Database: MEDLINE <: biomedical, nursing & dental literature, 1966 - Oct 2000.> Search Strategy (You Saved Citations 1-300 From Set 57): ----------------------------------------------------------------------------- 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 Fiber optics/ 7856 48 ((fiber or fibre) adj optic:).mp. 1588 49 Transillumination/ 936 50 transillumination.mp. 1397 51 exp Light/ 72339 52 Microradiography/ 1886 53 "DI-FOTI".mp. 1 54 "DIFOTI".mp. 2 55 "FOTI".mp. 18 56 or/47-55 83421 57 46 and 56 810 58 from 57 keep 1-300 300 59 from 57 keep 301-600 300 *************************** <1> UI - 94088198 AU - Powell GL AU - Morton TH AU - Whisenant BK IN - University of Utah, Salt Lake City 84132. TI - Argon laser oral safety parameters for teeth. SO - Lasers in Surgery & Medicine 1993;13(5):548-52 AB - Argon lasers have been reported to prevent or reduce demineralization of enamel in extracted teeth and to polymerize dental composites (using 25-100 J/cm2). Prior to clinical trials on caries prevention and curing composites, safety parameters for intraoral use of the argon laser need to be established. This study was conducted to determine the enamel damage, pulp temperature changes, and associated pulpal tissue damage following irradiation at various argon laser energy levels using 1.6-6.0 watts, approximately 1 and 2 mm diameter beam for 0.2-5.0 seconds. To evaluate pulpal damage, selected dogs' teeth were irradiated in vivo, extracted 7 days postlasing, fixed, decalcified, sectioned, stained, and read for pulpal damage. Pulp temperature and enamel damage tests utilized extracted dog and human teeth. Temperature probes were inserted in the pulp chambers and temperature changes recorded as enamel surface was lased. Enamel surface damage was evaluated by visual and microscope examination. Results showed that histologic pulpal damage occurred at > 600 J/cm2. Temperature changes were < 6 degrees F in human teeth with approximately 900 J/cm2. No enamel damage was observed at these energy densities. At energy densities needed for proposed uses, no apparent damage would be expected to pulp or enamel. <2> UI - 94075741 AU - Exterkate RA AU - Damen JJ AU - ten Cate JM IN - Department of Cariology and Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands. TI - A single-section model for enamel de- and remineralization studies. 1. The effects of different Ca/P ratios in remineralization solutions. SO - Journal of Dental Research 1993 Dec;72(12):1599-603 AB - A prerequisite for the accurate measurement of differences between pre- and post-experimental mineral profiles in single sections by quantitative microradiography is a high degree of reproducibility of the analytical procedures. We have determined the reproducibility of both the production and analyses of microradiographs. Lesions were made in seven single bovine enamel sections and radiographed three times. Each microradiograph was then analyzed on three different occasions by use of an image analysis system. This resulted in only small standard deviations in the lesion parameters. The method was used to determine the sites of mineral deposition in lesions in single sections during remineralization in three different solutions, one of which contained 1.5 mmol/L Ca and 0.9 mmol/L PO4 (standard solution); the other two solutions were low in either Ca or PO4, but all three had the same degree of supersaturation. The mineral profiles and lesion parameters were determined after lesion formation and after remineralization for 4 days, 1, 2, and 3 weeks. The decrease in IML (integrated mineral loss) in the lesions remineralized in the standard solution was greatest during the first week. Lesion profiles revealed that, under non-standard conditions, mineral deposition was retarded in the deeper part of the lesion, in contrast to the even distribution of mineral deposition from the standard solution. Differences in IML changes and lesion profiles between these bovine enamel experimental groups diminished when remineralization continued for 2 and 3 weeks. Possibly, the reactivity of mineral surfaces in newly made lesions affected the diffusion of remineralizing ions from low concentration solutions to the lesion front. <3> UI - 94082856 AU - Angmar-Mansson B AU - ten Bosch JJ IN - Department of Cariology, School of Dentistry, The Karolinska Institute, Huddinge, Sweden. TI - Advances in methods for diagnosing coronal caries--a review. [Review] [56 refs] SO - Advances in Dental Research 1993 Aug;7(2):70-9 AB - Diagnostic methods for coronal caries in common use include visual inspection, tactile examination with a probe, bite-wing radiography, and often fiber-optic-transillumination (FOTI). Early diagnosis enables small lesions to be identified so that remineralization of lesions by preventive measures can be attempted; in clinical research, it may shorten the time for clinical trials. Quantitative methods may potentially decrease interexaminer variations and facilitate the determination of small progressions or regressions. This review discusses recent advances in the development of such methods, i.e., endoscopic methods, FOTI, light-scattering, laser fluorescence, ultraviolet illumination, penetration of dyes, iodide penetration, electrical resistance, ultrasonic imaging, and improved radiographic imaging techniques. Diagnosis of occlusal surfaces gains from the use of the electrical resistance method (preferable when the emphasis is on finding lesions) or radiography (when the emphasis is on identifying sound surfaces). Digitized radiography with simple contrast enhancement gives some further improvement. Quantitative methods are not yet proven to be good enough to measure small changes. Quantitative methods are not yet proven to be good enough to measure small changes. For occlusal surfaces, the electrical resistance method may be, but this has to be confirmed. For approximal surfaces, digitized radiography and fluorescent dye penetration have to be tested for clinical feasibility. It is concluded that there are many methods in development, but all require clinical testing, and many still need development before clinical use. [References: 56] <4> UI - 94081198 AU - Manabe A AU - Debari K AU - Itoh K AU - Hisamitsu H AU - Wakumoto S IN - Department of Operative Dentistry, Showa University School of Dentistry, Tokyo, Japan. TI - Effect of delayed light curing of a resin composite on marginal integrity in cylindrical dentine cavities. SO - Journal of Dentistry 1993 Dec;21(6):344-9 AB - The effect of delayed light curing of resin composite on marginal adaptation has been examined by measuring the wall-to-wall polymerization contraction gap when using a commercial resin composite together with experimental dentine bonding systems to restore cylindrical preparations in dentine. Morphological changes in dentine during dentine bonding procedures were observed using a scanning electron microscope. In a previous report, the contraction gap width for a resin composite increased when irradiation of the resin system was delayed, despite the use of a dentine bonding system considered to be 'contraction' gap free. Such deterioration in marginal adaptation was minimized by use of an experimental dentine primer, 40% erythritol methacrylate aqueous solution (EM), followed by the use of a commercial dual- or autocured dentine bonding agent. Under scanning electron microscopy, the dentine surface microstructure became unclear after EM priming, and a polymer film was detected after polymerization of the dual-cured dentine bonding agent. The hydrogelled primer and the formation of a polymer network on the dentine surface may prevent the flow of fluid from the pulp through the dentine tubules, and maintain marginal integrity if there is delay in light curing of light-activated resin composite systems. <5> UI - 94081195 AU - Kidd EA AU - Ricketts DN AU - Pitts NB IN - Guy's Hospital Dental School, London, UK. TI - Occlusal caries diagnosis: a changing challenge for clinicians and epidemiologists. [Review] [87 refs] SO - Journal of Dentistry 1993 Dec;21(6):323-31 AB - The diagnosis of occlusal caries is an integral part of an epidemiologist's task, whether carrying out cross-sectional national caries prevalence surveys to assist with planning and the evaluation of service provision, or clinical trials of caries preventive agents. Similarly, the clinician also carries out this same overall diagnostic procedure in order to plan care for individual patients, although he/she will usually have access to improved facilities and diagnostic aids. This paper reviews the different problems now being encountered by both epidemiologists and clinicians in the face of changes in the presentation of the disease at this site and the qualifications which should now be appreciated when extrapolating from the results of surveys employing comparatively gross criteria. It explores recent developments in diagnostic aids and makes suggestions as to how further information might be obtained in future which would aid the valid comparison of diagnoses made by these two groups of dentists. [References: 87] <6> UI - 94059481 AU - Davis EL AU - Yu X AU - Joynt RB AU - Wieczkowski G Jr AU - Giordano L IN - State University of New York at Buffalo 14214. TI - Shear strength and microleakage of light-cured glass ionomers. SO - American Journal of Dentistry 1993 Jun;6(3):127-9 AB - Bond to dentin and marginal integrity of three light activated glass ionomer cements were evaluated, and compared to a traditional chemical-cured glass ionomer cement. Results indicated no significant difference in shear bond strength among the glass ionomer cements tested. However, there was a significant difference among glass ionomer cements in bond strength variability, with coefficients of variation ranging from 55 to 102%. A discrepancy between manufacturers' instructions and optimum curing times is one possible explanation for these results. There were also no significant differences in microleakage among glass ionomer cements. Most samples exhibited minimal or no microleakage. <7> UI - 94042561 AU - Wilson M IN - Department of Microbiology, Institute of Dental Surgery, London, UK. TI - Photolysis of oral bacteria and its potential use in the treatment of caries and periodontal disease. [Review] [41 refs] SO - Journal of Applied Bacteriology 1993 Oct;75(4):299-306 <8> UI - 94054477 AU - Korzhova VV AU - Kopeikin VN AU - Aleksandrov MT AU - Litvintseva TA TI - [The characteristics of treating the early stages of caries in pregnant women by using laser phoresis]. [Russian] SO - Stomatologiia 1993 Jul-Sep;72(3):10-2 <9> UI - 94055638 AU - Scheinin A AU - Soderling E AU - Scheinin U AU - Glass RL AU - Kallio ML IN - Department of Cariology, University of Turku, Finland. TI - Xylitol-induced changes of enamel microhardness paralleled by microradiographic observations. SO - Acta Odontologica Scandinavica 1993 Aug;51(4):241-6 AB - The study, aimed to analyze the feasibility of a prospective field study, was carried out in Polynesian children with rampant untreated caries. Slabs of bovine enamel were inserted for 8-12 days in cavities and subsequently replaced by permanent fillings. Before use, the surface of the slab was polished, and one half predemineralized and tested for microhardness. The follow-up in 30 subjects involved 54 slabs, 30 from negative controls with no added sweets and 24 from subjects receiving 20 g/day of xylitol in candy. The microhardness of the slabs was reassessed, and the difference between measurements calculated and tested for significance. The differences between the groups were highly significant, the predemineralized halves showing pronounced rehardening at exposure to xylitol. Parallel microradiographic observations conformed with the above findings. The results indicate that the use of a noncariogenic sweetener might be of value in high caries risk subjects. <10> UI - 94006438 AU - Peers A AU - Hill FJ AU - Mitropoulos CM AU - Holloway PJ IN - University Dental Hospital of Manchester, UK. TI - Validity and reproducibility of clinical examination, fibre-optic transillumination, and bite-wing radiology for the diagnosis of small approximal carious lesions: an in vitro study. SO - Caries Research 1993;27(4):307-11 AB - This study measured validity and reproducibility of unaided clinical diagnosis, fibre-optic transillumination (FOTI), and bite-wing radiology in the diagnosis of approximal caries. Sixty models were made using extracted premolars and molars, each containing four teeth with six contacting approximal surfaces. The teeth were examined first using unaided clinical examination and then using FOTI. Bite-wing radiographs were then taken of the teeth set in the models and examined. The three examinations were repeated after 1 week. Histological sections of the undecalcified teeth were prepared following their removal from the models, and those showing signs of caries were examined to give the valid state of disease in each surface. The diagnostic threshold was caries penetrating into dentine. The reproducibility of all three methods was acceptable with kappa values exceeding 0.6. All specificity values exceeded 0.95. Statistically significant differences were seen between sensitivities for clinical (0.38) and bite-wing (0.59) diagnosis and between clinical and FOTI (0.67) examination, but not between bite-wing and FOTI. It is