Search

Background: In recent literatures, much attention has been given to natural products for their health benefits., Aims: In this study, the objective was to measure the efficacy of the ginger-honey-chocolate mixture as the remineralization effect has been shown in the literature previously and to evaluate the individual contributions of this mixture; ginger, natural honey, bitter chocolate separately on remineralization of initial enamel caries lesion., Materials and Methods: All specimens were divided into eight groups as: Ginger (Arifoglu®, Turkey) in powder form, (n = 8); Ginger-Honey-Chocolate (n = 8); Natural honey (Balparmak Plateau Blossom Honey®, Turkey) (n = 9); Bitter chocolate (Nestlé®, Switzerland) (n = 8); MI Paste (GC, Japan) (n = 8); Paradontax (Sensodyne, Glaxosmithklein, USA) (n = 9); Pronamel (Sensodyne, Glaxosmithklein, USA) (n = 9); Control (n = 9) groups. Samples were carried out five pH cycles along 7 days at 37°C for each group. During pH cycling, blocks were put in a demineralization (6 h) and a remineralization solution (18 h). The treatment consisted of 1 min. interaction of enamel surfaces with agent/deionized slurries (1:3 w/w) on a daily basis. The surface microhardness (SMH) was determined before and after pH cycling with a Digital Micro-Vickers Hardness Tester (Wilson Wolpert; Europe BV, 401 MVD, Netherlands). Mineral changes were determined by using FluoreCam® and recovery values were calculated as SMHR% and FΔ%, respectively., Results: All groups showed an enhanced remineralization. There was no significant difference in terms of FΔ% (F = 1.223, P = 0.304) and SMHR% (F = 0.709, P = 0.664) between all groups., Conclusion: The herbals (ginger, honey, and bitter chocolate) examined in this study gave promising results with a high remineralization potential., Competing Interests: None

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.

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: 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.

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)

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.

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.

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)

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.

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.

As with any disease process, the early initiation of therapy for dental caries is often the most effective means to ensure resolution. However, for any therapy to be effective, early diagnosis is paramount to success. Unfortunately, current 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. Quantitative light-induced fluorescence, electrical conductance measurements, direct digital radiography, and direct fiber optic transillumination are methods that may offer promise as effective tools in diagnosing early dental caries. This article describes some of the research that has been performed to make these methods a reality.

Secondary dental caries remains an unresolved problem in dentistry and little is known of its microbial etiology. The purpose of this study was to compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci. Actinomyces naeslundii genospecies 2 and lactobacilli, in natural secondary caries around amalgam restorations. Extracted teeth with secondary caries were sectioned to obtain three samples that were randomly distributed to three different groups. Each group was immunolabeled with antibodies to either Streptococcus mutans, A. naeslundii genospecies 2 or Lactobacillus casei and subsequently labeled with secondary fluorescent antibodies. All samples were analyzed three-dimensionally using confocal microscopy. The results indicated that the three different bacteria were widely present and could have an important role in the development of secondary caries around amalgam restorations.

Streptococcus mutans has been identified as the major etiological agent of human dental caries. The first step in the initiation of infection by this pathogenic bacterium is its attachment (i.e., through bacterial surface proteins such as glucosyltransferases, P1, glucan-binding proteins, and fimbriae) to a suitable receptor. It is hypothesized that a mucosal vaccine against a combination of S. mutans surface proteins would protect against dental caries by inducing specific salivary immunoglobulin A (IgA) antibodies which may reduce bacterial pathogenesis and adhesion to the tooth surface by affecting several adhesins simultaneously. Conventional Sprague-Dawley rats, infected with S. mutans at 18 to 20 days of age, were intranasally immunized with a mixture of S. mutans surface proteins, enriched for fimbriae and conjugated with cholera toxin B subunit (CTB) plus free cholera toxin (CT) at 13, 15, 22, 29, and 36 days of age (group A). Control rats were either not immunized (group B) or immunized with adjuvant alone (CTB and CT [group C]). At the termination of the study (when rats were 46 days of age), immunized animals (group A) had significantly (P < 0.05) higher salivary IgA and serum IgG antibody responses to the mixture of surface proteins and to whole bacterial cells than did the other two groups (B and C). No significant differences were found in the average numbers of recovered S. mutans cells among groups. However, statistically fewer smooth-surface enamel lesions (buccal and lingual) were detected in the immunized group than in the two other groups. Therefore, a mixture of S. mutans surface proteins, enriched with fimbria components, appears to be a promising immunogen candidate for a mucosal vaccine against dental caries.

