Search

OBJECTIVE: To evaluate the effectiveness of ultrasound on measuring the thickness of enamel in abrasion. STUDY DESIGN: Flat areas on occlusal surfaces of 20 premolar teeth were marked. Two initial ultrasonic measurements on marked areas were obtained by the first researcher. Then the tooth was measured in the axial direction with a compass. The cusp tips were abraded by an abrasive paper, then the second and third ultrasonic measurements were taken. The second researcher repeated the third ultrasonic measurement to evaluate the interobserver variation. All specimens were sectioned and the remaining enamel thickness was measured under polarized light microscope. RESULTS: Pearson's correlation analysis showed a high level of intraobserver agreement for the ultrasonic measurements of the first researcher (r = .891, P < .000 initial; r = .690, P < .001 first abrasion; r = .885, P < .000 second abrasion). Third ultrasonic measurements of the first and second researchers were positively and significantly correlated with histological readings (r = .966, P < .000; r = .466, P = .039). CONCLUSIONS: The ultrasonic system used in this study was reliable in measuring enamel thickness. [ABSTRACT FROM AUTHOR]

In the spring of 1996, foods and beverages most commonly consumed by adolescents were analyzed for fluoride as part of a larger investigation. These foods were selected by interviewing 711 adolescents, 12-14 years of age, who were long-time residents of either an optimally or negligibly fluoridated community. The brand names of the identified foods and beverages most commonly purchased were determined by interviews with the parents. A total of 441 brand-name food and beverage items were purchased from both communities and were individually analyzed for fluoride. These analyses were done in order to estimate the fluoride content of various kinds of foods and beverages and to determine whether or not there was a significant difference between the two communities in the amount of fluoride ingested from these dietary sources. The food and beverage items were classified into dietary groups based on US Department of Agriculture (USDA) guidelines. Overall, the fluoride content of the sampled foods and beverages was low. In addition, there was no significant difference in the fluoride content of the same pre-packaged or ready-to-eat food or beverage items purchased in the two communities. However, a significant difference was found between the two communities in the fluoride content of fountain beverages and in cooked or reconstituted foods prepared using local water from the respective communities. Based on these results, we have estimated the mean daily, dietary fluoride intake for 3-5-year-old children who are more susceptible to developing dental fluorosis. [ABSTRACT FROM AUTHOR]

Tooth minerals are lost and regained constantly in a normal, human oral environment. Different methods have been developed to measure this gain and loss in enamel minerals; however, these methods deal with different problems, such as being time consuming or involving the use of X-rays. The aim of this study was to determine if remineralization measured in a thin enamel section (TS) by transversal microradiography (MR) can be reliably monitored by measuring lesion parameters (area, total and average dye fluorescence) on the same TS or on half a tooth (HT) with confocal laser scanning microscopy (CLSM). Thirty-six human enamel specimens were demineralized for 96h, and then half of each specimen was covered with an acid-resistant nail varnish. Specimens were divided into three groups (12/group) and subjected for 20 days to a cyclic remineralization regimen with consisted daily of a 4-hour acid challenge, four 1-min treatment periods with 0, 250 or 1,100 ppm F dentifrice slurries (1:2; dentifrice:water) and 20 h in pooled, human saliva, at room temperature. Specimens were cut and analyzed by MR, then stained with a fluorescent dye (0.1mM rhodamine B) for 1 h and analyzed using CLSM. Both MR and CLSM detected significantly greater remineralization (p<0.05) in the specimens treated with the fluoride-containing dentifrices than in the specimens treated with 0 ppm F. Significant differences were detected between specimens treated witht the fluoride-containing dentifrices by MR and CLSM (HT area and total fluorescence). Statistically significant (p<0.05) Pearson correlation coefficients were calculated between the MR and CLSM data: difference in MR mineral content (DeltaM) versus HT lesion area = 0.71; DeltaM versus HT total fluorescence = 0.70; DeltaM versus HT average fluorescence = 0.61; DeltaM versus TS lesion area = 0.88; DeltaM versus TS total fluorescence = 0.63, and DeltaM versus TS average fluorescence = 0.40. It is concluded that confocal microscopy in either TS or HT may provide valid surrogates (area and total fluorescence) for MR measurements in enamel remineralization studies. [ABSTRACT FROM AUTHOR]

It has been demonstrated that when excited by laser light carious enamel appears dark compared to luminescent sound enamel. The aim of this study was to compare the sensitivity and specificity of visual exams (V), laser fluorescence (LF) and dye-enhanced LF (DELF) for detecting demineralization in occlusal pits and fissures. The actual presence of lesions was determined by subsequent confocal laser microscopy (CM), which was compared to histology (H). Independent clinical examiners visually graded three sites on occlusal surfaces of extracted, human premolars as sound or carious and also rated the color of each graded site as: 0 = same as surrounding enamel; 1 = white; 2 = light brown, or 3 = brown/dark brown. An argon laser was used to illuminate the teeth for LF and DELF; the images were captured with a CCD camera and then analyzed. DELF images were captured after the teeth had been exposed to 0.075% sodium fluorescein. Sections were then cut from each specimen and analyzed by CM and H for the presence or absence of caries. Results showed that DELF (0.72) was significantly more sensitive (p<0.05) than LF (0.49) and V (0.03) for detecting caries, but there were no significant differences among the methods in specificity (V 1.00; LF 0.67; DELF 0.60). When color was used as an indication of caries in V (VC, sensitivity 0.47; specificity 0.70), V exams were not different from LF. The area under the ROC curve, using H as the gold standard and CM as the test, was 0.78. Results indicated that DELF was the best diagnostic tool and that VC and LF were equally effective as diagnostic methods, when color of fissures was included as an indication of demineralization in the visual exam. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the ability of quantitative light-induced fluorescence (QLF) to assess caries lesion activity using visual examination (VE) as the gold standard. Twenty-four visible white spot lesions on buccal surfaces were examined from 23 children, ages 9 to 14 years. At baseline, the surface was hydrated with water, and thereafter, it was dehydrated with continuous compressed air during image acquisition. QLF images were acquired at 0 (baseline), 5, and 15 s. QLF variables [ QLF V : fluorescence loss ( ? F ), lesion size (S), ? Q : ? F × S ] was recorded. Changes-in- QLF V per second ( ? QLF V ) were determined: ? QLF V = ( QLF VN ? QLF V Baseline ) / N , where N indicates dehydration time. One experienced dentist conducted VE independently using a dental unit’s light, compressed air, and explorer.

