. sobrinus-specific streptococci and a selective reaction with serologically related streptococci. These antigens are probably involved in anticaries reactions in experimental dental caries. <8> UI - 20101172 AU - Shimada Y AU - Kondo Y AU - Inokoshi S AU - Tagami J AU - Antonucci JM IN - Department of Operative Dentistry, Faculty of Dentistry, Tokyo Medical and Dental University, Japan. TI - Demineralizing effect of dental cements on human dentin. SO - Quintessence International 1999 Apr;30(4):267-73 AB - OBJECTIVE: This study was undertaken to verify the hypothesis that dentin surfaces are demineralized during placement of four kinds of chemically setting cements (zinc phosphate cement, luting glass-ionomer cement, restorative glass-ionomer cement, and zinc polycarboxylate cement). METHOD AND MATERIALS: Sixty cemented dentin disks were observed under scanning electron microscopy and with confocal laser scanning microscopy after use of an argon-ion etching technique. To determine the surface effects of the cements, 30 dentin surfaces were treated with 1 of 6 freshly mixed cements (5 per group) for 60 seconds. The disks were subjected to rinsing with a water spray and ultrasonic washing prior to scanning electron microscopic observation. RESULTS: Observation of cemented dentin specimens revealed that the dentin was not completely demineralized at the interface formed by the cement and dentin and that the extent and depth of demineralization along the interface tended to be nonuniform. Zinc phosphate cement caused the greatest demineralization of dentin, followed by luting glass-ionomer cement. The extent of demineralization with restorative glass-ionomer cement or zinc polycarboxylate cement was less discernible. Confocal laser scanning microscopy generally confirmed scanning electron microscopic observations and revealed that most of the specimens showed close adaptation of the cements to the dentin surfaces. CONCLUSION: Acid-containing cements have self-etching properties that are effective, to various degrees, in removing the smear layer and promoting close adaptation to dentin surfaces. <9> UI - 20101137 AU - Yaccino JM AU - Walker WA 3rd AU - Carnes DL Jr AU - Schindler WG IN - Department of Endodontics, Wilford Hall Medical Center, Lackland AFB, TX 78284-7892, USA. TI - Longitudinal microleakage evaluation of Super-EBA as a root-end sealing material. SO - Journal of Endodontics 1999 Aug;25(8):552-4 AB - This study evaluated the sealing ability of fast and regular set Super-EBA with different powder-to-liquid ratios as a root-end filling material. Fifty extracted maxillary central incisors were uniformly cleaned and shaped using a crown-down technique with Gates-Glidden drills and Profile series 29.04 taper rotary instruments. After root-end resection and ultrasonic preparation, 48 root sections were randomly assigned to 4 groups of 12 teeth each and filled with a thick or thin mix of fast or regular set Super-EBA. Fast and regular set Super-EBA were mixed to a thick (1 scoop powder:1 drop liquid) or a thin (1 scoop powder:2 drops liquid) consistency. Positive and negative controls were used. Microleakage was assessed at 24 h, 72 h, 1 wk, 2 wk, 4 wk, 6 wk, and 8 wk using a fluid filtration system. There were no significant differences in the microleakage measured for any group at any of the time points evaluated. These results suggest that either fast or regular set Super-EBA mixed to various consistencies may be acceptable for root-end filling. <10> UI - 20069196 AU - Laugier P AU - Novikov V AU - Elmann-Larsen B AU - Berger G IN - Laboratoire d'Imagerie Parametrique UMR 7623, 15 Rue de l'Ecole de Medecine 75006 Paris, France. TI - Quantitative ultrasound imaging of the calcaneus: precision and variations during a 120-Day bed rest. SO - Calcified Tissue International 2000 Jan;66(1):16-21 AB - This study reports on the precision and variation of quantitative ultrasound (US) parameters [broadband ultrasonic attenuation (BUA) or slope of the frequency-dependent attenuation in dB/MHz and speed of sound (SOS m/second)] after 120 days of continuous bed rest in six normal male volunteers. Quantitative US was measured at the calcaneus using a new US bone imaging scanner. The measurements were carried out on both heels at approximately 2-week intervals. The short-term precision was 0.31% for SOS and 2.8% for BUA. The long-term precision was 0.58% for SOS, 4.7% for BUA. A significant decrease of SOS values of -26 m/second (P < 0.0001) for the right heel and -17 m/second (P < 0.05) for the left heel was found at the group level. In terms of percentage change this represents -1.7% for the right heel and -1.1% for the left heel. These percentage decrements were 3.5-5.5 times that of the short-term precision and 2-3 times that of the long-term precision of the technique. At the individual level, the decrease of SOS was statistically significant (P < 0.05) or marginally significant (P < 0.1) for four out of 6 subjects. For 2 other subjects, similar trends were observed, but without reaching statistical significance. BUA did not change significantly during follow-up. These results are consistent with previous findings on changes of ultrasonic properties from the calcaneus during aging, pregnancy, or therapy, showing that calcaneus SOS is a valuable index of bone loss. These preliminary data suggest that prolonged exposure to simulated weightlessness may lead to a lower SOS, which then could be used for the follow-up of bone demineralization occurring during long-term space flights. <11> UI - 20064442 AU - Daugherty D AU - Biggs JT TI - A preliminary evaluation of the effect of ultrasonic root end cavity preparation and reverse filling on the ability of plastic core Thermafil obturations to maintain an air-tight seal. SO - Journal - Oklahoma Dental Association 1998 Fall;89(2):38-44 <12> UI - 20032664 AU - Kocian J AU - Kocianova J IN - I. interni klinika IPVZ-FTN, Praha, Gastroenterologicke pracoviste, Praha. TI - [Bone demineralization in Crohn's disease, its diagnosis, therapy and prevention]. [Review] [30 refs] [Czech] SO - Casopis Lekaru Ceskych 1999 Aug 30;138(17):522-4 AB - In 20-60% of patients with Crohn's disease bone demineralization is found, usually osteoporosis, but also osteoporosis with malatic features. The cause is the reduced calcium intake (loss of appetite, lactose intolerance and malabsorption), reduced vitamin D intake and corticoid therapy. Nowadays the diagnosis is facilitated by the use of densitometers (ultrasonic and DEXA) and markers of osteoresorption and new bone formation. In treatment in addition to calcium and vitamin D used for a long time, fluorides are administered (only as monofluorophosphate), nasal thyrocalcitonin and bisphosphonates of the third series (alendronate). In postmenopausal women also hormonal treatment can be used unless contraindicated. However, burdening of the bones with regular exercise is a necessity. For prevention adequate calcium and vitamin D intake is important, non-smoking, and exercise. [References: 30] <13> UI - 99362185 AU - Janjan NA AU - Abbruzzese J AU - Pazdur R AU - Khoo VS AU - Cleary K AU - Dubrow R AU - Ajani J AU - Rich TA AU - Goswitz MS AU - Evetts PA AU - Allen PK AU - Lynch PM AU - Skibber JM IN - Department of Radiation Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA. TI - Prognostic implications of response to preoperative infusional chemoradiation in locally advanced rectal cancer. SO - Radiotherapy & Oncology 1999 May;51(2):153-60 AB - BACKGROUND AND PURPOSE: To evaluate the influence of response to preoperative infusional chemoradiation on outcome parameters among patients with locally advanced rectal cancer. MATERIALS AND METHODS: Preoperative chemoradiotherapy, 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil (300 mg/m2 per day), was given to 117 patients. As determined by pretreatment endorectal ultrasound (EUS), 96% of cases were Stage T3, and 51% had EUS evidence of perirectal adenopathy. Surgery was performed approximately 6 weeks after chemoradiation therapy. Postoperatively adjuvant systemic therapy, consisting of 400-425 mg/m2 of 5-fluorouracil plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for six cycles. Outcome parameters of local control (LC), freedom from distant metastases (DMC), disease-free survival (DFS) and cancer specific survival (CSS) were evaluated relative to primary tumor characteristics. RESULTS: The final post-treatment pathological tumor stages were complete response in 27%, Tis-2 N0 in 26%, T2 N1 in 5%, T3 N0 in 21%, T3 N1 in 15%, T4 N0 in 5% and T4 N1 in 1%. Down-staging occurred in 61% of cases. The pretreatment primary tumor size only influenced rates of local control (P < 0.03) and had no other influence on outcome parameters. Pretreatment evidence of perirectal lymph node involvement had no impact on outcome parameters. Pathologic evidence of nodal involvement did affect DMC (P < 0.002) and DFS (P < 0.003). Pathologic evidence of response did influence freedom from the development of distant metastases (P < 0.004). On pairwise analysis this relationship held only when responders were compared to non-responders. No difference was observed based on the level of downstaging at the primary tumor. Correspondingly, DFS was improved when non-responders were compared to downstaged patients (P < 0.01). Response to preoperative chemoradiation failed to affect rates of LC or CSS. For the group as a whole, adjuvant chemotherapy improved only CSS (P < 0.03). Adjuvant chemotherapy was given to 74 patients, 36 of whom had responded to preoperative chemoradiation. Improvements were only seen in DFS (P < 0.03) when down-staged patients were compared to the non-responders who received adjuvant chemotherapy. In addition, the DFS rates were lower in the non-responder group who received adjuvant chemotherapy even when they were compared to down-staged patients who did not receive adjuvant chemotherapy (P < 0.04). CONCLUSION: Consistent with other reports, disease free survival and subsequent development of distant metastases is reduced in the more than 60% of patients who respond to preoperative infusional chemoradiation. Evidence of response appears more significant than the degree of response. At present, no impact is seen on cancer specific survival rates. Consideration should be given for strategies that base selection of subsequent adjuvant chemotherapy on response to preoperative chemoradiation. <14> UI - 99209261 AU - Hugo B IN - Klinik und Poliklinik fur Zahnerhaltung und Parodontologie, Bayerische Julius-Maximilians-Universitat, Wurzburg. TI - [Oscillating procedures in the preparation technic (II). Their development and application possibilities]. [Review] [42 refs] [German, French] SO - Schweizer Monatsschrift fur Zahnmedizin 1999;109(3):269-85 AB - The acceptance and use of amalgam as an everyday filling material is decreasing. Today, direct composite fillings are widely used to restore even extensive lesions in premolars and molars. The sonoabrasive method presented here uses special working tip geometries (SONSICSYS approx) to a allow a "finishing preparation" of standardized interproximal cavities. In this process, the "negative shape" of the working tip is transferred to the tooth. It is now possible, for the first time, to accurately restore class II box cavities using prefabricated ceramic inlays. Complicated layering techniques are no longer necessary and there is no risk of compromising interproximal contacts remaining occlusal defects can be restored with conventional composites. The use of special SONICSYS working tips for ceramic and cast gold cavity preparations ensures precise cavity geometries with "close-to-perfect" margins. The sonoabrasive method greatly lowers the technique sensitivity of such difficult types of preparations. [References: 42] <15> UI - 99132447 AU - Hetzel A AU - Braune S AU - Guschlbauer B AU - Dohms K IN - Department of Neurology, University of Freiburg, Freiburg, Germany. HETZEL@NZ11.UKL.Uni-Freiburg.DE TI - CO2 reactivity testing without blood pressure monitoring?. SO - Stroke 1999 Feb;30(2):398-401 AB - BACKGROUND AND PURPOSE: Responsiveness to CO2 is an established test of cerebrovascular reserve capacity. Arterial partial pressure of CO2 (PCO2) and arterial blood pressure (BP) are key parameters for cerebral blood flow. To investigate the interaction between PCO2 and BP, we performed a study with simultaneous measurement of CO2 and BP during CO2 reactivity testing with transcranial Doppler sonography. METHODS: Eighty-one healthy volunteers, aged 19 to 74 years, underwent examination defined by a protocol with multimodality monitoring of BP, heart rate (HR), PCO2, and Doppler frequencies (DFs) of the left middle cerebral artery (MCA). Reproducibility was tested in a subgroup of 14 volunteers >/=65 years of age by CO2 reactivity testing on different days. RESULTS: Increase of PCO2 was accompanied by a parallel increase of mean+/-SD time values of DF (3. 