Purpose: To determine the comparative effects of sodium (NaF) and amine fluoride dentifrices, as well as the effect of different silica abrasives used in NaF dentifrices, on caries formation in rats., Materials and Methods: Harlan Sprague Dawley mixed sex, weanling, littermate rats were fed a cariogenic diet and inoculated with S. sobrinus strain 6715 to induce caries formation. The dentifrices evaluated contained 0.31% NaF with precipitated silica I as the abrasive system; 0.31% NaF with sodium bicarbonate and hydrated silica; placebo; amine fluoride (0.14%) containing silica (Elmex); 0.31% NaF with precipitated silica II (Sensodyne F); and 0.31% NaF with hydrated silica. Dentifrice slurries were administered 7 days per week for 3 weeks at which time the animals were euthanized and the hemijaws removed, coded and stained with a murexide solution. The recovery of S. sobrinus after the 3-week study clearly showed that all of the six groups were infected with S. sobrinus. The Keyes scoring method was then used to assess the caries formation within the six groups., Results: Caries scores showed that all five experimental fluoride dentifrices were equally efficacious statistically in reducing caries formation when compared to the placebo with reductions ranging from 26 to 43%.

To determine the effect of chewing sugar-free gum on caries incidence, the authors conducted a randomized clinical study. A total of 1,402 children in Puerto Rico, in grades 5 through 7 at baseline, completed the study. They were randomized by classroom into a control group or chewing gum group; those in the gum group were instructed to chew sugar-free gum for 20 minutes after each of three meals a day. Clinical and radiographic evaluations were performed at baseline and after two and three years. The results show that all subjects and high-risk subjects, respectively, in the gum group developed 7.9 percent and 11.0 percent fewer decayed, missing or filled surfaces than subjects in the control group. Based on these findings, the authors concluded that chewing sorbitol-based sugar-free gum after eating significantly reduces the incidence of dental caries.

It is apparent that the use of fluoride in multiple measures has a significant impact upon the prevention of dental caries. These measures involve public health benefits of water fluoridation, professional fluoride treatments in the dental office, and the home use of effective fluoridated dentifrices, with the use of fluoride rinses and gels as adjuncts when needed. In many clinical situations, professional judgment is required to identify the most appropriate treatment measures to address the needs of individual patients.

Laser fluorescence (LF) is thought to be a quantitative technique for the measurement of mineral loss from dental caries. These studies aimed to demonstrate the quantitative nature of LF, by means of transverse microradiography (TMR), in addition to the possible use of LF on small specimens suitable for in situ studies. Studies also aimed to determine the ability of LF to detect caries adjacent to amalgam restorations. The results demonstrated reasonable correlation between both the histological depth and mineral loss measured by TMR compared with the % change in mean fluorescence radiance measured by LF (r = 0.70 and 0.83, respectively). Studies with small specimens demonstrated that in vitro remineralization could be observed with LF for comparison of the demineralized specimen with an undemineralized reference. ANOVA showed significant mineral gain (p < 0.0001). The detection and quantification of mineral loss adjacent to amalgam restorations may have potential for the management of recurrent caries. Studies have demonstrated that LF can detect such mineral loss, and, with refinement of the image analysis system, LF was capable of detecting remineralization. Remineralization of such lesions is controversial, but it is suggested that LF may have a role in secondary caries management.

This crossover study determined the ability of an interproximal, intra-oral model to demonstrate a fluoride dose response to 0-, 250- and 1,100-ppm fluoride (sodium fluoride) dentifrices with respect to fluoride uptake into, and remineralization of, incipient subsurface enamel lesions. Following a 1 week 'lead in' period during which 30 panelists were randomly assigned to use one of the products, two enamel specimens with artificial carious lesions were mounted into a specially designed functional partial denture worn by each panelist. Panelists continued to brush three times daily with their test dentifrice for 4 weeks, after which the specimens were removed and analyzed for fluoride uptake and remineralization. The procedure was repeated until each panelist had followed all three treatment regimens. Fluoride analyses were performed using a microdrill biopsy technique, and mineral content changes were determined by transverse microradiography. Fluoride uptake data were significantly different (p < 0.01) for all three products with the effect of 1,100 ppm F > 250 ppm F > placebo. The 1,100 ppm F dentifrice also effected significantly greater remineralization (p < 0.01) than did the 250-ppm-F or placebo dentifrices. Relative efficacy of the three fluoride dentifrices tested in this study was similar to that established in a clinical trial, and, therefore, supports the use of this model for in situ studies of the effects of fluoride-containing products on enamel lesions.