concluded that the validity of FOTI is at least as high as that of bite-wing radiology, and both are superior to unaided clinical diagnosis. <11> UI - 94006430 AU - Ruben J AU - Arends J IN - Laboratory of Materia Technica, State University of Groningen, The Netherlands. TI - Shrinkage of sound and demineralized human coronal dentine slabs. SO - Caries Research 1993;27(4):266-70 AB - In this article a method is presented for dentine shrinkage measurements. The relative shrinkage of sound dentine slabs is assessed using a Perthometer with respect to a steel reference. The relative shrinkage of lesions in dentine slabs can be estimated using combined Perthometer/microradiography measurements. The results show that the relative lesion shrinkage of lesions in thick slabs is quite different from the shrinkage of lesions in thin sections used for microradiography. The relative lesion shrinkage is, for periods up to 30 min, linear with the air drying period and increases strongly with the demineralization period. The previously published diol treatment is capable of reducing the relative lesion shrinkage in thick dentine slabs to negligible values. <12> UI - 94006429 AU - Ruben J AU - Arends J IN - Laboratory for Materia Technica, State University of Groningen, The Netherlands. TI - Shrinkage prevention of in vitro demineralized human dentine in transversal microradiography. SO - Caries Research 1993;27(4):262-5 AB - The shrinkage of demineralized dentine is a serious problem in the assessment of mineral distributions and mineral changes by means of microradiography. In this article it is shown that a treatment with ethanediol of the thin slices used for transversal microradiography prevents shrinkage for about 1 h. Without this so-called diol treatment, the shrinkage effects in demineralized dentin are about 20% in lesion depth and about 30% in mineral loss (delta Z) after 120-second drying in air. The prevention of shrinkage by diol treatment of dentine lesions is not influenced by the presence of a surface layer. <13> UI - 94006428 AU - van der Veen MH AU - ten Bosch JJ IN - Laboratory for Materia Technica, University of Groningen, The Netherlands. TI - An in vitro evaluation of fluorescein penetration into natural root surface carious lesions. SO - Caries Research 1993;27(4):258-61 AB - In order to develop a method for detection and quantification of initial root surface carious lesions, the use of fluorescein sodium as a fluorescent dye is evaluated. The penetration depth of fluorescein sodium into human roots containing natural carious lesions was measured on approximately 130-microns-thick slices, cut in a direction perpendicular to the pulp. This depth was compared to the lesion depth that was measured on the same slice with transversal microradiography. The results indicate that fluorescein sodium in water penetrates into demineralized layers of root dentine even if a surface layer with a high mineral content is present. The penetration depth is about 1.1 times the microradiographically determined lesion depth. <14> UI - 93380287 AU - Verdonschot EH AU - Wenzel A AU - Bronkhorst EM IN - Department of Cariology and Endodontology, University of Nijmegen, The Netherlands. TI - Assessment of diagnostic accuracy in caries detection: an analysis of two methods. SO - Community Dentistry & Oral Epidemiology 1993 Aug;21(4):203-8 AB - The quality of a diagnostic tool for caries detection is usually evaluated by quantification of observer performance using sensitivity and specificity values calculated from data obtained from ordinal caries depth rating scales. The application of Receiver Operating Characteristic (ROC) analysis has been restricted to the use of confidence rating scales. The aim of this investigation was to study the appropriateness of ROC analysis using caries depth ratings by comparing sensitivity and specificity values to parameters of diagnostic performance obtained by ROC analysis. In two recent reports, sensitivity and specificity values were utilized to express diagnostic accuracy of observer performance from specified caries diagnostic systems. The raw data from these investigations were subjected to ROC analysis in the current study. The results illustrated that ROC analysis, producing estimates of sensitivities for all specificities, yielded more comprehensive measures of diagnostic performance than single values for sensitivity and specificity. In particular, the area under the ROC curve constituted a clearly interpretable parameter representing the quality of diagnostic performance. <15> UI - 93390903 AU - Alhadainy HA AU - Himel VT IN - Division of Endodontics, College of Dentistry, University of Tennessee, Memphis. TI - Comparative study of the sealing ability of light-cured versus chemically cured materials placed into furcation perforations. SO - Oral Surgery, Oral Medicine, Oral Pathology 1993 Sep;76(3):338-42 AB - Two light-cured materials, Vitrebond and Prisma VLC Dycal, were compared with two chemically cured materials, Ketac Fil and Dycal, for ability to seal furcation perforations. Access openings and furcation perforations were prepared in 60 teeth and randomly divided into four equal groups. Furcation perforations were repaired with each of the tested materials, and the access openings were filled with composite resin. After teeth were immersed in 2% erythrocin B dye solution for 10 days, they were sectioned longitudinally and dye penetration was measured. The light-cured materials allowed statistically significant less dye leakage than did the chemically cured materials. <16> UI - 93359568 AU - Longbottom C AU - Pitts NB IN - Department of Dental Health, Dental School, Dundee, UK. TI - CO2 laser and the diagnosis of occlusal caries: in vitro study. SO - Journal of Dentistry 1993 Aug;21(4):234-9 AB - The diagnosis of small lesions in pit and fissure sites is becoming increasingly problematical. This study was designed to evaluate, in vitro, the potential use of a carbon dioxide (CO2) laser technique as an aid to the diagnosis of incipient pit and fissure caries. Vaporization of the organic material in the 'early' carious lesion should lead to its carbonization and thus make it more conspicuous. Pilot studies were carried out to identify lasing parameters which produced no visible effect on sound enamel but which caused charring (carbonization) of white spot fissure lesions. Fifty extracted human molars and premolars were air-polished on the occlusal surfaces and independently scored clinically for caries, both before and after lasing. The teeth were subsequently sectioned and examined histologically. Of the 37 sites histologically scored as sound or exhibiting precavitation lesions, eight were correctly scored as sound both prelasing and postlasing. Of the 29 precavitation lesions detected histologically, five were detected clinically prelasing and 11 were detected postlasing. This 21% difference in the sensitivity of caries diagnosis between the prelasing and postlasing examinations was statistically significant (at the 95% level). There were no false-positive caries diagnoses. Further research, in particular the refining of lasing parameters employed, is indicated. <17> UI - 93340333 AU - Hicks MJ AU - Flaitz CM AU - Westerman GH AU - Berg JH AU - Blankenau RL AU - Powell GL IN - Department of Pathology, Texas Children's Hospital, Baylor college of Medicine, Houston. TI - Caries-like lesion initiation and progression in sound enamel following argon laser irradiation: an in vitro study. SO - ASDC Journal of Dentistry for Children 1993 May-Jun;60(3):201-6 <18> UI - 93306695 AU - Iijima Y AU - Ruben JL AU - Zuidgeest TG AU - Arends J IN - Nagasaki University, Japan. TI - Fluoride and mineral content in hyper-remineralized coronal bovine dentine in vitro after an acid challenge. SO - Caries Research 1993;27(2):106-10 AB - In this paper the acid resistance of hyper-remineralized dentine was quantified by means of fluoride and mineral measurements. Hyper-remineralization was achieved by demineralization of dentine in an acidic gel system (pH 5) for 3 weeks, followed by remineralization in a solution containing 1.5 mM Ca, 0.9 mM phosphate and 10 ppm F at pH 7 and 37 degrees C for 8 days. The samples were subsequently again demineralized in the gel system mentioned for 1, 2 and 3 weeks. Analysis for fluoride was done by means of the microdrill biopsy technique and to obtain information on the fluoride distribution by secondary ion mass spectrometry (SIMS); mineral was assessed by microradiography. The results showed that in hyper-remineralized dentine the original fluoride content was approximately 30,000 ppm F. This value was still in the same order after the acid challenge of 3 weeks at pH 5. These values were substantially higher than the baseline values in sound or in demineralized dentine being about 900 ppm F. The main microradiographic result was that there was no significant mineral change in the hyper-remineralized dentine due to the acid challenges. There was, however, a tendency for mineral redistribution deeper into the dentine lesion leading to lamination phenomena. The SIMS experiments on some of the samples showed a fluoride distribution in agreement with the microdrill fluoride data. Furthermore a fluoride redistribution took place in deeper parts of the lesion due to the acid challenges. The combined fluoride concentration and microradiographical data indicate that fluoride-enriched and highly mineralized hyper-remineralized dentine is more acid resistant than sound or demineralized dentine. <19> UI - 93306694 AU - Almqvist H AU - Lagerlof F IN - Department of Cariology, School of Dentistry, Karolinska Institute, Huddinge, Sweden. TI - Influence of constant fluoride levels in solution on root hard tissue de- and remineralization measured by 125I absorptiometry. SO - Caries Research 1993;27(2):100-5 AB - To study the effect of fluoride on de- and remineralization of root hard tissue, an automatic pH-cycling caries model, simulating Stephan curves, was used for 21 days. From each of 13 unexposed human roots, four cementum/dentin blocks were prepared. Four experiments were carried out: one block from each tooth as subjected to pH cycling without and with fluoride at the concentrations of 0.02 ppm (1.0 mumol/l), 0.20 ppm (10.5 mumol/l) and 2.00 ppm (105.3 mumol/l) in the de- and remineralizing solutions, respectively. Mineral change in the specimens was monitored by 125I absorptiometry. When no fluoride was added to the solutions the change in transmission (delta T) increased continuously over 21 days, indicating loss of mineral. In the 0.02-ppm F experiment, there was a marked decrease in delta T, but almost no change in the 0.20-ppm F experiment. pH cycling with 2.00 ppm F in the solutions resulted in a gain of mineral in or most likely on the surface of the cementum/dentin blocks, indicated by a continuously decreasing delta T. The fluoride level in the solution significantly influenced the change in the mineral content of the specimens. Microradiographs of the sectioned blocks showed radiodense surface zones, varying degrees of subsurface demineralization and signs of remineralization or mineral deposition. <20> UI - 93306696 AU - Lamb WJ AU - Corpron RE AU - More FG AU - Beltran ED AU - Strachan DS AU - Kowalski CJ IN - School of Dentistry, University of Michigan, Ann Arbor 48109-1078. TI - In situ remineralization of subsurface enamel lesion after the use of a fluoride chewing gum. SO - Caries Research 1993;27(2):111-6 AB - In situ remineralization of early enamel lesions by a fluoride chewing gum was studied. Human enamel specimens with subsurface lesions were mounted in removable lower appliances for 6 adults. Subjects used a F-free dentifrice 3x/day and chewed five sticks/day for the F gum group (0.1 mg F/stick) or five sticks of sugarless gum. No gum was chewed for controls. Surface microhardness was performed on: (1) sound enamel; (2) lesions; (3) after intraoral exposure, and (4) after acid-resistance testing (ART). Separate specimens were etched and measured for F uptake and image analyses on microradiographs were performed for all regimens. delta Z values were calculated and converted to percent of mineralization. Values for F gum were significantly higher (p > 0.05) than non-F gum and controls for ART, percent remineralization, and F uptake up to 70 microns depth. <21> UI - 93307825 AU - Newbrun E IN - Department of Stomatology, University of California, San Francisco 94143-0512. TI - Problems in caries diagnosis [published erratum appears in Int Dent J 1993 Oct;43(5):454]. [Review] [83 refs] SO - International Dental Journal 1993 Apr;43(2):133-42 AB - This paper reviews some of the problems in the diagnosis of primary and secondary caries, particularly with respect to the questionable lesion that has neither penetrated to dentine nor cavitated. Because tactile diagnosis of caries with sharp probes can be unreliable as well as damaging, diagnosis should include careful visual inspection (preferably with magnification), radiographic examination, fibre optic transillumination (FOTI), and/or measurement of electrical resistance depending on the anatomical location. Probably the most important and difficult diagnostic decision for the clinician is whether the patient is at high, moderate or low risk of caries. Consideration of various factors in the patient's history, and clinical and