6+/-1.6%/mm Hg CO2). BP levels were significantly elevated after 60-second hypercapnia (mean values, 0.5+/-0.55 mm Hg/mm Hg CO2). A significant decrease over time was seen only for pulsatility in DF but not in BP. Analysis of variance and covariance with repeated measures revealed a highly significant effect of CO2 on MCA Doppler shift. A less-pronounced effect on DF was seen for BP. Correlation analysis showed no significance for CO2 reactivity, but a significant correlation between test and retest was seen in BP-related CO2 reactivity. CONCLUSIONS: The CO2 response curve showed the known linear increase of DF. The parallel significant increase in BP most likely results from activation of the central sympathetic nervous system. The poor reproducibility for Doppler CO2 reactivity is to some extent explainable by variability of BP. CO2-induced increases in BP can have relevant influence on MCA Doppler shift and lead to misinterpretation of Doppler CO2 test results. <16> UI - 99459765 AU - Adamo HL AU - Buruiana R AU - Schertzer L AU - Boylan RJ IN - Department of Endodontics, New York University College of Dentistry 100104086, USA. TI - A comparison of MTA, Super-EBA, composite and amalgam as root-end filling materials using a bacterial microleakage model. SO - International Endodontic Journal 1999 May;32(3):197-203 AB - AIM: The aim of this study was to compare traditional and newly developed root-end filling materials for resistance to bacterial microleakage. METHODOLOGY: Sixty extracted single-rooted teeth were randomly divided into five groups for root-end filling with mineral trioxide aggregate, Super-EBA, TPH composite resin with ProBond dentine bonding agent, Dispersalloy amalgam with and without ProBond, and positive and negative control groups. Root canals were instrumented using the step-back technique and simulated root-end resections performed. Root-end filling materials were placed in 3 mm ultrasonic retropreparations. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakage. Samples were sterilized in an ethylene oxide sterilizer for 12 h. Using a newly designed model system, the apical 3-4 mm of the roots were immersed in BHI culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 h with a suspension of Streptococcus salivarius. Culture media were observed every 24 h for colour change indicating bacterial contamination. Media demonstrating colour change were plated for S. salivarius. Samples were observed for 12 weeks. RESULTS: At 4 weeks 10% of specimens from each experimental group had evidence of leakage. At 8 weeks 20% of specimens filled with amalgam without dentine bonding agent, Super-EBA and MTA had evidence of leakage. At 12 weeks minor differences between materials were noted. CONCLUSIONS: Under the conditions of the study, despite some variations, there were no statistically significant differences in rate of microleakage among the five groups tested at either 4, 8 or 12 weeks. <17> UI - 99314441 AU - Yip HK AU - Samaranayake LP IN - Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, Hong Kong, SAR. hkyip@hkusua.hku.hk TI - Caries removal techniques and instrumentation: a review. [Review] [47 refs] SO - Clinical Oral Investigations 1998 Dec;2(4):148-54 AB - The invention of rotary instruments not only improved the speed of caries removal but also the destruction of sound tooth substance. Hence, as early as the 1950s, there were attempts to develop a less invasive technique, such as the air-abrasive and ultrasonic technique, for the purpose of caries removal. The proposed use of air-polishing was published in the early 1980s. Subsequent better understanding of the carious process saw the introduction of the enzyme technique in the late 1980s. Other techniques, such as chemomechanical caries removal and laser systems, have also been attempted and researched during the last four decades to minimise the unnecessary removal of sound tooth substance, although these and other techniques reviewed in this article have not yet superseded the use of rotary instruments. Furthermore, the concept of micro-cavity preparation developed in recent years and the introduction of acid-etch techniques, resin bonding and the use of glass-ionomer cements have also revolutionised the principles of cavity preparation in conservative dentistry. This article reviews the development of these various caries removal techniques and instrumentation and the evolutionary philosophies of cavity preparation promulgated over the last century or so. [References: 47] <18> UI - 99147338 AU - Forte SG AU - Hauser MJ AU - Hahn C AU - Hartwell GR IN - Department of Endodontics, MCV/Virginia Commonwealth, University School of Dentistry, Richmond 23298-0566, USA. TI - Microleakage of super-EBA with and without finishing as determined by the fluid filtration method. SO - Journal of Endodontics 1998 Dec;24(12):799-801 AB - Super-EBA (SEBA) has been used as a root-end filling material because of its superior sealing properties and clinical success. The purpose of this study was to evaluate whether finishing SEBA after it had set would affect the apical seal. Sixty-five extracted maxillary anterior teeth were instrumented and obturated with a single gutta-percha master cone. The root end was resected, and a 3 mm deep root-end preparation was made using ultrasonic tips. Teeth were randomly divided into three groups. Group 1 received SEBA and was finished with a 30-flute high-speed finishing bur. Group 2 received SEBA, which was cold-burnished with a ball burnisher. Temporary Endodontic Restorative Material was used as the negative control in group 3. Microleakage (microliter/min) was measured under 10 psi using the fluid filtration method at days 1, 7, 30, 90, and 180. SEBA/finished exhibited significant microleakage at day 1 when compared with the burnished group. The differences in leakage were not significant at any other time period. <19> UI - 99073053 AU - Gagliani M AU - Taschieri S AU - Molinari R IN - University of Milan, Dental School, Istituto di Scienze Biomediche Ospedale S. Paolo, Dentistry Department, Milan, Italy. TI - Ultrasonic root-end preparation: influence of cutting angle on the apical seal. SO - Journal of Endodontics 1998 Nov;24(11):726-30 AB - Apical resection is fundamental in obtaining a correct apical seal. The purpose of this study was to evaluate how the apical root resection angle and the cavity made by ultrasonic retrotips may influence the apical seal. A total of 48 extracted teeth were endodontically treated and sealed by guttapercha vertical compaction: 24 were resected with a 45 degrees angle and 24 with a 90 degrees one. An ultrasound source (P.M. 400 EMS) and a CT5 Scaler were used to make the retrograde cavity that was filled afterwards with EBA-zinc oxide-eugenol alumina-added cement. Apical leakage was determined using fuchsin and assessed after the roots were sectioned longitudinally. Linear dye penetration in dentin and at the interface between dentin and cement was measured with a stereomicroscope (x 12 magnification), and the results were statistically analyzed. Results showed that there was less infiltration both in dentin and in the space between the filling and the dentinal wall in the group with the 90 degrees angle, but this difference was statistically significant (p < 0.0001) only for the dentin. None of the samples showed leakage greater than the depth of the preparation. An apical cavity of 3 mm or more along the vertical axis can produce a safe and effective seal. <20> UI - 99040472 AU - Chailertvanitkul P AU - Saunders WP AU - Saunders EM AU - MacKenzie D IN - Faculty of Dentistry, Khon Kaen University, Thailand. TI - Polymicrobial coronal leakage of super EBA root-end fillings following two methods of root-end preparation. SO - International Endodontic Journal 1998 Sep;31(5):348-53 AB - The aim of this study was to compose in vitro coronal leakage of a super EBA root-end filling material after two root-end cavity preparation techniques. A mixed anaerobic microbial marker was used. Forty-five extracted human teeth with straight, single root canals were prepared chemo-mechanically to a size 40 master apical file. The teeth were divided into experimental groups (35 teeth) and control groups (10 teeth). Forty teeth (35 experimental teeth and five negative control teeth) were obturated by lateral condensation of cold gutta-percha with Tubliseal EWT sealer. The remaining five teeth were not obturated and served as positive controls. These teeth were stored for 6 months in artificial saliva. The apical 3-4 mm of each root was resected perpendicular to the long axis of the root and a root-end cavity prepared to a depth of 3 mm using either a size 008 rosehead burr or an ultrasonic retroprep tip. Freshly mixed EBA cement was placed into the root-end cavity. The entire root surface of each tooth, except the cutting surface of the apical end, was sealed with nail varnish. The coronal part of each root canal was sealed with the cut end of a tube and placed in a bottle containing sterile Brain Heart Infusion Broth (BHIB). A marker consisting of Anaerobic streptococci and Fusobacterium nucleatum in BHIB was placed in each coronal chamber at 7-day intervals and daily observations were made for bacterial growth in the apical chamber for 60 days. All positive control teeth exhibited bacterial leakage within 48 h, whilst the apical chamber of negative control teeth remained uncontaminated throughout the test period. Fifty-nine percent (n = 10) of the specimens prepared with a burr showed leakage after 90 days, whilst only 22% (n = 4) of the ultrasonically prepared group showed leakage after the same time. The group prepared with ultrasonic tips showed statistically significant less specimens with leakage (P < 0.05) than the group prepared with burrs. <21> UI - 99040447 AU - Huque J AU - Kota K AU - Yamaga M AU - Iwaku M AU - Hoshino E IN - Department of Operative Dentistry and Endodontics, Niigata University School of Dentistry, Japan. TI - Bacterial eradication from root dentine by ultrasonic irrigation with sodium hypochlorite. SO - International Endodontic Journal 1998 Jul;31(4):242-50 AB - The study aimed to evaluate intracanal irrigation procedures in eradicating bacteria from surface, shallow and deep layers of root dentine using extracted human teeth. Artificial bacterial smear layer was successfully produced by rubbing a mixture of dental plaque and artificially decalcified dentine or carious dentine on root canal walls. The reservoir holes were 3.5 mm in depth, 1 mm in diameter prepared 1.5 mm apart and parallel to the root canals on the decrowned planes, in which five separate bacterial species were placed (Actinomyces israelii, Fusobacterium nucleatum, Propionibacterium acnes, Streptococcus mutans and Streptococcus sanguis). Bacterial eradication after irrigation of the prepared canals was determined by bacterial recovery (i) from the root canal surfaces and shallow layers where bacteria were smeared artificially and (ii) from deeper layers of root canal dentine reservoir holes. Ultrasonic irrigation with 5.5% and 12% NaOCl eradicated bacteria from artificial smear layer (P < 0.0001), whilst 12% NaOCl irrigation with a syringe was insufficient. Ultrasonic irrigation with water or 15% EDTA-failed to eradicate bacteria from smeared surfaces. Ultrasonic irrigation with 12% NaOCl killed A. israelii, F. nucleatum, P. acnes, S. mutans, and S. sanguis placed in reservoir channels, although for F. nucleatum, a very small number of bacteria remained in five samples out of 12. Ultrasonic irrigation with less concentrated NaOCl failed to eliminate bacteria completely from reservoir channels in most samples. Ultrasonic irrigation with 12% NaOCl appeared to eliminate bacteria efficiently from surface, shallow and deep layers of root dentine. <22> UI - 98415977 AU - Sananes C AU - Giaroli A AU - Soderini A AU - Guardado N AU - Snaidas L AU - Bermudez A AU - Ferreira M AU - di Paola G AU - Sardi J IN - Gynecologic Oncologic Unit, 1st Clinic of Gynecology, Buenos Aires University Hospital, Argentina. TI - Neoadjuvant chemotherapy followed by radical hysterectomy and postoperative adjuvant chemotherapy in the treatment of carcinoma of the cervix uteri: long-term follow-up of a pilot study. SO - European Journal of Gynaecological Oncology 1998;19(4):368-73 AB - OBJECTIVE: The aim of the study was to determine if ACH given after NCH followed by RH could decrease the incidence of distant metastases in patients with locally advanced carcinoma of cervix uteri. MATERIAL: 