Purpose: To demonstrate the robustness of the Featherstone pH cycling model when tested in three independent laboratories and to evaluate the use of "non-inferiority" testing at those laboratories., Methods: The fundamental principles for the Featherstone laboratory pH cycling model to be an appropriate alternative to animal testing is that it must demonstrate equivalent accuracy to the "Gold Standard" (rat caries model) by: (1) providing a meaningful representation of the caries process; (2) demonstrating a proportionate response to fluoride dose (or concentration); (3) being able to show that clinically proven formulations perform similarly relative to the controls; and (4) differentiating products that have attenuated fluoride activity., Results: This cross-validation study confirmed the ability of the three independent laboratories to discriminate between various concentrations of fluoride-containing dentifrice formulations, demonstrated that clinically proven formulas perform as expected and identified an attenuated fluoride formulation (NaF/CaCO3 dentifrice - 1100 ppm NaF) as inferior compared to the 1100 ppm F (NaF/silica) positive control.

Purpose: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug products for over-the-counter human use", the toothpaste industry has been conducting animal caries tests on every fluoride-containing toothpaste introduced into the U.S. market since 1996. The practice of testing in animals, although required by law, is in stark conflict with the corporate policy of many U.S. and global toothpaste manufacturers, in which, if possible, alternatives to animal testing are utilized. A provision does exist within the regulation which allows the use of an alternative method to demonstrate efficacy. However, to take advantage of this provision, a petition must be submitted to the FDA and in this petition data demonstrating the alternative provides results of "equivalent accuracy" must be included. After many years of research, model development and model comparisons, we have identified one particular laboratory model that demonstrated excellent correlation with the currently accepted animal caries models. This model, known as the Featherstone pH cycling model, is discussed in this paper., Methods: The Featherstone pH cycling model has been shown to produce results of equivalent accuracy to the animal caries model by: (1) demonstrating a clinically relevant fluoride dose response similar to that shown in the animal caries model (including 1100 ppm F, 250 ppm F and placebo); (2) demonstrating similar results to the animal caries model for clinically proven dentifrice formulations relative to positive and negative controls; (3) demonstrating discriminating ability in strong agreement with the animal caries model for differentiating between a dentifrice formulation with attenuated fluoride activity and a USP standard; and (4) providing a clinically relevant representation of the caries process, as demonstrated by orthodontic banding studies. In addition, the model sufficiently addresses both salivary and abrasive/anticalculus agent interference concerns., Results: For more than 50 years, fluoride has been the first defense in the fight against dental caries. The clinical effectiveness of fluoride is well accepted and documented extensively in the literature. The mechanism through which fluoride provides its benefit is very straightforward and well understood. The proposed laboratory model effectively simulates the effect of the caries process and has been shown to demonstrate equivalent accuracy to animal caries. This indicates that there are strong scientific grounds for the use of this model as an alternative to the animal caries test. Based on the strength of the data and the correlations noted between the two models, we recommend that the scientific community and the toothpaste industry broadly accept the Featherstone laboratory pH cycling model as an appropriate alternative to animal testing, particularly for ionic fluoride based dentifrices.

The purpose of this study was to identify risk factors to predict caries progression in toddlers in primary-healthcare settings for the cost-effective targeting of preventive and referral strategies. We examined 329 children (26 ± 6 mos old) twice, one year apart, in Indiana, USA. A 107-item structured interview was used to collect information from the primary caregiver and child on factors/beliefs/perceptions/behaviors that could affect caries development, transmission of bacteria, medical-dental health, and access to care. Bacterial levels, gingivitis, dental plaque, and caries experience were assessed. Multiple-variable logistic regression models of caries progression toward cavitation included family caries experience, transmission-related behaviors, dietary factors, health beliefs, and lower income, but differed in selected predictors/predictive power by race/ethnicity. Addition of clinical variables did not significantly improve the prediction.

Background/aims: Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research., Methods: A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode., Results: Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies., Conclusion: The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values., (2010 S. Karger AG, Basel.)

Objectives: To estimate the prevalence of erosive tooth wear in children aged 12-17 years in the southwest region of San Antonio, Texas, within Bexar County., Methods: A convenience sample of 307 children aged 12-17 years was selected from two junior high schools. The population consisted predominantly of Hispanic Mexican Americans. The true prevalence of erosive tooth wear within the US is known from only one study, and then only for limited sectors of the population. The Tooth Wear Index, Screening for Oral Health using the Association of State and Territorial Dental Directors (ASTDD) criteria and oral health and dietary assessment questionnaires were used as survey parameters. The questionnaire included data on detailed dietary habits relating primarily to the consumption of acidic beverages and foods., Results: The overall prevalence of erosion within our convenience sample was 5.5 percent. All affected children showed erosive tooth wear low in severity and confined to the enamel with no exposed dentin. A chi-square test was performed to test for associations between the presence of erosion and consumption level of certain acidic foods at a significance level of 5 percent. Few significant and consistent associations were found between erosive tooth wear and consumption frequency categories of groups of acidic foods and beverages using a non-validated food intake questionnaire on purported risk foods. Soda drinks were associated. Mexican acidic foods were not., Conclusion: This study indicated a low prevalence and low severity of dental erosion in a convenience sample of children aged 12-17 years in southwest San Antonio, Texas. Issues of sampling and response bias preclude these findings being generalized to other populations and regions.The results should be viewed with caution. Because the local consumption of some purported risk foods appears to be increasing, this study provides a base-line for future assessments of erosive tooth wear in this population.

