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This study explored salivary fluoride levels following toothbrushing with 5000 and 1450 ppm fluoride toothpaste and determined the decline in salivary fluoride levels following the return from 5000 to 1450 ppm fluoride toothpaste. The study was a randomised, controlled double‐blind parallel clinical trial (n = 24/group) measuring salivary fluoride five times during a 3‐week trial phase involving 2×/day use of 5000 or 1450 ppm fluoride toothpaste, and five times during an ensuing 2‐week wash‐out phase where all participants used 1450 ppm toothpaste. Salivary fluoride was measured using a fluoride electrode and data were analysed using multilevel mixed‐effects linear regression. Baseline salivary fluoride geometric means were 0.014 and 0.016 ppm for the 1450 and 5000 ppm groups, while the values at the end of the trial phase were 0.023 and 0.044 ppm, respectively. During the trial phase, except at baseline, differences between groups were statistically significant. The salivary fluoride levels for the 5000 ppm group remained statistically significantly higher than for the 1450 ppm group only at the first measurement in the wash‐out phase (≈30 h after the last 5000 ppm brushing), indicating that higher salivary fluoride levels resulting from use of 5000 ppm are sustained only as long as the brushing habit continues. [ABSTRACT FROM AUTHOR]

The effect of non-operative caries control at cavity level is often questioned. This prospective study of cases aimed to evaluate the suitability of non-operative treatment of active cavitated approximal caries lesions in primary molars by assessing clinical changes of lesions over time. Further, we evaluate children's and parents' attitudes in response to non-operative cavity treatment. Thirty-nine children attending a community dental service, aged 5-11 years, joined the evaluation based on the following criteria: (i) the presence of at least one active cavitated caries lesion in the distal surface of first primary molar or mesial surface of the second primary molar extending up to two-thirds into dentin assessed radiographically, (ii) the absence of spontaneous pain, (iii) the absence of pulpal or periapical pathology. After informed consent, one randomly selected lesion per child had overhanging enamel margins adjusted and was treated non-operatively by the child/parent performing daily site-specific oral hygiene with a fluoridated toothpaste, supplemented by professional topical fluoride treatment and dietary advice. Nine lesions/children dropped out. Fifteen lesions survived without pulpal or periapical pathology for an average of 26 m (range 9-44). Lesion failure was associated with poor compliance or lesions not suited for the method. Children and parents were highly satisfied with the treatment. Our study identifies key factors in the performance of non-operative cavity treatment in a dental practice setting. It is concluded that non-operative cavity treatment can be a helpful method to control caries lesion progression in primary teeth and may familiarise the child with dental treatment. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the diagnostic accuracy of visual, fibreoptic transillumination (FOTI), and bite-wing radiographic examination performed by 4 observers for the identification of cavitated carious lesions in contacting approximal surfaces, and to assess the inter-observer agreement with these methods and with direct visual examination conducted after tooth separation, the method used as validation for definitive determination of cavitation. A total of 338 unrestored approximal surfaces in 53 students were examined independently by 4 dentists using the diagnostic methods under study. The results from the diagnostic methods were compared with the results from the validation method for each observer. The sensitivities for identification of cavitated lesions using visual examination ranged from 0.12 to 0.50. For FOTI and radiography, the sensitivities ranged from 0.00 to 0.08 and from 0.56 to 0.69, respectively. The specificities exceeded 0.90 for all observers with all methods. Kappa values expressing inter-observer reproducibility were lowest for FOTI, followed by visual and radiographic examination. On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. For the validation method, the inter-observer agreement was only 'substantial'. This implies that the method cannot be used as a validation for other diagnostic methods applied for the identification of cavitated carious lesions in contacting approximal surfaces. However, visual inspection after tooth separation may serve as a supplementary diagnostic tool to conventional visual and radiographic examination for clinical management of aproximal carious lesions. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of the study was to examine pre-brushing saliva fluoride concentrations before and during a large, 3-year, prospective toothpaste study on the effect of post-brushing rinsing on dental caries. The aims were to study saliva fluoride over time and the effect of rinsing on saliva fluoride and to relate saliva fluoride to caries increments and accumulation of plaque. Materials and methods: Saliva samples (baseline and 1, 2, and 3 years) were collected from 11-year-old children attending two schools (A and B) in Kaunas, Lithuania, who refrained from brushing the evening and morning before saliva collection. Numbers of saliva samples collected varied from 264 at baseline to 188 at the 3-year follow-up. Children in school A rinsed with water after daily brushing, while children in school B did not rinse. Total caries and visible plaque were registered at baseline and after 3 years. Results: Mean saliva fluoride concentrations at baseline and after 1, 2, and 3 years from school A (rinsing) were 0.014, 0.026, 0.029, and 0.034 ppm and from school B (no rinsing) were 0.013, 0.028, 0.031, and 0.031 ppm, respectively. Increases in saliva fluoride from baseline were significant (Wilcoxon’s test, p < 0.001), but the increase from baseline to year 1 was not statistically significantly different between schools. Saliva fluoride did not increase beyond year 1 and did at no time point differ between schools. Reductions in numbers of tooth surfaces with dental plaque were significantly positively related to the number of caries reversals over the 3 years. Conclusions: Background saliva fluoride concentration is increased by brushing at least once daily on schooldays, does not increase further over 3 years, and is not affected by rinsing after brushing. Clinical relevance: Continuous use of fluoride toothpaste produces ambient saliva fluoride levels similar to saliva fluoride in areas with fluoridated water. [ABSTRACT FROM AUTHOR]