56 pts (34 Ib, 18 IIb, 4 IIIb) with confirmed diagnosis of squamous cervical cancer were enrolled in this phase II trial. The methodology used was: 1) Figo clinical staging; 2) Ultrasonographic determination of tumor volume in < or > 4 cms; 3) V.B.P. scheme: cis-platinum 50 mg/m2/day 1; vincristine 1 mg/m2/day 1; bleomycin 25 mg/m2/days 1-2-3 (3 courses with 10 days interval); 4) Clinical and sonographic tumor response evaluation following U.I.C.C. response criteria; 5) Radical hysterectomy; 6) Pathological risk factor evaluation; 7) ACH with P.M.C. (cis-platinum 50 mg/m2, methotrexate 30 mg/m2, cyclophosphamide 500 mg/m2) 3 courses every 21 days; 8) Comparison and location of recurrences with a neoadjuvant group (NCH + RH + RT to whole pelvis), and with a control group treated with conventional radiotherapy were done. For statistical analysis the Chi-Square was used and D.F.S. and overall survival (O.S.) were calculated according to the Kaplan Meier and Log Rank Test. RESULTS: After a median follow-up of 75 months (range 42-108), O. S. for stage Ib was 88%, Stage IIb 78%, and 50% for IIIb. The recurrences were 12% (4/34) for Stage Ib (3 local and 1 distant); 28% for IIb (5/18) (4 pelvic and 1 distant); 50% (2/4) for IIIb (2 pelvic recurrences). When residual tumor volume was < 2 cm in the surgical specimen (n=39) there were 4 recurrences (3 pelvic and 1 distant), and 7 (6 pelvic and 1 distant) for tumors > 2 cm. (p<0.01 for pelvic recurrences). For the stage Ib with residual tumor <2 cm (n=14) there were no pelvic recurrences and only 1 distant. Comparing for Stage Ib with previous tumor volume >4 cm of the ACH Group (n=17) with a classical NCH (n=51) and control (n=51) groups, there were observed 2 (11.7%) pelvic and 1 (5,8%) distant relapses for the 1st Group, 3 (5.9%) pelvic and 3 (5.9%) distant relapses for the 2nd, and 11 (21.6%) pelvic and 5 (9.8%) distant relapses for the 3rd Group. From the comparison of locally advanced tumors (Stages IIb + IIIb) of ACH group (n=22), with a Stage IIIb surgically removed of classical NCH group (n=38) and with a control group of conventional RT (n=51), there were observed 6 (27%) pelvic and 1 (4.5%) distant relapses for the 1st Group, 4 (11%) pelvic and 7 (18.4%) distant relapses for the 2nd, and 31 (60.7%) pelvic and 5 (9.8%) distant for the 3rd one. CONCLUSION: ACH after NCH + RH could be used for stage Ib with tumor volume > 4 cm, with complete clinical response or residual tumor < 2 cm. The results of this group of tumors suggest the importance of going on phase III trials comparing NCH+RH alone vs. NCH+RH+ACH. ACH could also be used to try to obtain better control of distant metastases in Stages IIb and IIIb. In these cases radiotherapy to the whole pelvis must not be excluded. <23> UI - 99007429 AU - Lowe E IN - edlowe@axionet.com TI - Restoring form, function, and aesthetics in Class II direct composite restorations. SO - Dentistry Today 1998 Apr;17(4):72-4, 76-7 <24> UI - 99009759 AU - Scotti R AU - Fenzi GV AU - Arcidiacono A IN - Cattedra di Protesi Dentaria, Universita degli Studi, Bologna. TI - [Effect of ultrasonic scalers, burs and silicone points on the resins for denture bases]. [Italian] SO - Minerva Stomatologica 1998 Jul-Aug;47(7-8):303-8 AB - BACKGROUND: Complete dentures in elderly patients often present a large build-up of dental calcolus. In order to avoid this leading to the onset of mycosis or other infections of the oral cavity, all the dental calcolus must be removed during check-ups. METHODS: In order to analyse the consequences of removing the dental calcolus by mechanical means on the resin of the dentures, a polymethylmetacrylate (PMMA) plate was treated with a ultrasonic scaler, with rotating silicone points and with tungsten carbide burrs mounted on a straight hand-grip. The specimens were observed under a light stereomicroscope and their surface was analysed using a surface roughness tester. Observation under the stereomicroscope showed that in all cases the smooth surface of the resin is damaged and modified. RESULTS: The analysis using the surface roughness tester revealed that only very limited quantities of resin are removed whatever the method. Using the lateral edge of the ultrasonic scaler tip and the rotating silicone points mounted on a hand-grip were the techniques that gave the best results, causing the least abrasions. CONCLUSIONS: The results obtained show that after removing the dental calcolus with the instruments tested, the dentures need to be polished in order to prevent the roughness and irregularities caused by the instruments from favouring plaque retention and the consequent reformation of dental calcolus. <25> UI - 98390120 AU - Pachnis A AU - Pritchard J AU - Gaze M AU - Levitt G AU - Michalski A IN - Department of Haematology and Oncology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom. TI - Radiotherapy omitted in the treatment of selected children under 3 years of age with stage III favorable histology Wilms tumor. SO - Medical & Pediatric Oncology 1998 Sep;31(3):150-2 AB - BACKGROUND: Current treatment of stage III favorable histology (FH) Wilms tumor is surgery, radiotherapy to residual disease, and "triple" chemotherapy (vincristine, dactinomycin, and doxorubicin) for 12 months. This study tests the hypothesis that some stage III patients, especially very young children with minimal residual abdominal disease, might be successfully treated without radiotherapy, thereby avoiding the adverse late effects associated with radiotherapy. PROCEDURE: From 1984, radiotherapy was omitted from the treatment of 8 carefully selected children who were younger than 3 years of age at diagnosis with stage III Wilms tumor by virtue of microscopic residual disease after surgery and whose lymph nodes were not involved by tumors. They were followed with bimonthly abdominal ultrasound examinations to assess local control. RESULTS: Follow-up is now from 2 to 12 years (median 6 years) and 7 of the 8 children are alive and well with no abdominal recurrence. One child relapsed in the lungs and despite further treatment died of progressive disease. The disease-free survival (DFS) and overall survival (OS) are therefore both 87.5%. CONCLUSIONS: The DFS and OS in this admittedly small sample are consistent with the survival rates for stage III FH Wilms tumor in the first United Kingdom Children's Cancer Study Group (UKCCSG), North American (NWTS), and European (SIOP) Wilms Tumor studies, Larger numbers of patients are needed to determine whether or not this treatment approach is generally applicable, but we conclude that some children in this stage III "substage" may be treated successfully without radiotherapy. <26> UI - 98364594 AU - Yamashita J AU - Shiozawa I AU - Takakuda K AU - Miyairi H IN - Department of Fixed Prosthodontics, Faculty of Dentistry, Tokyo Medical and Dental University, Japan. TI - Deformation of restoration and fracture of luting cement film. SO - Journal of Dentistry 1998 Jul-Aug;26(5-6):459-66 AB - OBJECTIVES: Functional occlusal loading can generate complicated stresses in the luting cement film between a restoration and its abutment. Such stresses may lead to cement fractures, which can promote cement dissolution and induce clinical problems. The purpose of this study is to determine the function of the cement film under loading, and to clarify the relationship between the deformation of the restoration and the cement fractures. METHODS: Eccentric loads were applied onto model extension bridges which were cemented on brass dies with zinc phosphate cement. Strain measurements were recorded using of a strain gauge method, ultimate strength by tensile tests, leakage by dye penetration tests and cement fractures by ultrasonic microscopic analyses. Additionally, the bridges which were just seated on their dies without cementation were loaded, and strain measurements were recorded. RESULTS: The cases for linear strain increment with loading showed high tensile strength and minimal dye penetration. The cases with non-linear strain behavior showed low tensile strength and considerable dye penetration. However, no fracture was observed in the occlusal cement film in both cases. The cement fracture first occurred at the opposite marginal region to the loading side. CONCLUSIONS: One of the significant functions of the cement film is diminishing the deformation of restorations during loading. The deformation of the restoration affects initiation and propagation of the cement fracture considerably. <27> UI - 98373276 AU - Gultz JP AU - Scherer W IN - Division of Restorative and Prosthodontic Sciences, New York University College of Dentistry, USA. TI - The use of resin-ionomer in restorative procedures. SO - New York State Dental Journal 1998 Jun-Jul;64(6):36-9 AB - As the average age of the population increases, we are seeing a significant rise in root caries and in the need for restorative procedures associated more often with an older population. This paper describes the subgingival placement of a resin-ionomer for several restorative procedures, including root caries, resorption, endodontic perforation and root fracture. After endodontic therapy, full thickness flaps may be used to gain access to the lesion or root defect. The defects may be prepared with ultrasonic instruments and the preparations treated with a dentin conditioner. The preparations are then washed and lightly air-dried and treated with a dentin bonding agent. A resin-ionomer may then be syringed into the preparations and either light-activated or allowed to undergo a chemical set. No untoward effect has been observed during the time frame of this project. The cases presented indicate that a resin-ionomer may be used as a subgingival restorative and may be placed in lesions originally thought to be unrestorable. Thus, teeth may be saved that were previously designated for extraction. <28> UI - 98261401 AU - Sone T AU - Imai Y AU - Tomomitsu T AU - Fukunaga M IN - Department of Nuclear Medicine, Kawasaki Medical School, Okayama, Japan. tsone@med.kawasaki-m.ac.jp TI - Calcaneus as a site for the assessment of bone mass. [Review] [28 refs] SO - Bone 1998 May;22(5 Suppl):155S-157S AB - The calcaneus is a skeletal site frequently used for monitoring bone loss after spaceflight, because it is sensitive to microgravity-induced bone mineral loss and reflects the degree of demineralization in the vertebra and the femoral neck. In this article, methods for assessing the calcaneus are reviewed, and their potential applications and limitations as the monitoring site for bone loss in weightlessness are discussed. Currently, single or dual energy X-ray absorptiometry appears to be most sensitive for monitoring bone mineral loss in weightlessness. The results of recent studies suggest two- to threefold longer follow-up times required for ultrasound techniques. However, ultrasound devices can be designed to be portable, making them attractive for inflight use, and ultrasound techniques are expected to provide information related to bone quality. Additional investigations that assess new ultrasound techniques would be important to determine and utilize the full potential of this technology for monitoring bone loss in weightlessness. [References: 28] <29> UI - 98327597 AU - Bergenholtz A AU - Babay N IN - Department of Preventive Dental Sciences, College of Dentistry, King Saud University College of Dentistry, Riyadh, Kingdom of Saudi Arabia. TI - Scanning electron microscopy of the root surface texture of extracted periodontally diseased teeth following various etching and chelating regimens. SO - International Journal of Periodontics & Restorative Dentistry 1998 Apr;18(2):171-9 AB - Scanning electron microscopy of root surfaces that had been ultrasonically scaled and subjected to various conditioning regimens revealed the presence of two distinct types of cracks: extensive cracks, presumed to have been caused by drying before and during sputter-coating procedures; and smaller cracks that reflected the pattern of the irregular underlying dentin. Both etching and chelating agents appear to cause demineralization of the interfacial layer between cementum and dentin, causing a "peeling off" of cementum and exposure of the underlying dentin. The results suggest that burnishing the scaled root surface with either saline or any of the etching or chelating agents for at least 10 seconds, followed by soaking the cementum in 8% ethylenediaminetetraacetic acid for about 40 seconds, achieved a root surface that might be regarded as optimal for regeneration of periodontal tissues. <30> UI - 98327529 AU - Noro A AU - Suyama Y AU - Takahashi E AU - Chattin BR AU - Hirai Y AU - Takahashi K AU - Ishikawa T IN - Third Department of Conservative Dentistry, Tokyo