Purpose: To determine the fluoride dose response of experimental NaF dentifrices containing a prospective calcium phosphate technology, along with the corresponding relative enamel and dentin abrasion values., Methods: 3 mm diameter bovine enamel specimens were mounted, ground and polished, and softened in a carbopol-lactic acid solution (pH = 5.0) for 36 hours at 37 degrees C. Specimens were then measured for baseline Vickers microhardness and stratified (N = 18, mean VHN = 33) into eight groups. These groups consisted of a placebo paste, four test dentifrices (A, B, C, D) with three of the four (A, B, C) containing a promising calcium phosphate ingredient, Crest Cavity Protection, MI Paste Plus, and PreviDent Booster 5000. The groups were cycled in a lesion reversal pH cycling model consisting of four 2-minute treatment periods (diluted 1:3 with DI water) and one 4-hour acid challenge (carbopol-lactic acid, pH = 5.0) per day. Between these events, specimens were immersed in artificial saliva (pH = 7.0). After 20 days of cycling, the specimens were microdrilled and analyzed for fluoride content, and also measured for Vickers surface microhardness after 10 and 20 days of cycling and after a 2-hour and 16-hour post-cycle acid challenge (carbopol-lactic acid, pH = 5.0). Separately, relative dentin and enamel abrasion (RDA and REA) were performed using the ADA recommended radiotracer method., Results: A fluoride dose response was observed for the test dentifrices after 10 and 20 days of pH cycling, with test dentifrice C promoting the highest remineralization among the groups while both the MI Paste Plus and PreviDent systems provide the least remineralization (one-way ANOVA, SNK, P < 0.05). With respect to enamel fluoride uptake, the group facilitating the highest incorporation of fluoride into the enamel lesion was test dentifrice C, while the least effective NaF system was the MI Paste Plus (one-way ANOVA, SNK, P < 0.05). In terms of formulation abrasion, the REA scores were similar among the test dentifrices, MI Paste Plus, and PreviDent and compared favorably to the ADA reference material score (one-way ANOVA, SNK, P < 0.05); relative to the ADA reference material RDA score, the data indicate that MI Paste Plus was essentially non-abrasive, while PreviDent was significantly more abrasive to dentin (one-way ANOVA, SNK, P < 0.05). Altogether, these data show the developmental test dentifrices demonstrate a fluoride dose response and show great promise in remineralizing white-spot enamel lesions relative to MI Paste Plus and PreviDent.

This clinical investigation was conducted to evaluate the impact of a unique soft rawhide product on the formation of dental calculus in a housed colony of beagle dogs. The study was designed as a 2-way crossover test with 4-week test periods and a 1-week wash-out period between the test periods. All dogs were provided a dry commercial diet and tap water ad libitum. The dogs were stratified into two groups of matched pairs on the basis of their calculus and plaque formation rates. Each test period was initiated immediately following a complete supragingival scaling and crown polishing and the dogs in the test group received a soft rawhide treat about 4-hours after their normal feeding. Examinations were performed about 20 to 24-hours after the last feeding by an experienced clinical examiner using conventional indices. The data indicated that once daily feeding of the soft rawhide chew product resulted in statistically significant reductions in the formation of dental calculus (28.0%), dental plaque (19.0%), and gingivitis (46.0%).

Purpose: To determine the in vitro remineralization potential of a new calcium phosphate technology in a 1000 ppm F system., Methods: 3 mm diameter bovine enamel specimens were mounted, ground and polished, and softened in a carbopol-lactic acid solution (pH = 5.0) for 36 hours at 37 degrees C. Specimens were then measured for baseline Vickers microhardness and stratified (N = 10, mean VHN = 35) into the following groups: Group A: distilled water (negative control); Group B: MI Paste Plus (900 ppm F); Group C: Theramed SOS (1450 ppm F); Group D: "control" dentifrice (1000 ppm F); and, Group E: "test" dentifrice (1000 ppm F) admixed with a new functionalized calcium phosphate system. The groups were then cycled for 10 days in a pH cycling model consisting of four 2-minute treatment periods (diluted 1:3 with distilled water) and one 4-hour acid challenge (carbopol-lactic acid, pH = 5.0) per day. Between these events, specimens were immersed in artificial saliva (pH = 7.0). After 10 days of cycling, the specimens were measured for Vickers surface microhardness and were subsequently microdrilled, with the powder measured for fluoride content using a calibrated fluoride-sensitive electrode., Results: Significant differences resulted between the distilled water and fluoride-containing groups. Among the fluoride-containing groups, Group B demonstrated statistically low levels of enamel fluoride deposition and deltaVHN, while Group E statistically outperformed Group D. Among the groups with different calcium systems (Groups B, C, and E), Groups C and E were found to be statistically equivalent and superior to Group B with respect to both bioavailable fluoride and deltaVHN. Based on our results, these data demonstrated the combination of a new calcium phosphate technology plus 1000 ppm F, produced significantly greater remineralization relative to both the 1000 ppm F test dentifrice and MI Paste Plus, and was statistically equivalent to Theramed SOS.

Objective: The objective of this study was to evaluate the repeatability of 2 nondestructive caries detection methods, ultrasound (ULS) and DIAGNOdent, for the detection of approximal caries lesions, and to evaluate 2 tips provided for the DIAGNOdent., Study Design: White/brown-spot lesions (n = 42) were captured by a digital camera, and measured by test methods and confocal laser scanning microscope (CLSM). Intra- and inter-observer reliability, accuracy, and Cohen's kappa and Spearman's rho statistics were used., Results: At DIAGNOdent, intra-observer agreements were 78.5%, 66.7% for A tip and 59.5%, 47.6% for B for 2 examiners, respectively. Accuracy of both tips was 50% for the first examiner; 45.3% for A and 47.6% for the B tip for the second examiner. All ULS measurements were accurate, reliable, and positively and significantly correlated between examiners., Conclusion: The A tip of the DIAGNOdent was found to be better than the B tip for the detection of enamel caries. All DIAGNOdent and ULS measurements were positive and significantly correlated for both examiners. Both methods demonstrated high repeatability and accuracy.

Background: The multiple functions of saliva play a significant role in the prevention of dental caries., Methods: Chewing gum is known to stimulate salivary flow, and the results of studies of the role of stimulated saliva in the oral clearance of food particles, neutralization of dental plaque acids and reduction of the incidence of dental caries have been reported. The author reviews the results of these clinical caries trials., Results: Seven clinical trials have evaluated the impact of chewing gum on caries incidence. These studies have shown that chewing sugar-free gum after meals results in a significant decrease in the incidence of dental caries and that the benefit is due to stimulating salivary flow rather than any chewing gum ingredient., Conclusions: Stimulating salivary flow through the chewing of sugar-free gum after meals has been shown to reduce the incidence of dental caries., Clinical Implications: Practical measures for stimulating salivary flow after meals or snacks should be considered in caries prevention programs.