We aimed to determine the bacterial diversity of different oral micro-niches and to assess whether saliva and plaque samples are representative of oral microbial composition. We took minute samples from each surface of the individual teeth and gingival crevices of two healthy volunteers (112 samples per donor), as well as samples from the tongue dorsum and non-stimulated and stimulated saliva. DNA was extracted from 67 selected samples of each donor, and the 16S rRNA gene was amplified by PCR and pyrosequenced to obtain, on average, over 2,700 reads per sample, which were taxonomically assigned to obtain a geographic map of bacterial diversity at each tooth and sulcus location. Analysis of the data shows considerable differences in bacterial composition between teeth at different intra-oral locations and between surfaces of the same tooth. The most pronounced differences were observed in incisors and canines, where genera like Streptococcus were found at 40% to 70% on the vestibular surfaces but were almost absent on the lingual sides. Saliva samples, especially non-stimulated saliva, were not representative of supra-and subgingival plaque in the two individuals tested. We suggest that more precise sampling is required for the proper determination of oral microbial composition and to relate that diversity to epidemiological, clinical, and etiological parameters. [ABSTRACT FROM PUBLISHER]

This study aimed at testing how active and inactive enamel caries lesions differ by their degree of resin infiltration, and whether the choice of acid pretreatment plays a crucial role. Four examiners assessed 104 human molars and premolars with noncavitated enamel lesions and classified them as 'active' or 'inactive' using the Nyvad criteria. Forty-five teeth were included in this study after independent unanimous lesion activity assessment. Lesions were cut perpendicularly into 2 halves. Each half lesion was pretreated with either 15% hydrochloric acid or 35% phosphoric acid. The lesions were infiltrated after staining with rhodamine isothiocyanate. Thin sections of 100 μm were prepared and the specimens were bleached with 30% hydrogen peroxide. The specimens were then counterstained with sodium fluorescein, subjected to confocal laser scanning microscopy and analyzed quantitatively. Outcome parameters were maximum and average infiltration depths as well as relative penetration depths and areas. In active lesions no significant difference of percentage maximum penetration depth and percentage average penetration depth between lesions pretreated with hydrochloric or phosphoric acid could be observed. In inactive lesions, however, phosphoric acid pretreatment resulted in significantly lower penetration compared to hydrochloric acid pretreatment. Surface conditioning with hydrochloric acid led to similar infiltration results in active and inactive lesions. Moreover, inactive lesions showed greater variability in all assessed infiltration parameters than did active lesions. In conclusion, caries lesion activity and acid pretreatment both influenced the infiltration. The use of phosphoric acid to increase permeability of the surface layer of active lesions should be further explored. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Dental caries results from an imbalance of the metabolic activity in the dental biofilm. The microbial communities of teeth have traditionally been studied by standard cultural approaches. More recently, cloning and sequencing of the 16S rRNA gene have been used to characterize the microbial composition of the oral biofilm, but the methodological limitations of this approach have now been recognized. Next-generation high-throughput sequencing methods have the potential to reveal the composition and functioning of the biofilm by means of metagenomic and metatranscriptomic analyses. Currently available high-throughput sequencing approaches are reviewed and discussed in relation to studying the biofilm associated with dental caries. Important in understanding the dynamic processes in caries is the metabolic activity of the biofilm; metabolome analysis is a new tool that might enable us to assess such activity. As caries is a localized disease, it is essential that biofilm samples are taken from precisely determined tooth sites; pooling samples is not appropriate. This paper presents the case that culture-based studies are important, but that the fullest understanding of the role of the biofilm in the caries process will only come from an integrated approach determining biological function and metabolic output. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Scarce information exists on the clinical features of dental caries in the Imperial Roman population and no structural data on caries lesions from this period have so far been published. We report on the findings of 86 teeth (50-100 AD) found during archaeological excavations of the temple of Castor and Pollux in the Forum Romanum. We found that nearly all teeth had large carious cavities extending into the pulp. The distribution and size of the caries lesions were similar to those found in contemporary adult populations in Africa and China living without access to dental care. Most lesions had a hypermineralized zone in the dentin at the advancing front of the carious cavities as revealed by micro-computed tomography. This biological dentin reaction combined with the morphology of the cavities might indicate that some temporary topical pain relief and intervention treatment slowed down the rate of lesion progression. This is indirectly supported by examination of cavities of similar size and depth from a contemporary population without access to dental health care. In contrast to the lesions in the Roman teeth, these lesions did not exhibit a hypermineralized dentin reaction. We investigated whether the Pb isotopic composition of enamel and/or dentin of a single tooth matched that of a sample of an ancient Forum water lead pipe. The Pb isotopic composition of the tooth did not match that of the tube, suggesting that the subjects were exposed to different Pb sources during their lifetime other than the lead tubes. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate if three probiotic bacteria present in the milk product Cultura Dofilus(R) naturell could be detected in saliva and on oral mucosal surfaces, and if they colonized dental surfaces in situ in 8 caries-inactive individuals after 8 daily exposures to the milk product for up to 3 days. Bacteria were identified by fluorescence in situ hybridization and confocal laser scanning microscopy. While probiotic bacteria were present sporadically in the oral cavity on mucosal surfaces and in saliva after 3 days of frequent use of the probiotic milk, they were not detected on dental surfaces. Probiotic bacteria may thus contribute to general oral health, but their potential role in biofilm-induced dental diseases remains unclear. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate if three probiotic bacteria present in the milk product Cultura Dofilus® naturell could be detected in saliva and on oral mucosal surfaces, and if they colonized dental surfaces in situ in 8 caries-inactive individuals after 8 daily exposures to the milk product for up to 3 days. Bacteria were identified by fluorescence in situ hybridization and confocal laser scanning microscopy. While probiotic bacteria were present sporadically in the oral cavity on mucosal surfaces and in saliva after 3 days of frequent use of the probiotic milk, they were not detected on dental surfaces. Probiotic bacteria may thus contribute to general oral health, but their potential role in biofilm-induced dental diseases remains unclear. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate, using visual assessment, an experimental optical sensor measuring perpendicular reflection intensity (PRI) as an indicator of enamel caries lesion activity/inactivity. Forty teeth with either an active or an inactive enamel lesion were selected from a pool of extracted teeth. Each tooth was cut into halves, with a clinically sound half and a half with a non-cavitated enamel lesion. After gentle plaque removal, the teeth were kept moistened. The lesions were then photographed and a defined measuring site per lesion was chosen and indicated with an arrow on a printout. Independently, the chosen site was visually assessed for lesion activity, and its glossiness was measured with PRI assessment. Surface roughness (SR) was assessed with optical profilometry using a confocal microscope. Visual assessment and PRI were repeated after several weeks and a reliability analysis was performed. For enamel lesions visually scored as active versus inactive, significantly different values were obtained with both PRI and SR. PRI values of the clinically sound control surfaces were significantly different only from active lesions. Generally, inactive lesions had the same glossiness and the same roughness as the sound control surfaces. The reliabilities for visual assessment (κ = 0.89) and for PRI (ICC = 0.86) were high. It is concluded that, within the limits of this study, PRI can be regarded as a promising tool for quantitative enamel lesion activity assessment. There is scope and potential for the PRI device to be considerably improved for in vivo use. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Dental biofilms produce acids from carbohydrates that result in caries. According to the extended caries ecological hypothesis, the caries process consists of 3 reversible stages. The microflora on clinically sound enamel surfaces contains mainly non-mutans streptococci and Actinomyces, in which acidification is mild and infrequent. This is compatible with equilibrium of the demineralization/ remineralization balance or shifts the mineral balance toward net mineral gain (dynamic stability stage). When sugar is supplied frequently, acidification becomes moderate and frequent. This may enhance the acidogenicity and acidurance of the non-mutans bacteria adaptively. In addition, more aciduric strains, such as ‘low-pH’ non-mutans streptococci, may increase selectively. These microbial acid-induced adaptation and selection processes may, over time, shift the demineralization/ remineralization balance toward net mineral loss, leading to initiation/progression of dental caries (acidogenic stage). Under severe and prolonged acidic conditions, more aciduric bacteria become dominant through acid-induced selection by temporary acid-impairment and acid-inhibition of growth (aciduric stage). At this stage, mutans streptococci and lactobacilli as well as aciduric strains of non-mutans streptococci, Actinomyces, bifidobacteria, and yeasts may become dominant. Many acidogenic and aciduric bacteria are involved in caries. Environmental acidification is the main determinant of the phenotypic and genotypic changes that occur in the microflora during caries. [ABSTRACT FROM PUBLISHER]

