Database: MEDLINE <: biomedical, nursing & dental literature, 1966 - Oct 2000.> Search Strategy (You Saved Citations 1-222 From Set 63): ----------------------------------------------------------------------------- 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 Electric conductivity/ 21009 48 Electrodiagnosis/ 2868 49 Electronics, medical/ 4737 50 ECM:.mp. 4559 51 resistance:.mp. 163539 52 conductance:.mp. 24826 53 impedance:.mp. 9598 54 diagnos:.mp. 791703 55 detect:.mp. 606416 56 measurement$1.mp. 274952 57 meter:.mp. 8164 58 monitor:.mp. 187594 59 or/51-58 1818433 60 (electric: or electron:).mp. and 59 83772 61 (current or waveform or volt:).mp. and 59 66774 62 or/47-50,60-61 157749 63 46 and 62 522 64 from 63 keep 1-300 300 65 from 63 keep 301-522 222 *************************** <1> UI - 93193124 AU - Kuroiwa M AU - Kodaka T AU - Kuroiwa M IN - Kuroiwa Dental Clinic, Fujisawa City, Japan. TI - Microstructural changes of human enamel surfaces by brushing with and without dentifrice containing abrasive. SO - Caries Research 1993;27(1):1-8 AB - Toothbrushing with and without dentifrice containing abrasive was performed on human enamel pieces attached to resin plates exposed to the oral cavities of 3 human subjects for 8 weeks. The effects on the ground enamel surfaces with engraved scratches were examined by scanning electron and scanning laser microscopy. Brushing with such a dentifrice caused smaller scratches to disappear, large scratches to expand and new microwear to appear; in some samples, prism structures were exposed. Under brushing without dentifrice, these scratches were protected by an organic pellicle with mineral deposits, and also the experimental surface was entirely covered with these membranous deposits. The results indicate that toothbrushing with no dentifrice but saliva induces an organic-mineral protective membrane on the enamel surface. The membrane may increase the enamel resistance to caries. On the other hand, the use of abrasive-containing dentifrice causes slight abrasion with microwear. This roughness may contribute to the formation of dental plaque. <2> UI - 93193134 AU - Russell M AU - Pitts NB IN - Dental Health Services Research Unit, Dental School, University of Dundee, UK. TI - Radiovisiographic diagnosis of dental caries: initial comparison of basic mode videoprints with bitewing radiography. SO - Caries Research 1993;27(1):65-70 AB - Radiovisiography (RVG) is a commercially available, dental radiographic digital imaging system which is claimed to rival conventional techniques in terms of decreased radiation dose and the production of instantaneous images. The aim of this study was to compare in vitro the sensitivities and specificities derived from three examiners using conventional bitewing radiographic film (D and E speed) with those achieved by the same examiners using basic mode RVG bitewing videoprints of occlusal and approximal caries. Videoprints were used in this study, as they are the principal method of archiving radiovisiographic images, unless a separate compatible personal computer is used. The histological appearance of the subsequently sectioned teeth was used as the validating criterion. The in vitro results of basic mode RVG suggest that for occlusal caries, overall the sensitivity and specificity of RVG videoprints are similar to those of bitewing radiography. For approximal caries, the specificity of RVG videoprints was similar to that of bitewing radiography, but the sensitivity was slightly lower. Further work using the different modes available and electronically modified images is indicated. <3> UI - 93148813 AU - Arima M AU - Matsumoto K IN - Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan. TI - Effects of ArF:excimer laser irradiation on human enamel and dentin. SO - Lasers in Surgery & Medicine 1993;13(1):97-105 AB - Round enamel and dentin surfaces of sound and carious extracted human teeth were irradiated by an ArF:excimer laser for up to 180 sec. Thermographic measurements indicated that the temperature rise due to heat accumulation caused by laser irradiation on these enamel and dentin surfaces was up to 19 degrees C (10 HZ with 540 J/cm2), and the temperature returned to the preirradiation value within 10 sec after the irradiation was stopped. Under light microscopy, no carbonization was evident on these surfaces, and a simple recess was formed by abrasion or vaporization in the irradiated regions. In the secondary SEM, uniformly distributed fine pores and prism structures appeared slightly on the enamel surfaces. Between the peritubular and the intertubular dentin, there appeared a distinct difference in the dissolved area. The laser almost completely removed carious regions of the enamel and the dentin, and penetration extended beyond the carious regions. In the backscattered electron SEM, highly mineralized layers were observed on the enamel and dentin surfaces dissolved by the laser. <4> UI - 93236932 AU - McIntyre JM IN - Department of Dentistry, The University of Adelaide, Adelaide SA. TI - Erosion. SO - Australian Prosthodontic Journal 1992;6:17-25 AB - With the current substantial decline in dental caries in adults, and increasing retention of teeth into old age, dental erosion is now being recognised as a major cause of tooth damage. It is easily recognised in its more advanced form, though more difficult to detect in its initial stages. Its mechanisms of action is generally not well understood. In this paper, current concepts of the chemistry of demineralisation of the mineral components of teeth are examined, with view to their providing a better understanding of some of the clinical characteristics of dental erosion of enamel. Categories and properties of potential erosive substances are reviewed. Speculation as to the potential effects of erosive substances on exposed root surfaces leads to consideration of the possible relationship between erosion and rapid caries development. The more commonly recommended mechanisms of control or prevention of erosion are described, and the rationale of their use analysed. <5> UI - 93178707 AU - Pitts NB IN - Department of Dental Health, University of Dundee, UK. TI - The diagnosis of dental caries: 3. Rationale and overview of present and possible future techniques. [Review] [62 refs] SO - Dental Update 1992 Jan-Feb;19(1):32, 34, 37-8, possim AB - A number of changes have taken place recently which may influence a practitioners choice of diagnostic methods for detecting and monitoring dental caries. The first two articles described the use of current diagnostic methods at various specific sites. This third paper discusses the rationale behind the use of these techniques and provides an overview of present techniques and those which may be useful in the future. [References: 62] <6> UI - 93183293 AU - Anusavice KJ IN - College of Dentistry, University of Florida, Gainesville 32610. TI - Degradability of dental ceramics. [Review] [42 refs] SO - Advances in Dental Research 1992 Sep;6:82-9 AB - The degradation of dental ceramics generally occurs because of mechanical forces or chemical attack. The possible physiological side-effects of ceramics are their tendency to abrade opposing dental structures, the emission of radiation from radioactive components, the roughening of their surfaces by chemical attack with a corresponding increase in plaque retention, and the release of potentially unsafe concentrations of elements as a result of abrasion and dissolution. The chemical durability of dental ceramics is excellent. With the exception of the excessive exposure to acidulated fluoride, ammonium bifluoride, or hydrofluoric acid, there is little risk of surface degradation of virtually all current dental ceramics. Extensive exposure to acidulated fluoride is a possible problem for individuals with head and/or neck cancer who have received large doses of radiation. Such fluoride treatment is necessary to minimize tooth demineralization when saliva flow rates have been reduced because of radiation exposure to salivary glands. Porcelain surface stains are also lost occasionally when abraded by prophylaxis pastes and/or acidulated fluoride. In each case, the solutes are usually not ingested. Further research that uses standardized testing procedures is needed on the chemical durability of dental ceramics. Accelerated durability tests are desirable to minimize the time required for such measurements. The influence of chemical durability on surface roughness and the subsequent effect of roughness on wear of the ceramic restorations as well as of opposing structures should also be explored on a standardized basis. [References: 42] <7> UI - 93157655 AU - Bacarini L AU - Giacomich R AU - Saccavini C IN - I Servizio di Radiodiagnostica, Ospedale Regionale di Treviso. TI - [Bone mineral content measurement: reflections on the equipment]. [Review] [57 refs] [Italian] SO - Radiologia Medica 1992 Dec;84(6):716-24 AB - Metabolic bone disorders are extremely interesting from an epidemiological, clinical and social point of view. In particular, some of them are important for they are typical of elderly people--i.e., the portion of population which is on the increase due to the lengthening of the average life. On the other hand, thanks to the current intervention techniques, the number of chronic nephropathics (in whom metabolic bone conditions may develop) has markedly increased. Therefore, sufficiently reliable methods are needed to allow the thorough evaluation of bone mineral components. Unfortunately, these methods are only of quantitative value because they are unable to discriminate the statuses of the two essential bone components--i.e., cortex and spongiosa--; we all know that bone mineral loss can currently be quantified only when amounting to < 20% of the total value, due to the addition of the mineral contents of the two components. In this paper the authors briefly report on the noninvasive techniques currently in use for the measurement of bone mineral components, especially relative to their physical bases, the knowledge of which is essential for a correct evaluation. The authors accurately reviewed the literature data relative to the various techniques and compared the results obtained by the different authors. Thus, no personal experience is reported, since this paper is aimed at being considered as a reference mark for the reader to be helped in the choice of the equipment suiting him most. However, as to preventing metabolic osteopathies, quantitative methods cannot yield absolute data, which addresses the current research to densitometry by means of the Compton method. The latter may finally lead to the development of operative equipment allowing not only the separate measurement of cortical and spongiose values, but also the qualitative evaluation of bone status--i.e., not limited to mineral loss but including also the determination of the protein, fat and water components. [References: 57] <8> UI - 93109876 AU - McLean JW IN - Eastman Dental Hospital, Institute of Dental Surgery, London, England. TI - Clinical applications of glass-ionomer cements. [Review] [24 refs] SO - Operative Dentistry 1992;Suppl 5:184-90 AB - The use of glass-ionomer cements in clinical dentistry is now well established. They have a number of unique properties, including adhesion to moist tooth structure, biological compatibility, and anticariogenic properties due to their fluoride release. Their use in treating early carious or erosion lesions has been widely investigated. Established techniques include fissure filling and sealing, restoration of class 5 erosion lesions without cavity preparation, and the internal occlusal fossa or tunnel restoration. The "sandwich" technique using glass-ionomer cements as "dentin substitutes" has enabled composite restorations to be used with greater safety where pulpal damage may occur. The future probably lies in using a laminate technique where materials that attach to dentin and form a biological seal can be covered by tougher and harder enamel veneers, thus mimicking the structure of the tooth. The deficiencies of glass-ionomer cements are well known, including lack of toughness, early water sensitivity, low abrasion resistance, and porosity leading to poor surface polish. Solving these problems is formidable, since inherently the strength of these cements is related to their water content. The clinician should be aware of these deficiencies and stay within the parameters of the techniques outlined in this paper. In particular, clinical success depends upon early protection of the cement from hydration or dehydration, and the current use of light-cured bonding agents has largely solved this problem. [References: 24] <9> UI - 93109882 AU - Wieczkowski G Jr AU - Yu XY AU - Davis EL AU - Joynt RB IN - State University of New York at Buffalo, School of Dental Medicine. TI - Microleakage in various dentin bonding agent/composite resin systems. SO - Operative Dentistry 1992;Suppl 5:62-7 AB - One important consideration in the selection of a dentin bonding agent/composite resin system is its resistance to marginal leakage. The purpose of this study was to compare both the extent and the pathways of marginal leakage for four currently available dentin bonding agent/composite resin systems. Class 5 restorations were placed in the buccal and lingual surfaces of 20 extracted human teeth. Specimens were subjected to thermal stress before being placed in silver nitrate solution. They were then sectioned longitudinally and observed under a light microscope. Selected samples were further studied using scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDX). Different systems exhibited different leakage patterns. Findings suggest that the smear layer should be either conditioned or removed prior to dentin bonding agent application to provide optimal resistance to microleakage. <10> UI - 93080930 AU - Andreasen FM AU - Daugaard-Jensen J IN - The Royal Dental College, Copenhagen, Denmark. TI - Treatment of traumatic dental injuries in children. [Review] [126 refs] SO - Tandlaegernes Nye Tidsskrift 1992 Mar;(3):76-89 AB - The major emphasis of this review should rest on articles written within the past 12 months. Many of these papers comprise comprehensive surveys of treatment of various aspects of dental trauma in the primary and permanent dentition, as well