Purpose: This study evaluated the agreement between clinical and photographic assessment of dental fluorosis (DF) in 73 children during a field study, using portable equipment and a standardising device., Materials and Methods: A dental exam was performed using the Tooth Surface Index of Fluorosis (TSIF). Photographs of the facial aspects of front teeth and from the occlusal aspect of the mandibular posterior teeth were taken. All photographs were taken following a standard operating procedure. Photographs of anterior and posterior teeth were coded and assigned a random study number. Examiners scored photographs as fluorosis cases or non-cases., Results: Agreement among the clinical examiners ranged from good to excellent. Agreement was also good for the repeated photographic evaluations. In total, 22% of the children were diagnosed with DF during a clinical exam, and 19% were diagnosed with DF using the photographs., Conclusions: Development of this method aided in the photographic assessment of DF. The photographs obtained were a useful tool for documenting DF, to re-train examiners, and to determine intra- and inter-examiner agreement.

Purpose: To determine the ability of QLF to assess the activity of white spots using visual examination (VE) as the gold standard., Methods: Thirty-four specimens were prepared from extracted human permanent posterior teeth presenting natural white spots on the approximal surface. Fluorescence images were acquired at 1-second intervals for the first 10 seconds and every 5 seconds thereafter to 45 seconds. During image acquisition, specimens were dehydrated with compressed air. QLF variables of fluorescence loss (deltaF [%]), lesion size (S [mm2]), and deltaQ (deltaFxS [% x mm2]), were determined. Change in QLF variables per second (deltaQLF(D): deltaF(D), deltaS(D), deltaQ(D)) was determined using the following equation: (subsequent QLF-variables--baseline QLF-variables)/dehydration time. Five experienced dentists independently conducted VE under standardized conditions using a dental unit's light, compressed air, with an explorer, used only to check surface structure. Prior to VE, examiners had participated in a half-day training seminar on VE. After drying the specimens, examiners graded the lesions according to dullness of surface, roughness and presence of microcavitation. Agreement by at least three of them determined the activity status of lesions., Results: deltaQLF(D) values of Active white spot group (n = 7) were compared with those of Inactive white spot group (n = 27) using a two-sample t-test. In general, the active group presented larger values of deltaQLF(D) than the inactive group; however, there were no differences in deltaF(D) and deltaS(D). There were significant differences in deltaQ(D) up to 6 seconds of dehydration (P < 0.05), and no differences after 7 seconds. The results suggest that deltaQ(D) can differentiate between active and inactive white spot lesions using QLF during the first few seconds of dehydration.

Quantitative light fluorescence (QLF) can detect about twice as many demineralized precavitated enamel areas a conventional visual examination or any other caries detection instrument. This technology has been used in several controlled clinical trials with the consistent observation that it is capable of monitoring and quantifying changes in the mineral content and size of clinically visible noncavitated white spot lesions; therefore, it can be used to assess the impact of preventive measures on the remineralization and reversal of the caries process. The anticipated future use of QLF with dehydration to identify active areas of demineralization will markedly enhance the utility of this technology in clinical dental research and dental practice.

Purpose: To evaluate the effects of two experimental cetylpyridinium chloride (CPC) mouthrinses containing 0.075% and 0.10% CPC on the development of gingivitis and plaque versus a placebo control over a period of 6 months., Methods: This was a randomized, single center, parallel group, double blind, positive and placebo controlled clinical trial. A 0.12% chlorhexidine rinse served as the positive control for validation of the methodology. At the beginning of the trial, 366 subjects were balanced and randomly assigned to treatment groups. Subjects received a dental prophylaxis and began rinsing twice a day with 15 ml of their assigned mouthwash for 30 seconds after brushing their teeth. Subjects were assessed for gingivitis and gingival bleeding by the Löe-Silness Gingival Index method and plaque by the Turesky modification of Quigley Hein Plaque Index at baseline and after 3 and 6 months of product use. Oral soft tissue health was also assessed., Results: After 3 and 6 months, subjects rinsing with either 0.075% or 0.10% CPC had significantly (P< 0.0001) less gingivitis, gingival bleeding, and plaque, on average, than those on placebo. The 6-month mean reductions in gingivitis, gingival bleeding, and plaque for the 0.075% and 0.10% CPC rinses versus placebo were 23%, 30% and 17%, and 20%, 27% and 19%, respectively. There was no statistically significant difference in efficacy between the two CPC mouthrinses. Reductions at 3 months were similar to those seen at 6 months. Significant benefits were observed with chlorhexidine, thereby validating the study., Clinical Significance: This study clearly demonstrates that CPC mouthrinses formulated to deliver therapeutic benefits when used twice daily can significantly prevent the development of gingivitis, gingival bleeding, and plaque over a 6-month period.

This study aimed to evaluate the effectiveness of an ultrasonic system for in vitro measurement of cusp tips of human teeth. Each worn cusp of 12 molar teeth was measured with an industrial ultrasonic system. The teeth were sectioned and measured by polarized light microscopy. The ultrasonic measurements and histological readings were moderately correlated (r = 0.601, p < 0.01). The ultrasonic system used in this study seemed a promising method for measuring thickness of worn cusp tips of extracted human molar teeth., (Copyright (c) 2005 S. Karger AG, Basel.)

Objective: To develop a questionnaire in English and Spanish to measure concerns caused by children's (and their parents') perceptions of dental appearance., Materials and Methods: The questionnaire addressed concerns in the physical, mental, and social domains, perceptions about discolourations and other oral conditions including tooth colour. Test-retest and internal reliability, and construct and criterion validity, were assessed as part of the development process. Children in Mexico City, Mexico and Indianapolis, Indiana answered the questionnaire and were examined for fluorosis using the TSIF index. Data were analysed using Cronbach's alpha, Pearson's, Spearman's and intraclass correlations, and percentage agreement tests., Results: Ninety-five children and 28 parents participated in Mexico City; fluorosis was diagnosed in 66% of children. Seventy-one children and 65 parents participated in Indianapolis; fluorosis was diagnosed in 63% of children. English and Spanish questionnaires had acceptable test-retest performance, and moderate internal reliability. Criterion validity was acceptable, and the translated versions retained acceptable construct validity. Perceptions of discolourations were associated with concerns of the participants. Level of concern was higher in Indianapolis than in Mexico City, generally. Many participants reported that they were at least occasionally distressed or worried over the appearance of the children's teeth, that it hindered children from smiling freely, and that it was an unsatisfactory appearance., Conclusion: The developed questionnaire allowed children and parents to report perceived dental appearance problems and concerns.