Introduction: Quantative confocal laser scanning microscopy (CLSM) in combination with fluorescent in situ hybridization (FISH) may help to increase our knowledge about biofilm formation. The purpose of this study was to develop and evaluate a stereological method for quantification of bacteria in intact biofilm. The method was applied in a quantitative study of the proportion of streptococci relative to other bacteria in initial in-situ-grown dental biofilms as a function of time. Methods: Biofilms were collected on standardized glass slabs mounted in intra-oral appliances and worn by 10 individuals for 6, 12, 24, and 48 h. Biofilms were analysed using CLSM. Quantification of bacteria labelled with 16S ribosomal RNA oligonucleotide probes was performed with stereological tools: the unbiased counting frame and the two-dimensional fractionator. Results: Results showed a notable increase in the total number of bacteria and streptococci over time, with a considerable inter-individual variation at each time-point. After 48 h there was a 12.5-fold difference between individuals in the total number of bacteria and a 12.6-fold difference in the number of streptococci. The number of streptococci exceeded that of other bacteria and over the examination period there was a relatively constant relationship between the number of streptococci and other bacteria (streptococci vs. non-streptococci: median 15.2; minimum 1.0; maximum 89.3). Conclusion: The study demonstrates that the combined use of FISH and stereology is a relevant and reliable tool for obtaining unbiased information about the numerical contributions of specific bacterial populations during early biofilm formation. [ABSTRACT FROM AUTHOR]