Dental College, Chiba, Japan. TI - The effectiveness of the "Clean-Area-System" for infection control in the dental clinic. SO - Bulletin of Tokyo Dental College 1998 Feb;39(1):15-24 AB - The use of effective infection control procedures and universal precautions in dental clinics, prevents cross contamination that could extend to dental health care workers and patients. The present study was initiated to investigate airborne environmental contamination in the dental clinic by viable cell count of oral streptococci grown on Mitis-Salivarius and blood agar plates. The reduction of the contamination by the "Clean-Area-System" was evaluated. "Andersen-Microbe-Sampler-Apparatus" and "Laser-Particle-Counter-System" were used for sampling and counting the bacterial cells and airborne dust, respectively. Numbers of viable cells counted as total colony forming units (CFUs) in the dental clinic were found to be significantly higher than those in the waiting room and the research laboratory. We found that the "Clean-Area-System" significantly reduced the CFUs grown on blood agar plates (p < 0.05), and that using the "Clean-Area-System" combined with the "Extra-Oral-Vacuum-Aspirator" is desirable in dental procedures such as cavity preparation. The "Extra-Oral-Vacuum-Aspirator" reduced airborne environmental contamination during tooth cutting and ultrasonic scaling procedures. In non-grinding procedures, this system proved to be very useful for infection control in the operative area. The authors concluded that the combined use of "Clean-Area-System" (dust collection ablation) and "Extra-Oral-Vacuum-Aspirator" (absorb dust ablation) was effective to reduce airborne environmental contamination in the dental clinic. We also fully confirmed that oral streptococci were an adequate indicator in the assessment for infection control in dental institutions. <31> UI - 98319139 AU - Hugo B AU - Stassinakis A IN - Department of Operative Dentistry and Periodontology, University of Wurzburg, Germany. TI - Preparation and restoration of small interproximal carious lesions with sonic instruments. SO - Practical Periodontics & Aesthetic Dentistry 1998 Apr;10(3):353-9; quiz 360 AB - Partially diamond-coated oscillating preparation instruments are particularly suited for cutting minute interproximal cavities. This review presents an oscillating preparation system with newly designed working tips for cutting and finishing proximal microcavities. Analysis of the margins of various cavity designs prepared with this instrumentation exhibited outlines that were essentially free of defects. The method and instruments presented allow cutting of minute first intervention cavities of interproximal lesions with defect-related extension. Enhanced margins can be attained without concomitant damage to adjacent tooth surfaces. <32> UI - 98319132 AU - Krejci I AU - Dietschi D AU - Lutz FU IN - Department of Preventive and Restorative Dentistry, University of Geneva School of Dentistry, Switzerland. krejci@zzmk.unizh.ch TI - Principles of proximal cavity preparation and finishing with ultrasonic diamond tips. SO - Practical Periodontics & Aesthetic Dentistry 1998 Apr;10(3):295-8; quiz 300 AB - Conventional treatment of proximal cavities can result in significant damage to the adjacent dentition. This paper describes a recently developed technique of proximal cavity preparation and finishing by use of selectively diamond-coated, ultrasonically driven instruments. By using these instruments for composite, compomer, ceramic, amalgam, and even gold restorations, the inadvertent damage to neighboring teeth is completely avoided. This article demonstrates the effective utilization of the diamond-tipped ultrasonic instruments for the preparation of primary lesions and the replacement of existing restorations. <33> UI - 98205451 AU - Haase SL TI - An innovative approach to Class II preparation and restoration. SO - Signature 1998 Spring;5(1):16-9 AB - When patients exhibit Class II defects requiring restoration, the treatment modality and respective preparation requirements may present challenges to the clinician. Aesthetics, chairside time, and expense become factors for the consideration of both dentist and patient. However, a new sonically driven system for the preparation and restoration of proximal defects was recently introduced (SONICSYS, Ivoclar Vivadent, Amherst, NY). This system, composed of diamond-coated tips and prefabricated ceramic inserts, promises to enable clinicians to efficiently, confidently, and expertly prepare and restore Class II defects in a timely, consistent, and cost-efficient manner. This article describes the components of the system and demonstrates its utilization in a case report. <34> UI - 98219273 AU - Fischer EJ AU - Arens DE AU - Miller CH IN - Indiana School of Dentistry, Indianapolis 46202, USA. TI - Bacterial leakage of mineral trioxide aggregate as compared with zinc-free amalgam, intermediate restorative material, and Super-EBA as a root-end filling material. SO - Journal of Endodontics 1998 Mar;24(3):176-9 AB - Several dye leakage studies have demonstrated the fact that mineral trioxide aggregate (MTA) leaks significantly less than other root-end filling materials. The purpose of this study was to determine the time needed for Serratia marcescens to penetrate a 3 mm thickness of zinc-free amalgam, Intermediate Restorative Material (IRM), Super-EBA, and MTA when these materials were used as root-end filling materials. Fifty-six, single-rooted extracted human teeth were cleaned and shaped with a series of .04 Taper rotary instruments (Pro-series 29 files). Once the canals were prepared in a crown down approach, the ends were resected and 48 root-end cavities were ultrasonically prepared to a 3 mm depth. The teeth were then steam sterilized. Using an aseptic technique, under a laminar air flow hood, the root-end cavities were filled with amalgam, IRM, Super-EBA, and MTA. Four root-end cavities were filled with thermoplasticized gutta-percha without a root canal sealer and served as positive controls. Another four root-end cavities were filled with sticky wax covered with two layers of nail polish and served as negative controls. The teeth were attached to presterilized (ethylene oxide gas) plastic caps, and the root ends were placed into 12-ml vials of phenol red broth. Using a micropipette, a tenth of a milliliter of S. marcescens was placed into the root canal of each tooth. To test the sterility of the apparatus set-up, the root canals of two teeth with test root-end filling materials and one tooth from the positive and negative control groups were filled with sterile saline. The number of days required for S. marcescens to penetrate the four root-end filling materials and grow in the phenol red broth was recorded and analyzed. Most of the samples filled with zinc-free amalgam leaked bacteria in 10 to 63 days. IRM began leaking 28 to 91 days. Super-EBA began leaking 42 to 101 days. MTA did not begin leaking until day 49. At the end of the study, four of the MTA samples had not exhibited any leakage. Statistical analysis of the data indicated Mineral Trioxide Aggregate to be a most effective root-end filling material against penetration of S. marcescens. <35> UI - 98099732 AU - Wu C AU - Gluer C AU - Lu Y AU - Fuerst T AU - Hans D AU - Genant HK IN - Osteoporosis and Arthritis Research Group, Musculoskeletal Radiology, University of California, San Francisco 94143-0628, USA. TI - Ultrasound characterization of bone demineralization. SO - Calcified Tissue International 1998 Feb;62(2):133-9 AB - Quantitative ultrasound (QUS) assessment of bone may permit an assessment of bone properties currently not available by bone densitometry techniques. To explore the effects of the quantity of bone mineral on acoustic parameters, we carried out an in vitro study of the impact of demineralization on attenuation of ultrasound in trabecular bone. Ten fresh cubes of trabecular bone obtained from bovine distal femurs were progressively demineralized using formic acid solution. The progression of demineralization was controlled by monitoring the specimen bone mineral density (BMD) using dual x-ray absorptiometry (DXA). At five stages of demineralization-0% (baseline), 25%, 50%, 75%, and 100% (all mineral removed)-the US properties of the specimens were assessed (Walker Sonix UBA 575+). The US parameters investigated were broadband ultrasound attenuation (BUA) and ultrasound attenuation in bone (UAB). Both DXA and QUS measurements were made along the three orthogonal axes of each cube. Our results demonstrated significant variability in both BUA and UAB along the three principle axes of the cubes whereas BMD did not differ in the different directions. A strong but nonlinear correlation was found between BMD and US attenuation. A reduction in BMD to 50% of the baseline values resulted in BUA (UAB) reduction to 25% and 19%, respectively. A random effect model analysis supported a multiplicative relationship between BMD and the US parameters. US attenuation is a sensitive indicator of bone mineral changes with nonlinear dependence on bone mineral loss. Bone collagen structure reinforced by hydroxyapatite crystal accounts for fundamental US characteristics. Ultrasound attenuation associated with trabecular orientation is basically dominated by the mineral spread in a collagen framework. <36> UI - 98100051 AU - Ghorayeb SR AU - Xue T AU - Lord W IN - Department of Engineering, Hofstra University, Hempstead, New York 11549, USA. TI - A finite element study of ultrasonic wave propagation in a tooth phantom. SO - Journal of Dental Research 1998 Jan;77(1):39-49 AB - Ultrasound is used extensively in industry for the detection and characterization of defects in critical engineering structures. Similar techniques could be used in dentistry if a thorough understanding of ultrasonic wave propagation in teeth were available. This paper presents a hypothesis that finite element analysis can be used to solve the hyperbolic partial differential equation which governs ultrasonic wave propagation in teeth. A three-layer tooth phantom based on the geometry of a human second molar is used to illustrate the validity of this hypothesis. Simulated wave propagation studies are described for the tooth phantom with a gold crown layer, with an amalgam restoration insertion, and containing a cavity. Results clearly show the finite element code's ability to predict and visualize ultrasonic wave propagation in complex dental structures. <37> UI - 98253155 AU - Vansan LP AU - Pecora JD AU - da Costa WF AU - Silva RG AU - Savioli RN IN - Disciplina de Endodontia, Faculdade de Odontologia de Ribeirao Preto, Universidade de Sao Paulo, Brasil. TI - Comparative in vitro study of apically extruded material after four different root canal Instrumentation techniques. SO - Brazilian Dental Journal 1997;8(2):79-83 AB - Forty newly extracted human upper central incisors were submitted to root canal instrumentation 1 mm from the apex using four different techniques: standard, step-preparation, crown-down, and ultrasound, with distilled and deionized water as the irrigating solution. The extrusion product was collected into a collecting device constructed for this purpose. Extrusion was calculated by the determination of the mass of extruded material. The step-preparation technique caused a larger amount of extrusion than the standard technique, which in turn caused greater extrusion than the crown-down and ultrasound techniques. All techniques used caused extrusion of material beyond the apical foramen. <38> UI - 98248846 AU - Fitzpatrick EL AU - Steiman HR IN - Department of Endodontics, University of Detroit Mercy School of Dentistry, Michigan, USA. TI - Scanning electron microscopic evaluation of finishing techniques on IRM and EBA retrofillings. SO - Journal of Endodontics 1997 Jul;23(7):423-7 AB - Various techniques have been advocated for finishing retrofilling materials. This study evaluated marginal interfaces between tooth structure and the retrofilling material following three techniques of finishing IRM and EBA. This interface was evaluated for the presence of flash and for adaptation to the prepared canal walls. Thirty-one teeth were divided into six groups of five and one control. The teeth were instrumented to a minimum of a 35 K-file, obturated with gutta-percha, resected perpendicular to their long axes and ultrasonically prepared to receive a retrofilling. The teeth were filled with either IRM or EBA cement and finished by ball burnishing, burnishing with a moistened cotton pellet, or with a carbide finishing bur in a high-speed handpiece with air/water spray. Photomicrographs were made and examined by four evaluators. Retrofillings finished