The objective of this research was to evaluate the anticaries effectiveness of a low-dose (500 ppm F, low-NaF) sodium fluoride dentifrice, a high-dose (2,800 ppm F, high-NaF) sodium fluoride dentifrice and an experimental 0.454% stabilized stannous fluoride (1,100 ppm F) with sodium hexametaphosphate (SnF2-HMP) dentifrice, each relative to a standard 1,100 ppm F sodium fluoride positive control dentifrice. Subjects (n = 955, with approximately 239 per group) with a mean age of 10.6 (approximately 9-12 years) were randomly assigned to one of four dentifrice treatments. Two calibrated examiners independently measured visual-tactile caries as DMFS that was supplemented with a radiographic examination at baseline, 12 months and 24 months for each subject. Generally similar results were independently observed by both examiners at the conclusion of the 2-year study period. Considering all subjects that attended at least 60% of the supervised brushing sessions, statistically significantly less caries was observed in the high-NaF group compared to the control group. Similarly, statistically significantly less caries was observed in the SnF2-HMP group as compared to the control group. Differences in caries increments between the low-NaF and control groups were not statistically significant. One of the examiners observed these same statistically significant differences after 1 year. In conclusion, the results of this clinical trial indicated that while no difference in caries increments was observed between the low-NaF and control groups, both the high-NaF and the SnF2-HMP groups experienced significantly fewer lesions than the control group., (2004 S. Karger AG, Basel.)

The objective of this study was to determine the ability of several techniques to detect natural secondary caries adjacent to proximal class II amalgam restorations. Two sites were selected and marked on each of 50 human extracted posterior teeth. Three examiners visually characterized each site independently for signs of demineralization (VI), ditching presence (VD), and color change, and utilized light-induced fluorescence (QLF), and infrared laser fluorescence (LF) techniques. The teeth were sectioned through the selected sites, and the severity of each lesion was determined by confocal laser scanning microscopy (CLSM) as the 'gold standard'. Agreement among examiners was assessed using weighted kappa statistics and showed fair to moderate correlation with all techniques. Sensitivity, specificity, positive predictive value (PPV), negative predictive value and accuracy were determined by utilizing three arbitrary CLSM thresholds. Higher sensitivity was indicated by the QLF and LF than by VI. For PPV and accuracy, QLF and LF showed values higher or similar to VI. Low sensitivity was found for VD. The results obtained in this study suggest that LF and QLF may improve the ability to detect early secondary caries around amalgam restorations., (Copyright 2004 S. Karger AG, Basel)

Purpose: To assess the "whitening" through stain removal benefit delivered by a prototype power toothbrush and a positive control power toothbrush over a 2-week period., Methods: Four independent studies with identical protocols were conducted to examine tooth whitening through the removal of extrinsic stain with power toothbrushes. These were randomized, positive-controlled, two treatment, parallel group, examiner-blind, 2-week studies involving approximately 20 healthy adults with longstanding visible extrinsic stain on the facial surfaces of the 12 anterior teeth. Approximately 10 subjects per group were enrolled into the study for each of the two treatment groups; a prototype-powered toothbrush group (Crest SpinBrush Pro Whitening) and a positive control powered toothbrush group (Sonicare Personal 4100)., Results: In these four studies, the positive control sonic power toothbrush statistically significantly (P < 0.05) reduced stain scores by 84%, 77%, 44% and 49% following 2 weeks of brushing. Importantly, the prototype whitening power toothbrush statistically significantly (P < 0.05) reduced stain scores by 88%, 65%, 59% and 57% following 2 weeks of brushing. In both the individual studies and a combined analysis involving all four studies, the adjusted mean changes between treatment groups did not differ significantly between the two treatment groups. In the combined analysis, a one-sided upper 95% confidence bound on the difference in stain reduction scores between the two toothbrushes (positive control minus prototype) was found to be 8.3% of the prototype toothbrush adjusted mean change. This supports that the prototype power toothbrush removed extrinsic stain at least as well as the positive control toothbrush across these four studies.

Considerable research during the past two decades has focused upon the development of new technologies for the detection of dental caries. Of these technologies, the method that has been most extensively studied is based upon the indirectly assessed changes in the fluorescence of enamel associated with the loss of mineral. The purpose of this presentation was to review the available information regarding the use of this technology, commonly known as quantitative light fluorescence, for caries detection, particularly early caries detection, and the potential for the routine use of this technology in clinical caries trials. This technology is unique in its ability to measure small changes in the mineral content of enamel lesions quantitatively. The results of recent small-scale clinical trials have indicated that the impact of caries-preventive measures can be determined within a six-month period. With current hardware and software refinements and the results of long-term clinical validation studies that are in progress, it may be that this technology will be the future method of choice for caries clinical trials.

Purpose: Previous studies have reported higher dental fluorosis prevalence in high-altitude communities than in low-altitude communities. This investigation determined and compared dental fluorosis prevalence in populations of children living at high and low altitudes in Mexico., Materials and Methods: Fluorosis prevalence was determined in 7 to 10-year-old children: 67 in Mexico City (2,240 m) and 71 in Veracruz (sea level). Previous fluoride exposure of those children was surveyed by retrospective, questionnaire data. The fluoride content of water and salt from those communities was also documented., Results: Fluorosis prevalence in Mexico City (53.0%) was significantly higher than in Veracruz (24.3%) (p < 0.0001). While there were statistical differences in one of the fluorosis risk factors between the two communities, the observed difference in fluorosis prevalence was still significant when data were analyzed after adjusting for the reported differences in that factor., Conclusion: Our results led to the conclusion that the difference in fluorosis prevalence in Mexico City and Veracruz could not be explained by differences in fluoride content of the salt or water samples, self-reported exposure to fluorosis risk factors or estimated fluoride intake.