as epidemiological studies. There have also been some very good experimental studies which have attempted to standardize luxation injuries as well as tooth replantation in order to study pulpal and periodontal healing in reproducible animal models. However, it can be seen from the reference list that one year's production in dental traumatology would not suffice to cover the scope of the treatment needs nor to adequately orient the reader on the progress made with respect to our present knowledge of wound healing following injury and the most recent developments in the restoration of the traumatized dentition. To present an overall view of the philosophy which has evolved concerning wound healing in the dental pulp and periodontium following injury as well as innovations in the treatment of acute dental trauma, this review must of necessity delve back into the mid-80's and probe forward into publications which are on the way in 1991. In 1984, in Dallas, Texas, the American Association of Endodontists' Endowment and Memorial Foundation convened the first International Conference on Oral Trauma. In 1989, in Stockholm, Sweden, this was followed up with the second International Conference on Dental Trauma. The one-day program summarized the state of the art of dental traumatology with respect to various aspects of epidemiology, diagnosis, treatment and prevention as well as the biological principles which form a basis for our present knowledge about healing and healing complications in the pulp and periodontium after traumatic dental injuries. The proceedings from this conference have been compiled in a newly published volume. Where applicable, these presentations have been cited as current reviews. It could also be mentioned that at the conclusion of the second conference, in recognition of the need to promote research and propagate knowledge in the area of dental traumatology, the International Association of Dental Trauma (IADT) was founded. The third International Conference on Dental Trauma was convened in Copenhagen, Denmark, June 1991. The major theme was restoration of the traumatized dentition. Proceedings from this conference are to be published. However, new information from that program is also cited in the following where applicable. Finally, the second Charlotte Conference on Pathobiology of the Dentin/Pulp Complex was held in Charlotte, North Carolina in May 1991.(ABSTRACT TRUNCATED AT 400 WORDS) [References: 126] <11> UI - 93045714 AU - Cuisinier FJ AU - Steuer P AU - Senger B AU - Voegel JC AU - Frank RM IN - Centre de Recherches Odontologiques, Universite Louis Pasteur, Strasbourg, France. TI - Human amelogenesis. I: High resolution electron microscopy study of ribbon-like crystals. SO - Calcified Tissue International 1992 Oct;51(4):259-68 AB - Ribbon-like crystals, from developing enamel of human fetuses, were studied by high resolution electron microscopy. These crystals were classically described as the first organized mineral formed during amelogenesis. They were characterized by a mean width-to-thickness ratio (W.T-1) of 9.5, and 40% were bent. On lattice images we noted the presence of the central dark line (CDL) associated with white spots. Both structures were found in crystals with a minimum thickness of 8-10 nm. CDLs were localized in the center of the crystals and seemed to be linked to the initial growth process, but their exact structure and function were not fully determined. We were able to study the structure of the ribbon-like crystals with a Scherzer resolution close to 0.2 nm. The good correspondence between experimental and computed images showed that their structure was related to hydroxyapatite (HA). In addition, the presence of ionic substitutions and deficiencies were also compatible with HA. In this study, about 50% of the crystals showed structural defects. Screw dislocations were the most often noted defects and were observed within crystals aligned along five different zone axes. Low- and high-angle boundaries were also detected. Low-angle boundaries, found in the center of the crystals, could thus be related to CDLs and be implicated in the nucleation step of crystal formation, whereas high-angle boundaries could result from the fusion of ribbon-like crystals. Such mechanisms could induce an acceleration of the growth in thickness of the crystal observed during the maturation stage of amelogenesis. <12> UI - 93007441 AU - Walton JN IN - Department of Clinical Dental Sciences, Faculty of Dentistry, University of British Columbia. TI - Esthetic alternatives for posterior teeth: porcelain and laboratory-processed composite resins. [Review] [29 refs] SO - Journal / Canadian Dental Association. Journal de l Association Dentaire Canadienne 1992 Oct;58(10):820-3 AB - Porcelain and laboratory-processed composite inlays and onlays are enjoying increasing popularity as a result of heightened patient concern over the esthetics and biocompatibility of restorative materials. This paper reviews current clinical concerns about porcelain and indirect composite restorations, focusing on indirect procedures, microleakage, technique sensitivity, long-term serviceability, finish and polish, abrasion, and wear resistance. The available data indicate that there are still significant limitations to the routine use of these esthetic alternatives for posterior restorations. [References: 29] <13> UI - 93007757 AU - Jansma J AU - Vissink A AU - Spijkervet FK AU - Roodenburg JL AU - Panders AK AU - Vermey A AU - Szabo BG AU - 's-Gravenmade EJ IN - Department of Oral and Maxillofacial Surgery, University Hospital Groningen, The Netherlands. TI - Protocol for the prevention and treatment of oral sequelae resulting from head and neck radiation therapy. [Review] [45 refs] SO - Cancer 1992 Oct 15;70(8):2171-80 AB - In addition to the desired antitumor effects, head and neck radiation therapy induces damage in normal tissues that may result in oral sequelae such as mucositis, hyposalivation, radiation caries, taste loss, trismus, soft-tissue necrosis, and osteoradionecrosis. These sequelae may be dose-limiting and have a tremendous effect on the patient's quality of life. Current policies to prevent these sequelae primarily are based on clinical experience and show great diversity. A protocol for the prevention and treatment of oral sequelae resulting from head and neck radiation therapy, based on fundamental research and data derived from the literature, is presented. The protocol is particularly applicable in centers with a dental team. This team should be involved at the time of initial diagnosis so that a successful preventive regimen is an integral part of the overall cancer treatment regimen. [References: 45] <14> UI - 93012134 AU - McLean JW IN - Institute of Dental Surgery, Eastman Dental Hospital, London, England. TI - The clinical use of glass-ionomer cements. [Review] [31 refs] SO - Dental Clinics of North America 1992 Jul;36(3):693-711 AB - The use of glass-ionomer cements in clinical dentistry has expanded greatly over the last decade. Their use in treating early carious or erosion lesions has been investigated widely and established techniques include fissure filling, restoration of erosion lesions without cavity preparation, and the internal or tunnel restoration. Because of their adhesion to moist tooth structure, biologic compatibility, and fluoride release, increasing use also has been made of their anticariogenic properties in treating geriatric patients. Glass-ionomers have proved very successful as dentin substitutes for attaching composites to enamel without involving risk of pulpal damage in the deeper cavity. The deficiencies of glass-ionomer cements are well known, including lack of toughness, early water sensitivity, low abrasion resistance, and porosity, leading to poor surface polish. Solving these problems is formidable because inherently the strength of these cements is related to their water content. The clinician should be aware of these deficiencies and stay within the parameters of the techniques outlined in this article. In particular, clinical success depends on early protection of the cement from hydration or dehydration and the current use of light-cured bonding agents largely has solved this problem. The future probably lies in using laminate techniques in which materials that attach to dentin and form a biologic seal can be covered by tougher and harder enamel veneers, thus mimicking the structure of the tooth. It is possible that future materials will be developed on the lines of these polyelectrolyte cements in which higher molecular weight polymers are used in conjunction with polymers that contain photoinitiators to effect light curing and toughen the matrix. In addition, the possibility of developing laboratory-cured glass-ionomer inlays in which porosity can be reduced and tougher polymers used should be considered. [References: 31] <15> UI - 93020717 AU - Hunt RJ AU - Fann SJ AU - Kantor ML AU - Morris AL IN - College of Dentistry, University of Iowa, Iowa City. TI - Assessing dental practice quality by evaluating radiology items. SO - Journal of Public Health Dentistry 1992 Fall;52(5):264-8 AB - The DEMCAD dental office assessment instrument was developed to evaluate practice quality using Donebedian's quality assessment model of structure, process, and outcome. This previously validated instrument takes about six hours to complete. Subsequent analysis was undertaken to determine whether an abbreviated office assessment based on the evaluation of radiology items was sufficiently sensitive, specific, and practical to be used as a screening instrument for identifying dental offices with very low evaluation scores. Data for this analysis were obtained from 300 volunteer general dental practices evaluated in the field testing of the DEMCAD instrument. The nine radiology structure items predicted very poorly the overall structure scores. However, 13 radiology process items predicted overall process scores quite accurately. Four of the 13 radiology process items (periodontal diagnoses recorded, interdental bone shown on x-rays, caries diagnoses recorded, and current x-rays mounted) produced a combined R2 of .58. These four radiology variables predicted the 10 percent of the dental practices with the lowest overall process score with 87 percent sensitivity and 93 percent specificity. This analysis showed that an abbreviated dental practice process quality assessment using oral radiology items in an audit of patients' records may be feasible as a screening test for dental office assessment. <16> UI - 93027801 AU - Li QY AU - MacAulay MA AU - Landymore RW AU - Marble A AU - Dean S AU - Fris J AU - Kerstein F IN - Dept. of Pathology, Dalhousie University, Halifax, N.S., Canada. TI - Morphometric analysis on myocardial injury related to the use of high volume potassium cardioplegic solution during ischemic arrest. SO - Pathology, Research & Practice 1992 Jun;188(4-5):668-71 AB - We correlated the effects of high volumes of K+ cardioplegic solution on myocardial structure and function in 16 dogs following open-heart surgery. Eight animals received high volume potassium cardioplegic solution (25 cc/kg body weight, every 30 min) during 90 min of ischemic arrest (HVK-C group). The others received sufficient cardioplegic solution to maintain complete electrical arrest as defined by voltage monitoring criteria (VM group). Cardiac index (CI), left ventricular stroke work index (LVSWI), and myocardial contractility (dp/dt) were determined before arrest and after 90 min of ischemia and 45 min of reperfusion. Biopsies were taken for EM ultrastructure and ATP estimation. Morphometric analysis of EM micrographs found increased volume of damaged mitochondria (DMR) (p less than 0.025), damaged myofibrils (DMF) (p less than 0.001), intermyofibrilar edema (p less than 0.005), T-tubule and sarcoplasmic reticulum (p less than 0.05) in the HVK-C group. Left ventricular (LV) function was more depressed in animals receiving HVK-C. CI decreased by 1.8 +/- 0.4 l/min/square meter (p less than 0.01), LVSWS fell by 3.3 +/- 0.8 gm-m/beat/Kg (p less than 0.01), dp/dt decreased by 684 +/- 135 (p less than 0.0025). ATP decreased by 26% in HVK-C and by 12% in VM group (0.1 less than p less than 0.05). Structural damage (scores of injured volume of mitochondria and myofibrils) correlated with post-ischemic depression of LV function (Cardiac output and myocardial contractility), r = -0.72 and -0.66 (p less than 0.001 and 0.004). <17> UI - 93031928 AU - Elizova LA AU - Dmitrieva LA TI - [Changes in the electric conductivity of the dentin during caries treatment]. [Russian] SO - Stomatologiia 1992 Mar-Apr;(2):30-2 AB - Dentin permeability at the bottom of carious cavities of 124 teeth was studied by electrometry. Dentin permeability was found to be higher in deep caries than in moderate-severe and higher in the teeth that had not been treated before than in those filled. Treatment of the cavities with potassium oxalate before filling helped rapidly and effectively lower the dentin permeability in order to prevent involvement of the pulp. <18> UI - 92350869 AU - Nakabayashi N AU - Ashizawa M AU - Nakamura M IN - Tokyo Medical and Dental University, Japan. TI - Identification of a resin-dentin hybrid layer in vital human dentin created in vivo: durable bonding to vital dentin. SO - Quintessence International 1992 Feb;23(2):135-41 AB - The present study investigated the bond of 5% 4-methacryloxyethyl trimellitate anhydride in methyl methacrylate, initiated by partially oxidized tri-n-butyl borane in the presence of poly(methyl methacrylate) powder, to vital human dentin. In vivo dentinal substrates were pretreated for 10 or 30 seconds with an aqueous solution of 10% citric acid and 3% ferric chloride. Transmission electron microscopic examination of the bonded cross sections revealed the formation of a transitional, or "hybrid," layer of resin-reinforced dentin created by the impregnation, co-mingling and envelopment of collagen bundles, and encapsulation of hydroxylapatite crystals. The in vivo adhesion was assumed to be durable, because results of microscopic examinations were comparable to those of durable bonding of the same resin to extracted bovine dentin. Vital dentin exhibited greater resistance to demineralization by the acid solution than do extracted teeth. Carious