with a finishing bur displayed significantly better marginal adaptation and little evidence of flash when compared to the other techniques (p < 0.05). There were no significant differences between ball burnished or moistened cotton pellet techniques or between retrofilling materials used in this study (p < 0.05). <39> UI - 98148834 AU - Aguirre AM AU - el-Deeb ME AU - Aguirre R IN - Department of Endodontics, UMKC-School of Dentistry, Kansas City, MO 64108, USA. TI - The effect of ultrasonics on sealer distribution and sealing of root canals. SO - Journal of Endodontics 1997 Dec;23(12):759-64 AB - The purpose of this study was to compare the ultrasonic and hand methods of sealer placement using three types of sealers: Sultan "Grossman's formula," AH-26, and CRCS. The effect of these methods on radiographic density, sealer distribution, and on the apical seal of the different sealers was evaluated. The in vitro experiment was carried out using human extracted mandibular incisors and mesio-buccal roots of maxillary first and second molars. Following standardized canal instrumentation, 120 single canal mandibular incisors were randomly assigned to six groups, depending on the type of sealer and method of sealer placement (hand versus ultrasonic). An additional ten teeth were used as controls. In the molar groups 40 canals were randomly assigned to two groups, with the method of sealer placement as the variable. Eight canals were used as controls. Postsealer analyses using radiographic density scores transformed to mm of sealer indicated that ultrasonics was superior to manual placement only for CRCS. Taken together, our investigation suggests that ultrasonics may enhance the placement of some sealers (i.e. CRCS) but not of others (i.e. AH-26 or Sultan). Method of sealer placement had no effect on apical leakage and therefore apparently on apical seal. <40> UI - 98207564 AU - Beling KL AU - Marshall JG AU - Morgan LA AU - Baumgartner JC IN - Oregon Health Sciences University, Portland, USA. TI - Evaluation for cracks associated with ultrasonic root-end preparation of gutta-percha filled canals. SO - Journal of Endodontics 1997 May;23(5):323-6 AB - Many clinicians use ultrasonics for root-end preparations. The purpose of this study was to evaluate resected root-end surfaces of bilaterally matched human teeth for cracks before and after ultrasonic root-end preparation. Twenty matched pairs of extracted single rooted teeth were divided into two experimental groups. In group 1, root-end resection was performed on uninstrumented teeth. In group 2, root-end resection was performed after the canals were instrumented and filled with gutta-percha. All teeth in both groups received root-end preparations using ultrasonic instrumentation at low power. Two examiners evaluated the root-ends after root-end resection and again after root-end preparation using zoom magnification of 20x to 63x. The number, types, and location of cracks were mapped. There were no significant differences when gutta-percha filled roots were compared to uninstrumented roots with regard to the number or type of cracks after root-end resection or root-end preparation. In addition, there were no significant differences in the number or type of cracks following root resection and ultrasonic root-end preparation when compared to teeth with root resection alone. <41> UI - 98091116 AU - Dearnaley DP AU - Shearer RJ AU - Ellingham L AU - Gadd J AU - Horwich A IN - Academic Unit of Radiotherapy, Royal Marsden Hospital, Sutton, England. TI - [Basic principles and initial results of adjuvant hormone therapy and irradiation of prostatic carcinoma]. [Review] [33 refs] [German] SO - Schweizerische Rundschau fur Medizin Praxis 1997 Nov 26;86(48):1895-901 AB - Radiotherapy is an effective treatment for localized prostate cancer. A dose response relationship has been demonstrated for both local tumor control and complications. Reducing the volume of normal tissue treated may allow dose escalation without an increase in RT induced side effects. Androgen blockade before RT could, by reducing tumor volume, increase local control, disease-free (DFS) and overall survival in patients (pts) with prostatic adenocarcinoma. A total of 79 patients with T2-T4 prostate cancer have been treated initially with LHRH agonists and cyproterone acetate followed by radical irradiation between 1988 and 1993. The first cohort of 22 patients were monitored intensively by transrectal ultrasound and computed tomography. For each patient conformal photon beam radiotherapy and conventional treatment plans were produced and dose volume histograms compared for total volume, rectal volume, and bladder volume. Overall mean reduction of prostate volume was about 50%, and radiotherapy target volume was reduced by 37%. 53 further patients without clinical evidence of regional or distant metastases were given 3 months preradiotherapeutic hormonal cytoreduction with a short course of cyproterone acetate and LHRH. PSA level fell rapidly in most patients and after 3 months treatment the median PSA level was 1 ng/ml and 83% had PSA level 10 ng/ml. At 18 months PSA levels continued to be < 2 ng/ml in 70% of the patients. Combined modality treatment with the neoadjuvant or adjuvant androgen deprivation and conformal therapy show considerable promise as novel methods to improve the therapeutic ratio. This treatment approach may be used to explore the possibility of dose escalation in prostate cancer to enhance local control, and therapeutic randomised studies are underway to test these approaches. [References: 33] <42> UI - 97313597 AU - Bruschi G AU - Cabassi A AU - Orlandini G AU - Regolisti G AU - Zambrelli P AU - Calzolari M AU - Borghetti A IN - Istituto di Clinica Medica e Nefrologia, Universita di Parma, Italy. TI - Use of Fourier shape descriptors to improve the reproducibility of echographic measurements of arterial intima-media thickness. SO - Journal of Hypertension 1997 May;15(5):467-74 AB - BACKGROUND: A major source of error in the longitudinal assessment of the intima-media thickness (IMT) is the difficulty in retrieving the same echographic view of the vessel. OBJECTIVE: To present a method for increasing the reproducibility of IMT measurements by ultrasound in large arteries. METHOD: The Fourier descriptor is a well-known means of describing an object's shape. By means of the discrete Fourier transform (DFT), the shape was represented in a frequency domain; the computational advantages of the DFT then permitted a measure of unlikeness between different shapes (the 'distance' measure; DM) to be defined and used as a criterion for reproducing the contour. When the sonographer compared successive images of a complex vascular segment, like the carotid bifurcation, the identity of the echographic cut was deduced from the identity of the vessel's contour. The best match of the baseline image was the view that minimized the contour DM. RESULTS: Preliminary studies in the carotid artery bifurcations of eight subjects showed that the DM responds to systematic variations in the ultrasound interrogation angle and reveals minimal changes in transducer position. Duplicate scans of 12 subjects were performed by three sonographers with different strategies for acquisition of the same images: a low DM was associated with a low difference in pairs of IMT measurements. Data were classified into two groups (normal or borderline vessels with a pooled mean IMT of 0.62 mm and overtly thickened segments with a pooled mean IMT of 1.31 mm). When minimization of the DM was the criterion for the acquisition of replicate scans, the mean absolute difference of paired data for the mean IMT of the distal common carotid artery was 0.03 +/- 0.02 mm for the first group and 0.06 +/- 0.03 mm for the second group. This is a significant reduction in comparison with non-quantitative alternative criteria for image reproduction. For the maximum IMT of the same segments the mean absolute differences were 0.07 +/- 0.03 and 0.13 +/- 0.06 mm in the first and second groups, respectively. CONCLUSION: This method can be applied to the serial assessment of single atherosclerotic segments. The computational time is negligible. By reducing the scatter in sequential IMT data, longitudinal investigations (e.g. of the results of antihypertensive therapy) with shorter durations and smaller sample groups may be rendered feasible. <43> UI - 97371540 AU - Grubb BP AU - Durzinsky D AU - Brewster P AU - Gbur C AU - Collins B IN - Department of Medicine, Medical College of Ohio, Toledo 43699, USA. TI - Sudden cerebral vasoconstriction during induced polymorphic ventricular tachycardia and fibrillation: further observations of a paradoxic response [see comments]. CM - Comment in: Pacing Clin Electrophysiol 1998 Feb;21(2):483-4 SO - Pacing & Clinical Electrophysiology 1997 Jun;20(6):1667-72 AB - To determine the effect of induced polymorphic VT/VF on the cerebral circulation, transcranial Doppler (TCD) ultrasonography was used to prospectively assess changes in cerebral blood flow velocity during ICD implantation. Fourteen patients (13 men, 1 woman, mean age 58 +/- 20 years, range 34-74 years) who were survivors of an out of hospital cardiac arrest, were evaluated during routine ICD implantation. TCD ultrasonography was used to assess middle cerebral artery systolic velocity (Vs), diastolic velocity (Vd), pulsatility index (PI = Vs-Vd/Vmean) and resistance index (RI = Vs-Vd/Vs) before, during, and after DFT testing with alternating current induction of polymorphic VT/VF. In each of the 14 patients studied, concomitant with the abrupt onset of hypotension, TCD sonography demonstrated a 33% +/- 28% decrease in diastolic velocity, a 42% +/- 28% increase in systolic velocity, a 190% +/- 141% increase in PI, and a 44% +/- 19% increase in RI. These findings reflect an increase in cerebrovascular resistance secondary to arteriolar vasoconstriction distal to the point of insonation of the middle cerebral artery. This response is paradoxic, as the expected response of the cerebral circulation to hypotension is vasodilation, but it is consistent with observations made in other acute hypotensive settings, such as tilt induced neurocardiogenic syncope. <44> UI - 97284905 AU - Spencer T AU - Ramo MP AU - Salter DM AU - Anderson T AU - Kearney PP AU - Sutherland GR AU - Fox KA AU - McDicken WN IN - Department of Medical Physics, Edinburgh University, Western General Hospital, Scotland, UK. timsp@tattoo.ed.ac.uk TI - Characterisation of atherosclerotic plaque by spectral analysis of intravascular ultrasound: an in vitro methodology. SO - Ultrasound in Medicine & Biology 1997;23(2):191-203 AB - Raw 30-MHz intravascular ultrasound data have been captured from postmortem coronary arteries (n = 4) to develop radio frequency analysis techniques for the characterisation of atherosclerotic plaque. Digitised data acquired from positions (n = 8) within diseased sections of artery were compared with the corresponding histology and radiology. Scan-converted images were used to locate regions of interest (ROI = 33) within areas of tissue composition: loose fibrotic tissue (LFT), dense fibrotic tissue (DFT) and calcium (CA). A range of parameters was extracted from the normalised power spectrum of each ROI within the bandwidth 17-42 MHz. Significant discrimination between LFT/DFT and between LFT/CA was provided by maximum power and spectral slope (dBMHz-1). However, the greatest discriminative power was given by the y-axis (0 Hz) intercept of the spectral slope: LFT/DFT (p = 0.001); LFT/CA (p = 0.0001); and DFT/CA (p = 0.089). <45> UI - 97173957 AU - Chen CP AU - Chern SR AU - Liu FF AU - Jan SW AU - Lee HC AU - Sheu JC AU - Lee WT AU - Wang TY IN - Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. TI - Prenatal diagnosis, pathology, and genetic study of fetus in fetu. SO - Prenatal Diagnosis 1997 Jan;17(1):13-21 AB - We report the prenatal diagnosis, pathology, cytogenetics, and molecular studies of a retroperitoneal fetus in fetu. Prenatal ultrasonography of the host fetus in the third trimester showed an anencephalic, acardiac mass with identifiable extremities and spine within an intra-abdominal cystic mass. Pathological examination revealed a fetiform mass weighing 20 g with four extremities, digits, vertebral bodies, an oral cavity with developing teeth, primitive male external genitalia, a urinary bladder, a cloaca with an external opening, large intestines, a membranous capsule, and an umbilical cord with one artery, one vein, and Wharton's jelly. Histological examination demonstrated nerve bundles in the fibrocollagenous tissue below the cuboidal surface epithelium of the membranous capsule, and absence of lamina elastica interna and vasa vasorum in the single artery of the umbilical cord. Both the host infant and the fetus in fetu had a normal 46,XY karyotype. Molecular analysis using informative genetic markers showed no genetic difference between the host infant and the fetiform mass. We report this case as an unusual example of fetus in fetu in co-existence with an amnion-like membrane containing nerve bundles and with a well-formed umbilical cord. We demonstrate that fetus in fetu can be diagnosed prenatally if the fetiform mass has well-developed limbs and spine. We emphasize the necessity for suspicion of fetus in fetu when a well-defined encapsulated cystic mass with calcified solid components is detected prenatally in a fetus by ultrasonography. <46> UI - 97206681 AU - Yoneyama K AU - Ikeda J AU - Nagata H IN - Nara University of Education, Japan. TI - [Interrelations of the calcium concentration in breast milk with maternal intake of cow's milk and milk products, bone resorption and bone mineral density during lactation]. [Japanese] SO - Nippon Eiseigaku Zasshi - Japanese Journal of Hygiene 1997 Jan;51(4):770-9 AB - The interrelations of the calcium (Ca) concentration in breast milk with maternal intake of cow's milk and milk products, 24-hour urinary hydroxyproline and Ca concentrations adjusted by creatinine (H.P/Cre, Ca/Cre) and bone mineral density measured by ultrasonic bone densitometry were examined to study the mechanism regulating the calcium concentration in breast milk. Subjects were 105 lactating women, aged 21 to 42 years, at 21.590 days postpartum. 