In this essay we propose an extension of the caries ecological hypothesis to explain the relation between dynamic changes in the phenotypic/genotypic properties of plaque bacteria and the demineralization/remineralization balance of the caries process. Dental plaque represents a microbial ecosystem in which non-mutans bacteria (mainly non-mutans streptococci and Actinomyces) are the key microorganisms responsible for maintaining dynamic stability on the tooth surface (dynamic stability stage). Microbial acid adaptation and subsequent acid selection of ‘low-pH’ non-mutans bacteria play a critical role for destabilizing the homeostasis of the plaque by facilitating a shift of the demineralization/remineralization balance from ‘net mineral gain’ to ‘net mineral loss’ (acidogenic stage). Once the acidic environment has been established, mutans streptococci and other aciduric bacteria may increase and promote lesion development by sustaining an environment characterized by ‘net mineral loss’ (aciduric stage). Hence, high proportions of mutans streptococci and/or other aciduric bacteria may be considered biomarkers of sites of particularly rapid caries progression. This cascade of events may change the surface texture of caries lesions from smooth to rough (enamel) or hard to soft (dentin). These clinical surface features can be reversed at any stage of lesion development provided that the acidogenic/aciduric properties of the biofilm are resolved. From an ecological point of view it is therefore not only important to describe which bacteria are involved in caries, but also to know what the bacteria are doing. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse possible associations between caries increments and selected caries determinants in children with type 1 diabetes mellitus and their age- and sex-matched non-diabetic controls, over 2 years. A total of 63 (10–15 years old) diabetic and non-diabetic pairs were examined for dental caries, oral hygiene and salivary factors. Salivary flow rates, buffer effect, concentrations of mutans streptococci, lactobacilli, yeasts, total IgA and IgG, protein, albumin, amylase and glucose were analysed. Means of 2-year decayed/missing/filled surface (DMFS) increments were similar in diabetics and their controls. Over the study period, both unstimulated and stimulated salivary flow rates remained significantly lower in diabetic children compared to controls. No differences were observed in the counts of lactobacilli, mutans streptococci or yeast growth during follow-up, whereas salivary IgA, protein and glucose concentrations were higher in diabetics than in controls throughout the 2-year period. Multivariable linear regression analysis showed that children with higher 2-year DMFS increments were older at baseline and had higher salivary glucose concentrations than children with lower 2-year DMFS increments. Likewise, higher 2-year DMFS increments in diabetics versus controls were associated with greater increments in salivary glucose concentrations in diabetics. Higher increments in active caries lesions in diabetics versus controls were associated with greater increments of dental plaque and greater increments of salivary albumin. Our results suggest that, in addition to dental plaque as a common caries risk factor, diabetes-induced changes in salivary glucose and albumin concentrations are indicative of caries development among diabetics. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of saliva composition on caries lesion development independently of the flow rate of unstimulated whole saliva (UWS) and other caries-related variables such as lesion progression time, oral hygiene level, and fluoride exposure. We hypothesized that this could be done by developing experimental root caries under carefully controlled conditions in situ in test subjects with UWS flow rates within a narrow window of normalcy. Fifteen female and 5 male subjects (66 ± 6 years) were selected for the study according to their UWS flow rates between 0.2 and 0.4 ml/min. All subjects developed experimental root caries lesions during a 62-day period in which UWS as well as stimulated whole saliva (SWS) were repeatedly collected and analysed for flow rate, pH, buffer capacity, inorganic, and organic composition. Caries lesion development was determined by quantitative microradiography. The mean UWS flow rate was 0.30 ± 0.05 ml/min. Significant negative correlations were obtained between UWS total phosphate concentration and mineral loss (ΔZ; rs = –0.72, p < 0.001) and UWS total protein concentration and ΔZ (rs = –0.70, p < 0.01). SWS and its constituents had only limited or no effect on ΔZ. Qualitative UWS protein analysis (SDS-PAGE) revealed that subjects with low ΔZ values had broader and more stained amylase bands than subjects with high ΔZ values. These findings were confirmed quantitatively by HPLC. We conclude that, within a group of subjects with normal UWS flow rates, the UWS composition was more important for caries lesion development than the SWS composition. Furthermore, high UWS concentrations of phosphate, protein, and amylase were caries-protective. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Caries diagnosis is the art or act of identifying a disease from its signs and symptoms. This is distinct from the detection of the signs and symptoms themselves. The diagnosis forms the basis for making informed treatment decisions. Hence, if there is no diagnostic step expressed in terms of the probability of present and future occurrence of disease, practitioners may resort to treatments guided by previous experiences with similar clinical manifestations. This paper reviews various methodological aspects of caries diagnostic testing. It is concluded that rather than continuing to search for the truth of the diagnosis, it may be more informative to consider the consequences of the diagnosis. This view is supported by results from caries-preventive trials in which the activity of carious lesions has been monitored longitudinally over years. [ABSTRACT FROM AUTHOR]

The article focuses on a study which examined the effect of unstimulated saliva flow rate on experimental root caries lesion characteristics. These characteristics include mineral loss, lesion depth and mineral distribution in experimental root caries lesions in situ. It showed that all demineralization parameters were correlated with the unstimulated saliva flow rate. Multiple regression analyses showed that the unstimulated saliva flow rate alone explained the variance in the demineralization parameters.

Even though there is no "gold standard" for determining caries lesion activity, it is nonetheless possible to evaluate the validity of such diagnostic measures. The aim of this study was to estimate the construct and predictive validity of caries lesion activity assessments by means of their ability to reflect known effects of fluoride on caries. A three-year trial of the effect of daily supervised brushing with fluoride toothpaste was carried out among 273 12-year-old children. All children were examined clinically according to diagnostic criteria for activity assessment. The relative risk (fluoride vs. control) for caries lesion transitions among diagnostic categories was calculated. Fluoride inhibited progression of caries at all stages of lesion formation while at the same time enhancing lesion regression. The effects were most pronounced for active non-cavitated lesions. It is concluded that the clinical diagnostic criteria have construct and predictive validity for the assessment of caries lesion activity. [ABSTRACT FROM AUTHOR]