extracted teeth were more easily dissolved in acid than were noncarious extracted teeth. <19> UI - 92375968 AU - Tagami J AU - Hosoda H AU - Burrow MF AU - Nakajima M IN - Department of Operative Dentistry, Tokyo Medical and Dental University, Japan. TI - Effect of aging and caries on dentin permeability. SO - Proceedings of the Finnish Dental Society 1992;88 Suppl 1:149-54 AB - Extracted human teeth were collected from young (20-28 yrs) versus old (45-69 yrs) patients. The teeth were divided into carious and noncarious groups. Slabs were created from the mid-coronal occlusal dentin. Carious lesions were excavated and the smear layers on both normal and excavated carious dentin were removed with 37% phosphoric acid (1 min). The permeability (hydraulic conductance) of old normal dentin was only 20% of that obtained in young normal dentin but all of the specimens were permeable. Young carious dentin was only 14% as permeable as young normal dentin and only 1 out of 7 specimens was not permeable. All 7 specimens of old carious dentin were impermeable. Scanning electron microscopy of old and carious dentin exhibited far more intratubular crystals than normal dentin, providing a structural basis for the functional observation. <20> UI - 92312427 AU - Natale A AU - Montenero AS AU - Bombardieri G AU - Barilaro C AU - Kim YH AU - Klein GJ AU - Jones DL IN - Department of Cardiology, Catholic University of the Sacred Heart, Rome, Italy. TI - Effects of acute and prolonged administration of propafenone on internal defibrillation in the pig. SO - American Heart Journal 1992 Jul;124(1):104-9 AB - Some antiarrhythmic sodium channel blocking drugs have been found to increase the energy necessary for internal defibrillation. Propafenone is a new drug that has been shown to be efficacious in the therapy of supraventricular and ventricular arrhythmias, and is of potential use in patients with defibrillators. The effects of short-term and prolonged propafenone administration on the internal defibrillation threshold (DFT) were determined in 43 pigs randomized to one of four groups: saline infusion (n = 10); propafenone infusion (n = 10); placebo administration for 8 days (n = 10); or propafenone administration for 8 days (n = 13). Two mesh electrodes were sutured on the right lateral and left lateral epicardial surface and current was delivered from the right electrode to the left electrode. Triplicate DFTs were obtained before and at 40 and 80 minutes after infusion of drug or placebo. In pigs receiving long-term administration, after baseline DFTs were obtained the electrodes were removed and the chest was closed. Following 8 days of drug or placebo administration, DFTs were redetermined. No changes were observed in the short- or long-term control groups. DFTs were lower after propafenone administration: either short-term infusion (20 +/- 6.2 joules at baseline; 15.6 +/- 5 joules at 40 minutes, p less than 0.05; 10.2 +/- 6 joules at 80 minutes, p less than 0.001) or long-term administration (17.8 +/- 2.6 joules at baseline versus 12 +/- 3.2 joules on drug, p less than 0.002). Decreased ventricular cycle lengths were found with acute administration of propafenone. Three pigs died during long-term administration of propafenone.(ABSTRACT TRUNCATED AT 250 WORDS) <21> UI - 92331082 AU - Nammour S AU - Renneboog-Squilbin C AU - Nyssen-Behets C IN - Service de Stomatologie, Hopital St-Pierre, Belgique. TI - Increased resistance to artificial caries-like lesions in dentin treated with CO2 laser. SO - Caries Research 1992;26(3):170-5 AB - The crowns of 60 permanent human molars were sectioned transversally. The exposed dentin surface was divided into different parts: a first part was kept as control, a second part was immediately varnished, and a third part was irradiated with a CO2 laser using the same irradiation conditions as those applied for caries removal (10 impulses of the same energy; 0.2 s/impulse; energy density/impulse 280-715 J/cm2. After irradiation, a small portion of this area was varnished. The teeth were immersed for 4 weeks in a cariogenic gel (pH = 4.5) at 36 degrees C. Twenty teeth were studied by scanning electron microscopy, and longitudinal sections of the other teeth were prepared for microradiography and microdensitometry measurements. The lased dentin surface appeared smooth for energy densities lower than 425 J/cm2. Longitudinally fractured samples revealed a layer of dentin devoid of tubular structure (20-70 microns thick, depending on the energy density used), whereas below the sealed layer, the dentinal tubules retained their normal aspect. Although the sealed layer showed no demineralization when exposed to acid, demineralization of the underlying dentin occurred, but to a much lesser extent than in the unlased dentin. <22> UI - 92321097 AU - Dubowitz H AU - Feigelman S AU - Zuravin S AU - Tepper V AU - Davidson N AU - Lichenstein R IN - Department of Pediatrics, University of Maryland School of Medicine, Baltimore 21201. TI - The physical health of children in kinship care. SO - American Journal of Diseases of Children 1992 May;146(5):603-10 AB - OBJECTIVE--The objectives of this study were to assess the current and chronic health problems and the adequacy of primary health care of children placed with a relative (kinship care) by a public agency. RESEARCH DESIGN--Population survey. SETTING--Children in kinship care in Baltimore, Md. PARTICIPANTS--Four hundred seven (78%) of 524 children in kinship care in 1989. INTERVENTIONS--None. MEASUREMENTS/MAIN RESULTS--Information on the child's health status and care was obtained via a review of medical records; questionnaires sent to primary care physicians, parents, care givers, and caseworkers; and clinical assessment of the child by a nurse, pediatrician, and child psychologist. The children were found to have health problems similar to those in foster and poor children, but more problems than American children in general. Frequent diagnoses included impaired visual acuity and hearing, obesity, dental caries, and asthma; often, these problems had not been identified or treated. Gaps in the medical records precluded firm conclusions concerning the children's primary care, but suggest an inadequate system for ensuring their health care. CONCLUSIONS--There is a need for improving the system of health care for children in kinship care. There is also a need for additional research on this high-risk group of children. <23> UI - 92284132 AU - Newbrun E IN - School of Dentistry, University of California San Francisco 94143-0512. TI - Preventing dental caries: current and prospective strategies. [Review] [42 refs] SO - Journal of the American Dental Association 1992 May;123(5):68-73 AB - Strategies of caries prevention can be directed at the resistance of the host/teeth, at the diet, at the microflora or all three. The appropriate preventive interventions depend on the level of caries risk. [References: 42] <24> UI - 92302058 AU - Frame R AU - Brodman R AU - Furman S AU - Kim SG AU - Roth J AU - Ferrick K AU - Hollinger I AU - Gross J AU - Fisher JD IN - Department of Cardiothoracic Surgery, Montefiore Medical Center, Bronx, NY 10467. TI - Clinical evaluation of the safety of repetitive intraoperative defibrillation threshold testing. SO - Pacing & Clinical Electrophysiology 1992 Jun;15(6):870-7 AB - One goal of the initial implantation procedure for a cardioverter defibrillator is determination of the configuration and patch location with the lowest defibrillation threshold (DFT). To determine the safety of multiple defibrillation tests, an analysis of the intraoperative defibrillation threshold tests (DFTT) in our patients was performed. In 84 patients, the mean number of DFT trials was 5.27; the mean number of joules received was 275.0. The maximum number of shocks in one implant procedure was 50 for a total of 4,895 joules without complications. Four patients received 30 or more DFT shocks without complication. There were two complications related directly to the DFTT: one patient with severe noninflammatory cardiomyopathy developed electromechanical dissociation and was subsequently resuscitated and survived; the second patient with severe triple vessel coronary artery disease suffered an intraoperative myocardial infarction during testing and eventually died 22 days postoperatively. All patients received an ICD unit; six patients had DFTs of greater than 20 joules. Based on our experience, we followed the clinical status (heart rate, blood pressure, ECG changes, fluid status, total anesthesia time) during the DFTT to determine the extent and duration of our testing protocol. Multiple shocks due to repositioning of the leads in a stable patient should not prohibit extensive testing as adverse consequences do not appear to be cumulative. <25> UI - 92247563 AU - Hardie JM IN - Department of Oral Microbiology, London Hospital Medical College. TI - Oral microbiology: current concepts in the microbiology of dental caries and periodontal disease. [Review] [89 refs] SO - British Dental Journal 1992 Apr 11;172(7):271-8 AB - The microbial flora of the mouth is highly complex, containing a wide variety of bacterial species. The most common types of oral disease, dental caries and periodontal disease, are both related to dental plaque and seem to occur when the normal balance between the microorganisms and the host is disturbed in some way. Dental caries is usually associated with increased numbers of mutans streptococci and lactobacilli at the sites of disease; estimation of salivary levels of these organisms may be useful for assessing caries risk in patients and for monitoring their response to preventive measures. A large number of 'candidate pathogens' have been identified as potential aetiological agents in different types of periodontal disease, although the 'specific plaque hypothesis' may still be controversial. Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, together with the poorly understood spirochaetes, have most frequently been reported as significant periodontopathogens and a number of possible virulence factors have been described. Application of modern molecular techniques to the study of the microbiology of oral diseases should allow rapid further progress to be made and will lead, hopefully, to improved methods of diagnosis, risk assessment and treatment. [References: 89] <26> UI - 92209071 AU - Wharton JM AU - Wolf PD AU - Smith WM AU - Chen PS AU - Frazier DW AU - Yabe S AU - Danieley N AU - Ideker RE IN - Department of Medicine, Duke University Medical Center, Durham, N.C. 27710. TI - Cardiac potential and potential gradient fields generated by single, combined, and sequential shocks during ventricular defibrillation. SO - Circulation 1992 Apr;85(4):1510-23 AB - BACKGROUND. Potential gradient field determination may be a helpful means of describing the effects of defibrillation shocks; however, potential gradient field requirements for defibrillation with different electrode configurations have not been established. METHODS AND RESULTS. To evaluate the field requirements for defibrillation, potential fields during defibrillation shocks and the following ventricular activations were recorded with 74 epicardial electrodes in 12 open-chest dogs with the use of a computerized mapping system. Shock electrodes (2.64 cm2) were attached to the lateral right atrium (R), lateral left ventricular base (L), and left ventricular apex (V). Four electrode configurations were tested: single shocks of 14-msec duration given to two single anode-single cathode configurations, R:V and L:V, and to one dual anode-single cathode configuration, (R+L):V; and sequential 7-msec shocks separated by 1 msec given to R:V and L:V (R:V----L:V). Defibrillation threshold (DFT) current was significantly lower for R:V----L:V than for the other configurations and markedly higher for L:V. Despite these differences, the minimum potential gradients measured at DFT were not significantly different (approximately 6-7 V/cm for each electrode configuration). Potential gradient fields generated by the electrode configurations were markedly uneven, with a 15-27-fold change from lowest to highest gradient, with the greatest decrease in gradient occurring near the shock electrodes. Although gradient fields varied with the electrode configuration, all configurations produced weak fields along the right ventricular base. Early sites of epicardial activation after all unsuccessful shocks occurred in areas in which the field was weak; 87% occurred at sites with gradients less than 15 V/cm. Ventricular tachycardia originating in high gradient areas near shock electrodes followed 11 of 67 successful shocks. CONCLUSIONS. These data suggest that 1) defibrillation fields created by small epicardial electrodes are very uneven; 2) achievement of a certain minimum potential gradient over both ventricles is necessary for ventricular defibrillation; 3) the difference in shock strengths required to achieve this minimum gradient over both ventricles may explain the differences in DFTs for various electrode configurations; and 4) high gradient areas in the uneven fields can induce ectopic activation after successful shocks. <27> UI - 92226331 AU - Pitts NB AU - Kidd EA IN - Dental Health Services Research Unit, University of Dundee, Dental School, UK. TI - Some of the factors to be considered in the prescription and timing of bitewing radiography in the diagnosis and management of dental caries. [Review] [106 refs] SO - Journal of Dentistry 1992 Apr;20(2):74-84 AB - This article describes some of the factors to be considered by the practitioner when prescribing bitewing radiographs in the diagnosis and management of dental caries and draws on the literature of a number of disciplines including restorative dentistry, cariology, epidemiology and oral radiology. It seems appropriate to re-assess current practice in the light of information on changes in the disease of dental caries, its behaviour and the way this behaviour may vary in high and low caries risk groups. The diagnostic potential of the bitewing examination appears, at present, to be unrivalled, but other diagnostic methods, such as fibreoptic transillumination and tooth separation, must also be considered. Some methods to minimize radiation doses and increase diagnostic yield are discussed. Current knowledge of prescribing