1) The geometric means (logarithmically transformed calculated M +/- SD) of H.P/Cre were 40.7 (31-61) and 36.3 (28-47) mg/g in women lactating less than 150 days and 150 days or more, respectively. These values indicated increased bone resorption. 2) Intake of cow's milk and milk products significantly negatively correlated with urinary H.P/Cre. For women consuming less than 100ml per day of cow's milk, a significant positive correlation was found between the urinary H.P/Cre and Ca concentration in breast milk. These results suggest that the extent of bone resorption depends on maternal Ca intake and the Ca transfer from maternal bone to breast milk in women with a low Ca intake. 3) For women with a cow's milk intake of less than 100ml per day, a significant positive correlation was found between the Ca concentration in breast milk and bone mineral density, indicating that women with bone mineral loss are not able to compensate for the low Ca level in breast milk. 4) Urinary Ca/Cre significantly negatively affected the Ca concentration in breast milk. This result indicates that some amount of Ca in breast milk is due to renal conservation. <47> UI - 98183174 AU - Nordbo H AU - Brown G AU - Tjan AH IN - Department of Preclinical Techniques and Material Sciences, School of Dentistry, University of Oslo, Norway. TI - Chemical treatment of cavity walls following manual excavation of carious dentin. SO - American Journal of Dentistry 1996 Apr;9(2):67-71 AB - PURPOSE: To improve the conditioning of cavity walls resulting from minimal mechanical preparation of carious lesions, such as is done in modified Class II tunnel preparations. MATERIALS AND METHODS: Proximal carious lesions in premolars and molars were excavated manually and the cavity walls studied using a stereomicroscope and by scanning electron microscopy (SEM) following treatment with either polyacrylic acid, sodium hypochlorite, the enzyme preparation Pronase, or sequential combinations of the agents. Polyacrylic acid (10%) was used according to the manufacturer's instructions, while concentrated sodium hypochlorite (5.25%) was applied with either intermittent scrubbing or with ultrasonic energy for 5-10 minutes, or the cavity wall was incubated with the agent at +/- 37 degrees C for periods up to 24 hours. Incubation with the proteolytic enzyme preparation Pronase was carried out at 37 degrees C for a period up to 48 hours. RESULTS: Manual excavation did not remove all carious dentin, neither did treatment with polyacrylic acid. Scrubbing or sonication with ample amounts of sodium hypochlorite, followed by treatment with polyacrylic acid, or prolonged incubation with sodium hypochlorite, removed most of the remaining carious dentin. However, the "cleanest" surfaces were obtained after 48 hours of incubation with Pronase. Spots of thicker, soft layers of decayed dentin that were left intentionally at some locations could be disintegrated only by the Pronase treatment. It was concluded that treatment with sodium hypochlorite and polyacrylic acid in tandem, or with Pronase may represent potential supplements to conventional cavity cleaning that deserve further investigation. In the clinic more efficient cavity cleaning may improve the bonding ability and thus reduce the risk of marginal ridge fracture in teeth with Class II tunnel restorations. <48> UI - 97342432 AU - Bates CF AU - Carnes DL AU - del Rio CE IN - Department of Endodontics, Wilford Hall Medical Center, Lackland Air Force Base, TX, USA. TI - Longitudinal sealing ability of mineral trioxide aggregate as a root-end filling material. SO - Journal of Endodontics 1996 Nov;22(11):575-8 AB - This study evaluated the ability of mineral trioxide aggregate (MTA) to seal the root end effectively. Seventy-six single-rooted, extracted human teeth were cleaned and shaped using a step-back technique. After root-end resection and ultrasonic preparation, 72 root sections were randomly allocated to three groups and filled with dental amalgam and cavity liner, Super-EBA, or MTA. Microleakage was assessed at 24 h, 72 h, 2 wk, 4 wk, 8 wk, and 12 wk, using a fluid filtration measurement system. MTA demonstrated excellent sealing ability throughout 12 wk of fluid immersion, comparable with that observed for Super-EBA. Microleakage in the MTA group, as well as the Super-EBA group, was significantly less (p < 0.05) than in the amalgam group at 24 h, 72 h, and 2 wk. At the subsequent periods, there were no significant differences among the three materials. In this study, MTA was determined to be superior to amalgam, and comparable with Super-EBA in preventing microleakage when used as a root-end filling. <49> UI - 97122406 AU - Turner CH AU - Takano Y AU - Hirano T IN - Biomechanics and Biomaterials Research Center, Indiana University Medical Center, Indianapolis 46202, USA. turnerch@indyvax.iupui.edu TI - Reductions in bone strength after fluoride treatment are not reflected in tissue-level acoustic measurements [see comments]. CM - Comment in: Bone 1997 Aug;21(2):207-8 SO - Bone 1996 Dec;19(6):603-7 AB - Acoustic velocity measurements are used to estimate tissue-level bone strength after fluoride therapy for osteoporosis. However, acoustic measurements provide information about elasticity, not strength, and bone elasticity does not necessarily correlate with bone strength at a tissue level. The current study was undertaken to evaluate the effects of fluoride treatment on tissue-level acoustic velocities, and to determine the relationship between acoustic velocity and bone strength measured in the femur, femoral neck, and spine. Young adult rabbits were treated with either 0 or 100 parts per million of fluoride in their drinking water for six months. After treatment, the bones were harvested for measurement of tissue fluoride, bone strength, and acoustic properties. Acoustic velocities were measured in the femoral midshaft using an acoustic microscope with a 50 MHz transducer. Both longitudinal and transverse velocities were measured. After the initial acoustic measurements the bone specimens were treated to remove either the organic matrix or mineral, and the acoustic measurements were repeated. Fluoride treatment increased bone fluoride levels 7-8 fold and reduced all biomechanical parameters. Most notably the fracture force of the femoral neck was reduced by 25% (p < 0.005), and the fracture stress of the L-5 vertebra was reduced by 19% (p < 0.05). Fluoride treatment had no significant effect on any of the measured acoustic velocities. The elastic anisotropy of the bone was decreased by demineralization (p < 0.0001) and increased by removal of the organic matrix (p < 0.0001), but unaffected by fluoride treatment. Acoustic measurements were not correlated with bone strength in the femoral neck or femoral midshaft. There was a positive correlation between the longitudinal velocity measured in the femur and the vertebral fracture stress, but this was the only positive association between acoustic velocities and strength measurements. These data cast doubt on the utility of high frequency (>2 MHz) acoustic measurements for evaluating the efficacy of fluoride therapy, especially in the hip. <50> UI - 97059368 AU - Misik V AU - Riesz P IN - Radiation Biology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA. TI - Peroxyl radical formation in aqueous solutions of N,N-dimethylformamide, N-methylformamide, and dimethylsulfoxide by ultrasound: implications for sonosensitized cell killing. SO - Free Radical Biology & Medicine 1996;20(1):129-38 AB - Sonodynamic therapy, which refers to a synergistic effect of drugs and ultrasound, is a promising new modality for cancer treatment. The sonodynamic effect was found for a number of structurally unrelated compounds, and the underlying mechanisms are still unknown. Recently, Jeffers et al. (J. Acoust. Soc. Am. 97:669-676; 1995) have shown that the sonodynamic action of nontoxic concentrations of N,N-dimethylformamide (DMF), N-methyl formamide (MMF), and dimethylsulfoxide (DMSO) combined with ultrasound, on killing of cultured HL-60 human promyelocytic leukemia cells, and attributed this toxic effect to unknown short lived reactive species produced from these solutes by ultrasonic cavitation. Using the spin trap 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS) in nitrogen-saturated aqueous solutions of DMF, MMF, or DMSO exposed to 50 kHz ultrasound, we detected formation of .CH3 and .CH2N(CH3)CHO radical adducts for DMF, mostly .CH2NHCHO adducts for MMF, and .CH3 adducts for DMSO. These radicals were formed either by reactions of the solutes with ultrasound-generated .H and .OH radicals (such as .CH2R-type radicals in DMF and MMF, and .CH3 radicals in DMSO), or by direct pyrolysis of the weak bonds in the solute molecules (e.g., .CH3 radicals from DMF). In air-saturated sonicated solutions these carbon centered radicals were converted to the corresponding peroxyl radicals and spin trapped with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO); .OOCH2N(CH3)CHO radicals were identified in DMF, .OOCH2NHCHO radicals in MMF, and .OOCH3 radicals in DMSO solutions. We suggest that these radical species by virtue of their longer lifetimes and higher selectivity, compared to .OH radicals, which are also formed in sonicated solutions, are the species responsible for sonodynamic cell killing by the combined effect of ultrasound with DMF, MMF, or DMSO. <51> UI - 97055499 AU - Perez F AU - Calas P AU - Rochd T IN - Department of Endodontics and Restorative Dentistry, University of Toulouse, France. TI - Effect of dentin treatment on in vitro root tubule bacterial invasion. SO - Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, & Endodontics 1996 Oct;82(4):446-51 AB - In light of the in vitro S. sanguis bacterial migration observed deep into root dentin, an in vitro system was developed to determine the viability of these bacteria at the end of migration. Also of interest is whether the smear layer formed during root canal instrumentation modifies migration into root dentinal tubules. Forty-eight bovine root dentin samples were randomly split into two groups. Group 1 dentin blocks were not instrumented and were treated with 17% ethylenediamine tetraacetic acid and 2.5% sodium hypochlorite for 4 minutes in an ultrasonic bath Group 2 root canals were conventionally instrumented. The smear layer formed was not removed. Dentin blocks were inoculated with a S. sanguis National Collection of Type Culture 7863 suspension. Each sample was immersed in a receiver broth, incubated at 37 degrees C, and checked daily for 14 days. After a 14-day incubation period, group 1 S. sanguis cells remained viable and capable of inoculating the receiver medium after migration through the tubules. Group 2 cells, where the smear layer was intact, revealed an absence of S. sanguis migration in 88% of the cases. It is therefore plausible that smear layer on canal walls limits S. sanguis penetration of dentinal tubules in vitro. <52> UI - 97018288 AU - Takano Y AU - Turner CH AU - Burr DB IN - Department of Anatomy, Indiana University Medical Center, Indianapolis, USA. TI - Mineral anisotropy in mineralized tissues is similar among species and mineral growth occurs