Previous studies have indicated that rinsing the mouth with a beaker of water after toothbrushing may compromise the caries reducing effect of fluoride toothpaste. A 3-year clinical trial of daily supervised brushing with fluoride toothpaste at school was used to test the effect of post-brushing rinsing with water on caries increment. A total of 407 children, mean age 11.8 years, attending three schools in Kaunas, Lithuania were enrolled following informed consent of the children and their parents. Caries was recorded at baseline and annually for 3 years. During the study, children in two schools (A and B) performed daily supervised brushing with a 1,500-ppm fluoride toothpaste. Children in school A rinsed their mouths thoroughly with a beaker of water after toothbrushing whereas children in school B were only permitted to spit out once after brushing. Furthermore, the children in these schools were supplied with toothpaste and toothbrushes for use at home and in school. A third school (C), without daily brushing and without supply of toothpaste, served as control. Compliance with the protocol was consistently better in school B. After 3 years 276 children were available for examination. Three-year DMFS increments, including non-cavitated lesions (mean, 95% CI), were: school A, 6.8 (5.3; 8.3); school B, 6.2 (4.6; 7.8), and school C, 12.4 (10.6; 14.1). Mean increments for schools A and B did not differ significantly but were both significantly lower than those of school C (p< 0.001). It is concluded that post-brushing rinsing with water, under the conditions of this study, does not significantly affect the caries reducing effect of a fluoride toothpaste. [ABSTRACT FROM AUTHOR]

Acid production, in particular at low pH, is thought to be an important ecological determinant in dental caries. The aim of the present study was to determine the acid producing capability at different pH levels of 47 streptococcal strains, representing 9 species, isolated from human dental plaque. The bacteria were grown until mid log-phase under anaerobic conditions and acid production was measured in a pH-stat system at pH 7.0, 6.0, 5.5 and 5.0. At all pH values, the mean velocity of acid production (Vap) by Streptococcus mutans and S. sobrinus was significantly higher (p<0.01; ANOVA) than that of the other oral streptococci, including S. mitis, S. oralis, S. gordonii, S. sanguis, S. intermedius, S. anginosus, S. constellatus, and S. vestibularis. However, the Vap of some strains of S. mitis biovar 1 and S. oralis, particularly at pH values of 7.0 and 6.0, exceeded that of some strains of S. mutans. The Vap decreased with pH for all strains, but some strains of S. mitis biovar 1 and strains of the mutans streptococci maintained a relatively high rate of acid production. The results suggest that some strains of S. mitis biovar 1 and S. oralis may play an important role in caries development by modifying the environment in dental plaque to become favourable for the succession of aciduric species. The study furthermore emphasises the need for detailed species and biovar identification of oral streptococci and for recognition of the significant physiological differences that occur within single species. [ABSTRACT FROM AUTHOR]

The capability of a soft drink or a juice to erode dental enamel depends not only on the pH of the drink, but also on its buffering effect. As the latter is the ability of the drink to resist a change of pH it may add to the effects of the actual pH. The aim of the present study was to compare the pH and the buffering effect of various soft drinks with their erosive effects and the solubility of apatite. In 18 soft drinks, mineral waters and juices available on the Danish market, pH and the concentrations of calcium, phosphate and fluoride were determined. The buffering effect was determined by titration with NaOH. Human teeth (n = 54) covered with nail varnish except for 3x4-mm windows were exposed to 1.5 liters of the drink for either 7 days or 24 h under constant agitation. The depth of the erosions was assessed in longitudinal sections. The depth was found to vary greatly from 3 mm eroded by the most acidic drinks and fresh orange juice to only slightly affected surfaces by most of the mineral waters. The dissolution of enamel increased logarithmically inversely with the pH of the drink and parallel with the solubility of enamel apatite. Orange juice, pH 4.0, supplemented with 40 mmol/l calcium and 30 mmol/l phosphate did not erode the enamel as the calcium and phosphate saturated the drink with respect to apatite. Generally, the lower the pH the more NaOH was necessary to bring the pH to neutrality. In particular the buffering effect of the juice was high. For all drinks, no effect of their low fluoride concentrations was observed. [ABSTRACT FROM AUTHOR]