The objective of this study was to determine the effect of imaging geometry on evaluating natural white-spot lesions with quantitative light-induced fluorescence (QLF). A total of 34 specimens were prepared from extracted human premolars and permanent molars with white spots on the interproximal surface. The specimens were each adjusted to a final thickness of 3.0 mm. Images were acquired with the QLF system perpendicular to the white spots and at 5 degrees intervals up to 30 degrees above and below the perpendicular. The specimens were rotated around the buccolingual axis of the tooth (pitch angle) and around the long axis of the tooth (roll angle). The averages of fluorescence loss (DeltaF, %) and lesion size (mm2) were determined with QLF. Another variable, DeltaQ, which was defined as the fluorescence loss integrated over the lesion size (% x mm2), was also calculated. DeltaF was smaller when lesions were viewed from the cervical direction (angles less than 90 degrees ), and became bigger when viewed from the coronal direction. Roll angle did not significantly affect DeltaF. Apparent lesion size diminished with deviations from 90 degrees in both directions for pitch and roll angles. DeltaQ was affected by pitch and roll angles with the largest value at 90 degrees and values decreasing in both directions from 90 degrees. In general, there were significant differences for angles larger than 20 degrees from the perpendicular for all three QLF variables. This study suggests that angle is an important factor to control when performing QLF studies; however, small changes (deviations within 20 degrees ) have a minimal effect on QLF variables., (Copyright 2004 S. Karger AG, Basel)

The authors hypothesize that the arrestment and remineralization of these lesions could be improved if secondary caries could be detected and monitored at earlier stages. Traditional diagnostic techniques detect secondary caries when it is relatively advanced and when significant tissue has been lost. This in vitro study evaluated the Quantitative Light-induced Fluorescence (QLF) system for detecting and monitoring demineralization surrounding tooth-colored restorations. This investigation was divided into three studies. The first study evaluated QLF for the detection and measurement of chemically induced lesions surrounding resin composite restorations. The second study evaluated QLF for the detection of demineralization around different tooth-colored restorations (glass ionomer, resin composite, compomer and smart material) created in a microbial caries model. Finally, the third study tested whether QLF was effective at detecting early wall lesions adjacent to resin composite restorations. Data from Study 1 demonstrated the potential for QLF to detect very early secondary caries and to distinguish between the different stages of early demineralization. Study 2 confirmed the potential for QLF to detect early secondary caries created by cariogenic bacteria and concluded that the four types of materials differed in their ability to prevent secondary caries in this model, with the glass ionomer being the most effective and the non-fluoride releasing composite performing the worst, which allowed for the development of larger lesions. The results of Study 3 suggest a potential application of the QLF system to detect early wall lesions. Data from this investigation strongly suggest that QLF is a potentially viable technology to detect and monitor early secondary caries.

Objectives: This investigation monitored fluoride ingestion in Mexican children who were susceptible to developing dental fluorosis., Methods: Total fluoride intake, from dietary and toothpaste samples, was determined in 15-36-month-old children from Mexico City and Veracruz, Mexico. A duplicate plate technique was used. Plasma fluoride levels were also determined in this group of children., Results: The children ingested a mean (+/-SD) of 0.20 +/- 0.08 and 0.18 +/- 0.07 mg fluoride/kg/day, in Mexico City and Veracruz, respectively. There was no statistically significant difference between the fluoride ingested by children in the two cities (P > 0.9). Plasma from children in Mexico City and Veracruz contained a mean of 1.30 +/- 0.81 and 0.87 +/- 0.72 micro mol fluoride/l, respectively, and these values were not significantly different., Conclusions: Our results lead to the conclusion that mean fluoride ingested from the combination of foods and beverages was within the proposed safe threshold for fluoride intake of 0.05-0.07 mg F/kg/day. Most of the fluoride intake by these children was derived from the ingestion of fluoridated toothpaste. When all sources of ingested fluoride were added and total fluoride intake was calculated, the children, both in Mexico City and Veracruz, were ingesting amounts of fluoride well above the upper limits of the proposed safe threshold for fluoride intake.

The objective of this study was to evaluate the effect of enamel thickness on the quantification of white-spot lesions with laser fluorescence. One hundred and twenty 3-mm-diameter human ground and polished enamel specimens were used. Specimens were illuminated by a 488-nm argon laser, images were acquired through a 540-nm high-pass filter and stored on the Quantitative Light-Induced Fluorescence (QLF) program. Specimens were divided into two groups and demineralized for 48 or 96 h and QLF images were again acquired. Fluorescence radiance (FR) of both sound (FR(s)) and demineralized (FR(d)) enamel was determined using the QLF program. Change in fluorescence radiance (Delta FR, %) was determined as follows: Delta FR = FR(d)/FR(s) x 100. One thin section was obtained for transverse microradiography analysis. Enamel and dentin thickness of the thin sections were measured. There was a good correlation between QLF parameters and enamel thickness. It can be concluded that the FR observed for similar lesions depends on the actual enamel thickness., (Copyright 2003 S. Karger AG, Basel)

Concurrent with the decline in dental caries has been an increase in the prevalence of dental fluorosis, a side-effect of exposure to greater than optimal levels of fluoride during amelogenesis. The mechanisms that underlie the pathogenesis of dental fluorosis are not known. We hypothesize that genetic determinants influence an individual's susceptibility or resistance to develop dental fluorosis. We tested this hypothesis using a mouse model system (continuous eruption of the incisors) where genotype, age, gender, food, housing, and drinking water fluoride level can be rigorously controlled. Examination of 12 inbred strains of mice showed differences in dental fluorosis susceptibility/resistance. The A/J mouse strain is highly susceptible, with a rapid onset and severe development of dental fluorosis compared with that in the other strains tested, whereas the 129P3/J mouse strain is least affected, with minimal dental fluorosis. These observations support the contribution of a genetic component in the pathogenesis of dental fluorosis.