laboratory examinations will assist in this classification of risk. [References: 83] <22> UI - 93328912 AU - White JM AU - Goodis HE AU - Setcos JC AU - Eakle S AU - Hulscher BE AU - Rose CL IN - Department of Restorative Dentistry, University of California, School of Dentistry, San Francisco 94143-0758. TI - Effects of pulsed Nd:YAG laser energy on human teeth: a three-year follow-up study [see comments]. CM - Comment in: J Am Dent Assoc 1993 Dec;124(12):12, 14, 16 SO - Journal of the American Dental Association 1993 Jul;124(7):45-51 AB - This study of laser use on dental hard tissues evaluated restorations and tooth vitality in teeth treated three years earlier. All teeth remained vital and asymptomatic. Restorations placed after caries removal were intact and clinically serviceable. <23> UI - 93306092 AU - Bouvier D AU - Duprez JP AU - Bonin P AU - Dumas J IN - UFR d'Odontologie, Lyon, France. TI - [An analysis by scanning electron microscopy and surface roughness meter of the impact of the CO2 laser on the dentin]. [French] SO - Bulletin du Groupement International Pour la Recherche Scientifique en Stomatologie et Odontologie 1993 Mar-Jun;36(1-2):7-13 AB - The aim of the study was to compare the morphology of craters produced on the dentinal surface by CO2 laser beams (LASERSAT CO2) before and after the removal of the carbonized layer, besides with different settings of the power and duration of the laser beam. Thirty-three recently extracted non carious young third molar teeth were sectioned from vestibular and lingual surfaces, exposing a planed dentinal surface. Twenty impacts were made on each of dentinal surface producing 20 individual craters. The duration and the power of each laser beam were different on each tooth. The duration varied from 0.1 to 0.4 second (0.1-0.2-0.3-0.4 s). The power varied from 1 to 5 watts (1, 2, 3, 4, 5 w). Specimens obtained for a power of 3 and 4 watts and a duration of 0.1 and 0.2 second were examined with a JEOL 35CF (25 KV, magnification: x 30, x 110, x 200), before and after the removal of the carbonized layer. The carbonized layer of the craters was removed with an air polisher (HEATCO). Craters obtained for all duration values as well as for all power values were analyzed with a profilometer. The chosen profilometer was: TALISURF 10; horizontal amplification Vh = 20; vertical amplification Vv = 200. Samples were observed by a SEM and the craters depth and diameter were measured with a profilometer. Then, the carbonized layer of the craters was removed with an air polisher and the cleaned dentinal surface was observed again with the SEM and the profilometer.(ABSTRACT TRUNCATED AT 250 WORDS) <24> UI - 93287080 AU - Burns T AU - Wilson M AU - Pearson GJ IN - Department of Microbiology, Institute of Dental Surgery, London. TI - Sensitisation of cariogenic bacteria to killing by light from a helium-neon laser. SO - Journal of Medical Microbiology 1993 Jun;38(6):401-5 AB - Suspensions of the cariogenic bacteria Streptococcus mutans, S. sobrinus, Lactobacillus casei and Actinomyces viscosus were exposed to light from a 7.3-mW helium-neon laser in the presence of toluidine blue O. A substantial killing rate (c. 10(6) cfu) of all four species was achieved with a dye concentration of 50 micrograms/ml and a light energy dose of 33.6 J/cm2. This was achieved in 60 s, an exposure time that is clinically acceptable. Exposure to laser light in the absence of the dye did not significantly affect the viability of any of the organisms. This approach may be useful in dentistry to sterilise a carious lesion prior to its repair. <25> UI - 93280369 AU - Bader JD AU - Brown JP IN - Department of Operative Dentistry, School of Dentistry, University of North Carolina, Chapel Hill. TI - Dilemmas in caries diagnosis [see comments]. CM - Comment in: J Am Dent Assoc 1993 Sep;124(9):16, 18 SO - Journal of the American Dental Association 1993 Jun;124(6):48-50 AB - New criteria and methods are needed to identify the changing expression of caries and to classify carious lesions into categories keyed to treatment strategies. Symposium speakers identified these problems and reviewed the changing philosophy of diagnosis. <26> UI - 93274020 AU - Gao XJ AU - Elliott JC AU - Anderson P IN - Department of Child Dental Health, London Hospital Medical College, United Kingdom. TI - Scanning microradiographic study of the kinetics of subsurface demineralization in tooth sections under constant-composition and small constant-volume conditions. SO - Journal of Dental Research 1993 May;72(5):923-30 AB - The kinetics of subsurface demineralization of tooth sections has been studied in real-time by scanning microradiography (SMR). Demineralization was carried out: (1) with a large volume of solution buffered to pH = 4 to maintain a constant composition; and (2) in a small constant volume (approximately 3 mL), buffered initially at pH = 4, so that the degree of saturation at the tooth surface increased as the tooth dissolved. At constant composition, the change in lesion depth, Y, with time, T, followed a linear relation, Y = a + bT, for T > 44 +/- 5 h. Before this time, the relation could be approximated by a linear one with different a and b constants. At constant volume, Y = q(1-e-r(T + s)) for all T, where q, r and s are constants. Similar relations, with different constants, were found for the mineral loss per unit area of lesion exposed to acid. These results showed that the process of demineralization under the rather severe conditions used was essentially a surface-controlled process. The change of slope at approximately 44 h and the presence of the constant s in the exponential function were attributed to a change in kinetics after formation of the surface layer. <27> UI - 93271089 AU - Lohmann CP AU - Fitzke FW AU - O'Brart D AU - Muir MK AU - Marshall J IN - University Eye Clinic Regensburg, Germany. TI - Halos--a problem for all myopes? A comparison between spectacles, contact lenses, and photorefractive keratectomy. SO - Refractive & Corneal Surgery 1993 Mar-Apr;9(2 Suppl):S72-5 AB - After photorefractive keratectomy (PRK) using excimer lasers (193 nm) many patients report the presence of halos around light sources at night. However, halos are not unique to PRK patients, as they are a common observation in myopic contact lens wearers. We present an objective measurement of the halos using a computerized technique. The patient fixated on a red cross within a white circle in the center of a video monitor which served as the halo source. The screen surrounding the circle was not illuminated. The operator controlled the movement of the white spot and moved the spot toward the halo source until the subject indicated when the cursor was at the outer parameter of the halo. Measurements were made at 30 degree intervals around the halo source and expressed as square degrees. The study found that spectacles, soft contact lenses, and excimer laser surgery were superior to hard contact lenses in terms of the size of the halo. A mean value of 2.51 square degrees was obtained for spectacles wearers compared with 3.18 square degrees for soft contact lenses, 3.14 square degrees for excimer laser patients with 4-millimeter ablation zone, 2.76 square degrees for excimer laser patients with a 5-millimeter ablation zone, and 89.5 square degrees for hard contact lenses. It appears that this device is very useful for measuring the halo size after excimer laser PRK. We concluded that halos were not a problem for our patients after excimer laser photorefractive keratectomy. <28> UI - 93187871 AU - Arys A AU - Philippart C AU - Dourov N IN - Laboratory of Pathology and Electron Microscopy, Free University of Brussels, Belgium. TI - Microradiography and light microscopy of mineralization in the pulp of undemineralized human primary molars. SO - Journal of Oral Pathology & Medicine 1993 Feb;22(2):49-53 AB - This study was undertaken to investigate the prevalence, location and histologic features of the different types of mineralization observed in the pulp of human primary molars. Microradiography and light microscopy of undemineralized material disclosed that 95% of primary molars contain pulp calcifications. Histologically, their structure may be classified into four different types: (1) pulp stones, (2) diffuse calcifications, (3) eburnoid tissue and (4) spherulitic calcifications. <29> UI - 93193137 AU - Theuns HM AU - Shellis RP AU - Groeneveld A AU - van Dijk JW AU - Poole DF IN - Caries Research Unit NIPG-TNO, Utrecht, The Netherlands. TI - Relationships between birefringence and mineral content in artificial caries lesions of enamel. SO - Caries Research 1993;27(1):9-14 AB - The microradiographic mineral content and birefringence in water and Thoulet's solution were measured at selected points in sections of caries-like lesions. Birefringence was not related to mineral content in sound superficial enamel immersed in Thoulet's solution or in the lesion body immersed in water. For the surface layer of the lesion, birefringence in water could be used to obtain qualitative information about mineral content. For the lesion body, birefringence in Thoulet's solution was linearly related to mineral content and can be used to estimate the latter with a standard error of about 7 vol%. The intrinsic birefringence for the lesion body was estimated as -34.5 (+/- 2.3) x 10(-4); This value may also be valid for other parts of the lesion. From consideration of ionic sizes, it is argued that Thoulet's solution cannot necessarily penetrate all enamel pores accessible to water. It appeared that there is a progressive fall in the content of pores inaccessible to Thoulet's solution in the surface layer of the lesion as demineralisation increases. <30> UI - 93206060 AU - Boonstra W AU - de Vries J AU - ten Bosch J AU - Ogaard B AU - Arends J IN - Laboratory of Materia Technica, University of Groningen, The Netherlands. TI - Inhibition of bovine dentin demineralization by a glutardialdehyde pretreatment: an in vitro caries study. SO - Scandinavian Journal of Dental Research 1993 Apr;101(2):72-7 AB - Intact bovine dentin specimens were demineralized in 25 mmol acetic acid buffers (pH 5), with and without a 5-min pretreatment with an acidic 2% glutardialdehyde (GDA) solution. The results demonstrate that GDA inhibits dentin demineralization and that the inhibition depends strongly on the initial calcium and phosphate concentration in the demineralization solution. The observed inhibition increases from about 5% without calcium and phosphate to 38% with a calcium and phosphate concentration initially of 6.4 mmol and 4.1 mmol, respectively. The inhibition can be explained either by a reduction of calcium and phosphate diffusion out of the lesion or by the retention of mineral inhibitors in the dentin. <31> 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. <32> UI - 94015942 AU - Morioka T IN - Department of Preventive Dentistry, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. TI - Applicability and future scope of lasers in dental practice. SO - Journal of the Philippine Dental Association 1992 Sep-Nov;44(2):5-8 <33> UI - 93322127 AU - Stabholz A AU - Khayat A AU - Weeks DA AU - Neev J AU - Torabinejad M IN - Hebrew University, Hadassah School of Dental Medicine, Jerusalem, Israel. TI - Scanning electron microscopic study of the apical dentine surfaces lased with ND:YAG laser following apicectomy and retrofill. SO - International Endodontic Journal 1992 Nov;25(6):288-91 AB - The purpose of this investigation was to study the effects of a Nd:YAG laser on the cut surface of teeth using scanning electron microscopy (SEM). Eighteen single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. The apical 3 mm of each tooth were resected with a diamond fissure bur, and the teeth were randomly divided into two groups of nine teeth each. The resected surface of each root in one group was lased twice. The duration of lasing and the number of pulses were recorded for each tooth. The teeth were air dried, mounted on stubs, sputter-coated with gold-palladium and examined under SEM. Application of the Nd:YAG laser caused melting of apical dentine surfaces. The melted material resembled the appearance of glazed interconnected droplets. Resolidification and recrystalization of the melted areas appeared to be incomplete and discontinuous. Some areas between the glazed regions appeared similar to those of non-lased apical dentine resected root surfaces. <34> UI - 93288809 AU - Lutz F AU - Krejci I AU - Barbakow F IN - Department of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Dental Institute, Switzerland. TI - Restoration quality in relation to wedge-mediated light channeling. SO - Quintessence International 1992 Nov;23(11):763-7 AB - Thirty large mesio-occlusodistal cavities with their margins totally in enamel were restored using the three-sited light-curing technique in five different ways: group 1 = Mark I version of a light-reflecting wedge; groups 2 and 3 = interproximal curing with transparent, nonreflecting wedges; groups 4 and 5, Mark II version of the light-reflecting wedge with increased resiliency. In groups 3 and 5, the light that was not conducted by the transparent wedges was shielded by a piece of aluminum foil. It was found that, when used directly and unshielded, both Mark I and Mark II versions of the light-reflecting wedge induced significantly better