Bite-wing radiography has been recommended for use in adolescents as clinical examinations alone may lead to underestimation of carious lesions in approximal and occlusal surfaces. The aim of this study was to describe the relationship between clinical and radiographic caries diagnoses among 12-year-old Lithuanians using a new clinical scoring system which differentiates between cavitated and non-cavitated caries lesions. Eight hundred and seventy-two children were examined clinically and two standardized posterior bite-wing radiographs were taken of each participant. Bite-wing radiography contributed significantly to the total number of lesions diagnosed only at the dentin level in approximal surfaces. Clinical examination performed better than radiographic examination at the non-cavitated/enamel level, particularly on occlusal surfaces. Less than 2% of the clinically sound surfaces were diagnosed with dentin lesions/fillings radiographically. When using the cavitated level of clinical diagnosis, the frequency of 'hidden' caries lesions increased from 1.9 to 2.9% in approximal surfaces, and from 1.7 to 5.2% in occlusal surfaces. The intra-examiner reliability data for the clinical and radiographic recordings supported the conclusion of an additional diagnostic value of bite-wings only for approximal surfaces. The findings demonstrate that the diagnostic yield of bite-wing radiography is higher for approximal than for occlusal surfaces. The efficacy of bite-wings depends on the refinement of the clinical caries diagnostic criteria. 'Hidden' caries does not seem to be a major problem when the clinical caries diagnostic criteria include non-cavitated diagnoses. [ABSTRACT FROM AUTHOR]

Current scoring systems for dental caries do not consider the dynamic nature of the disease. The aims of the present study were to describe a new set of clinical caries diagnostic criteria which differentiate between active and inactive caries lesions at both the cavitated and non-cavitated levels and to evaluate the reliability of this criteria system in a population with high caries experience. Ten diagnostic codes were defined: 0 = sound; 1 = active (intact); 2 = active (surface discontinuity); 3 = active (cavity); 4 = inactive (intact); 5 = inactive (surface discontinuity); 6 = inactive (cavity); 7 = filling; 8 = filling with active caries; 9 = filling with inactive caries. Distinction between active and inactive caries lesions was made on the basis of a combination of visual and tactile criteria. The inter- and intra-examiner reliability was assessed through repeated examinations of 50 children by 2 recorders over a period of 3 years. The percentage agreement of caries diagnoses varied between 94.2 and 96.2%. The kappa values ranged between 0.74 and 0.85 for intra-examiner examinations and between 0.78 and 0.80 for inter-examiner examinations; 81.6% of all misclassifications involved non-cavitated caries lesions. Disagreement between sound surfaces and non-cavitated active or non-cavitated inactive lesions (31.3 and 31.2%, respectively) was more common than disagreement between non-cavitated active and non-cavitated inactive lesions (10.6%). The probability of reconfirming a sound, non-cavitated active or non-cavitated inactive caries lesion - given that the surface was diagnosed as either sound, non-cavitated active or non-cavitated inactive at the first examination - was 98.0, 68.7 and 72.5%, respectively. The results show that the use of a new set of clinical caries diagnostic criteria based on activity assessment can be performed with a high reliability, even when non-cavitated diagnoses are included in the criteria system. [ABSTRACT FROM AUTHOR]

Three siblings with Morquio’s syndrome are described. Cultured fibroblasts from the youngest sibling demonstrated a total absence of N-acethylgalactosamine-6-sulphate-sulphatase whereas β–galactocidase activity was normal, thus verifying the diagnosis of MPS-IV A. Dental features such as pointed cusps, spade-shaped incisors, thin enamel and pitted buccal surfaces were observed in all three children. Furthermore, in all three siblings the TMJ was affected with severe resorption of the head of the condyle. Histological examination of exfoliated primary molars showed a band of increased porosity following the striae of Retzius in the outer part of the enamel. These developmental disturbances were occasionally associated with minor localized defects in the enamel surface. The importance of close monitoring of dental development and regular dental care in order to prevent attrition of the teeth, loss of vertical face height and subsequent risk of TMJ dysfunction is emphasized. [ABSTRACT FROM AUTHOR]