This study investigated the ability of a new fluorescence method to detect residual caries in vitro. Gross caries was removed from 40 teeth with D2 caries. Samples were excited with violet-blue light and viewed through a 530-nm high-pass filter. Residual caries (orange-red fluorescing dentin) was detected in all samples. Further tooth substance was removed from half of the samples until no residual caries was detectable using the new method. Half of the samples remained untreated. A blinded examiner checked all samples for residual caries using DIAGNOdent, a visual tactile examination, and Caries Detector dye. Presence or absence of residual caries in each sample was determined using a fluorescent nucleic acid stain in conjunction with confocal microscopy. The new method, Visible Fluorescence, had the greatest sensitivity, specificity, percent correct score and predictive values of any of the methods tested. The new method had significantly higher percent correct score than any of the other methods and significantly higher specificity than visual tactile and Caries Detector. It was concluded that Visible Fluorescence is an improvement on the currently available aids for residual caries detection., (Copyright 2002 S. Karger AG, Basel)

The aim of the study was to find the optimal illumination and camera angulations for interproximal use of quantitative light-induced fluorescence (QLF). A multiaxis optical bench was developed and interproximal tooth assemblies were investigated using a modified version of QLF. Extracted human premolars without caries (n = 8) and with interproximal D1, D2 and D3 caries (n = 20) were selected. Tooth-pair models without caries and with interproximal caries of matching size, location, and shape were imaged with varying camera and illumination directions from buccal (0 degrees) to occlusal (90 degrees) to lingual (180 degrees) in steps of 30 degrees using a PC and framegrabber and examined for observed presence. Interproximal lesions could be detected in all teeth, but observed presence was dependent on camera angulation (p < 0.05), rather than on illumination angulation (p = 0.32). No caries could be detected with the camera in the 90 degree position., (Copyright 2002 S. Karger AG, Basel)

Purpose: To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci, Actinomyces naeslundii genospecies 2, and lactobacilli in carious lesions around tooth-colored restorations., Materials and Methods: Samples from extracted teeth with clinical secondary caries around tooth-colored restorations were immuno-labeled with antibodies to the referred groups of bacteria and subsequently analyzed three dimensionally using confocal microscopy., Results: The three different bacterial groups were usually present in secondary caries around tooth-colored restorations suggesting that they are involved in its formation and development.

The purpose of this study was to determine the efficacy of fluoride varnish (FV) in inhibiting progression of secondary caries (SC). In a first experiment, human teeth, restored either with amalgam or resin composite, were exposed for 4 days to a microbial caries model. Half of each specimen was then painted with an acid-resistant nail varnish to maintain the baseline SC lesion. Specimens were then either treated with a FV (removed after 24 h) or not treated (control groups) prior to being exposed for 4 more days to the caries model. A second experiment was conducted to compare the effect that the varnish (with and without fluoride) had on SC development around amalgam. Confocal laser scanning microscopy data from these experiments suggested that the application of a FV to early, active SC lesions significantly slowed down their progression. Furthermore, the application of a placebo varnish showed a trend towards slowing down lesion progression, suggesting that the effect of FV on SC is not only due to its fluoride release., (Copyright 2002 S. Karger AG, Basel)

Quantitative light-induced fluorescence (QLF) is based on the dark appearance of a white spot in otherwise highly fluorescent enamel. This can be explained by the increased scattering coefficient in the white spot compared with that of sound enamel. The aim of this study was to estimate the effect of different sound enamel scattering coefficients (s(SE)) and enamel thickness d, caused by developmental enamel differences, on the fluorescence appearance of white-spot lesions. We ran a Monte Carlo simulation of a 4 x 4 mm(2) illuminated enamel slab on a highly fluorescent background. The slab had a 0.7 x 0.7 mm(2), 100-microm-deep, white spot in the center. Fluorescent and back-scattered photons re-emitted from the central 2 x 2 mm(2) were recorded. We found that the fluorescence photon excitance from the white spot (F(WS)) was less than that of sound enamel (F(SE)), with an optimum difference for S(SE) between 20 and 80/mm. For s(SE) <20/mm, both F(SE) and F(WS) decreased with d. We found no relation with d for s(SE) >20/mm. The results indicate that for small s(SE), we are suffering from edge losses, which explains why the optimum for lesion visibility is not found at s(SE) = 0/mm, as would be expected., (Copyright 2002 S. Karger AG, Basel)

A major curriculum revision involving the utilization of problem-based learning was implemented at Indiana University School of Dentistry in the summer of 1997. Two of the main goals of this new student-centered curriculum were to promote critical thinking skills and to encourage a desire for lifelong learning, both of which were anticipated to increase student use of the library. This study examined circulation at the library for three years immediately prior to, and for three years immediately following, the curricular change. Results show that library circulation has increased significantly since the pedagogical change. This suggests that students in the new curriculum place more emphasis on the library as a learning resource than did their traditional curriculum counterparts.

Caries is a disease that affects both deciduous and permanent dentitions. Caries progresses more rapidly in deciduous enamel than in permanent enamel. Therefore, new caries diagnostic methods need to be tested on the deciduous teeth as well. Quantitative laser-induced fluorescence (QLF I) as well as the quantitative light-induced fluorescence (QLF II) seem promising for the quantification of mineral loss from dental caries but have only been tested on the permanent dentition. The objective of this study was to determine and compare the ability of QLF I and QLF II to quantify mineral loss from carious lesions in both deciduous and permanent teeth. Thirty sound deciduous and 30 sound permanent teeth were cleaned and divided into three groups each containing 10 deciduous and 10 permanent teeth. Windows on the buccal or labial enamel surfaces were demineralized for 48, 72, or 96 h. Images of demineralized enamel were captured using QLF I and QLF II. The images were analyzed to determine the mean change in fluorescence radiance (Delta F, %). The teeth were then sectioned for assessment of lesion depth (microm) and integrated mineral loss (IML, vol% x microm) using transverse microradiography (TMR), as the 'gold standard' for lesion analysis. The results indicated a good correlation for Delta F between QLF I and QLF II in both deciduous (r = 0.96) and permanent teeth (r = 0.98). There was a good correlation between Delta F and TMR (lesion depth and IML) in deciduous teeth (r = 0.76 and 0.84 with QLF I, r = 0.81 and 0.88 with QLF II). In permanent teeth, the correlation between Delta F and TMR (lesion depth and IML) was lower than in deciduous teeth (r = 0.07 and 0.53 with QLF I, r = 0.15 and 0.62 with QLF II). From these results it can be concluded that either QLF method is capable of quantifying mineral loss in early carious lesions in deciduous teeth. Moreover, under the conditions of this study, the use of either QLF method to quantify mineral loss in early carious lesions in deciduous teeth is slightly more accurate than in permanent teeth.