patterns is reviewed and areas of ignorance are mentioned as findings from future research in these areas may influence decisions about when to use and re-use bitewing radiographs. [References: 106] <28> UI - 92233455 AU - Verdonschot EH AU - Bronkhorst EM AU - Burgersdijk RC AU - Konig KG AU - Schaeken MJ AU - Truin GJ IN - Department of Cariology and Endodontology, University of Nijmegen, The Netherlands. TI - Performance of some diagnostic systems in examinations for small occlusal carious lesions. SO - Caries Research 1992;26(1):59-64 AB - The objective of this study was to compare the performance in occlusal caries diagnosis of various available diagnostic systems when applied to the same teeth. The sample investigated consisted of 13 children for whom 4 premolar and 19 molar teeth were judged to require a sealant. The indication was based on the criteria 'fissure discoloration', 'enamel decalcification' and 'absence of dentinal decay'. For predefined locations within these occlusal fissures a diagnosis was obtained by the following diagnostic systems: clinical examination, examination on fiber-optic transillumination (FOTI), fissure discoloration, electrical resistance measurement, radiographic examination and ratings of fissure morphology. Tooth material was removed until no (more) carious enamel or dentin was left. Two dentists then jointly decided on the status of decay for each of the defined locations within the fissure. These ratings served as the 'gold standard' diagnoses. The electrical resistance measurement with a sensitivity of 0.96 and a specificity of 0.71 was the only diagnostic tool with acceptable performance. Radiographic diagnosis was characterized by a moderate sensitivity and specificity. All other diagnostic systems had either very low sensitivities or very low specificities, or both. The positive predictive value of FOTI examination and the negative predictive value of the electrical resistance measurements were very high, irrespective of the prevalence of occlusal dentinal decay. <29> UI - 92137368 AU - Di Carlo C AU - Shoham Z AU - MacDougall J AU - Patel A AU - Hall ML AU - Jacobs HS IN - University College, London, United Kingdom. TI - Polycystic ovaries as a relative protective factor for bone mineral loss in young women with amenorrhea. SO - Fertility & Sterility 1992 Feb;57(2):314-9 AB - OBJECTIVE: To examine the impact of polycystic ovaries (PCO) on bone mineral density in amenorrheic women of reproductive age. DESIGN: A retrospective analysis and comparison of polycystic ovarian syndrome (PCOS) with non-PCOS amenorrheic women. A subgroup of patients with ultrasound (US)-diagnosed PCO was also investigated. SETTING: Specialist clinic in reproductive endocrinology. PATIENTS, PARTICIPANTS: Six hundred ten consecutive cases, mean age of 29.8 +/- 7.5 years, with current history of amenorrhea of various causes. MAIN OUTCOME MEASURE: Bone mineral density in the lumbar spine (L1 to L4) as measured by dual energy x ray absorptiometry, in relation to PCOS, US-diagnosed PCO, and US findings of normal ovaries. RESULTS: Amenorrheic patients with PCOS were found to be younger (P less than 0.001), with higher body mass index (P less than 0.001), were more estrogenized, as measured by endometrial thickness and uterine cross-sectional area (P less than 0.001), and had higher bone mineral density (P less than 0.001) compared with non-PCOS amenorrheic patients. CONCLUSIONS: Patients with amenorrhea because of PCOS and those with US-diagnosed PCO have a higher bone density compared with amenorrheic patients with normal ovaries as detected by US scan. <30> UI - 92334276 AU - Bokor M AU - Hillier-Kolarov V IN - Institut za stomatologiju, Medicinski fakultet, Novi Sad. TI - [Diagnosis of precancerous conditions of the oral cavity]. [Serbo-Croatian (Roman)] SO - Medicinski Pregled 1991;44(11-12):482-4 AB - Malignant neoplasms take the second place among the leading causes of death. The investigation was aimed at the determination of the incidence of precancerous states of the oral cavity according to the sex, localization and etiological factors. The diagnosis of the disease was based on anamnesis, clinical examination and pathohistological data. In 1987 chronic oral changes were detected in 53 patients--40 men and 13 women. The mean age of the subjects was 50.3 years. The results reveal that of 53 patients 17 had oral changes of whom 5 were diagnosed to have cancer, while in 2 patients with leukoplakia the presence of atypical cells was detected pathohistologically. The changes were most frequently localized on the left and right cheek, left lateral side of the tongue and the lower lip. Smokers comprised 71%, alcohol consumption and caries made up for 15.3%, while inappropriate dentures and the presence of galvanic current was found in 9.6% of the cases. <31> UI - 92269736 AU - Masoni S AU - Panattoni E AU - Rolla P AU - Rossi M AU - Giuca MR AU - Gabriele M IN - Istituto di Clinica Odontostomatologica, Universita degli Studi di Pisa. TI - [Stomatological problems related to pregnancy. A statistical study]. [Italian] SO - Minerva Stomatologica 1991 Dec;40(12):791-6 AB - Pregnancy is related to particular dental issues, such as the increased incidence of diseases( gingivitis, caries, epulis), the fluoride supplementation, and the limits of diagnostics and therapy. Moreover, the mysterious halo surrounding pregnancy often makes the dentist uneasy. In order to objectively evaluate the implications of pregnancy in dentistry, we distributed a form to 100 pregnant women. The results of the form showed that 53 of them had gingival bleeding, 22 had toothache, 19 had caries but that just 12 of them had gone to the dentist because of dental troubles while 54 had not gone at all. Among the pluri-gravidae, all the women with dental diseases in their previous pregnancies had them again in their current pregnancy but nonetheless only some had undergone a dental check-up. The dentists did not show any uneasiness, as they performed tooth extractions in 5 women, endodontics in 2 women and fillings in 11 women. Just 4 out of 100 women had taken a fluoride supplementation. We deem advisable a stronger collaboration between physician, gynecologist and dentist in order to resolve specialist problems and to make pregnant women more aware of the need for dental follow-ups and fluoride supplementations. <32> UI - 92265728 AU - Wirz J AU - Weidmann R AU - Schmidli F IN - Zahnarztlichen Institut der Universitat Basel. TI - [On the clinical relevance of the dimensional behavior of silver amalgam. A comparative in vitro and in vivo study]. [German] SO - Deutsche Stomatologie 1991;41(3):81-8 AB - The clinical relevance of the dimensional behavior of six different gamma-2-free silver amalgam products was examined in comparative in vitro and in vivo trials. Dye penetration tests, roughness measurements, and inspection of the marginal fit using a scanner electron microscope all showed that the results of the in vivo and the in vitro trials were in good agreement and that there was no significant difference between the various products tested, despite the fact that they differed both in morphology and in composition. Copalite exerts a favorable influence on the marginal fit of amalgam restorations, not only in laboratory trials, but also clinically. The results obtained show that the behavior of an amalgam with respect to changes in volume is not the sole criterion by which its quality is to be judged. Amalgams with a pronounced contraction tendency will seal the marginal gap with their corrosion products (SnCl). Here copalite serves as a temporary stand-in. There was no leakage of metal ions from the restoration into the dentin for any of the products tested, including those with a high copper content. <33> UI - 92134420 AU - Fonseca MM AU - Uribe Echevarria J AU - Gendelman H IN - Facultad de Odontologia, Universidad Nacional de Cordoba. TI - [Incipient cariogenic demineralization of human enamel]. [Spanish] SO - Avances en Odontoestomatologia 1991 Sep;7(7):553-8, 560 AB - 32 teeth (12 premolars and 20 molars) were studied under light microscopy, polarized microscopy, transparence light microscopy and scanning electron microscopy. These teeth presented changes in colour in their free and proximal surface as well as close to pits and fissures. As an extra diagnostic test the PAS reaction was used to assess descalcifying processes in both light and transparence microscopy. Polarized light was used to assess normal enamel. Scanning electron microscopy corroborated the lesions produced in the enamel surface in the form of micropores. PAS reaction diagnosed decalcifying processes in yellow, brown and brownish stains. White staims not always were PAS-positive and when they reacted in the same manner as other positive stains, with the immersion technique. This penetrated 40-60 umtrs. and in some areas in relation to lamellae they reached dentin. Light, polarized and scanning electron microscopy showed the presence of micropores in the external surface of enamel in PAS-positive cases. The possibility of a modified PAS technique to use in clinical practice is discussed. It is concluded that PAS relation is useful as "ex situ" test to detect the first signs of mineral salt loss at the enamel surface. More research is needed to transfer these results to clinical practice. <34> UI - 92116298 AU - Svenson B AU - Petersson A IN - Department of Oral Radiology, Postgraduate Dental Education Center, Orebro, Sweden. TI - Influence of tube voltage on radiographic diagnosis of caries in premolars and molars. SO - Swedish Dental Journal 1991;15(5):245-50 AB - The influence of tube voltage on radiographic diagnosis of caries in extracted premolars and molars was examined. Five combinations of dental X-ray machines and kV-settings were used (Philips Oralix 65 kV; Siemens Heliodent EC 60 kV; Siemens Heliodent 70 kV; Soredex Minray DC 60 kV and 70 kV). The diagnostic accuracy was evaluated with the ROC-technique. The results showed no significant differences in the diagnostic accuracy between premolars and molars. However, the diagnostic accuracy tended to be better with low kilovoltage for radiography of premolars and high kilovoltage for radiography of molars. <35> UI - 92086546 AU - Singer I AU - van der Laken J AU - Edmonds HL Jr AU - Slater AD AU - Austin E AU - Shields CB AU - Kupersmith J IN - Cardiovascular Division, University of Louisville, Kentucky 40292. TI - Is defibrillation testing safe?. SO - Pacing & Clinical Electrophysiology 1991 Nov;14(11 Pt 2):1899-904 AB - Determination of defibrillation thresholds (DFTs) and implantable cardioverter defibrillator (ICD) testing requires repeated inductions of ventricular fibrillation (VF) and defibrillation attempts using known energy outputs. Little is known about the individual and cumulative effects of repetitive brief episodes of VF and hypoperfusion on cerebral function. The potential clinical utility of quantitative electroencephalographic (QEEG) monitoring during intraoperative ICD testing, by using processed 19-channel EEG (0.5-35 Hz bandwidth), was examined in ten anesthetized patients, five males and five females (mean age 62 +/- 10 years), who underwent ICD implantation and testing. Ischemic QEEG patterns were defined as those with a 3 standard deviation increase (P less than 0.01) in absolute delta (1.5-3.5 Hz) power persisting for greater than or equal to 2.5 minutes. The majority (80%) of the VF episodes (70) were accompanied by QEEG "slowing" (doubling of the pre-VF low frequency delta waves amplitude). All the patients (5/5) experiencing greater than 6 VF episodes showed a statistically significant increase in the low frequency amplitude. In contrast, this EEG abnormality was apparent in only one of five patients experiencing less than 6 VF episodes. These results suggest a cumulative QEEG depression associated with ICD testing. QEEG may provide an objective means for establishing an individualized upper safe limit of DFT testing and the total number of induced VF episodes. <36> UI - 92074056 AU - de Wet FA AU - Exner HV AU - du Preez IC AU - van Niekerk JP IN - University of Pretoria. TI - The effect of placement technique on marginal adaptation of posterior resins. SO - Journal of the Dental Association of South Africa 1991 Mar;46(3):171-4 AB - Polymerization shrinkage of posterior resin restorations leads to margins that pull away from the tooth, or to cracks in the material itself. The purpose of this study was to determine the effect of three different placement techniques on the marginal adaptation (or in effect the amount of polymerization shrinkage) of posterior resin restorative materials. Three posterior resin materials, namely, Distalite, Heliomolar and P30 were included in this study. Each of these materials were placed by means of three different placement techniques (Bulk pack, Horizontal layering and Vertical layering) into class II cavities in extracted human molars. No dentine bonding agents were used. The samples were light cured, the teeth sectioned longitudinally and stored dry before examination in a Scanning Electron Microscope. Results showed polymerization shrinkage with all three techniques, with the poorest the bulk pack technique where large marginal discrepancies were visible. No significant differences were detected between the horizontal and vertical placement techniques, but the two microfilled resins Heliomolar and Distalite showed significantly poorer marginal adaptation than the small particle conventional resin, P30. All three materials had better adaptation on the occlusal margins than on the margins situated along the floor of the cavity or the gingival margins of the proximal box of the cavity. It can be concluded that the bulk pack technique should be avoided as this leads to large contraction gaps at most of the margins of the restoration. <37> UI - 92086538 AU - Wesley RC Jr AU - Morgan D AU - Zimmerman D IN - Division of Cardiology, VA Medical Center, Long Beach, CA 90822. TI - Limitations of the countershock dose response: a study of transthoracic current. SO - Pacing & Clinical Electrophysiology 1991 Nov;14(11 Pt 2):1855-9 AB - Dose response assessment of countershock efficacy has been widely determined with respect to energy but not current. The purpose of this study was to examine the utility of the dose response method in a current-based model of transthoracic defibrillation (pentobarbital anesthetized dogs, n = 8). Ventricular fibrillation induction lasting 15 seconds was separated by 5-minute intervals. Current defibrillation threshold (DFT; the lowest current that successfully defibrillated) was determined by decreasing current on successive trials. Energy DFT equaled the energy value of the corresponding current DFT. Subsequent data were expressed in normalized terms with each DFT assigned a normalized value of 1.00. Three shocks were delivered in random order at each of seven normalized current nodes (total of 21 shocks): 0.55, 0.70, 0.85, 1.00, 1.15, 1.30, and 2.00 x DFT (early testing). Randomization was repeated, and a second set of 21 trials were performed (late testing). Composite plots were made relating normalized current and energy to the percent successful defibrillation. The dose response expressed in normalized energy demonstrated an overall shift to the left compared to current. The difference was significant at every node value below the estimated DFT. Ninety percent of successful trials with respect to current and energy occurred at or above 0.85 DFT and 0.55 DFT, respectively. Significant changes in impedance occurred between early testing (60 +/- 6 ohms) and late testing (47 +/- 5 ohms), n = 8, mean +/- SD. Current, compared to energy, is a more accurate parameter in the dose response assessment of transthoracic defibrillation.