marginal adaptation than the transparent, nonreflecting wedge, especially gingiovproximally. With both the nonreflecting and reflecting wedges, the shielding had no effect on the overall percentage of excellent margin. However, gingivoproximally, the shielding significantly improved the marginal quality in the nonreflecting wedge groups, leading to the conclusion that the first increment should be cured as thoroughly as possible from a gingivoproximal direction, preferably indirectly via light-conducting wedges. Direct irradiation from a lingual or buccal direction is less favorable. <35> UI - 93228924 AU - Wendt SL Jr AU - Leinfelder KF IN - UCONN Health Center, School of Dental Medicine, Department of Restorative Dentistry and Endodontology, Farmington, CT 06032. TI - Clinical evaluation of a heat-treated resin composite inlay: 3-year results. SO - American Journal of Dentistry 1992 Oct;5(5):258-62 AB - The purpose of this study was to evaluate a resin composite inlay system in clinical trials involving human subjects. A total of 60 restorations were inserted equally in Class I and II preparations and in premolars and molars. A glass ionomer liner was applied to the dentin. Light-cured direct inlays were fabricated in the oral environment. Thirty inlays were heat-treated for 7.5 minutes at 125 degrees C in a dry heat oven. Enamel margins of the preparations were etched with 37% phosphoric acid gel. All inlays were cemented with a light-cured enamel bonding resin. Restorations were evaluated using the USPHS system and M-L indirect scale. Six, 12, 24 and 36-month recalls were compared to baseline. Color, interfacial staining, secondary caries, and wear were unchanged from baseline for all restorations. Marginal integrity and surface texture show a differential change from baseline and with respect to restoration type. Indirect wear was not significantly different between restoration types (P < 0.05). Wear resistance was not significantly improved with heat treatment, but marginal integrity and surface characteristics showed marked improvement in the heat-treated group at 24 and 36-month recalls. <36> UI - 93178719 AU - Clarkson DM IN - Radiotherapy Centre, Walsgrave Hospital, Coventry, UK. TI - Lasers in dentistry. SO - Dental Update 1992 Apr;19(3):115-6, 118 AB - Lasers, which are constantly evolving, can be customized to meet dental requirements and could become a very useful tool for dental practitioners. The article provides an introduction to the instruments, which includes a description of how they work and discusses their applications in dentistry. <37> UI - 93178661 AU - Gaspar L IN - Semmelweis Orvostudomanyi Egyetem, Szajsebeszeti es Fogaszati Klinika, Budapest. TI - [Laser in contemporary dentistry]. [Review] [64 refs] [Hungarian] SO - Fogorvosi Szemle 1992 Nov;85(11):343-53 AB - In the 30 years of laser history the oral cavity application has always played an important role. In the laboratory diagnostics the analysis of the saliva, tissues and hard dental tissues is performed by laser. In the clinical diagnostics the laser is used for examining the caries, dental matter, in orthodontics, in the surgical analysis of splanchnocranium and the teeth. The photodynamic treatment involves the diagnostic and therapeutic use of the lasers in the management of oral cavity cancers. The soft laser therapy is widely applied in diseases of the oral mucosa, parodontal and pain syndromes, temporomandibular articular diseases, dental inflammations, salivary gland diseases and in osseal healing processes. The surgical lasers are applied in the treatment of teeth, in preprosthetic surgery, salivary gland diseases, precancerous conditions, tumour surgery and in the surgery of hemophilic patients, respectively. In the 90s one cannot speak about modern oral surgery or dentistry without the application of lasers. Though in various fields the research is merely in initial phase (holography, caries-treatment, photodynamic therapy, etc.), the lasers are becoming an indispensable (treatment of precancerous conditions, hemophilic patients, diseases of the oral mucosa, etc.). The oral surgical use of lasers might bring about fundamental changes in diagnosis and treatment, becoming a new professional branch, opening up new vistas, representing "future" today. The invention of lasers in 1960 and their broad dissemination in oral surgery and dentistry since 1980 have resulted in basic changes in numerous diagnostic and therapeutic approaches. The medical use of lasers is of such an extent that it can well justifiably regarded as a new branch of science namely the laser medicine. This considerably relates to stomatology, too. [References: 64] <38> UI - 93176735 AU - Kuba Y AU - Miyazaki K AU - Ichiki K AU - Kawazoe H AU - Motokawa W IN - Department of Pediatric Dentistry, Fukuoka Dental College, Japan. TI - Clinical application of visible light-cured fluoride-releasing sealant to non-etched enamel surface of partially erupted permanent molars. SO - Journal of Clinical Pediatric Dentistry 1992 Fall;17(1):3-9 AB - A visible light-cured fluoride-releasing sealant was applied to non-etched enamel surfaces of partially erupted permanent molars. A scanning electron microscope was used to find an effective procedure to clean pits and fissures of the occlusal surfaces prior to application of the sealant. This procedure proved clinically acceptable and effective for prevention of dental caries immediately after eruption of permanent molars. <39> 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] <40> UI - 93165898 AU - Segura A AU - Donly KJ AU - Croll TP IN - University of Iowa, College of Dentistry, Iowa City 52242. TI - The effect of polymerization shrinkage during veneer placement. SO - Quintessence International 1992 Sep;23(9):629-32 AB - This study evaluated the relationship of polymerization shrinkage during composite resin veneer placement to direction of the polymerization light source. Fifty maxillary permanent incisors were obtained and divided into five groups of ten. Groups I and II had preparations placed in enamel. Groups III, IV, and V had preparations placed in dentin. In groups I and III, an unfilled bonding resin was placed and polymerized from the facial aspect, followed by placement and polymerization of a hybrid composite resin. Groups II and IV were initially polymerized from the lingual direction. In group V, the unfilled resin and hybrid composite resin were polymerized simultaneously from the facial aspect. Statistical analysis indicated that there was significantly less axial microgap formation during lingual polymerization when the preparation remained in dentin, but demonstrated that there was no statistically significant difference when the preparation remained in enamel. <41> UI - 93105454 AU - Fox JL AU - Yu D AU - Otsuka M AU - Higuchi WI AU - Wong J AU - Powell G IN - Department of Pharmaceutics, University of Utah, Salt Lake City 84112. TI - Combined effects of laser irradiation and chemical inhibitors on the dissolution of dental enamel. SO - Caries Research 1992;26(5):333-9 AB - It has previously been shown that the susceptibility of human teeth to acid dissolution can be reduced by the presence of various chemical agents in the dissolution medium or by pretreatment of the teeth with laser irradiation. Now synergism between these two approaches to improving acid resistance has been demonstrated. Extracted human teeth were irradiated with a continuous-wave carbon dioxide laser at a wavelength of 10.6 microns. Energy doses of either 65 or 130 J/cm2 given over periods of 2 or 4 s, respectively, were applied and the teeth subjected to a severe acid challenge (0.1 M acetate buffer, pH 4.5, no calcium or phosphate common ion present) for 24 h. Mineral loss was assessed by measurement of mineral density profiles with quantitative microradiography. Experiments were carried out in the presence or absence of three chemical inhibitors with distinctly different mechanisms of action: ethane-1-hydroxy-1, 1-diphosphonic acid, fluoride, and dodecylamine HCl. Laser irradiation alone was found to lead to increased resistance of the teeth to acid challenge, with the higher energy dose being more effective than the lower dose. Each of the chemical inhibitors was effective on both lased and unlased teeth, with the percent reduction of dissolution greater when the inhibitors were applied to teeth lased with an energy dose of 130 J/cm2 which were already more resistant to acid challenge than were unlased teeth or teeth lased with a dose of 65 J/cm2.(ABSTRACT TRUNCATED AT 250 WORDS) <42> UI - 93085030 AU - Wenzel A AU - Verdonschot EH AU - Truin GJ AU - Konig KG IN - Department of Oral Radiology, Royal Dental College, Aarhus, Denmark. TI - Accuracy of visual inspection, fiber-optic transillumination, and various radiographic image modalities for the detection of occlusal caries in extracted non-cavitated teeth. SO - Journal of Dental Research 1992 Dec;71(12):1934-7 AB - Occlusal caries lesions may progress into the dentin without this resulting in a macroscopic breakdown of the enamel surface. Imaging methods may therefore be needed to aid in the visual detection of occlusal caries. It was the aim of this study to evaluate diagnostic accuracy in a laboratory set-up of visual inspection (VI), fiber-optic-transillumination (FOTI), conventional radiography (CR), and two digital radiographic image modalities (DRm and DRr) for detection of occlusal caries in clinically non-cavitated teeth. Eighty-one extracted third molars from 18-20-year-old males were assessed by four observers on a five-rank confidence scale by the five methods. Ground sections (500-600 microns) served as validation for true state of disease: 1 = no caries in dentin, 2 = caries just beyond dentino-enamel junction, or 3 = deep dentinal caries, halfway or more to the pulp. ROC analysis was performed on the basis of the confidence rank scale data on two diagnostic thresholds, T1 = caries in dentin (disease state 2+3) and T2 = caries deep in dentin (state 3). On the T1 level, use of the FOTI method gave on average the most accurate diagnosis, closely followed by VI, both performing better than use of radiography. On the T2 level, all five diagnostic methods performed equally well. <43> UI - 93085023 AU - Creanor SL AU - Strang R AU - Gilmour WH AU - Foye RH AU - Brown J AU - Geddes DA AU - Hall AF IN - Oral Biology Group, University of Glasgow Dental School, Scotland, United Kingdom. TI - The effect of chewing gum use on in situ enamel lesion remineralization. SO - Journal of Dental Research 1992 Dec;71(12):1895-900 AB - Two independent cross-over studies investigated the possibility of enhanced early enamel lesion remineralization with the use of chewing gum. The first study involved a sorbitol-containing chewing gum, and the second, which had an identical protocol, tested a sucrose-containing chewing gum. In each study, 12 volunteers wore in situ appliances on which were mounted enamel sections containing artificial caries lesions. Subjects brushed twice daily for two min with a 1100-ppm-F (NaF) dentifrice (control and test) and in the test phase chewed five sticks of gum per day for 20 min after meals and snacks. Microradiographs of the enamel lesions were made at baseline and at the end of the seven-week experimental period. In the sugar-free gum study, the weighted mean total mineral loss (delta z) difference [(wk7-wk0) x (-1)] was 788 vol.% min. x micron for the gum, corresponding to remineralization of 18.2%, vs. the control value of 526 vol.% min. x micron, 12.1% remineralization (p = 0.07). There were no significant differences for the surface-zone (p = 0.20) and lesion-body (p = 0.28) values. In the sucrose-containing gum study, the delta z difference was 743 vol.% min. x micron for the gum, corresponding to a remineralization of 18.3%, vs. the control value of 438 vol.% min. x micron, 10.8% remineralization (p = 0.08). The surface-zone values were not significantly different (p = 0.55). For the lesion body, however, the sucrose-containing gum value of 6.11 vol.% min. was significantly different (p = 0.01) from that of the control (2.81 vol.