independently of collagen orientation in rats: results from acoustic velocity measurements. SO - Journal of Bone & Mineral Research 1996 Sep;11(9):1292-301 AB - It has been reported that the mineral crystals in long bones have their c-axis aligned with the bone axis, presumably because collagen fibrils in bone also align with the bone axis. However, the predominant collagen orientation in bone often does not appear to be aligned with the mineral crystals, especially in rat primary bone. We hypothesized that mineral orientation in bone is not necessarily related to collagen orientation. An acoustic microscope was used to measure elastic constants of mineralized tissues from rat, cow, monkey, and human bone, and mineralized turkey leg tendon (MTLT). Measurements were made before and after demineralization with 10% ethylenediaminetetraacetic acid (EDTA) or decollagenization with 7% sodium hypochlorite. The elastic anisotropy ratio (AR) was defined as the ratio of the elastic coefficient in the longitudinal direction to the elastic coefficient in the transverse direction. Anisotropy ratios of mineralized tissues were not affected by formalin fixation or plastic embedding. An evaluation of tissues from the different species showed that the AR after decollagenization was not significantly different (p > 0.4, analysis of variance) among the groups, while AR after demineralization varied from 1.04 (rat bone) to 1.51 (MTLT). There was no correlation between AR after demineralization and AR after decollagenization (r = 0.13, p = 0.5). This showed that the elastic anisotropy of collagen is more variable than mineral anisotropy in bone and MTLT. Another experiment showed that mineralization of turkey leg tendon changes the elasticity of the collagen matrix, making it less anisotropic. A final, prospective experiment was performed in which tibiae of rats were subjected to mechanical loading for 16 weeks. After 12 days, new periosteal woven bone was observed on the tibiae and, after 16 weeks, this new bone was consolidated and mineralized. Mineral in the newly formed woven bone was virtually isotropic (AR = 1.07) after 12 days of loading, then became more anisotropic (AR = 1.52) after 16 weeks of mechanical loading, as the mineral density of the new bone increased. This increase in anisotropy of bone mineral occurred even though the collagen matrix was woven and had no measureable fibril orientation. We conclude that (1) collagen anisotropy and mineral anisotropy are not necessarily correlated in mineralized tissues, (2) mineralization can affect the collagen matrix elasticity of mineralized tissues, and (3) an organized mineral structure can form in the absence of an organized collagen matrix. <53> UI - 97089115 AU - Levy G AU - Rizoiu I AU - Friedman S AU - Lam H IN - Laser Hard Tissue Institute, San Clemente, CA, USA. TI - Pressure waves in root canals induced by Nd: YAG laser. SO - Journal of Endodontics 1996 Feb;22(2):81-4 AB - Recently, root canal preparation using Nd:YAG laser has been introduced. Laser interaction with matter may generate cavitation and subsequent pressure waves. This study characterized the pressure waves induced in root canals by either Nd: YAG laser, sonically vibrated files, or ultrasonically vibrated files. The root canals of 14 single-rooted teeth were prepared conventionally and filled with water. In 12 teeth, a pulsed Nd:YAG laser was activated in the canal using optical fibers of various diameters and various power settings. In the remaining two teeth, either a sonic or ultrasonic file was activated. The pressure waves induced in the canals were detected by a piezoelectric transducer. The results were analyzed using correlation coefficient and coefficient of variation. Laser irradiation resulted in pressure waves with amplitudes varying from 35.78 to 79.26 mV, being positively correlated with the laser power density (R2 = 0.870). Sonic and ultrasonic vibrations resulted in pressure waves with mean amplitudes of 60.51 mV and 7.02 mV, respectively. It was concluded that Nd:YAG laser irradiation induced pressure waves, with different characteristics from waves induced by freely vibrating sonic and ultrasonic endodontic instruments when applied to water-filled root canals. <54> UI - 96274997 AU - Hofbauer LC AU - Spitzweg C AU - Tammen AR AU - Heufelder AE IN - Klinikum Innenstadt der Universitat, Munchen. TI - [Infectious thyroiditis as initial manifestation of embolizing endocarditis of the aortic valve]. [German] SO - Deutsche Medizinische Wochenschrift 1996 Mar 22;121(12):369-74 AB - HISTORY AND CLINICAL FINDINGS: A 47-year-old patient was admitted to hospital with fever (39.2 degrees C), weight loss and sore throat. The right thyroid area was painful on palpation. INVESTIGATIONS: The erythrocyte sedimentation rate was 56/86 mm, white blood cell count 10,600/l, with shift to the left and toxic granulations. Blood culture grew Streptococcus mitis; the echocardiogram showed vegetations on the aortic valve. Therefore aortic valve endocatidits was suspected. Ultrasound examination of the thyroid gland showed an echo poor area with an enlarged thyroid artery; thyroid cytodiagnosis was unremarkable. TREATMENT: The fever quickly subsided on administration of penicillin G (7.5 mill I.U. three times daily) and tobramycin (80 mg three times daily) for two weeks, followed by penicillin G in the same dosage for four more weeks. Vancomycin was then given for two weeks (1 g twice daily intravenously). The aortic valve vegetations were no longer seen three weeks after onset of treatment. Two months after discharge the thyroid and heart were normal on ultrasound examination. CONCLUSION: Bacterial thyroiditis was caused by embolisation to the thyroid artery from vegetations on the aortic valve in aortic valve endocarditis, probably due to carious teeth. <55> UI - 96230281 AU - Sultan M AU - Pitt Ford TR IN - Department of Conservative Dental Surgery, United Medical and Dental Schools, Guy's Hospital, London, UK. TI - Ultrasonic preparation and obturation of root-end cavities. SO - International Endodontic Journal 1995 Sep;28(5):231-8 AB - This study evaluated the preparation of root-end cavities using an ultrasonically activated file, and the obturation of such cavities. In the first part, the root canals of 40 extracted teeth were prepared to size 40 and irrigated with NaOCl and EDTA. The root ends were resected and the teeth inoculated with Enterococcus faecalis, incubated for 10 days and divided into four groups: control; saline; irrigation; hand instrumentation performed via a retrograde approach up to size 50 using saline irrigant; ultrasonic instrumentation with prebent size 40 K-flex file inserted into a Piezon Master using saline irrigant. The teeth were fixed, sectioned longitudinally and viewed under scanning electron microscopy. Bacterial and smear layer scores were obtained at 1, 3, and 5 mm from the resected end. The bacterial scores for control and saline groups were similar; the scores for each instrumentation group were significantly lower than the control group (P<0.001). In addition, there were significantly fewer bacteria in the ultrasonic group compared with the hand instrument group (P<0.001). The smear layer scores for control and saline groups were similar, and significantly lower than in either instrumentation group (P<0.001). In the second part, root-end cavities were ultrasonically prepared in 20 extracted teeth. Ten cavities were filled with amalgam, and 10 with thermoplasticized gutta-percha and Grossman's sealer. After 24-h storage, the root ends were immersed in dye for 48 h. Cross-sectional slices of the obturated part of the root were evaluated using both light and confocal microscopy for dye leakage along the interface of filling material and dentine. There were no statistical differences between the leakage of amalgam and gutta-percha root-end fillings, nor between the two methods of microscopy. <56> UI - 96230304 AU - Sen BH AU - Wesselink PR AU - Turkun M IN - Department of Endodontics, Ege University, Izmir, Turkey. TI - The smear layer: a phenomenon in root canal therapy. [Review] [90 refs] SO - International Endodontic Journal 1995 May;28(3):141-8 AB - When the root canals are instrumented during endodontic therapy, a layer of material composed of dentine, remnants of pulp tissue and odontoblastic processes, and sometimes bacteria, is always formed on the canal walls. This layer has been called the smear layer. It has an amorphous, irregular and granular appearance under the scanning electron microscope. The advantages and disadvantages of the presence of smear layer, and whether it should be removed or not from the instrumented root canals, are still controversial. It has been shown that this layer is not a complete barrier to bacteria and it delays but does not abolish the action of endodontic disinfectants. Endodontic smear layer also acts as a physical barrier interfering with adhesion and penetration of sealers into dentinal tubules. In turn, it may affect the sealing efficiency of root canal obturation. When it is not removed, the durability of the apical and coronal seal should be evaluated over a long period. If smear layer is to be removed, EDTA and NaOCl solutions have been shown to be effective, among various irrigation solutions and techniques, including ultrasonics, that have been tested. Once this layer is removed, it should be borne in mind that there is a risk of reinfecting dentinal tubules if the seal fails. Further studies are needed to establish the clinical importance of the absence or presence of smear layer. [References: 90] <57> UI - 96179261 AU - Whitworth JM AU - Khan AQ IN - Department of Restorative Dentistry, Newcastle Dental School, Newcastle-upon-Tyne, UK. TI - Marginal leakage of Gallium Alloy root-end fillings: an in-vitro assessment. SO - International Endodontic Journal 1995 Jul;28(4):194-9 AB - The sealing ability of amalgam and Gallium Alloy Gallium Filling (GF) root-end fillings was evaluated in vitro using a highly uniform collection of sheep incisor roots. Following ultrasonic canal debridement and orthograde obturation with gutta-percha and sealer, root-end cavities were prepared in 100 roots and filled with amalgam (50 teeth) or Gallium Alloy GF (50 teeth), Twenty-five teeth from each group were subjected to immediate dye leakage assessment under vacuum conditions with methylene blue dye (2%), pH 7. Linear dye penetration was measured following longitudinal splitting. The other 25 teeth from each group were incubated in Ringer's solution for 12 weeks before leakage assessment by the same method. Control teeth were included in each component of the study. Mean linear dye penetration was: amalgam--5.17 mm at baseline, 2.33 mm after 12 week's incubation; Gallium Alloy GF--2.21 mm at baseline, 1.41 mm after 12 week's incubation. The apical marginal seal of both materials improved significantly following storage in Ringer's solution (P<0.001). Gallium Alloy GF provided a better apical seal than amalgam, both at baseline and following storage (P<0.001). Subjective evaluation of the general handling characteristics of Gallium Alloy GF revealed that it was a more difficult material to manipulate than amalgam, largely because of its wetting ability and consequent adhesion to dental instruments. <58> UI - 96122693 AU - Higashi T AU - Okamoto H IN - Department of Endodontology and Periodontology, Hiroshima University School of Dentistry, Japan. TI - The effect of ultrasonic irrigation before and after citric acid treatment on collagen fibril exposure: an in vitro SEM study. SO - Journal of Periodontology 1995 Oct;66(10):887-91 AB - The surface characteristics of periodontally diseased human teeth after two treatments were compared both before and after partial demineralization with citric acid. Thirteen teeth were obtained from patients with advanced periodontal disease. Three teeth were selected for control groups and 10 were used for experimental groups. All diseased root surfaces were identified and outlined. The roots were cut longitudinally into two sections. They were then scaled and root planed and the paired sections were separately classified into two control or two experimental groups. Three sections in control group 1 were rinsed by syringe with saline solution. The three sections in control group 2 were treated with ultrasonic irrigation. The 10 sections in experimental group 1 were rinsed by syringe with saline solution before and after citric acid application; the 10 sections in experimental group 2 were irrigated ultrasonically before and after citric acid application. The concentration of the citric acid was 25% (pH 1.62) and the immersion time was 3 minutes. The root samples were examined by scanning