(ABSTRACT TRUNCATED AT 250 WORDS) <38> UI - 92029419 AU - Yamashita Y AU - Kunimori A AU - Takehara T IN - Department of Preventive Dentistry, Kyushu Dental College, Kitakyushu, Japan. TI - Effect of calcium ions on cell surface electrostatics of Bacteroides gingivalis and other oral bacteria. SO - Zentralblatt fur Bakteriologie 1991 Apr;275(1):46-53 AB - Surface electrostatics of Bacteroides gingivalis and other oral bacteria were examined. A polarization circuit was employed using platinum electrodes exposed in each bacterial suspension and the number of bacteria adsorbed to the anode and cathode were then estimated. In all bacteria (B. gingivalis, Streptococcus sobrinus, S. mutans, S. salivarius, S. sanguis and Actinomyces viscosus), the number of cells adsorbed to the anode were much greater than the number of cells adsorbed to the cathode. Treating these bacteria with calcium ions tended to decrease the ratio of the number of cells adsorbed to the anode to the number of cells adsorbed to the cathode in all bacteria examined. Moreover, in the case of B. gingivalis, the number of cells adsorbed to the anode and cathode was in an inverse relationship to the number counted before calcium ion treatment. These findings indicate that the cell surfaces of oral bacteria are generally negatively charged but only the cell surface electrostatics of B. gingivalis was dramatically affected by calcium ion treatment. Thus, divalent metal bridges such as calcium bridges contribute to the adherence of the periodontopathic bacterium, B. gingivalis rather than to that of other oral bacteria including cariogenic bacteria. <39> UI - 92007556 AU - Zmener O AU - Gimenes Frias J IN - Department of Oral Pathology, University of Buenos Aires, Argentina. TI - Thermomechanical compaction of gutta-percha: a scanning electron microscope study. SO - Endodontics & Dental Traumatology 1991 Aug;7(4):153-7 AB - The root canals of 20 freshly extracted maxillary central incisors and canines were prepared and filled by thermo-mechanical or lateral condensation of gutta-percha cones without sealer. The adaptation of the filling material to the root canal walls was then examined with a scanning electron microscope. A more homogenized mass of gutta-percha could be detected in teeth filled by thermomechanical compaction of gutta-percha cones. The morphology of the prepared root canal system was well reproduced by the use of both techniques. <40> UI - 91328416 AU - Eskandar E AU - Kimmel DB AU - Wronski TJ IN - Department of Medicine, Creighton University, Omaha, Nebraska. TI - Rapid determination of cancellous bone mineral loss in ovariectomized rats by a subtraction technique. SO - Anatomical Record 1991 Jun;230(2):169-74 AB - We present a rapid technique for determining cancellous bone mineral changes in small experimental animals. We used the distal centimeter of the right femur from ovariectomized (OX) (N = 30) and shamovariectomized (ShOX) (N = 28) rats, aged 90 days at surgery and killed at times from 125-540 days postsurgery. We used dual photon absorptiometry to scan the segment three times: intact, after parasagittal splitting, and after removing all cancellous bone. We equated the difference between the second and third scans to cancellous bone mineral content (Cn.BMC). To validate this, we compared it with histomorphometrically determined bone volume (BV/TV) of the proximal tibial metaphysis of the same rat. Parasagittally splitting the segment removed no detectable mineral. OX rats had 40% less Cn.BMC than ShOX rats. However, OX rats had 80% lower BV/TV than ShOX rats. The subtraction technique not only makes a rapid, reasonable assessment of cancellous bone loss in OX rats but permits a smaller sample size than histomorphometry. The histomorphometric technique finds a greater difference between OX and ShOX rats because it examines a region where cancellous bone loss is more marked than does the scanning technique. The current technique measures bone of not only the central secondary spongiosa but also the juxtacortical region and the primary spongiosa, where OX-related differences are less prominent. The principles of this subtraction technique proved workable. However, for the future, we recommend a two-scan technique using a dual energy X-ray scanner. It is likely to take only 20-30 min per specimen to assess cancellous bone mineral. <41> UI - 91291867 AU - Hamilton CL AU - Ma L AU - Renner MW AU - Scott RA IN - Department of Chemistry, University of Georgia, Athens 30602. TI - Ni(II) and Ni(I) forms of pentaalkylamide derivatives of cofactor F430 of Methanobacterium thermoautotrophicum. SO - Biochimica et Biophysica Acta 1991 Jul 8;1074(2):312-9 AB - A series of pentaalkylamide forms of F430 and of its 12,13-diepimer have been generated and characterized. Carbodiimide-assisted N-hydroxysulfosuccinimide activation of all five peripheral carboxylates of the F430 macrocycle allows nucleophilic attack by a number of primary amines (RNH2, R- = CH3-, CH3CH2-, CF3CH2-, CH3(CH2)3-) generating the pentaalkylamide derivatives. The identity of each derivative has been verified by fast-atom bombardment mass spectrometry (FAB-MS). The solubility of these derivatives in aprotic organic solvents varies as the amine alkyl substituent (R-) is changed. Electrochemical measurements have shown that the Ni(II/I) reduction potentials in N,N-dimethylformamide (DMF) are approximately -1 V (Ag/AgCl). Reduction by sodium amalgam in THF generates the Ni(I) form of the F430 diepimer pentabutylamide. The visible and EPR spectra of this Ni(I) species are very similar to the corresponding spectra of Ni(I) F430M (Jaun, B. and Pfaltz, A. (1986) J. Chem. Soc. Chem. Commun. 1327-1329.). <42> UI - 91309017 AU - Steinherz PG AU - Siegel SE AU - Bleyer WA AU - Kersey J AU - Chard R Jr AU - Coccia P AU - Leikin S AU - Lukens J AU - Neerhout R AU - Nesbit M AU - et al IN - Memorial Sloan-Kettering Cancer Center, New York, New York. TI - Lymphomatous presentation of childhood acute lymphoblastic leukemia. A subgroup at high risk of early treatment failure. SO - Cancer 1991 Aug 15;68(4):751-8 AB - Multivariate analyses of the clinical course of 1537 children with acute lymphoblastic leukemia (ALL) identified a subgroup which experienced short remission duration and a high incidence of extramedullary relapse. The patients differed from other ALL patients by the presence at diagnosis of two or more of a constellation of clinical and laboratory features: organomegaly or mass disease, E-rosette positivity, hemoglobin level greater than 10 g/dl, leukocyte count greater than 50,000/microliters, male predominance, and older age. This type of presentation of ALL is referred to as the "lymphoma syndrome" (LS) since such patients exhibit a pattern of several clinical and laboratory features which were observed repeatedly but in differing combinations, and some of which clinically resemble lymphoma. A subsequent database from 2231 patients was analyzed. Patients with a mediastinal mass, massive splenomegaly, or massive adenopathy, alone or in combination, had a worse outcome when the patient also had either leukocytosis, E-rosette-positive lymphoblasts, or a normal or near normal hemoglobin (Hb) level at diagnosis. Similarly, the above three laboratory features alone or in combination did not predict less than 40% disease-free survival (DFS) unless they were accompanied by at least one of the clinical features of mass disease. When at least one clinical feature and at least one laboratory feature were present, the overall DFS was 36% 6 years after diagnosis versus 64% for all other patients. The association of these features with poor prognosis remained significant after adjusting for the level of leukocyte count at diagnosis, age at diagnosis, and sex of the patients. Patients with this recurrent syndrome of features do not represent a homogeneous biologic entity but they constitute a subgroup of patients with ALL having a high risk of treatment failure using current therapies, including failure to achieve remission, early relapse, and increased frequency of relapse in extramedullary sites. They deserve early recognition at diagnosis and selection of treatment strategies appropriate for very high risk ALL. <43> UI - 91310822 AU - Lang NP AU - Nyman S AU - Senn C AU - Joss A IN - University of Berne, School of Dental Medicine, Switzerland. TI - Bleeding on probing as it relates to probing pressure and gingival health. SO - Journal of Clinical Periodontology 1991 Apr;18(4):257-61 AB - The present study was designed to determine the threshold pressure value to be applied in provoking bleeding on probing (BOP) in clinically healthy gingival units. 12 female dental hygiene students volunteered for the study. They were selected on the basis of excellent oral hygiene standards, absence of probing depths greater than 3 mm and absence of caries or dental restorations on smooth and proximal tooth surfaces. Applying a probing force of 0.25, 0.5, 0.75 and 1.0 N in one of the 4 jaw quadrants, respectively, on 2 different occasions with an interval of 10 days, bleeding on probing was assessed. Oral hygiene and gingival conditions were determined using the criteria of the plaque control record and the gingival index. On the basis of the BOP values, obtained using the lowest probing force (0.25 N), the subjects were divided into 2 groups: group 1 ("minimal BOP" value) consisted of 6 subjects yielding practically no bleeding (mean BOP = 0.9%) at both examinations, while the subjects of group 2 ("low BOP" value) had slightly higher BOP% (mean BOP = 13.4%). Both groups showed significant increase in mean BOP% with increasing probing force (0.9%-36.1% in group 1 and 13.4%-47.0% in group 2). Regression analysis revealed an almost linear correlation and a high correlation coefficient between BOP% and probing force. The comparison of the regression lines of the 2 groups showed almost identical slope inclination. However, slight differences in slope inclination were found for different sites: approximal sites clearly yielded steeper regression lines than buccal/oral sites.(ABSTRACT TRUNCATED AT 250 WORDS) <44> UI - 91314032 AU - Lemmer B IN - Zentrum der Pharmakologie, Klinikum der J.W. Goethe-Universitat, Frankfurt/Main. TI - [Analysis of the circadian rhythm of pain]. [German] SO - Zeitschrift fur Rheumatologie 1991;50 Suppl 1:49-54 AB - An electronic pulp tester was used to study the stimulus threshold in human teeth of 28 healthy volunteers for 1,5-4 days and the duration of local anaesthesia in 55 patients with caries. Rhythm analysis was performed with a non-linear fitting program on an IBM computer (PHARMFIT); in 21 out of the 28 volunteers significant daily rhythms in stimulus threshold could be detected. In the patients the maximum duration of local anaesthesia was after drug application at 2 p.m. <45> UI - 91268658 AU - Shiikawa A AU - Koyanagi H AU - Endo M AU - Yagi Y AU - Nakano H AU - Hayashi K AU - Yamazaki K AU - Akimoto T IN - Department of Cardiovascular Surgery, Heart Institute of Japan, Tokyo. TI - [The automatic implantable cardioverter defibrillator--clinical experience in patients with life-threatening ventricular tachyarrhythmias]. [Japanese] SO - Nippon Kyobu Geka Gakkai Zasshi - Journal of the Japanese Association for Thoracic Surgery 1991 Mar;39(3):294-300 AB - Five patients (pts) with life-threatening ventricular tachyarrhythmias (idiopathic VF; 2 pts, Torsade de pointest; 1 pt, VT/VF after valve replacement; 2 pts) underwent surgical treatment of the automatic implantable cardioverter defibrillator (AICD). Implantation of an AICD was indicated for patients who survived circulatory arrest due to documented VT and/or VF. The patient should be medically refractory or medical treatment precluded by hemodynamic instability; other surgical treatment should not be possible. We selected myocardial electrode for sensing and small and large patch electrodes for defibrillating. VF/VT was induced 1 to 6 times for the measurement of defibrillation threshold (DFT). In all of our pts, the AICD appropriately discharged at postoperative EPS. In three of pts, the AICD discharged within the postoperative hospital phase, in two because of sinus tachycardia during treadmill test and restored sinus rhythm after non-sustained VT. As for complications, in one pt. with severe LV dysfunction, incessant form of VT/VF occurred after DFT testing and LV assist circulation and IABP were needed. In two pts, inappropriate discharge and in two, pericarditis were recognized postoperatively. It was considered that this system was effective for the treatment of life-threatening ventricular tachyarrhythmias but strict indication was necessary because of unsolved problems. <46> UI - 91262467 AU - Granath L AU - Svensson A IN - Department of Pedodontics, University of Lund, Sweden. TI - Elastic outward bending of loaded buccal and lingual premolar