% min.). <44> UI - 93080943 AU - Wenzel A IN - Odontologisk Institut, Aarhus Universitet. TI - [Diagnosis of caries in occlusal plane]. [Danish] SO - Tandlaegernes Nye Tidsskrift 1992 Sep;(9):260-5 <45> UI - 93057220 AU - Stabholz A AU - Khayat A AU - Ravanshad SH AU - McCarthy DW AU - Neev J AU - Torabinejad M IN - Hebrew University-Hadassah School of Dental Medicine, Jerusalem. TI - Effects of Nd:YAG laser on apical seal of teeth after apicoectomy and retrofill. SO - Journal of Endodontics 1992 Aug;18(8):371-5 AB - The application of Nd:YAG laser to tooth surface can change its surface permeability. The purpose of this study was to investigate the effects of Nd:YAG laser on the permeability of dentin following apicoectomy and retrofill. Sixty single-rooted teeth were randomly assigned to six groups of 10 teeth each. The six groups were arranged in three pairs, experimental and control groups. The canals of teeth in pairs 1 and 2 were cleaned, shaped, obturated, and their apical 2 mm were resected. A class I preparation was prepared and filled with amalgam in each tooth in pair 1. The apical 2 mm of each tooth in pair 3 was removed, and a class I preparation was prepared and filled with amalgam. The apical surface of resected roots in half of the samples in each pair was lased twice by using Nd:YAG laser. The duration of lasing and the number of pulses were recorded for each tooth. After application of nail polish to the unoperated surface of each tooth, the teeth were placed in 0.5% methylene blue dye for 48 h. The amount of dye penetration in sagittal sections of each tooth was measured. The amount of dye penetration was significantly lower in lased roots than in nonlased ones (p < 0.05). Based on our results, it appears that application of Nd:YAG laser reduces the permeability of resected roots. <46> UI - 93046443 AU - Dijkman GE AU - de Vries J AU - Arends J IN - Laboratory for Materia Technica, Groningen, The Netherlands. TI - Effect of glutardialdehyde on secondary caries in situ. SO - Caries Research 1992;26(4):293-8 AB - In this paper the results are presented on the effect glutardialdehyde (GDA) on the in situ demineralization of human enamel and dentine around an artificial gap of 200 microns width. In this model secondary enamel and dentine caries is simulated in situ; the mineral loss was quantified. The results show that a 2-min application of a 2% acidic GDA solution reduces dentine demineralization substantially, but does not influence enamel demineralization. Microradiography showed a reduction of mineral loss values around the gap in dentine by about 30%. The beneficial effect of GDA on dentine is presumably a combined result of collagen fixation, the reduced diffusion of calcium and phosphate ions out of the dentine lesion, and antibacterial action. The results indicate that GDA might play a role in the future reduction or prevention of secondary dentine caries. <47> UI - 93046434 AU - Hafstrom-Bjorkman U AU - Sundstrom F AU - de Josselin de Jong E AU - Oliveby A AU - Angmar-Mansson B IN - Department of Cariology, School of Dentistry, Karolinska Institutet, Stockholm, Sweden. TI - Comparison of laser fluorescence and longitudinal microradiography for quantitative assessment of in vitro enamel caries. SO - Caries Research 1992;26(4):241-7 AB - A new quantitative, non-destructive method using laser-induced fluorescence (LAF) was compared with longitudinal microradiography (LMR) for assessment of mineral changes in enamel slices using an in vitro caries model. Ten enamel slices, cut longitudinally from sound natural smooth surfaces of human teeth, were exposed to de- and remineralization in a pH-cycling model. The enamel slices were subjected to LAF and LMR measurements before and at 2, 4, 7, and 9 days of demineralization. For LAF, the average fluorescence radiance decreased during the demineralization period with 11% by day 2 and 49% by day 9. For LMR, the corresponding average loss of mineral content changed with 0.01 and 0.10 kg.m-2 over the same time period. The mineral losses in each individual enamel slice measured with the two techniques were strongly correlated, r = 0.97. The Spearman rank correlation coefficient for all LAF and LMR demineralization results was 0.86. The precision (coefficient of variation) for LAF was 3.1%, corresponding to 0.005 kg.m-2, and the repeatability error for LMR was 0.02 kg.m-2, indicating a lower discrimination threshold for LAF compared to LMR. It was concluded that the new, sensitive, non-destructive LAF method provides possibilities for further improvement in the quantification of initial caries lesions in natural smooth enamel surfaces for use in in vitro studies. Furthermore, it offers potential in in situ caries studies as well as a tool in the diagnosis of early enamel caries in vivo. <48> UI - 93005477 AU - Midda M IN - University of Bristol Dental Hospital. TI - Lasers in periodontics. SO - Periodontal Clinical Investigations 1992 Spring;14(1):14-20 AB - Clinical lasers are of two types. Soft lasers are essentially an aid to healing, with relatively few rigorous studies available to support their use. Surgical hard lasers, however, can cut both hard and soft tissues, replacing the scalpel and drill in many areas. After initial experiments with the ruby laser, most clinicians have been using argon, carbon dioxide, and now Nd:YAG systems. The first dental laser based on a Nd:YAG engine provides handpieces of similar size to conventional instrumentation, and being fed by a fibre-optic "cable," has the flexibility for intra-oral use that the carbon dioxide lasers, widely used in oral surgery, lack. Furthermore, extensive clinical investigation has demonstrated their safety in clinical practice, and the fact that procedures can usually be performed without a local anaesthetic is obviously seen as an advantage by patients. Sterilizing as it cuts, the Nd:YAG laser promises to find uses not only in caries removal and soft tissue surgery but also in periodontics and endodontics. <49> UI - 93026050 AU - Anonymous TI - NIH backs Rochester study of lasers and tooth decay [news]. SO - New York State Dental Journal 1992 Oct;58(8):49 <50> UI - 92393773 AU - Kobayashi Y AU - Ozeki M AU - Ogawa A AU - Matsumoto S AU - Sanjo M AU - Moriyama T IN - Department of Microbiology, Aichi-Gakuin University School of Dentistry, Nagoya, Japan. TI - Invasion of Streptococcus mutans, Streptococcus intermedius and Propionibacterium acnes into the teeth of gnotobiotic rats. SO - Caries Research 1992;26(2):132-8 AB - Germ-free rats, fed a modified cariogenic diet 2000 with a reduced sucrose content of 25%, were inoculated with a strain of Streptococcus mutans, Streptococcus intermedius or Propionibacterium acnes, respectively. After 100 days on the diet, the rats were sacrificed. Microscopic examination of stained decalcified tooth sections revealed marked destruction of the outer zones of the dentin infected with S. mutans. The destruction was closely associated with the formation of glucan-mediated large aggregates of S. mutans. The aggregates, however, were rarely formed in the deep zones of the infected dentin. Inoculation with S. intermedius and P. acnes had little effect on the microscopic outline of the decalcified tooth sections. However, the staining behavior of the sections with Mallory's method, Alcian blue-PAS and silver was like that of the tooth sections infected with S. mutans, even in the central and inner zones of the dentin. The histochemical alterations of the deep zones of the dentin induced by the three infected bacteria appeared to be due to their proteolytic rather than to their acidogenic activities. <51> UI - 92398865 AU - de Goes MF AU - Rubbi E AU - Baffa O AU - Panzeri H TI - Optical transmittance of reflecting wedges. SO - American Journal of Dentistry 1992 Apr;5(2):78-80 AB - This study quantified the light intensity transmitted by the reflecting wedges perpendicularly to the growth axis. The results demonstrated that the cervical wedges did reflect the light of 180 degrees and original light intensity diminished by 83.9%. The maximal light intensity transmitted to the resin by the wedge was less than 8% of that receiving direct exposure to the curing wand. Differential measurements made on points closely spaced along the sides of the wedge indicated a maximal intensity at approximately 2 mm from the base of the wedge. <52> UI - 92393769 AU - Manning RH AU - Edgar WM AU - Agalamanyi EA IN - Department of Clinical Dental Sciences, University of Liverpool, UK. TI - Effects of chewing gums sweetened with sorbitol or a sorbitol/xylitol mixture on the remineralisation of human enamel lesions in situ. SO - Caries Research 1992;26(2):104-9 AB - Intra-oral remineralisation of experimental caries-like lesions in human enamel, as determined by polarised light microscopy and quantitative microradiography, was promoted to a similar extent (% fall in delta Z, 18.6 and 19.0) by chewing a sorbitol or sorbitol/xylitol (3:1)-sweetened gum for 20 min after each of three meals and two sugary snacks daily. The results suggest that reported differences in the properties of the two sweeteners do not affect their ability to enhance remineralisation due to salivary stimulation. <53> UI - 92376007 AU - Liu M AU - Pertl C AU - Markowitz K AU - Dorscher-Kim J AU - Kim S IN - Department of Endodontics, School of Dental and Oral Surgery, Columbia University, New York. TI - The effects of capsaicin on pulpal blood flow. SO - Proceedings of the Finnish Dental Society 1992;88 Suppl 1:463-7 AB - One of the initial events in pulpal inflammation has been characterized as neurogenic inflammation: the release of neuropeptides following excitation of sensory C-fibers by noxious stimuli which alters microcirculatory parameters, that is, vasodilation and plasma extravasation. Thus, the purpose of the study was to investigate the effect of capsaicin on pulpal blood flow (PBF) with the aim of understanding neurogenic inflammation in the dental pulp by characterizing the response of the pulpal vasculature to repeated applications of various concentrations of capsaicin. Experiments were performed on canine teeth of cats anesthetized with sodium pentobarbital. PBF was measured by the laser Doppler flowmeter following the application of capsaicin into the dentinal cavities of the canine teeth. The increases of PBF to capsaicin were 31.8 +/- 6.3% (n = 6) and 54.2 +/- 6.2% (n = 9), for 1 microM and 100 microM capsaicin, respectively. The increase of PBF peaked at about 50 sec after the capsaicin placement and the PBF returned to control level within 20 min following capsaicin removal. Four repeated applications of 1 microM capsaicin caused a small change in the peak PBF amplitude. In contrast, a second application of 100 microM capsaicin caused a significantly smaller increase of PBF than the first application (26.8 +/- 6.4% vs. 54.2 +/- 6.2%). Results of the present study show that local application of capsaicin caused the increase of PBF and that repeated capsaicin stimulations inhibited PBF responses. Smaller PBF increases in response to high concentrations of capsaicin also suggested the depletion of vasoactive substances, e.g. substance P, from the sensory nerve terminals, which appears to be dose-dependent. The PBF response to capsaicin suggests that neurogenic inflammation in the dental pulp involves capsaicin-sensitive nerve endings. <54> UI - 92356773 AU - Okamoto H AU - Iwase T AU - Morioka T IN - Department of Preventive Dentistry, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. TI - Dye-mediated bactericidal effect of He-Ne laser irradiation on oral microorganisms. SO - Lasers in Surgery & Medicine 1992;12(4):450-8 AB - Little attention has been given to the bactericidal effect of laser irradiation, particularly using low-power energy lasers. It has been demonstrated that He-Ne laser light has an inhibitory action on dental plaque. The purpose of this study was to investigate the bactericidal effect of He-Ne laser irradiation on cariogenic microorganisms. The bactericidal effect was determined by the formation of a growth-inhibitory zone or by the counting of viable bacterial colonies. Streptococcus sobrinus AHT that is a Gram-positive microorganism was sensitive to He-Ne laser light, but Escherichia coli, a Gram-negative microorganism, was resistant. The effect of several dyes necessary to instigate a bactericidal action was also examined. A growth-inhibitory zone was observed using 10 kinds of blue, purple, or green dyes, which were mainly phenylmethane dyes. The leakage of potassium from S. sobrinus AHT following laser irradiation was determined using an atomic absorption spectrophotometer. The leakage began to increase following irradiation for 2 min, and reached a plateau following irradiation for 30-60 min. Moreover, to examine some changes in the dye itself following laser irradiation in the absence of bacteria, ultraviolet-visible absorption spectra and 1H NMR spectra were recorded. In this study, it was indicated that the bactericidal effect on cariogenic bacteria by He-Ne laser irradiation was efficient only in the presence of specific dyes. It is suggested that this laser may be suitable for clinical applications in preventive dentistry. <55> UI - 92373475 AU - Spencer P AU - Trylovich DJ AU - Cobb CM IN - Department of Pediatric Dentistry, University of Missouri-Kansas City School of Dentistry. TI - Chemical characterization of lased root surfaces using Fourier transform infrared photoacoustic spectroscopy. SO - Journal of Periodontology 1992 Jul;63(7):633-6 AB - Recently lasers have been recommended as an alternative or adjunctive therapy in the control and treatment of periodontally diseased root surfaces. The purpose of this in vitro investigation was to characterize the chemical structure of lased root surfaces using Fourier transform infrared photoacoustic spectroscopy (FTIR/PAS). Cementum samples, 6 mm x 2 mm, were cut from the root surface of extracted non-carious, unerupted human molars. The experimental samples were lased with a Nd:YAG laser at an average energy of 80 mJ at 10 pulses per second. Total lasing time ranged from 1 minute 45 seconds to 4 minutes. A non-lased cementum sample served as the control. All spectra were recorded from 4000 to 400 cm-1 using the photoacoustic cell attachment on an Analect RFX-65 FTIR Spectrometer. Photoacoustic FTIR spectra of lased cementum samples showed a decrease in the protein/mineral ratio in comparison to the control. Breakdown of protein at the root surface potentially contributed to an ammonium band at 2010 cm-1. The decreased protein/mineral ratio and the potential surface