electron microscope. A significant amount of grinding debris covered on all the root surfaces in control group 1, whereas smear was removed in control group 2. The features of root surfaces of the two experimental groups differed considerably. All specimens in experimental group 2 exhibited collagen fibrils exposed as a consequence of citric acid etching. On the other hand, the smear layer was not thoroughly removed from the root surface in experimental group 1, which meant that few collagen fibrils were exposed after partial demineralization. From these results, ultrasonic irrigation before and after citric acid application improves exposure of collagen fibrils, which may be desirable for clinical success in periodontal regenerative therapy. <59> UI - 95394493 AU - Youngson CC AU - Nattress BR AU - Manogue M AU - Speirs AF IN - Division of Restorative Dentistry, Leeds Dental Institute, United Kingdom. TI - In vitro radiographic representation of the extent of voids within obturated root canals. SO - International Endodontic Journal 1995 Mar;28(2):77-81 AB - The aim of this study was to determine whether radiographs provide an accurate representation of the degree of root canal obturation following a cold lateral condensation technique. A total of 40 extracted single-rooted lower premolar teeth were prepared using either a standardized step-back technique or an ultrasonic device by one of two operators. The four groups each of 10 teeth were obturated using lateral condensation by a third operator. To assess apical leakage the obturated teeth were coated with nail varnish to within 2 mm of the apex and immersed in methylene blue for 48 h. The teeth were then radiographed in bucco-lingual and mesio-distal planes prior to subsequent sectioning in a bucco-lingual plane. Sections and radiographs were analysed using an image analysis apparatus to determine the proportion of root canal occupied by gutta-percha, void and/or sealer. Mean percentages of void calculated from the bucco-lingual radiographs, mesiodistal radiographs and tooth sections were 4.14%, 5.98% and 4.98%, respectively. Statistical analysis showed no significant differences between the radiographic views and the tooth sections (P > 0.05). Both planes of radiograph accurately represented the proportion of void when compared with the tooth section. <60> UI - 95404100 AU - Stamos DE AU - Gutmann JL AU - Gettleman BH IN - Department of Restorative Sciences, Baylor College of Dentistry, Dallas, Texas 75204, USA. TI - In vivo evaluation of root canal sealer distribution. SO - Journal of Endodontics 1995 Apr;21(4):177-9 AB - The effectiveness of sealer placement and its distribution in the prepared root canal system by an energized ultrasonic file was evaluated in vivo. One hundred patients had sealer placed into prepared root canals with either the master gutta-percha cone or an ultrasonic file. Before placement of sealer with the file, canals were irrigated, debrided, and flushed with water for 10 s and an energized :20 ultrasonic file at 1.0 mm from the working length. Canals were obturated with gutta-percha using lateral condensation, and evaluations were based on the presence or absence of sealer-filled accessory canals. Chi-square analysis showed that a statistically significant difference existed in the number of radiographically visible accessory canals filled when the ultrasonic file was used to place the sealer. <61> UI - 95230199 AU - O'Connor RP AU - Hutter JW AU - Roahen JO IN - Endodontics Department, Naval Dental School, National Naval Dental Center, Bethesda, MD 20889-5602, USA. TI - Leakage of amalgam and Super-EBA root-end fillings using two preparation techniques and surgical microscopy. SO - Journal of Endodontics 1995 Feb;21(2):74-8 AB - An in vitro dye leakage study was conducted to test the root-end sealing ability of amalgam with varnish or Super-EBA using two root-end preparation techniques and surgical microscopy. Sixty-four single-rooted teeth were instrumented and obturated with gutta-percha. Teeth were randomly placed into four groups. Two groups received perpendicular root-end resections, 3-mm-deep ultrasonic root-end preparations, and either amalgam with varnish or Super-EBA root-end fillings. The other two groups received beveled root-end resections, 3-mm-deep micro-handpiece preparations, and either amalgam with varnish or Super-EBA. All root-end procedures were performed at x5 to x8 magnification. Micro-leakage was assessed at 4 months using methylene blue dye and a passive hydrostatic pressure technique. Statistical analysis showed that, regardless of technique, Super-EBA leaked significantly less than amalgam with varnish. There was no significant difference between the two root-end resection and preparation techniques. <62> UI - 95164797 AU - Jeffers RJ AU - Feng RQ AU - Fowlkes JB AU - Hunt JW AU - Kessel D AU - Cain CA IN - Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor 48019. TI - Dimethylformamide as an enhancer of cavitation-induced cell lysis in vitro. SO - Journal of the Acoustical Society of America 1995 Jan;97(1):669-76 AB - Polar solvents, including dimethylformamide (DMF), have been investigated as anticancer drugs, but their potential usefulness is constrained by hepatotoxic side effects. The ability to enhance drug cytotoxicity with ultrasound would be valuable in creating locally intense chemotherapy while minimizing effects peripheral to the treatment site. The effects of continuous wave ultrasound (US) (985 kHz; 0.5-2.5 W/cm2) were evaluated on cultured HL-60 human promyelocytic leukemia cells alone and with a noncytotoxic DMF dose (0.11 M). The cells were insonified in a configuration that created no cell lysis without the introduction of albumin-stabilized microbubbles into the exposure chamber. When microbubbles were introduced, US with bubbles induced cell lysis, and the presence of DMF significantly increased the lysis induced by ultrasound with bubbles. The necessary presence of microbubbles for the DMF-US synergism to occur suggests that a likely mechanism is acoustic cavitation, initiated by the presence of microbubbles as nuclei. Detection of subharmonics confirmed the presence of cavitation, and cell lysis was well correlated with the subharmonic amplitude. The results show that albumin-stabilized microbubbles, similar to those currently used as US contrast agents, may provide a significant source of nuclei and improve prospects for cancer therapy using acoustic cavitation. The evidence presented supports the hypothesis that cell damage is due to a sonochemical rather than to a sonomechanical process. <63> UI - 95270344 AU - Saunders WP AU - Saunders EM AU - Gutmann JL IN - Department of Adult Dental Care, Glasgow Dental Hospital and School, United Kingdom. TI - Ultrasonic root-end preparation, Part 2. Microleakage of EBA root-end fillings. SO - International Endodontic Journal 1994 Nov;27(6):325-9 AB - The effect of three methods of root-end preparation, following apical resection, on the apical seal of root-end fillings, was studied in vitro. Root canals of 116 single-rooted teeth with mature apices were prepared chemomechanically and obturated with gutta-percha and sealer. The root ends were resected with a diamond bur under water coolant and were prepared as follows: group I a size 010 round bur was used to prepare an apical cavity 2-3 mm down the long axis of the root; group II treatment as per group 1 followed by a 60-s rinse with a solution of 10:3 (10% citric acid: 3% Fe2Cl3); and group III an ultrasonic retrotip was used to prepare a 2-3 mm deep apical cavity. The root end was restored with an EBA cement. Apical leakage was determined using India ink after 7 days and 7 months. The teeth were demineralized, rendered transparent and linear dye penetration was recorded. Results showed that there was no significant difference in leakage between the groups at each time interval (P > 0.05) but there was increased leakage after 7 months (P < 0.01). Cracking of the root surface was seen most often with the ultrasonically prepared roots (P < 0.001). <64> UI - 95212106 AU - Laroche M AU - Pouilles JM AU - Ribot C AU - Bendayan P AU - Bernard J AU - Boccalon H AU - Mazieres B IN - Service de Rhumatologie, CHU Rangueil Toulouse, France. TI - Comparison of the bone mineral content of the lower limbs in men with ischaemic atherosclerotic disease. SO - Clinical Rheumatology 1994 Dec;13(4):611-4 AB - In a previous study, the authors demonstrated that in 17 men with ischaemic atherosclerotic disease the bone mineral density (BMD) of the femoral neck was lower than in matched control subjects. The patients with arterial disease were thinner and were heavier smokers than the controls. Osteoporosis and arterial disease of the lower limbs were perhaps due to common risk factors: tobacco consumption and a low body build index. In order to demonstrate the direct effect of atherosclerosis on bone mineral content (BMC), the authors studied by dual-energy X-ray absorptiometry the BMC of both legs in 18 men presenting symptomatic arterial disease of the lower limbs quantified by measurement of distal systolic indexes by doppler ultrasonography. The mean BMC of the leg more severely affected by arterial disease was significantly lower than the mean BMC of the leg less affected by arterial disease (512 +/- 76 g versus 495 +/- 80 g: p = 0.003). In 13 of the 18 patients, the BMC was lower in the leg more severely affected by arterial disease; in 4 of 18 the difference between the BMC of the left and right legs was less than 1%, and in a single patient the BMC was higher in the leg more affected by arterial disease. Arterial disease of the lower limbs could lead to bone mineral loss. <65> UI - 95171300 AU - Hasegawa K AU - Turner CH AU - Burr DB IN - Department of Anatomy, Indiana University School of Medicine, Indianapolis 46202. TI - Contribution of collagen and mineral to the elastic anisotropy of bone. SO - Calcified Tissue International 1994 Nov;55(5):381-6 AB - It has long been thought that collagen fibers within the bone matrix are deposited in an aligned pattern that channels mineral growth. If this model of bone structure is correct, both organic and inorganic phases of bone should have similar elastic anisotropy. Using an acoustic microscope, we measured longitudinal and transverse acoustic velocities of cortical specimens taken from 10 dog femurs before and after removal of either the mineral (using 10% EDTA) or collagen phases (using 7% sodium hypochlorite) and calculated longitudinal (CL) and transverse (CT) elastic coefficients. The anisotropy ratio (CL/CT) decreased significantly after demineralization (1.61 before versus 1.06 after, P < 0.0001, paired t-test). However, there was no significant change after decollagenization (1.51 before versus 1.48 after, P = 0.617, paired t-test). We conclude that the orientation of mineral crystals is the primary determinant of bone anisotropy, and the collagen matrix within osteonal bone has little directional orientation. <66> UI - 95149316 AU - Samsonov VE AU - Volova LT TI - [The use of demineralized bone brephomatrix in the plastic repair of different postoperative defects in the jaws]. [Russian] SO - Stomatologiia 1994 Jul-Sep;73(3):35-7 AB - The aim of this research was assessment of the results of bone brephoplasty of the jaws. Bone tissue defects after cystectomy, granulectomy, and tooth removal were filled with fragmented transplant, demineralized osseous brephomatrix. Low-frequency ultrasound was used for antibacterial treatment of the recipient osseous bed. A total of 103 patients were operated on, brephoplasty was carried out in 60. Demineralized osseous brephomatrix is characterized by excellent plastic and osteoinductive properties, due to which bone regeneration processes are completed 1.5-2 times sooner in comparison with the control. <67> UI - 95153732 AU - Bahar A AU - Tagomori S IN - Department of Preventive Dentistry, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. TI - The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth. SO - Caries Research 1994;28(6):460-7 AB - The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel. <68> UI - 95113545 AU - Nattress BR AU - Youngson CC AU - Martin DM AU - Cassidy M IN - Department of Restorative Dentistry, Leeds Dental Institute, UK. TI - Comparison of the quality of obturation following endosonic versus hand instrumentation. SO - International Endodontic Journal 1994 Jul;27(4):178-83 AB - This study was undertaken to compare the quality of root canal obturation following preparation by endosonic or hand instrumentation. Forty single-canal, extracted lower premolar teeth were selected. One group of 20 teeth was prepared using a standard step-back technique, the other 20