walls in relation to cavity size and form. SO - Scandinavian Journal of Dental Research 1991 Feb;99(1):1-7 AB - The aim was to study effects of the size and form of the occlusal part of Class II cavities on elastic outward bending during loading of buccal and lingual walls, separated by the preparation. Twenty newly extracted caries-free premolars were used. A special arrangement for standardized cavity preparation was set up. In order to obtain accurate measurements of the outward bending of loaded cavity walls, an electronic tensile test device was constructed. Methodologic studies showed an insignificant departure from linearity between between outward bending and load. All deformation was elastic. Correction factors were determined for strain of the apparatus as well as for indentation in the tooth substance. Measurement accuracy was calculated to +/- 0.12 N for force and +/- 0.2 micron for movement. In accordance with statistical principles, a few outlying measurements were discarded. The outward bending of buccal and lingual walls of cavities suitable for conservative restoration with dental amalgam was about 0.15 micron per Newton. Outward bending increased dramatically with exaggerated cavity depth and width. In the light of present knowledge of average chewing forces and tooth contacts in the habitual intercuspal position in young dentate adults, there seems to be little risk of leakage between conservative restorations and cavity walls as a result of elastic outward bending, though the risk certainly does increase with the depth and width of the cavity. <47> UI - 91219292 AU - Guse PA AU - Kavanagh KM AU - Alferness CA AU - Wolf PD AU - Rollins D AU - Hagler J AU - Smith WM AU - Ideker RE IN - Department of Medicine, Duke University Medical Center, Durham, NC 27710. TI - Defibrillation with low voltage using a left ventricular catheter and four cutaneous patch electrodes in dogs. SO - Pacing & Clinical Electrophysiology 1991 Mar;14(3):443-51 AB - The purpose of this study was to determine a lower limit of defibrillation thresholds (DFTs) that could be used to evaluate nonthoracotomy lead configurations for implantable defibrillators. A lead configuration that consisted of a left ventricular catheter and four circumferential cutaneous patches was tested because it was hypothesized to create a relatively uniform electric field for defibrillation. In eight anesthetized dogs, three 8F defibrillating catheters with 6 cm platinum clad titanium tips were inserted into the right ventricle (R), right ventricular outflow tract (O), and left ventricle (L). Four cutaneous patch electrodes (4P), each with a surface area of 42 cm2, were placed on the left lateral, right lateral, anterior and posterior thorax. DFTs for ten lead configurations, consisting of different combinations of these electrodes, were evaluated. DFTs were determined by using a modified Purdue technique and applying a single capacitor biphasic shock with both phases 6 ms in duration after 15 sec of electrically induced fibrillation. The L(-)----4P+ configuration produced a lower DFT than R(-)----4P+ (3.2 +/- 1.6 J vs 8.0 +/- 4.2 J, P less than 0.001) with reduced current (2.6 +/- 0.7 A vs 4.1 +/- 1.2 A, P less than 0.001). Lowering the impedance by a mean of 40%, configurations that used four patches produced lower DFTs than those that used a single left lateral patch. The use of an O catheter produced lower DFTs only when used in conjunction with an R catheter.(ABSTRACT TRUNCATED AT 250 WORDS) <48> UI - 91189508 AU - Wang WN AU - Sheen DH IN - Dental Department of Tri-Service General Hospital, School of Dentistry, National Defense Medical Center, Taipei, Taiwan, Republic of China. TI - The effect of pretreatment with fluoride on the tensile strength of orthodontic bonding. SO - Angle Orthodontist 1991 Spring;61(1):31-4 AB - White spot decalcifications and caries occurring adjacent to bonded orthodontic brackets have long been a concern to orthodontists. One procedure suggested to overcome this problem is fluoride treatment prior to bonding. The purpose of this study was to compare the tensile bond strength of orthodontic self-cured resin from Concise on teeth rinsed 4 minutes in 1.23% APF with untreated controls. Measurements were made on an Instron machine. Debonding interfaces were observed with a scanning electron microscope and energy dispersive x-ray spectrometry. Distributions were calculated. The tensile bond strengths of the fluoride-treated teeth and the untreated teeth were not significantly different. The debonding interfaces between resin and bracket base, within the resin itself, and between enamel and resin were similar in the two experimental groups. However, greater enamel detachment was seen within the fluoride pretreatment group. So while fluoride pretreatment does not significantly affect tensile bond strength, it may cause enamel detachment after debonding. <49> UI - 92245483 AU - Takarada K IN - Institute for Medical and Dental Engineering, Tokyo Medical and Dental University. TI - [Stable adhesion to dentin. Combination of EDTA 3-2 (NH4/Fe) pretreatment and 2% 4-META/MMA-TBB resin]. [Japanese] SO - Shika Zairyo, Kikai 1990 Nov;9(6):841-9 AB - An excellent durability of adhesion was obtained in the adhesion of 2% 4-META/MMA-TBB resin to dentin pretreated with EDTA 3-2 (NH4/Fe). Such high bond strength as 15 MPa did not change for up to one year even when they were immersed in water at 37 degrees C. The resin reinforced dentin, a hybrid, was identified between dentin and the cured resin by TEM. The collagen and hydroxyapatite were encapsulated with the copolymer and the crystals were not removed by the demineralization with either HCl or electronic staining. Tensile fracture between the hybrid and dentin like the adhered samples to 10-3 treated dentin did not occur and the cohesive failure in the resin was observed here after the storage in water for a year. EDTA 3-2 (NH4/Fe) could not completely demineralize the hydroxyapatite especially at the deeper portion and the width of the demineralized dentin became thinner than 1 micron. The encapsulated crystals with the resin could improve the resistance of collagen against deterioration in water and such good bonding durability could be obtained. <50> UI - 92225112 AU - Sun CH IN - Department of Orthodontics, Fukuoka Dental College. TI - [Relationship between length of resin tag and bond strength of bonding adhesive]. [Japanese] SO - Fukuoka Shika Daigaku Gakkai Zasshi 1990;17(4):383-99 AB - It is well known that the bond strength of direct bonding adhesive to etched enamel is dependent upon the formation of resin tags. So it is considered that there is a significant correlation between the bond strength and the length and shape of resin tags. However, there are very few reports on this correlation. In this study, a method of combining halogenated methacrylate and electron-probe microanalyzer (EPMA) was applied for measurement of resin tag length in order to investigate the correlation between the bond strength and resin tag length. Two experimental light cured adhesives were prepared for this study. One (CI-U) was prepared by blending microfiller (30 wt%) to the mixture of di (1-methacryloyl-oxyethyl-2-chloromethyl)-2,2,4-trimethylhexamethylene dicarbamate (50 wt%) and triethylene glycol dimethacrylate (TEGDMA: 59 wt%) and the other (Br-B) was prepared by blending microfiller (30 wt%) to the mixture of Bis-GMA (22.2 wt%), TEGDMA (65.9 wt%) and tetrabromobisphenol-A-glycidyl methacrylate (4Br-Bis GMA: 11.9 wt%). Preparation of 2%, 10%, 37%, and 60% phosphoric acid solutions, 2%, 5%, 10%, and 30% maleic acid solutions and 2%, 5%, 10%, and 30% citric acid solutions was carried out for use as etchants. The consistency and the bond strength to etched enamel for the adhesives and the amount of decalcification for the etchants were measured. The etched enamel surfaces, the resin tags on resin surfaces and the interfaces between the resin and enamel were observed with a SEM. The results were as follows: 1) The consistency of Cl-U was higher than that of Br-B. 2) The amount of decalcification was proportional to acid concentration, except for phosphoric acid solution. The amount of decalcification decreased in the order of citric acid solution, maleic acid solution and phosphoric acid solution when the concentration was 2% and 10%. 3) The SEM micrographs revealed that the enamel surface treated with the etchants containing a high concentration of acid was rougher. 4) The bond strength increased with increasing the concentration of the etchants except for the bond strength of Cl-U after being immersed in 37 degrees C water for 30 days and being thermal cycled. The bond strength for Cl-U was reduced greater than that of Br-B by long-term water immersion and thermal cycling.(ABSTRACT TRUNCATED AT 400 WORDS) <51> UI - 92179070 AU - Fernald GW AU - Roberts MW AU - Boat TF IN - Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill. TI - Cystic fibrosis: a current review. [Review] [29 refs] SO - Pediatric Dentistry 1990 Apr-May;12(2):72-8 AB - Cystic fibrosis (CF) is the most common severe genetic disorder seen in Caucasians. Defective exocrine gland secretions result in chronic diseases of the respiratory and gastrointestinal systems. However, the CF gene recently has been located and cloned. Currently, genetic technology allows identification of sibling carriers and antenatal diagnosis within families. Oral implications associated with CF include enamel hypoplasia and tooth discoloration, salivary gland involvement, reduced incidence of dental caries, reservoir for potentially pathogenic respiratory bacteria, mouth breathing, and anterior open bite associated with nasal and sinus obstruction. Continued efforts to improve early diagnosis and treatment of CF should increase life expectancy. Affected patients are expected to seek regular dental care more frequently as they learn to view the disease as manageable. [References: 29] <52> UI - 92075931 AU - Van Riper DF AU - Horrow JC AU - Kutalek SP AU - McCormick D AU - Goldman SM IN - Department of Anesthesiology, Hahnemann University School of Medicine, Philadelphia, PA 19102-1192. TI - Mixed venous oximetry during automatic implantable cardioverter-defibrillator placement. SO - Journal of Cardiothoracic Anesthesia 1990 Aug;4(4):453-7 AB - Mixed venous oxygen saturation (SvO2) monitoring was used to assess tissue and circulatory recovery following induced ventricular tachycardia or fibrillation in 17 patients undergoing surgery for automatic implantable cardioverter-defibrillator (AICD) placement. Return of systemic arterial pressure conventionally determines adequate recovery. The duration of circulatory arrest during defibrillator threshold (DFT) testing, measured from the moment of absent phasic pressure at the radial artery until its return, was 18 +/- 8 seconds (mean +/- SD, n = 118 episodes). The absolute decrease in SvO2 from baseline to nadir for these 118 episodes was 14% +/- 6% absolute, and correlated well with the duration of circulatory arrest (r = 0.757, P = 0.0001). The time from onset of phasic arterial blood pressure to the nadir of SvO2, available for 46 episodes, was 28 +/- 14 seconds, and did not correlate with the duration of arrest. The time from onset of phasic pressure to the return of SvO2 to within 1% (absolute) of baseline saturation, available for 84 episodes, was 52 +/- 32 seconds and, in the aggregate, correlated poorly (r = 0.401) with duration of arrest. Simultaneous recording of arterial pressure and SvO2 (n = 41) showed that arterial recovery (6 +/- 3 seconds) occurred long before SvO2 recovery (48 +/- 16 seconds, P = 0.0001). The authors interpret these data as showing that mixed venous oximetry, compared to arterial blood pressure, provides a more sensitive indicator of tissue recovery following periods of circulatory arrest during DFT testing of AICDs. <53> UI - 92002587 AU - Kaminsky LS AU - Mahoney MC AU - Leach J AU - Melius J AU - Miller MJ IN - Wadsworth Center for Labs and Research, New York State Department of Health, Albany 12201-0509. TI - Fluoride: benefits and risks of exposure. [Review] [215 refs] SO - Critical Reviews in Oral Biology & Medicine 1990;1(4):261-81 AB - This summarizes current knowledge of the benefits and risks of fluoride ingestion. The preponderance of evidence indicates that fluoride can reduce the incidence of dental caries and that fluoridation of drinking water can provide such protection. Due to the ubiquitous nature of exposures to fluoride sources other than drinking water, it is currently impossible to draw firm conclusions regarding the independent effect of fluoride in drinking water on caries prevalence using an ecologic study design. Moderate dental fluorosis occurs in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water and in about 10% of the population at 2 mg/l; moderate/severe fluorosis occurs in variable percentages ranging up to 33% of the population exposed to fluoride at 2.4 to 4.1 mg/l in drinking water. The issue of whether moderate or severe dental fluorosis represents an adverse health effect is still controversial. There is no evidence of skeletal fluorosis among the general U.S. population exposed to drinking water fluoride concentrations lower than 4 mg/l. Radiographically detected osteosclerosis after chronic exposure to fluoride in drinking water at 8 mg/l was not associated with clinical symptoms. Reports of crippling skeletal fluorosis associated with low concentrations of fluoride in drinking water in tropical countries have been attributed to other dietary factors. The available data suggest that some individuals may experience hypersensitivity to fluoride-containing agents. Further studies on hypersensitivity are required. There is no evidence of increased incidence of renal disease or renal dysfunction in humans exposed to up to 8 mg fluoride per liter in drinking water. Structural changes in kidneys of experimental animals have been detected at doses exceeding 1 to 5 mg fluoride per kilogram per day. Based on four case reports, individuals with renal insufficiency who consume large volumes of naturally fluoridated water at 2 to 8 mg/l are possibly at increased risk of developing skeletal fluorosis. Studies on the effects of fluoride in individuals with renal insufficiency are needed. There is no evidence that chronic exposure to concentrations of fluoride reported to be greater than 2 mg/l in drinking water increases human cancer mortality or incidence. A study of lifetime exposure to fluoride on cancer incidence in rats and mice has been completed, but assessment for cancer has not been completed. There is no evidence that fluoride is genotoxic except in some in vitro assays at cytotoxic concentrations. There is no in vivo evidence that fluoride affects human cellular enzyme activities.