contamination with protein by-products, may ultimately affect cell reattachment at the cementum surface. <56> 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. <57> UI - 92321033 AU - Aso S IN - Department of Ophthalmology, Nihon University School of Medicine, Chiyoda-ku, Japan. TI - [Histopathology of retinochoroidal adhesions of diode laser endophotocoagulation lesions in monkey eyes]. [Japanese] SO - Nippon Ganka Gakkai Zasshi - Acta Societatis Ophthalmologicae Japonicae 1992 May;96(5):620-7 AB - Retinochoroidal coagulation effect of 810 nm diode laser was studied using monkey eyes to determine the energy necessary to produce retinochoroidal adhesion safely. Power settings were at 100, 200 and 300 mW. The lesions produced with a power of 100 mW were faint grayish spots. One month after photocoagulation, there was degeneration from the outer granular layer to the superficial choroidal layer. However, chorioretinal adhesion was not obtained due to external limiting membrane formation. The lesions produced with a power of 200 mW were characterized by small whitish spots surrounded by grayish rings and retinochoroidal adhesions were produced by proliferated cells. However choroid were intensely coagulated, and there was a rupture of Bruch's membrane in one lesion. The lesions produced with a power of 300 mW were intense white spots surrounded by grayish rings. Histologically, severe cell loss of the retina was seen and three was no retinochoroidal adhesion. It can be said that it is difficult for 810 nm diode laser to obtain adequate retinochoroidal adhesion safely. <58> UI - 92331080 AU - Schupbach P AU - Lutz F AU - Guggenheim B IN - Department of Oral Microbiology, Dental Institute, University of Zurich, Switzerland. TI - Human root caries: histopathology of arrested lesions. SO - Caries Research 1992;26(3):153-64 AB - The histopathology of arrested root caries lesions was examined in extracted human teeth. The main structural characteristics of arrested lesions were the completely mineralized surface area and the formation of a distinct sclerosis of the dentinal tubules. Intertubular dentin was, with the exception of the dentinal tubules, fully mineralized up to the surface. Dentinal tubules near the surface were either filled with ghosts of microorganisms or with crystals of different shapes. Sclerosis of the dentinal tubules was characterized by the presence of three different patterns of intratubular mineralization that occur in distinct regions of the zone of tubular sclerosis. The patterns were distinguishable by the type of crystals and their association with organic structures such as collagenous fibrils or odontoblast processes. It is suggested that arrested lesions are based on (1) the formation of an inner barrier that interrupts the diffusion of substrata from the pulp to invaded bacteria, (2) the formation of an outer barrier by a compact, highly mineralized surface region which blocks the diffusion of products of bacterial metabolism into dentin, and (3) an area of mineralization which extends from the outer barrier toward the root canal within demineralized dentin. The present study demonstrates the considerable potential of caries lesions in dentin to become arrested, and subsequently partially remineralized. These phenomena seem to depend on the severity of an active lesion and its location on the root surface. This should be taken into account when diagnosing root caries lesions. The potential of root caries lesions to become arrested indicates that the treatment concept of active root caries lesions should be reconsidered. <59> UI - 92331081 AU - Anic I AU - Vidovic D AU - Luic M AU - Tudja M IN - Department of Dental Pathology, University of Zagreb Dental School, Croatia. TI - Laser induced molar tooth pulp chamber temperature changes. SO - Caries Research 1992;26(3):165-9 AB - Temperature changes in enamel tissue and the pulp chamber under the influence of a CO2 laser were measured by direct methods in vitro. X-ray diffraction analysis revealed alpha-Ca3(PO4), the high-temperature modification of enamel hydroxyapatite, thus indicating that the enamel melting temperature was above 1,000 degrees C in the interaction area of laser (continuous wave, 15 s exposure time, 1 mm spot size) and tissue. Powers of 0.5 and 1 W (continuous wave), 1.5 mm spot size, and 10 s exposure time vaporize and carbonize dentin tissue at the cavity bottom of class I preparation molars. The observed temperature rise of 4 degrees C indicates that thermal injury to the pulp tissue does not occur. <60> UI - 92276605 AU - Stephen KW AU - Damato FA AU - Strang R IN - Department of Oral Medicine and Pathology, University of Glasgow Dental Hospital and School, Scotland. TI - An in situ enamel section model for assessment of enamel re/demineralization potential. SO - Journal of Dental Research 1992 Apr;71 Spec No:856-9 AB - An enamel-section-carrying intra-oral appliance to predict the results of double-blind anti-caries studies has been developed. Initial validation was against the F concentration effect attained in a clinical trial where three sodium monofluorophosphate (SMFP) dentifrices were used. Original appliance-based work showed significant differences in remineralization between non-F and F dentifrices, but not between different F dentifrices. However, it was shown later that acidified gel-prepared lesions were not as responsive as solution-prepared lesions to de- and remineralizing processes, and lesion remineralization rates were found to be dependent on initial lesion size. An in situ cross-over study was then repeated with use of acid-solution-created lesions, and seven volunteers completed the project. Each brushed twice daily x 2 min with either 0, 1000, or 2500 ppm F, as SMFP dentifrice. After a two-week wash-out, subjects wore the appliances for four weeks. Enamel mineral content was assessed at 0, two, and four weeks via microradiography/microdensitometry, and a statistically significant dose-response was obtained between non-F and F as well as between 1000 and 2500 ppm F pastes, i.e., as per the three-year clinical trial data. Hence, the model's suitability for pre-clinical screening was confirmed. It has also been used in caries microbiological studies, in root caries investigations, and currently in chewing gum cariogenicity experiments. <61> UI - 92276603 AU - Heaven TJ AU - Firestone AR AU - Feagin FF IN - University of Alabama School of Dentistry, Birmingham, Alabama 35294. TI - Computer-based image analysis of natural approximal caries on radiographic films. SO - Journal of Dental Research 1992 Apr;71 Spec No:846-9 AB - This paper reports on the development of computer software for automatic detection and measurement of approximal caries lesions on digital images obtained from radiographic films. If the program detects a lesion, it defines the lesion's border and measures and reports these lesion parameters: percent mineralization, area, maximum enamel penetration, and mean enamel penetration. Two experiments are reported; both were conducted with the use of extracted human premolar teeth. In the first experiment, thin sections were obtained from 13 approximal surfaces with caries lesions. Microradiographs were made of the sections, and software measurements of the lesions were obtained from the microradiographs. The software was able to separate the lesions into two groups: those that had penetrated less than 100% of the enamel and those that had penetrated 100% of the enamel. The software measurements agreed with evaluation of lesion penetration by polarized light microscopy of the thin sections. In the second experiment, simulated clinical radiographs were made of 16 approximal surfaces, 12 with lesions and four without. Thin sections were obtained for microradiography. Software was used for automatic detection and measurement of the lesions on both types of film. The ability of the software to detect the lesions on the clinical films was compared with that of 10 experienced clinicians. Correlations of the same parameter from the two types of radiographic films were statistically significant, 0.86 less than or equal to r less than or equal to 0.95 and p less than 0.05. The coefficients of variation were low for both microradiographs, 0.4-2.3%, and for clinical films, 0.7-8.5%.(ABSTRACT TRUNCATED AT 250 WORDS) <62> UI - 92276599 AU - Corpron RE AU - More FG AU - Mount G IN - School of Dentistry, University of Michigan, Ann Arbor 48109-1078. TI - Comparison of fluoride profiles by SIMS with mineral density of subsurface enamel lesions treated intra-orally with a fluoride-releasing device. SO - Journal of Dental Research 1992 Apr;71 Spec No:828-31 AB - A variety of intra-oral model systems has evolved which allows for the study of remineralization of coronal and/or root-surface lesions following application of topical fluoride (F) agents. The problem of interpretation of the results has led to a variety of analytical methods (i.e., microhardness, F biopsy, microradiography, and polarizing light microscopy), each of which provides important but limited information related to the overall understanding of remineralization. Microhardness measures change in mineral content which is more precisely localized by microradiography and polarized light microscopy. F biopsy allows for assessment of the F uptake of lesions, but does not suggest the chemical state of the F. Previous work has demonstrated that patterns of mineral deposition during remineralization do not necessarily parallel the F uptake profiles, and fluoridated apatites cannot be distinguished from non-specifically-adsorbed F (Clark et al., 1988). Because artificial lesions demonstrate variations in depth and mineral content, complementary analytical methods that demonstrate profiles of both F content and mineral density curves on the same section are needed so that the process of remineralization can be more clearly understood. This study used secondary ion mass spectrometry (SIMS) for F profiles and quantitative microradiography for assessment of mineral deposition on the same section. These state-of-the-art methods demonstrate the precision with which information about remineralization can be obtained. Subsurface lesions in human enamel specimens were developed by immersion in 0.1 M lactate buffer with 1% CMC at a pH of 4.5 for 48 h.(ABSTRACT TRUNCATED AT 250 WORDS) <63> UI - 92276598 AU - Koulourides T AU - Chien MC IN - Department of Diagnostic Sciences, University of Alabama, School of Dentistry, Birmingham 35294. TI - The ICT in situ experimental model in dental research. SO - Journal of Dental Research 1992 Apr;71 Spec No:822-7 AB - The intra-oral cariogenicity test (ICT) in situ experimental model was introduced in 1964 for the study of caries on sample enamel in the human mouth. Slabs of human or bovine enamel are mounted with a Dacron gauze cover in the acrylic flanges of prosthetic appliances. The extent of enamel demineralization or remineralization of lesions is assessed from surface microhardness measurements and microradiography of the enamel sections. The ICT model offers the potential of studying various parameters related to caries. This publication presents a typical ICT study comparing the cariogenicity of 10% sucrose solutions containing 1, 3, 10, and 30 ppm F with that of the control solution, 10% sucrose (without fluoride). The treatments were applied to the ICT as 10-minute extra-oral immersions. The results indicate: (1) a strong effect of F in decreasing demineralization of sound enamel and increasing remineralization of pre-softened enamel in the ICT; (2) pronounced resistance to a subsequent in vitro acid test; (3) pronounced F incorporation into pre-softened enamel; and (4) a characteristic acid-resistant zone, as seen in microradiographs, associated with exposure to F. This in situ model enables one to study experimental caries with repeated testing of enamel that follows the development and/or the regression of subsurface enamel lesions, F incorporation, increased acid resistance, cariogenicity of substrates, and other parameters of caries that can be assessed under standard conditions of tooth substrate and microbial sheltering. <64> UI - 92276595 AU - Schafer F AU - Raven SJ AU - Parr TA IN - Unilever Dental Research, Port Sunlight Laboratory, Wirral, Merseyside, United Kingdom. TI - The effect of lesion characteristic on remineralization and model sensitivity. SO - Journal of Dental Research 1992 Apr;71 Spec No:811-3 AB - A major criterion for assessing the value of any experimental model in scientific research is the degree of correspondence between its results and data from the real-life process it is designed to model. Intra-oral models aimed at predicting the anti-caries efficacy of toothpastes or other topical treatments should therefore be calibrated against treatments proven to be effective in a caries clinical trial. For this to be achieved, it is necessary that a model with high sensitivity be designed, while at the same time retaining relevance to the process to be modeled. This means that the effects of the various experimental conditions and parameters of the model on its performance must be understood. The purpose of this paper was to assess the influence of two specific factors on the performance of an in situ enamel remineralization model, which is based on human enamel slabs attached to partial dentures. The