Secondary caries is a major reason for the replacement of restorations. Because it is hypothesized that the development of secondary caries is closely associated with pathogenic oral bacteria, an in vitro microbial model has been developed to produce secondary carious lesions. A mixture of overnight cultures of Streptococcus mutans and Lactobacillus casei in dextrose-free trypticase soy broth, supplemented with 5% sucrose (TSBS), at 37 degrees C was used in this model as the inoculum for the experimental groups. Uninoculated control groups were incubated with medium only. Groups of human tooth specimens restored using composite, together with their respective controls, were exposed for 7 or 12 days to circulating cycles of TSBS (30 min each, 3 times per day) and a mineral wash solution (for a total of 22.5 h per day), at 37 degrees C. The pH of the experimental groups dropped to 4.l-4.5 during the test periods. The pH of the control groups remained at 6.8-7.0. The inoculated bacteria remained viable throughout the study. No contamination of experimental or control samples occurred. Laser scanning confocal microscopy demonstrated the development of incipient surface and wall lesions in all the specimens of experimental groups in as few as 7 days. Reproducibility of the model was confirmed in a second investigation. Therefore, it was concluded that this model can be used for studying the microbial etiology and prevention of secondary caries.

To determine the ability of animal caries models to evaluate the cariostatic potential of fluoride dentifrices, we examined four different coronal caries models. These currently used rat caries models were: Francis' hypomineralized area model, Gaffar's CARA rat model, the Connecticut model, and the Indiana model. Available data indicated that all of these models were capable of detecting significant cariostatic benefits from clinically proven fluoride dentifrices. For the most part, these animal models were also able to demonstrate a response to increasing concentrations of fluoride, particularly if the fluoride was provided in an ionic rather than a complexed form. Data were also presented which indicated the potential for animal caries models to be used to predict the clinical benefits of non-fluoride systems as well as the utility of fluoride systems for the prevention of root-surface caries. It is concluded that animal caries models play a significant role in the development and evaluation of fluoride and other systems for the clinical prevention of dental caries.

Objectives: This study investigated the prevalence of dental fluorosis and caries in 7-14-year-old children residing in communities with negligible (NF: 0.2 ppm), optimal (OPF: 1.0 ppm), and four-times optimal (4X OPF: 4.0 ppm) naturally occurring fluoride in their water systems., Methods: Examinations were performed on 344 children who were lifetime residents of their communities., Results: Whether using the tooth surface index of fluorosis or Dean's index, children examined in the 4X OPF community had the highest prevalence of dental fluorosis. While the severity of fluorosis seen in the OPF and NF communities was mild in appearance, the results indicate that fluorosis does occur in optimally and negligibly fluoridated communities. Compared to the NF community, DMFT and DMFS scores in the OPF community were 9.2 percent and 21.2 percent lower, respectively., Conclusions: The ingestion of water containing 1 ppm or less fluoride during the time of tooth development may result in dental fluorosis, albeit in its milder forms. However, in these times of numerous products containing fluoride being available, children ingesting water containing 1 ppm fluoride continue to derive caries protection compared to children ingesting water with negligible amounts of fluoride. Thus, the potential for developing a relatively minor unesthetic condition must be weighed against the potential for reducing dental disease.

Secondary caries is one of the major reasons causing restoration failure; however, little is known of its microbial etiology, mainly because of the difficulties in eliminating bacterial contamination during collection and sample preparation. Therefore, the purpose of this study was to investigate the feasibility of immunofluorescent techniques and confocal laser scanning microscopy for identification and quantification of bacteria in secondary carious lesions. Thirty-six extracted human teeth, clinically diagnosed as having secondary caries, were used in the study. The teeth were sectioned in half across the secondary carious lesion. One half of each tooth was processed using the Brown and Hopps histologic staining method for bacterial detection. Sections (100 microns thick) were obtained from the other half of each tooth for immunofluorescence labeling to detect and identify mutans streptococci in the subsurface of the lesion using confocal imaging techniques. Mutans streptococci were detected in 88.9% of the samples analyzed with the immunofluorescent technique. The Brown and Hopps histopathologic examination demonstrated evidence of bacteria in 94.4% of the samples. In addition, quantification of bacteria was conducted by digitalization of confocal images. The results indicated that the immunofluorescence confocal laser scanning microscopy technique was sensitive and specific for detection and quantification of mutans streptococci in secondary carious lesions.

In spite of advances made during the past two decades, dental caries continues to be the major oral disease. The most effective means for the prevention and control of dental caries continues to be the professional, public health, and home use of fluoride. However, prudent use of these measures is required to minimize the risks of dental fluorosis in young children.