(ABSTRACT TRUNCATED AT 400 WORDS) [References: 215] <54> UI - 91329475 AU - Akkaya S AU - Alacam A IN - G.U. Dishekimligi Fakultesi, Ankara. TI - [The occurrence of cavitation after orthodontic bonding. A case report]. [Turkish] SO - Turk Ortodonti Dergisi 1990 Apr;3(1):123-8 AB - In this case report occurrence of cavitation on the lingual enamel surfaces of teeth after orthodontic direct bonding a canine to canine lingual retainer is presented and possible reasons which might play a role in their formation was investigated by "SEM" and "electron microprobe analyzer". Although the morphologic structure is normal, a mineral loss is detected and it is thought that an easier dissolution of enamel is occurred by the penetration of saliva and plaque microorganisms throughout the enamel-resin junction. <55> UI - 91338827 AU - Marchetti C AU - Piacentini C AU - Menghini P IN - Instituto di Istologia ed Embriologia gen., Universita' degli Studi di Pavia, Italy. TI - Lymphatic vessels in inflamed human dental pulp. SO - Bulletin du Groupement International Pour la Recherche Scientifique en Stomatologie et Odontologie 1990 Oct-Dec;33(3-4):155-9 AB - Investigation has been performed on both the light and electron microscopic characteristics of the lymphatic vessels present in the dental pulp of human teeth which have been affected by serious carious lesions. These conditions provoke a severe inflammatory response resulting in structural and functional modifications of the tissue; increase of the tissue pressure is followed by the need for a more intensive lymphatic drainage. In the inflamed pulps, dilated lymphatic vessels with distended walls and "open junctions" between endothelial cells are detectable. On the other hand they lack certain endothelial structures which characterize the morphology of these vessels under normal conditions. In the pulpal regions affected by fibrotic proliferation shrunken vessels with irregular profiles are present. From these observations it is possible to obtain other information on the mechanisms regulating the lymphatic drainage in different structural and functional conditions of the interstitium. <56> UI - 91276581 AU - Ewart A AU - Saunders WP IN - Glasgow Dental Hospital and School, UK. TI - Investigation into the apical leakage of root-filled teeth prepared for a post crown. SO - International Endodontic Journal 1990 Sep;23(5):239-44 AB - The effect of post canal preparation on the apical seal of endodontically treated teeth was studied in vitro. Single-rooted teeth with mature apices were prepared chemomechanically and obturated with gutta-percha and sealer using one of four techniques: cold lateral condensation, thermo-mechanical compaction, thermomechanical compaction as an adjunct to lateral condensation (hybrid technique), or lateral condensation using an electrically heated spreader, the Endotec. Forty-eight hours after obturation each group of 15 teeth was prepared to accept a post crown. Five teeth in each group were left unprepared as controls. The extent of apical leakage was then determined using a dye, Indian ink, and a clearing technique that rendered the teeth transparent. Linear measurement of the dye penetration was recorded. The results showed that, for each method of obturation, there were no statistically significant differences between the teeth prepared for a post and the unprepared controls. There were no significant differences in leakage between the different groups that had been prepared for a post, or between the control groups. <57> UI - 91260940 AU - Cox CF IN - School of Dentistry, UAB-University. TI - [Characterizing the smear layer]. [Dutch] SO - Nederlands Tijdschrift voor Tandheelkunde 1990 Mar;97(3):107-8 AB - The smear layer was first described as a debris layer which is left on all cavity walls following tooth preparation. It is composed of an outer contiguous layer of amorphous instrumentation matrix which covers all cavity walls, and a deeper zone of matrix plugs which obturate the cut tubules. Recent scanning electron microscopic (SEM) studies have characterized the smear layer as mineralized collagen fibers appearing as globules dispersed within an amorphous cutting matrix. Removal of smear plugs increases the outward hydraulic conductance (Lp) of dentinal fluid flow which may lead to dentinal hyperalgesia, bacterial infection and pulp pathosis if left untreated. <58> UI - 91179682 AU - Nelson JA AU - Miller DJ AU - Cardo VA Jr AU - Zambito RF IN - St. Mary's Hospital in Brooklyn. TI - Fetal alcohol syndrome: review of the literature and case report. [Review] [20 refs] SO - New York State Dental Journal 1990 Dec;56(10):24-7 AB - Fetal Alcohol Syndrome (FAS) is now recognized as a reality for the unborn if the pregnant woman ingests alcohol during the gestation period. Significant oro-facial problems occur as well as mental and behavior problems. This article reviews the current thought on oro-facial and dental diagnosis and therapy. [References: 20] <59> UI - 91166789 AU - Liu CF AU - Collard SM AU - Armeniades CD IN - Rice University, Houston, Texas. TI - Constant-volume polymerization of composites by addition of ammonia-modified montmorillonite. SO - American Journal of Dentistry 1990 Apr;3(2):44-50 AB - Polymerization shrinkage is a major limitation of dental composites. It generates internal stresses within bonded restorations and leads to marginal leakage, sensitivity and recurrent decay in the absence of adequate bonding. A method is presented for formulating composites that cure at constant volume by adding to the resin system small amounts of the hydrated mineral montmorillonite (MMT), which has been modified by replacing part of its hydration water with ammonia (NH3). The polymerization exotherm of composites containing ammonia-modified montmorillonite (NH3/MMT), cured at ambient temperatures, raises their temperature to between 60 and 80 degrees C, which causes the NH3/MMT particles to swell and counteract polymerization shrinkage. The polymerization shrinkage was measured for the BIS-GMA resin system, without filler, to which had been added NH3/MMT. The addition of 4 to 5 weight percent NH3/MMT resulted in zero polymerization shrinkage. An experimental composite was formulated using the BIS-GMA resin system, hydroxyapatite filler and 4 weight percent NH3/MMT. Cured samples developed compressive strength and hardness comparable to reported values for dental composite resins. Porosity was not detected by scanning electron microscopy. The use of NH3/MMT for formulating polymeric systems that cure at constant volume should be explored for application in direct dental composites. <60> UI - 91172664 AU - McKnight-Hanes C AU - Myers DR AU - Salama FS AU - Thompson WO AU - Barenie JT IN - School of Dentistry, Medical College of Georgia, Augusta. TI - Comparing treatment options for occlusal surfaces utilizing an invasive index. SO - Pediatric Dentistry 1990 Jul-Aug;12(4):241-5 AB - The purpose of this project was to develop an invasive index to: 1) compare the treatments recommended by dentists for the occlusal surfaces of molars; 2) compare the invasive index score of each tooth with the extent of the carious lesion as determined by electrical resistance and histological examination; and 3) compare the relative extent of the total crown destruction resulting from the carious lesion and the cavity preparation. Twenty dentists examined 19 extracted permanent molar teeth using a :23 explorer and selected the most appropriate treatment from the following options: no treatment (score 0), occlusal sealant (score 1), preventive resin (score 2), occlusal amalgam (score 3). The invasive index scores determined for each dentist and each tooth were compared using an analysis of variance. The electrical conductivity of each tooth was measured with an electronic caries detector (Vanguard). Electrical resistance scores were compared to the invasive index scores and to a histological examination. The results demonstrate that the invasive index is a useful means to compare treatments recommended by different dentists. The invasive index suggests there is considerable variation among dentists in the treatment they recommend for occlusal surfaces. Electrical resistance testing did not provide helpful information for treatment planning of questionably carious occlusal surfaces. <61> UI - 91126749 AU - Nikolishin AK AU - Maksimenko PT AU - Larionov GG AU - Moskalenko VN TI - [The UDK-87 device for the electrodiagnosis of caries]. [Russian] SO - Stomatologiia 1990 Sep-Oct;(5):26-8 AB - A new scheme of an device for electrodiagnosis of caries is suggested, based on studies of dental hard tissue electric resistance. A highly sensitive M136 gage with 0.5 microA complete deviation current is employed in the scheme, this permitting measurements of high electric resistance of dental hard tissues within a range of 1-200 M omega, painless for patients. The device may be useful for the diagnosis of fluorosis, hypoplasia, incomplete enamel mineralization, enamel microfissures, abnormal wearing of dental hard tissue. <62> UI - 91126747 AU - Leont'ev VK AU - Ivanova GG AU - Zhorova TN TI - [The electrometric diagnosis of lesions of the hard dental tissues]. [Russian] SO - Stomatologiia 1990 Sep-Oct;(5):19-24 AB - Electrometric examinations of hard tissues of the teeth were carried out in 342 subjects. These examinations have demonstrated the potentialities of the electrometric diagnosis of dental hard tissue injuries. This method developed by the authors may be used to detect different stages of caries, to assess the efficacy of conservative therapy of focal demineralization sites on dental surface and in fissures, to diagnose recurrent caries. An ELOZ-1 device for dental analgesia, commercially manufactured, may be used for the diagnosis of hard dental tissue injuries. <63> UI - 91099000 AU - Sonnabend E IN - Poliklinik fur Zahnerhaltung u. Parodontologie der Universitat Munchen. TI - [The role of x-ray films in diagnosis in operative dentistry]. [German] SO - Deutsche Zahnarztliche Zeitschrift 1990 Nov;45(11):691-5 AB - In operative dentistry x-ray films play an important part as a diagnostic procedure. Image quality depends on factors such as exposure and projection but also on optimum processing of the x-ray film. Of particular importance among the exposure-related factors are such features as variable voltage, short exposure time and narrow focussing. According to the new regulations in Germany x-rays may be used if this is indicated for medical reasons in dentistry. This condition is given far more frequently than x-rays are performed in the dental office. In the diagnosis of caries individual bitewing radiographs, if indicated, should always be preferred over panoramic radiographs. In pulp diseases radiographs may aid in detecting chronic pulpitis and in differential diagnosis with apical periodontitis. Both for diagnosis and documentation on intraoral films, tooth fractures are best imaged using two different projections. Radiovisiography facilitates radiographic diagnosis by employing a simple technique and operating with considerably lower doses. <64> UI - 91099009 AU - Pieper K AU - Visser H AU - Hulsmann M AU - Wahner M IN - Zentrum ZMK, Georg-August-Universitat, Gottingen. TI - [Test of an electronic fissure caries detector]. [German] SO - Deutsche Zahnarztliche Zeitschrift 1990 Nov;45(11):721-4 AB - The reliability of an electronic detector for caries in pits and fissures was tested by means of physical measurements, histological sections and clinical evaluation. The device measures the ohmic resistance of the tooth, technical data are given. First we compared measurements and histological sections of teeth due for extraction. The results indicated a high sensitivity of the device for caries, false positive diagnoses did not occur. Based on this, a clinical evaluation on 179 teeth was performed. Under practical conditions the sensitivity of the electronic detector (0.77) was lower than in the first part of the study; conventional diagnosis revealed more carious lesions in dentine (sensitivity: 0.82). <65> UI - 91028402 AU - Davies MC AU - Hall ML AU - Jacobs HS IN - Middlesex Hospital, London. TI - Bone mineral loss in young women with amenorrhoea. SO - BMJ 1990 Oct 6;301(6755):790-3 AB - OBJECTIVE--To examine the impact of amenorrhoea on bone mineral density in women of reproductive age. DESIGN--Cross sectional study of 200 amenorrhoeic women compared with normally menstruating controls. SETTING--Teaching hospital outpatient clinic specialising in reproductive medicine. SUBJECTS--200 Women aged 16-40 with a past or current history of amenorrhoea from various causes and of a median duration of three years, and a control group of 57 age matched normal volunteers with no history of menstrual disorder. MAIN OUTCOME MEASURE--Bone mineral density in the lumbar spine (L1-L4) as measured by dual energy x ray absorptiometry. RESULTS--The amenorrhoeic group showed a mean reduction in bone mineral density of 15% (95% confidence interval 12% to 18%) as compared with controls (mean bone mineral density 0.89 (SD 0.12) g/cm2 v 1.05 (0.09) g/cm2 in controls). Bone loss was related to the duration of amenorrhoea and the severity of oestrogen deficiency rather than to the underlying diagnosis. Patients with a history of fracture had significantly lower bone density than those without a history of fracture. Ten patients had suffered an apparently atraumatic fracture. CONCLUSIONS--Amenorrhoea in young women should be investigated and treated to prevent bone mineral loss. Menopausal women with a past history of amenorrhoea should be considered to be at high risk of osteoporosis. <66> UI - 91009515 AU - Guilbaud NF AU - Gas N AU - Dupont MA AU - Valette A IN - Laboratoire de Pharmacologie et Toxicologie Fondamentales, CNRS, Toulouse, France. TI - Effects of differentiation-inducing