two factors are initial lesion severity and origin of enamel sample. The results indicated that initial lesion size affected whether net remineralization or net demineralization occurred during in situ treatment. Samples with an initial range of from 1500 to 2500 (delta Z) tended more toward demineralization than did samples with delta Z greater than 3500. This means that treatment groups must be well-balanced with respect to initial lesion size. Differences in initial demineralization severity between different tooth locations must also be considered so that systematic treatment bias can be avoided. The solution used in the model discussed here is based on a balanced experimental design, which allows this effect to be taken into account in the data analysis. <65> UI - 92274252 AU - Crawford PR TI - Lasers--the new wave in dentistry. SO - Journal / Canadian Dental Association. Journal de l Association Dentaire Canadienne 1992 Apr;58(4):297-301 <66> UI - 92242629 AU - Chow LC AU - Takagi S AU - Shih S IN - American Dental Association Health Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, Maryland 20899. TI - Effect of a two-solution fluoride mouthrinse on remineralization of enamel lesions in vitro. SO - Journal of Dental Research 1992 Mar;71(3):443-7 AB - A previous study showed that a two-solution fluoride (F) rinse deposited significantly more loosely-bound F on the tooth surface than did a sodium fluoride (NaF) rinse with the same F concentration (12 mmol/L). In the present study, this experimental rinse was evaluated for its ability to cause remineralization of enamel lesions in an in vitro pH-cycling model. Caries-like lesions were formed in the enamel of extracted human molars by means of a pH 4 demineralizing solution. Fifty-one approximately 120-microns-thick sections containing lesions were randomly divided into (1) control, (2) NaF rinse, and (3) two-solution F rinse groups. With the cut surfaces protected, the control samples were immersed in a pH 7 remineralizing solution for 12 days, and twice daily the sections were also exposed to a pH 4 demineralizing solution for 30 min. Samples in the NaF group received an additional one-minute rinse with a NaF (12 mmol/L) solution twice daily. Samples in the two-solution rinse group received the rinse treatment with a 12 mmol/L F solution prepared by combination of a Na2SiF6 and phosphate-containing solution with a calcium solution just before use. The mineral contents of the lesions were assessed by quantitative microradiography. The results showed that (1) no significant de- or remineralization was detected in the controls; (2) a 46% decrease in mineral loss (delta Z) of the lesion was produced by the NaF rinses; and (3) a 94% decrease in delta Z and a 20-microns-thick, mineral-dense surface-coating were produced by the two-solution F rinse treatment. <67> UI - 92214427 AU - Ogaard B AU - Rezk-Lega F AU - Ruben J AU - Arends J IN - Department of Orthodontics, Dental Faculty, University of Oslo, Norway. TI - Cariostatic effect and fluoride release from a visible light-curing adhesive for bonding of orthodontic brackets. SO - American Journal of Orthodontics & Dentofacial Orthopedics 1992 Apr;101(4):303-7 AB - This study was designed to investigate the cariostatic potential in vivo of a visible light-curing adhesive for the bonding of orthodontic brackets. The fluoride release of the adhesive in water and saliva was also measured. Ten orthodontic patients with premolars to be extracted participated. One bracket with Heliosit-Orthodontic (no fluoride) was positioned on the buccal surface of one premolar (control), and another bracket with Orthodontic cement VP 862 (containing fluoride) was positioned on the experimental contralateral premolar. The adhesives were cured with a Heliolux II lamp, and the teeth were extracted after 4 weeks. The patients used a fluoride toothpaste during the experiment. The mineral content of the enamel adjacent to the brackets was determined by quantitative microradiography. The fluoride release from disk-shaped plates of the fluoride adhesive was measured in water for a 6-month period and in human saliva for 24 hours. The fluoride adhesive reduced lesion depths by about 48% than the nonfluoride adhesive (P less than 0.05, t test). The largest release of fluoride from the plates in water was observable within the first week. However, a significant amount of fluoride was still released after 6 months. The fluoride release in saliva was significantly lower in human saliva at pH 7 than in water (P less than 0.01, t test). When salivary pH was lowered to 4, to mimic a cariogenic challenge, the amount of fluoride released increased up to the value measured in water. It was concluded that the regular use of fluoride toothpastes is insufficient to inhibit lesion development around orthodontic brackets.(ABSTRACT TRUNCATED AT 250 WORDS) <68> 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] <69> UI - 92233445 AU - Lammers PC AU - Borggreven JM AU - Driessens FC AU - van 't Hof MA IN - Biochemistry MF, Trigon, Catholic University, Nijmegen, The Netherlands. TI - Acid-susceptibility of lesions in bovine enamel after remineralization in the presence of fluoride and/or carbonate. SO - Caries Research 1992;26(1):1-7 AB - After de- and subsequent remineralization at 0.03 and 1.0 ppm fluoride and either 0, 1, 10, 20 or 25 mM carbonate, artificial lesions in bovine enamel were demineralized again. The amount of secondary demineralization was determined after 15, 30 and 70 h of demineralization by means of quantitative microradiography. The results showed that fluoride incorporated during the remineralization period retards lesion formation during secondary demineralization. Carbonate incorporated during the remineralization period enhances secondary demineralization. An interaction between both ions was observed. <70> UI - 92233447 AU - Arends J AU - Christoffersen J AU - Christoffersen MR AU - Ogaard B AU - Dijkman AG AU - Jongebloed WL IN - Laboratory for Materia Technica, Groningen, The Netherlands. TI - Rate and mechanism of enamel demineralization in situ. SO - Caries Research 1992;26(1):18-21 AB - In this paper, data are presented on the in situ demineralization of human enamel as a function of the demineralization period. To quantify the mineral loss parameters versus time, it is important to obtain information on the kinetics, and thus on the mechanism of dental caries. The results show that for in situ enamel demineralization, the lesion depth as well as the mineral loss parameter both vary linearly with the demineralization time. This is in contrast to in vitro lesion formation where the third power, or the square power of the lesion depth is linearly related to the demineralization time. In in situ demineralization, the rate-determining step of the demineralization process is the inhibitor-controlled dissolution process at the enamel crystallite surfaces, while the inhibitor content (F-, proteins etc.) in the lesion originating from the plaque, saliva and enamel is high. Furthermore, the study indicates that in in situ demineralization, interprismatic mineral loss is very important. <71> 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. <72> UI - 92233457 AU - Lammers PC AU - Borggreven JM AU - Driessens FC IN - Biochemistry MF, Trigon, Catholic University, Nijmegen, The Netherlands. TI - Influence of fluoride and pH on in vitro remineralization of bovine enamel. SO - Caries Research 1992;26(1):8-13 AB - Subsurface lesions in bovine enamel slices were remineralized. The remineralization solutions contained either 0.03, 0.3, or 1.0 ppm fluoride at either pH 5.5 or 6.8. The amount of remineralization was determined after periods of up to 610 h, using quantitative microradiography. The results showed that after 126 h of remineralization in the presence of 0.03 ppm fluoride significantly (p less than 0.05) more remineralization occurred at pH 6.8 than at pH 5.5. At 0.3 and 1.0 ppm fluoride no significant differences between pH 5.5 and pH 6.8 were observed. An interaction between fluoride and pH was observed. The observed differences in the rates of remineralization are explained by the formation and subsequent transformation of the precursors octacalcium phosphate (pH 6.8) and brushite (pH 5.5) into (fluor)apatites. <73> UI - 92194181 AU - Tjan AH AU - Bergh BH AU - Lidner C IN - Department of Restorative Dentistry, Loma Linda University, School of Dentistry, Calif. TI - Effect of various incremental techniques on the marginal adaptation of class II composite resin restorations. SO - Journal of Prosthetic Dentistry 1992 Jan;67(1):62-6 AB - The effects of various placement techniques on the formation of microgaps were compared at the gingival margins of class II composite resin restorations. Three incremental techniques (occlusogingival layering, oblique layering, and faciolingual layering) and two one-bulk techniques of placing composite resin were studied. In the first one-bulk placement technique the composite resin was photocured occlusally; in the second one-bulk technique the composite resin was irradiated from three directions; facial, lingual, and occlusal. None of the incremental placement techniques improved the adaptation at the gingival margin compared with a one-bulk technique irradiated occlusally. However, the one-bulk placement technique that was irradiated from three directions created a substantial marginal discrepancy. <74> UI - 92156432 AU - Tsanidis V AU - Koulourides T IN - Department of Pediatric Dentistry, University of Alabama School of Dentistry, Birmingham 35294. TI - An in vitro model for assessment of fluoride uptake from glass-ionomer cements by dentin and its effect on acid resistance. SO - Journal of Dental Research 1992 Jan;71(1):7-12 AB - This investigation presents an experimental model for studying interactions of glass-ionomer cements (GICs) with bovine dentin slabs. Fluoride incorporation was studied with five serial abrasion biopsies, each being approximately 10 microns thick. The time of interaction was a very important parameter, indicating continuous fluoride release from the GIC and diffusion into dentin over a 30-day period. Expressed in mass per volume (mg F/cm3), the fluoride incorporation reached 12.0 mg at the first and 2.5 mg at the fifth layer, several times greater than the baseline of 0.27 mg/cm3 in bovine dentin. A subsequent test of acid resistance in a lactic acid buffer (pH 4.0), followed by microradiography of lesions, showed a characteristic 40-microns-wide acid-resistant zone on surfaces exposed to the GICs. In contrast, the untreated control surfaces had lesions demineralized evenly from the surface to the intact tissue, without the higher-density zone at the surface of the lesion. The model seems promising for screening fluoride incorporation into dentin from fluoride-releasing dental materials. <75> UI - 93170552 AU - Pitts NB IN - Department of Dental Health, University of Dundee, UK. TI - The diagnosis of dental caries: 2. The detection of approximal, root surface and recurrent lesions. SO - Dental Update 1991 Dec;18(10):436-8, 440-2 AB - The range of diagnostic techniques used to detect and monitor dental caries which are available to practitioners has broadened in recent years. Following the consideration of the assessment of caries in buccal, lingual and occlusal surfaces in the first article in this series, this second article gives a description of the diagnostic methods currently employed in the detection of primary caries in approximal and root surfaces as well as those used for recurrent lesions. The third paper will discuss the rationale for the use of these techniques and provide an overview of present and potential future diagnostic techniques. <76> UI - 92312425 AU - Levy G IN - Loma Linda University, California. TI - A new laser for soft and hard tissue applications. SO - Alpha Omegan 1991;84(4):51-2, 54 AB - Several new features of this Nd-Yag laser make it ideal for hard and soft tissue applications. Examples are given for treatment of pits and fissures, endodontics, surgery, and soft tissue applications. <77> UI - 92312391 AU - Anic I AU - Pavelic B AU - Vidovic D IN - Stomatoloskog Fakulteta Sveucilista u Zagrebu. TI - [Possibility of the application of CO2 laser in the prevention of demineralisation of the enamel]. [Serbo-Croatian (Roman)] SO - Acta Stomatologica Croatica 1991;25(2):103-8 AB - Tooth enamel laser irradiated under certain conditions previously has been shown to have reduced subsurface demineralizations rate. The teeth were cut vertically in half with a thin diamond disc. One half of each tooth served as a control and the other half was irradiated using the CO2 laser. Laser energy was applied at incisive labial surface (15 W, 0.5 s, spot size 3.5 mm). After irradiation the specimens were coated with wax leaving only the windows 3 x 3 mm on the labial surfaces. After experimental demineralisation with 0.2 M sodium acetate and 0.1 M lactic acid solution for 10 days, dissolved calcium and phosphorus were analyzed in the demineralizating solutions using atomic absorption spectrophotometry and colorimetric method (method described by Lowey), respectively. Ca and P concentrations in demineralizing solutions per unit surface area were lower then the controls. <78> UI - 92289542 AU - Frentzen M AU - Koort HJ IN - Klinik und Poliklinik fur Zahn-, Mund- und