While there is broad consensus in the research community that fluoride dentifrices provide important anticaries benefits, debate still remains as to the most efficient form of fluoride used in toothpastes. Recently, the authors of this paper collaborated as part of a scientific advisory group whose objective was to comprehensively review all clinical information available comparing the anticaries efficacy of the two agents most widely used in fluoridated toothpastes, sodium fluoride (NaF) and sodium monofluorophosphate (SMFP). This review included a detailed analysis of each published study pertinent to the question, a comprehensive meta-analysis of all available clinical findings, and an epidemiological assessment of how anticaries benefits of dentifrices may be anticipated to propagate with time. Overall, the use of meta-analysis of head-to-head clinical comparisons between the two fluoride-active systems was found to be the most valid means for comparing the relative efficacy of NaF and SMFP dentifrices. Results of this analysis demonstrated that NaF was significantly more effective than SMFP in preventing caries (p < 0.01). While the numerical difference in efficacy between NaF and SMFP measured between 5 and 10% (total DMFS) over a 2- to 3-year clinical period, this could be expected, on theoretical grounds, to propagate to substantially larger differences (e.g. 10-20%) over 10-20 years. Hence, the difference in efficacy between these two actives was judged to be clinically important as well as statistically significant. Based upon these findings the authors recommend that NaF be used as the active system in fluoridated dentifrices whenever practically feasible. However, the authors caution that this recommendation pertains to the formulation of NaF in highly compatible abrasive systems, which must be demonstrated by critical evaluation of ionic fluoride within formulations for stability, availability and bioavailability. One additional recommendation emanating from this review is that important improvements must be made in the design, execution and reporting of future caries clinical trials in order to bring these important methods up to scientifically acceptable standards.

Especially during recent years, the use of pre-clinical models for predicting the efficacy of fluoride systems has assumed greater importance within the scientific community. Originally utilized primarily to screen experimental fluoride delivery systems, preclinical models are now being considered as predictors of clinical efficacy in lieu of controlled clinical caries trials. Of the various preclinical models presently available, human intra-oral models have the greatest potential for reflecting intended usage conditions and therefore may be the most meaningful models for predicting clinical efficacy. However, only with the proper consideration of numerous critical variables can studies using intra-oral models be appropriately designed to achieve the desired objectives. Clearly, these models must provide relevant information in a manner which reflects clinically established cariostatic activity and be capable of detecting established differences in the amount of cariostatic activity, i.e., dose-response effects. Three sources of variation must be considered before an appropriate study design and sample size can be chosen. Based on fluoride uptake data from an intra-oral model with proximally-located enamel specimens, estimates of variation among subjects, within subjects, and among specimens within subjects were obtained. Multiple specimens per panelist do not affect the first two sources of variation. Thus, the number of panelists, and not the number of specimens, is of primary importance when pre-test data are used to choose the appropriate study design and calculate the required sample size.

Patient selection and appliance design are important factors in the development of intra-oral models. Adults, rather than children, are recommended as panelists due to their similarity to children in response to fluoride for caries prevention, greater likelihood of compliance with all study requirements, and greater availability for appointments. It may be desirable for additional factors--including the presence of cariogenic micro-organisms and the characteristics of their saliva with regard to remineralization--to be used in the selection of panelists. Cross-over test designs may be desirable to minimize the impact of these variables as well as of dietary differences. Appliances should be designed to approximate the normal oral conditions to the maximum extent possible. Intra-oral models should be capable not only of detecting the effects of clinically-proven fluoride treatments but also of detecting fluoride dosage responses.

Weanling rats were given high-sucrose cariogenic diets containing 2 per cent lauric acid, linoleic acid, nonanoic acid or monolaurin. Plaque accumulation was determined on the incisors of half the animals during only the last 3 days of the study and on the remaining animals at the conclusion of a 21-day test period when both sulcal and smooth-surface caries were assessed. No significant differences between the test groups in food consumption were observed nor were there any differences in body weight gain. The least amount of plaque was observed in the animals given monolaurin; the other fatty acids exerted no significant effect upon plaque accumulation. The smooth-surface caries data indicated that the least number of lesions occurred in the animals on the diet containing monolaurin. Nonanoic acid was significantly more effective in limiting sulcal caries than any of the other fatty acids studied. Thus both monolaurin and nonanoic acid have significant cariostatic activity in the rat.

A three-yr caries study was conducted to evaluate an SnF2 prophylactic paste and topical solution professionally applied to children on a semi-annual basis. The topical solution imparted a significant decrease in caries incidence while the prophylactic paste was without significant effect. The combination of treatments was not significantly more effective than the topical application alone.

Four studies were performed in rats and hamsters concerning the cariogenicity of cereals and the role of sucrose in that process. The findings indicate that sucrose content per se does not necessarily reflect the cariogenic potential. Presweetened cereals were more conducive to the formation of smooth surface caries in the hamster than were nonpresweetened cereals while no major differences between the cereals were observed in occlusal caries in rats.

A series of studies was performed to measure fluoride deposition in incipient caries-like lesions in enamel specimens contained in functional partial dentures in panelists who used fluoride dentifrices for periods ranging from two to nine weeks. The studies demonstrated the ability of the model to replicate the fluoride-uptake results obtained with a series of three dentifrices in two different panels of subjects. All fluoride dentifrices resulted in significant fluoride deposition, although significantly greater deposition was observed with a NaF-SiO2 dentifrice.