agents on maturation of human MCF-7 breast cancer cells. SO - Journal of Cellular Physiology 1990 Oct;145(1):162-72 AB - The effects of the differentiation inducing agents (DIAS), sodium butyrate (NaBu), retinoic acid (RA), dimethylformamide (DMF), hexamethylene bisacetamide (HMBA), forskolin, and 12-O-tetradecanoylphorbol-13-acetate (TPA), on the growth, morphology, and estrogen receptor (ER) content and epithelial membrane antigen (EMA) expression on a serumless human breast cancer cell line (MCF-7) were compared. All these agents reversibly caused a concentration-dependent growth inhibition in monolayers and markedly reduced colony-forming efficiency in soft agar. A twofold increase in doubling time was obtained with RA (1 microM), but cell replication ceased with NaBu (1 mM), forskolin (50 microM), DMF (1%), HMBA (5 mM), and TPA (8 nM). Total growth arrest induced by these last compounds was preceded by an accumulation of cells in G0/G1 phase observed at 24 h by flow cytometry and accompanied by a change in cell morphology as seen by light and electronic microscopy. An increase in cell volume and the presence of lipid droplets was noted in treated cells that were spread out, as compared with controls. The acquisition of a more mature phenotype was confirmed by an increased expression of EMA monitored by flow cytometry. A specific reduction in the number of ER without any constant dissociation (Kd) modification was also observed after treatment with the 5 DIAs. No modification of morphological or biochemical characteristics, including EMA expression and ER binding, were observed for RA (1 microM)-treated cells. All these results suggest that induction of a more differentiated phenotype is associated with a block in G1 cell cycle phase, resulting in total growth arrest. Apparently, RA (1 microM)-treated cells did not fulfill these criteria, since only a slight accumulation in G1 and a slowed growth rate were evaluated. <67> UI - 91010130 AU - Momoi Y AU - Iwase H AU - Nakano Y AU - Kohno A AU - Asanuma A AU - Yanagisawa K IN - Department of Operative Dentistry, School of Dental Medicine, Tsurumi University, Yokohama, Japan. TI - Gradual increases in marginal leakage of resin composite restorations with thermal stress. SO - Journal of Dental Research 1990 Oct;69(10):1659-63 AB - The effects of thermal stress on the marginal leakage of resin composite restorations in bovine teeth were investigated by a method that preserved the specimens. The changes in marginal leakage of specimens with increasing numbers of thermal cycles were measured by an electrical conductivity method. Four brands of posterior resin composites were used to fill cylindrical cavities (2.0 mm in diameter and 1.5 mm in depth) on the labial surfaces of bovine incisors, according to the manufacturer's instructions. Thermal cycling stress was applied to the specimens for up to about seven weeks (9000 cycles). During this time, the electrical conductance between the pulp and a drop of physiological saline solution covering the resin restoration was measured periodically by application of an electrical potential (60 Hz, 10 Vp-p). Thermal stress increased the marginal leakage gradually, rather than step-wise. Even before application of any thermal stress, wide variations of marginal leakage were found among different specimens restored with the same brand of resin. Specimens with less initial leakage showed less increase in leakage, and vice versa, throughout the experimental period. <68> UI - 90361068 AU - Nemes J AU - Banoczy J IN - Semmelweis Orvostudomanyi Egyetem Konzervalo Fogaszati Klinika, Budapest. TI - [Current viewpoints and methods in caries diagnosis]. [Review] [40 refs] [Hungarian] SO - Fogorvosi Szemle 1990 Jul;83(7):211-6 AB - Results obtained in the caries pathogenesis in recent years as well as the successes in the field of remineralization opened the way to heal the initial stage of the caries by means of preventive methods. Increased attention should be paid to early diagnostics of the caries, and evolution of the new diagnostics methods should be followed by attention. Combined employment of the various diagnostics methods should be aimed at. [References: 40] <69> UI - 90361424 AU - Kobayashi T AU - Hayashi A AU - Yoshikawa R AU - Okuda K AU - Hara K IN - Niigata University School of Dentistry, Japan. TI - The microbial flora from root canals and periodontal pockets of non-vital teeth associated with advanced periodontitis. SO - International Endodontic Journal 1990 Mar;23(2):100-6 AB - Microflora from root canals and periodontal pockets of periodontally affected teeth were compared in order to elucidate the as yet unknown relationship between pulpal and periodontal disease. Caries-free teeth affected with advanced periodontitis and diagnosed as clinically dead by electric pulp testing were selected. The root canals and periodontal pockets were sampled, and the bacterial flora examined by both culture and interference microscopy. The results indicated that the aerobe/anaerobe ratio in the periodontal pocket was 0.23, while it was 0.0022 in the root canal, the large predominance of obligate anaerobes reflecting the anaerobic environment found in the root canal. Morphological classification obtained from interference microscopy showed similar proportions of morphotypes in the two sites. Results of anaerobic culture demonstrated a significantly higher rate of detection of facultative Streptococcus bacteria in the periodontal pocket than in the root canal. The predominant bacterial species common to both regions were Streptococcus, Peptostreptococcus, Eubacterium, Bacteroides, and Fusobacterium for obligate anaerobes. As for facultative anaerobes, Actinomyces and Streptococcus were detected predominantly in the periodontal pocket. The occurrence of micro-organisms common to both sites in this study suggests that the periodontal pocket may be a possible source of root canal infections. <70> UI - 90372260 AU - Morimoto N AU - Shiraga F AU - Matsuo N AU - Matsuo T AU - Hara K IN - Department of Ophthalmology, Okayama University Medical School, Japan. TI - [A case of crystalline retinopathy with crystalline deposits in the cornea]. [Japanese] SO - Nippon Ganka Gakkai Zasshi - Acta Societatis Ophthalmologicae Japonicae 1990 Mar;94(3):321-7 AB - We experienced a case of crystalline retinopathy with crystalline deposits in the cornea and the limbal conjunctiva, and performed histological studies of the cornea, conjunctiva and peripheral blood cells. The patient was a 45-year-old man who had no abnormality in hematological studies and urinalysis. In the fundus diffuse atrophy of the retinal pigment epithelium and patchy foci of choroidal atrophy were observed, and sparkling yellowish-white spots were scattered, chiefly in the posterior region. Fluorescein angiography showed neither hyperfluorescence nor hypofluorescence at these spots. In the marginal cornea and the limbal conjunctiva crystalline deposits were observed. Histological findings by light microscopy and electron microscopy revealed sparse degeneration of epithelial cells in both the cornea and the limbal conjunctiva. But no substances corresponding to crystalline deposits could be identified. Inclusion bodies were detected including clefts in circulating lymphocytes and eosinophils. The inclusion bodies suggest that crystalline retinopathy results from a systemic metabolic abnormality. <71> UI - 90350563 AU - Bigeard L AU - Sommermater J AU - Juif J TI - [Oral evaluation in various pathological conditions in children]. [French] SO - Actualites Odonto-Stomatologiques 1990 Mar;44(169):141-52 AB - The current knowledge concerning the study of dental cavities cannot account for all clinical aspects of some subjects' resistance to cavity formation. This work concerned, in a first stage, the study of dental anomalies (number, shape and structure), in different groups of children with common diseases. This study has enabled us to evaluate the caries index of the same groups of children. It concerns 13 children with somatotropin deficiency (including 36% of children without any caries), 18 children with chronic renal insufficiency (including 56% of children without any caries), 4 children with Down's syndrome (no caries), one female child with erythropoietic porphyria (no caries), one girl with Incontinentia pigmenti (no caries) and one girl with familial, hypophosphatemic vitamin-resistant rickets (no caries). The percentage of children without any caries is particularly high in the groups under study, in spite of a poor oral hygiene. It seems that such factors as the conditions of dental development, the structure and morphology of the teeth or its environment, are capable of having an effect on caries formation. <72> UI - 90326776 AU - Kurosaki N AU - Kubota M AU - Yamamoto Y AU - Fusayama T TI - The effect of etching on the dentin of the clinical cavity floor. SO - Quintessence International 1990 Feb;21(2):87-92 AB - The most conservative cavity preparation, which takes full advantage of chemically adhesive composite resin, involves removal of only the infected outer carious dentin that is stainable by the caries detector. This preparation exposes in the cavity floor either the turbid layer at the top of the inner carious dentin or the underlying transparent layer. Examination by scanning electron microscope revealed that etching the cavity floor demineralized the intertubular dentinal surface slightly and produced tapered, cylindrical holes or ring-shaped holes at the dentinal tubule apertures of the turbid or transparent layer, respectively. The holes were blind with solid floors of intratubular crystal deposits of the transparent layer, suggesting that etching increases permeability little. Placement of the adhesive resin on the etched cavity floors produced a resin-impregnated dentinal layer and tapered, cylindrical or tubular-shaped resin tags, which apparently improved the bond and tubule aperture seal. <73> UI - 90252610 AU - Taylor ML AU - Maconnachie E AU - Frank K AU - Boyde A AU - Jones SJ IN - Department of Anatomy and Developmental Biology, University of College London, England. TI - The effect of fluoride on the resorption of dentine by osteoclasts in vitro. SO - Journal of Bone & Mineral Research 1990 Mar;5 Suppl 1:S121-30 AB - Osteoclasts were isolated mechanically from bones of prehatch chicks and cultured on dentine for 24 or 39 h in medium without or with added sodium fluoride at concentrations of 0.15, 1, 15, or 30 mg/liter. Fixed and toluidine blue-stained specimens were examined by light microscopy and osteoclasts were counted, all cells were removed and resorption pits were counted. The dentine was then prepared for scanning electron microscopy (SEM) and pits located on a raster search using backscattered electron imaging. Stereophotogrammetric measurements were made of the depths, plan and true surface areas and volumes of pits, and the volume:area ratio and a three-dimensional form factor calculated for each. The presence or absence of a ring of demineralization around each pit was recorded. Pits with the same plan area were significantly (p less than 0.001) less deep in cultures containing 15 or 30 mg/liter NaF and the incidence of rings around pits was higher (controls 2.7%, 15 mg/liter 31.3%, 30 mg/liter NaF 39.7%). In one experiment, pits were larger in the specimen cultured with added 1 mg/liter NaF, but in a much larger series of 631 (251 in the control and 380 in the 1 mg/liter NaF cultures) pits measured, depths, volumes and volume:plan-area ratios were significantly lower (p less than 0.001), and rings round pits 2.5 times more common, in the fluoride-treated group. A complex interplay of stimulation of some cells in the culture with indirect stimulation of osteoclasts and direct inhibition of osteoclastic resorptive function may be operating at this concentration of fluoride. In vivo, therapeutic doses of sodium fluoride would be expected to act not only to increase the formation of osteoid but also to suppress osteoclastic activity. <74> UI - 90243960 AU - Katz RV IN - Department of Behavioral Sciences & Community Health, School of Dental Medicine, University of Connecticut Health Center, Farmington 06032. TI - Clinical signs of root caries: measurement issues from an epidemiologic perspective. SO - Journal of Dental Research 1990 May;69(5):1211-5 AB - The measurement of root caries using a relatively precise, utilitarian, and universally-acceptable methodology based upon clinical signs is a critical and necessary step in the progression of the epidemiologic study of this oral disease. While a clinician directly involved in the care of a patient will always incorporate spontaneous judgment-based-upon-experience into the diagnostic process, the clinical investigator must rely upon a much more standardized approach to the diagnosis of root caries. A comprehensive overview of the current epidemiologic research findings and methodologic literature for root caries precedes a series of discussions on methodologic issues that relate to the measurement of root caries in epidemiologic study conditions. Topics discussed include: (1) appropriate categories of lesions for inclusion (active vs. inactive and supragingival vs. subgingival lesions), (2) surface visibility issues (clinical treatment effects and oral debris accumulations), and (3) examination techniques (examination instruments and use of radiographs). The final section of this article proposes seven diagnostic conventions for use by investigators when they are diagnosing root caries in descriptive, analytical, and experimental epidemiologic studies. <75> UI - 90133124 AU - Papagiannoulis L AU - Eliades G AU - Lekka M IN - University of Athens, School of Dentistry and Research Center for Biomaterials, Greece. TI - Etched glass ionomer liners: surface properties and interfacial profile with composite resins. SO - Journal of Oral Rehabilitation 1990 Jan;17(1):25-36 AB - The purpose of this study was to assess the surface alterations induced by acid etching on two glass ionomer lining cements (Ketac Bond, G-C lining cement) and to evaluate their interface with a composite resin (Herculite XR) following various surface treatments. The changes in the surface composition and topography of the etched liners were studied by electron microprobe and ESCA analyses. The