Current diagnostic tools used in dental caries detection are not sensitive enough to diagnose the disease process in its early stages and, frequently, once a diagnosis is made, restoration is the only effective means of treatment. The purpose of this review was to systematically assess the available literature for evidence to determine if emerging diagnostic methods for dental caries are more efficient than traditional methods for detecting and monitoring the progress of caries in permanent and primary teeth. Inclusion and exclusion criteria were established preceding the literature search. Included articles were grouped by type of emerging technology and study design. The types of emerging technologies included laser fluorescence, light fluorescence, digital imaging fiber optic transillumination, and ultrasound. Primarily on the basis of in vitro and preclinical data, some of the reviewed methodologies showed promising results for the detection and monitoring of early caries lesions. However, very little clinical data are available to validate these emerging technologies. It was concluded that, although significant promise is apparent with these technologies, there is not enough evidence available at this time for any of the reviewed diagnostic techniques to be recommended as a substitute for traditional diagnostic techniques.

Periodontal disease is considered the most common disease of dogs and cats. The clinical sign most frequently reported by clients is oral malodor. Clindamycin hydrochloride has been used for several years for the treatment of periodontal disease in both cats and dogs. This study was designed to assess the effect of clindamycin HCl when used in two different post-prophylaxis treatment regimens on oral malodor and periodontal disease in a controlled clinical trial. This study demonstrated that a 5-day postprophylaxis regimen was significantly effective in reducing oral malodor compared with a dental prophylaxis alone. Clindamycin HCl significantly reduced oral malodor from the animals' baseline levels through 42 days. In addition, although no effect was observed on periodontal pocket depth, this treatment regimen also resulted in significant reductions in dental plaque, dental calculus, and gingival bleeding.

The use of fluoride in water, professional topical applications, and dentifrices has resulted in a pronounced decline in dental caries. However, caries continues to afflict more 90% of the US population. Preventing and controlling dental caries requires the use of innovative measures to address the causes and reverse the caries process. This article provides an overview of the current strategies for the prevention of dental caries, the rationale for their use, and their relative efficacy.

Ultrasound has been used in industrial business as one of the nondestructive measurement methods. It was hypothesized that nondestructiveness of the ultrasonics could be useful in determination of demineralization of noncavitated carious lesions on human enamel. This investigation was designed to determine the presence of natural carious lesions on proximal surfaces of human molar teeth using an ultrasonic system compared to radiography and histology as the gold standards. Measurements were made directly from proximal surfaces of 20 mandible molar teeth with white spot carious lesion by 2 examiners independently with the ultrasonic system. Ultrasonic evaluation of each natural white spot lesion had a sensitivity of 88%, specificity of 86%, positive predictive value of 88% and a negative predictive value of 86%, and the chance-corrected agreement was also satisfactory (kappa=0.74) compared to histology. The radiograph demonstrated chance-corrected agreement of 0.41:0.38 for the first and second examiners, respectively. Duncan test analysis of the numerical values was significantly different for the intact and the noncavitated carious surfaces (p<0.05). The results indicated that the ultrasonic evaluation is a sensitive method for the detection of the natural white spot carious lesions and can differentiate the changes in elastic properties of enamel numerically.

Recent developments in the field of electronic imaging have provided a new set of imaging tools for intra-oral imaging and clinical diagnosis. In this chapter, we review the general structure and characteristics of image sensors used in digital radiography and their application for clinical caries detection and analysis. An overview of the literature, comparing the diagnostic accuracy of digital and film-based radiography and the impact of image-processing methods, is provided. We also describe several approaches for quantitative assessment of radiographic images for caries detection and assessment. Examples include digital subtraction radiography, and 2-D and 3-D density profiling. To increase the accuracy and reduce observer variability the use of 3-D imaging and computer-aided diagnosis is presented as future direction for clinical caries diagnosis.

The first step for a pathogenic bacterium to initiate infection is via attachment (i.e., through surface determinants) to a suitable receptor. An in vitro microbial artificial-mouth model was used to test the efficacy of polyclonal antibodies to Streptococcus mutans cell surface proteins (CsAb) and a cell surface 59-kDa protein (59Ab) in preventing S. mutans colonization and carious lesion formation. In study 1, groups of 12 human teeth specimens were inoculated with S. mutans, which were incubated with different concentrations of CsAb (A1 [positive control], sterile saline, no antibody; A2, 0.007 mg of antibody protein/ml; and A3, 0.7 mg of antibody protein/ml) for 1 h at 37 degrees C. The negative control group (B1) was not infected and was incubated with Trypticase soy broth (TSB) without dextrose supplemented with 5% sucrose (TSBS). In study 2, the same study design was used except that 59Ab was used instead of CsAb, normal rabbit serum was used in the positive control group (A1), and TSB supplemented with 1% glucose was used as the nutrient to control for sucrose-dependent colonization. All groups were exposed for 4 days to circulating cycles of TSBS and TSB (study 1 and study 2, respectively; 30 min each, three times per day) and a mineral washing solution (21 h per day). Prior to each nutrient cycle, 1 ml of the appropriate CsAb or 59Ab solution was administered to each group and allowed to mix for 30 min before cycling was resumed. Data obtained by confocal laser scanning microscopy demonstrated the presence of a significantly smaller (P < 0.05) lesion area and a smaller total lesion fluorescence in group A3 than in group A1 for both studies. In study 1, group A2 had significantly smaller values than A1 for lesion depth and area. There were no significant differences between groups A2 and A3 for lesion area or between groups A1 and A2 for total lesion fluorescence. In study 2, there were no significant differences among groups A1 and A2 for lesion depth or between groups A2 and A3 for all of the parameters studied. In both studies, there were no significant differences between S. mutans plaque CFU numbers among any of the groups. These studies demonstrated the efficacy of CsAb and 59Ab in reducing primary caries development in this model, although the underlying mechanism remains unclear.