Kieferheilkunde der Universitat Bonn. TI - [Laser technology in dentistry]. [Review] [116 refs] [German] SO - Deutsche Zahnarztliche Zeitschrift 1991 Jul;46(7):443-52 AB - Although dental laser treatment is receiving great attention in basic and clinical research, only very few clinical applications have emerged as accepted standard methods. The most promising range of possible applications includes diagnostics and surgery. Most laser systems developed for therapeutic use are heat-producing units, i.e. they convert electromagnetic energy into thermal energy. These systems are employed above all in oral surgery for vaporization, cutting or coagulation of soft tissues and in prosthodontics for welding. More recently, new types of lasers have been developed allowing non-thermal modes of tissue interaction. A great number of technical and biological problems will have to be solved, however, before these laser systems will be practically applicable in such clinical fields as, for instance, caries therapy. In the near future, laser systems are expected to complete and supplement conventional methods in diagnosis and treatment, but not to replace them. [References: 116] <79> UI - 92289507 AU - Raab WH AU - Rosiwal SM AU - Reithmayer K AU - Bergmann HW IN - Poliklinik fur Zahnerhaltung und Parodontologie, Zahn-, Mund- und Kieferklinik Erlangen. TI - [Difference reflectometry might permit process control for dental laser applications]. [German] SO - Deutsche Zahnarztliche Zeitschrift 1991 Nov;46(11):729-33 AB - Difference reflectometry is a new method for assessing material surfaces by measuring the relative amount of light reflected within a range of 300-720 nm. The in vivo and in vitro results of the present study indicate that it is possible to transfer this measuring principle to dental applications. Reflexion measurements allow the detection of hard tooth structures and their pathologic alterations with adequate exactness. With the aid of this method it is possible to differentiate between carious hard tissues and clinically healthy tissues by color and surface structure during excavation. It also allows a reliable demarcation from oral soft tissues. Due to its high measuring frequency it may be used as on-line process control. In contrast to other spectrometric methods it requires a minimum of equipment and is easy to handle. <80> UI - 92266921 AU - Reinhardt KJ IN - Zentrum fur Zahn-, Mund- und Kieferheilkunde, Munster. TI - [Effect of the light source on the marginal adaptation of composite fillings]. [German] SO - Deutsche Zahnarztliche Zeitschrift 1991 Feb;46(2):132-4 AB - The marginal situation of class I restorations is determined by the intensity of the light used for curing. In all composites the use of an intensive light-source (Osram HBO 100) leads to marginal gaps. This effect was demonstrated in three composites cured with light sources that are commonly used in practice. <81> UI - 92259732 AU - el-Mowafy OM AU - Brown JW AU - McComb D IN - Restorative Department, Faculty of Dentistry, University of Toronto, Ontario, Canada. TI - Radiopacity of direct ceramic inlay restoratives. SO - Journal of Dentistry 1991 Dec;19(6):366-8 AB - The radiopacity of two new ceramic restorative materials (Dicor MGC and Cerec Vita Blocks) manufactured for use in producing direct inlays with the 'Cerec CAD-CAM' system was determined. Dicor MGC had a radiopacity significantly greater than that of enamel, while Cerec Vita Blocks had a radiopacity significantly less than that of dentine. It is concluded that Dicor MGC has a radiopacity suitable for its use as an intracoronal restorative for posterior teeth. The low radiopacity of Cerec Vita Blocks means that the use of radiopaque luting cement is essential to permit detection of secondary caries around restorations of this material. Furthermore, marginal overhangs around restorations made from Cerec Vita Blocks will be difficult to detect radiographically. <82> UI - 92235592 AU - Friedman S AU - Rotstein I AU - Koren L AU - Trope M IN - Department of Endodontics, Hebrew University--Hadassah School of Dental Medicine, Jerusalem. TI - Dye leakage in retrofilled dog teeth and its correlation with radiographic healing. SO - Journal of Endodontics 1991 Aug;17(8):392-5 AB - In a previous study in beagle dogs, statistically significant differences in healing were observed radiographically 6 months after apicoectomy and retrofilling with amalgam and varnish, glass ionomer cement, or a composite resin. The purpose of this study was to compare the leakage of these retrofilling materials and to correlate leakage data with healing. After the dogs were sacrificed, 48 roots were extracted. Half of the roots had been irradiated with a CO2 laser on the bevelled root surface after retrofilling. The roots were coated with nail polish, except for their bevelled surface, and were suspended together with positive and negative controls in 2% methylene blue for 8 h. After the specimens were longitudinally split, they were ranked according to the severity of dye penetration, as observed with a dissecting microscope. The differences in dye leakage among the three retrofilling materials were not statistically significant. Consequently, dye leakage did not correlate with the previously assessed healing. Dye penetrated into the root through the bevelled root surface, regardless of CO2 laser exposure of that surface. <83> UI - 92188378 AU - Sluzhaev IF AU - Prokhonchukov AA AU - Kuzakova GM TI - [The effect of laser light on dental caries intensity in children]. [Russian] SO - Stomatologiia 1991 Sep-Oct;(5):73-4 <84> UI - 92142127 AU - Kunin AA AU - Kharin OV TI - [The use of a fluoride varnish and helium-neon laser light in preventing caries of the deciduous teeth]. [Russian] SO - Stomatologiia 1991 Jul-Aug;(4):71-2 <85> UI - 92129726 AU - Lammers PC AU - Borggreven JM AU - Driessens FC IN - Biochemistry MF, Trigon, The Netherlands. TI - Acid-susceptibility of lesions in bovine enamel after remineralization at different pH values and in the presence of different fluoride concentrations. SO - Journal of Dental Research 1991 Dec;70(12):1486-90 AB - Artificial caries lesions were created in sound bovine enamel slices demineralized at pH 5.0. The lesions were then remineralized at either pH 5.5 or pH 6.8 in solutions containing either 1.5, 15, or 50 mumol/L fluoride. The remineralized slices were then demineralized at pH 5.0 for investigation of acid-susceptibility by means of quantitative microradiography. The results indicated that fluoride, incorporated during the preceding remineralization, had a retarding effect on the demineralization after remineralization, and that for the lowest concentration of fluoride in the remineralizing solution, the inhibitory influence of fluoride depended on the pH of the remineralization solutions used. <86> UI - 92111232 AU - Verdonschot EH AU - Bronkhorst EM AU - Wenzel A IN - TRIKON, Department of Cariology and Endodontology, Faculty of Medicine and Dentistry, University of Nijmegen, The Netherlands. TI - Approximal caries diagnosis using fiber-optic transillumination: a mathematical adjustment to improve validity. SO - Community Dentistry & Oral Epidemiology 1991 Dec;19(6):329-32 AB - Several studies were conducted recently to evaluate the use of Fiber-Optic Trans-Illumination (FOTI) in the diagnosis of approximal carious lesions. All these studies utilized radiographic readings to validate the FOTI diagnoses. Other investigations studied the value of radiographic readings using more solid validating techniques, which made it possible to judge the true state of decay, such as histology, cavity preparation and microradiography. In this study, data from both types of studies were used to estimate the validity of FOTI diagnosis of approximal caries relative to the true status of decay through correction for radiographic misclassification. The results indicate that particularly the sensitivity of FOTI diagnosis has yet to be determined. <87> UI - 92096536 AU - Heinrich R AU - Kunzel W AU - Tawfiq H IN - Wissenschaftsbereich Praventive Stomatologie, Sektion Stomatologie der Medizinischen Akademie, Erfurt, Bundesrepublik Deutschland. TI - [Ther diagnosis of approximal caries--a comparison of clinical, fiber optic and x-ray diagnostic procedures (the diagnosis of approximal caries)]. [German] SO - Deutsche Zahn-, Mund-, und Kieferheilkunde Mit Zentralblatt 1991;79(7):535-42 AB - A comparison of the efficiency of fibre-optic transillumination with clinical and radiographic diagnosis of proximal caries in posterior teeth was carried out on 186 subjects aged 12 to 17 years. The proportion of diagnosed proximal lesions detected by fibre-optic transillumination was two times more often than by clinical examination while the increase in lesion detection by bitewing radiography was more than threefold. Taking radiographic diagnosis as the validating criteria, the sensitivity of clinical examination was 0.30 and of fibre-optic transillumination 0.68 resp. The specificity was 0.99 for both examinations. In patients with low prevalence of proximal caries and good preventive dental care fibre-optic transillumination should be used as an additional method before using of regular radiographic diagnosing of proximal caries. <88> UI - 92094798 AU - Mishen'kin NV AU - Krotov IuA TI - ["Closed" curative surgery and laser therapy in the early postoperative period in patients with chronic suppurative epimesotympanitis]. [Russian] SO - Vestnik Otorinolaringologii 1991 Sep-Oct;(5):31-6 AB - Taking into account the severity of middle ear pathology and the Eustachian tube function, three methods of "closed" surgery were applied to 132 patients with chronic purulent-caries epimesotympanitis. On post-operation days 2-15, 85 patients were exposed to internal or external laser therapy. As a result, the post-operation therapy period was 5-6 days shorter and the healing quality of the treated ear a year after was better than in the absence of laser therapy. It is concluded that the method of "closed" surgery should be chosen on an individual basis and that its combination with early post-operation laser therapy yields good results. <89> UI - 92094310 AU - Ogaard B AU - Rolla G AU - Dijkman T AU - Ruben J AU - Arends J IN - Department of Orthodontics, Dental Faculty, University of Oslo, Norway. TI - Effect of fluoride mouthrinsing on caries lesion development in shark enamel: an in situ caries model study. SO - Scandinavian Journal of Dental Research 1991 Oct;99(5):372-7 AB - Shark enamel consists of nearly pure fluorapatite and has been shown to demineralize in an in situ caries model. The present study was conducted to investigate whether additional fluoride supplementation in the form of mouthrinsing would inhibit lesion development in shark enamel. The study slabs of shark enamel were mounted in dental appliances. Six individuals wore the appliances while rinsing daily with a neutral 0.2% NaF solution for 4 wk. The specimens were analyzed by means of quantitative microradiography, and the data compared with a previous study using untreated shark enamel and the same participants. It was found that fluoride rinsing did not measurably inhibit enamel demineralization in 4 wk. Scanning electron microradiographs showed that calcium fluoride-like material was not formed on shark enamel after neutral fluoride treatment, supporting a previous study. The present study indicates, therefore, that formation of a calcium fluoride-like material on the enamel surface may be essential for the cariostatic effect of topical agents. <90> UI - 92094309 AU - Hals E IN - Department of Cariology and Endodontics, Dental Faculty, University of Bergen, Norway. TI - Column-like structures of human dentin in carious and artificial lesions. SO - Scandinavian Journal of Dental Research 1991 Oct;99(5):365-71 AB - Serial sections of 36 human teeth with minor to medium-sized carious lesions, adequate sections from previous studies of artificial lesions adjacent to fillings of amalgam (AM), silicate cement (SI) and glass ionomer cement (GI) were studied by ordinary light microscopy and microradiography. Six artificial primary root lesions were included. In carious lesions, dentin columns were visible in the demineralization zone and partly also in the translucent/radiopaque zone. A typical feature of the artificial lesions adjacent to SI fillings was highly radiopaque columns alternating with radiolucent ones. In the GI group such columns were seen at the cavity wall and the advancing front of the outer lesion. In the AM group dark columns were unveiled as pegs in the latter localization. The findings led to the assumption that the dark columns of intact dentin are preferred pathways of acid diffusion in artificial and, possibly, carious lesions. Increased radiopacity of columns in the SI and GI groups is explained by continued exposure of the tooth surface to fluoride dissolved from these fluoride-rich filling materials. <91> UI - 92083567 AU - Verdonschot EH AU - van de Rijke JW AU - Brouwer W AU - ten Bosch JJ AU - Truin GJ IN - TRIKON, Department of Cariology and Endodontology, Faculty of Medicine and Dentistry, University of Nijmegen, The Netherlands. TI - Optical quantitation and radiographic diagnosis of incipient approximal caries lesions. SO - Caries Research 1991;25(5):359-64 AB - The objectives of this study were to test the applicability of photocell