In situ caries models serve purposes other than just being a simpler way to obtain data than running a clinical trial. However, variation in information obtained not only among individuals but also, in particular, depending on different locations of the models within the oral cavity have so far been given little attention. In the present review, the aim has been to characterize the different designs of in situ caries models and to describe some important factors which may vary within the oral cavity and thus influence the outcome of the way the different in situ models are used. Advantages and disadvantages of in vivo models vs. in situ models are discussed. In the latter case, the distinction is made between dental appliance models and so-called "single tooth" models. The review concludes that in situ models differ distinctly with regard to their "biological potential". Because of regional differences in salivary film velocity, pH, and composition of the microflora, results obtained by the various models are not likely to be immediately comparable. Moreover, local factors in relation to specimen environment, such as degree of "protection" and plaque thickness, may further add to the differences. It is suggested that these observations are important in considerations of the relevance of substituting clinical trials with in situ studies. Because of the pronounced intra-oral variation in certain parameters thought to be important for caries lesion development, we conclude that no in situ model can, by itself, fulfill the role as the "model of choice". Finally, although in situ models are useful adjuncts in attempts to estimate the relative effects of new anticaries methods or compounds on caries initiation, the selection of in situ study model design will strongly depend on the aim and purpose of the study. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the diagnostic accuracy of visual, fibre-optic transillumination (FOTI), and bite-wing radiographic examination performed by 4 observers for the identification of cavitated carious lesions in contacting approximal surfaces, and to assess the inter-observer agreement with these methods and with direct visual examination conducted after tooth separation, the method used as validation for definitive determination of cavitation. A total of 338 unrestored approximal surfaces in 53 students were examined independently by 4 dentists using the diagnostic methods under study. The results from the diagnostic methods were compared with the results from the validation method for each observer. The sensitivities for identification of cavitated lesions using visual examination ranged from 0.12 to 0.50. For FOTI and radiography, the sensitivities ranged from 0.00 to 0.08 and from 0.56 to 0.69, respectively. The specificities exceeded 0.90 for all observers with all methods. Kappa values expressing inter-observer reproducibility were lowest for FOTI, followed by visual and radiographic examination. On the basis of these results, it was concluded that FOTI was the least reliable of the diagnostic methods tested. For the validation method, the inter-observer agreement was only 'substantial'. This implies that the method cannot be used as a validation for other diagnostic methods applied for the identification of cavitated carious lesions in contacting approximal surfaces. However, visual inspection after tooth separation may serve as a supplementary diagnostic tool to conventional visual and radiographic examination for clinical management of aproximal carious lesions. [ABSTRACT FROM AUTHOR]

In order to evaluate suitable strategies for control of dental caries, a longitudinal study of caries progression has been initiated among 12-year-old children in Kaunas, Lithuania. The aim of the present paper was to describe the baseline caries situation in a sample of 12-year-olds, who had been examined using caries diagnostic criteria which differentiate between active and inactive caries lesions at both the cavitated and non-cavitated levels. The mean fluoride concentration in the drinking waters of Kaunas is 0.16 mg/l. A total of 889 children in the 6th grade from seven selected schools were examined. Each tooth surface of all permanent teeth was classified according to one of the following criteria: 0 = sound; 1 = active, surface intact; 2 = active, surface discontinuity; 3 = active, cavity; 4 = inactive, surface intact; 5 = inactive, surface discontinuity; 6 = inactive, cavity; 7 = filled; 8 = filled with inactive lesion; 9 = filled with active lesion; X = extracted. Distinction between active and inactive lesions was made on the basis of a combination of visual and tactile criteria. Virtually all children (99.7%) had experienced at least 1 DMF surface. The mean DMFS was 15.8. Half of the mean caries experience consisted of surfaces with active lesions (7.9), of which two thirds (4.9) were non-cavitated. The mean number of surfaces with non-cavitated inactive lesions was 4.4. The mean DMFT constituted 7.9; 95% of all first molars were affected, followed by the second molars (61%). A comparison of the caries profile according to the present caries diagnostic criteria with those recommended by WHO revealed that the WHO criteria yielded much lower DMFS and DMFT values, because this scoring system does not include non-cavitated caries lesions. The high level of non-cavitated active caries lesions suggests that in this population caries may to a large extent be controlled by simple preventive measures including use of topical fluorides. [ABSTRACT FROM AUTHOR]

This study tests the hypothesis that daily oral hygiene combined with topical fluoride arrests active root- surface caries lesions without changing the mineral content of the lesions. Therefore, changes in mineral content and distribution were studied in root surfaces during caries lesion development and subsequent arrest of lesion progression in situ. In 18 subjects, lesions were developed during 3 months in sound root-surface specimens inserted into lower partial dentures. After 3 months, ground sections were prepared from each lesion prior to re-insertion of the specimens into the dentures. In addition, one sound root specimen was added per subject. During the following 3 months, half of the subjects cleaned both sound and carious specimens once a day with an 1100-ppm fluoride toothpaste, and the specimens were treated twice with 2% NaF for 2 min in situ. The other half of the subjects continued the experiment without cleaning. During the initial three-month period, all specimens developed subsurface lesions extending 187 to 583 pm into the dentin. Lesion depth increased somewhat in both experimental groups during the following 3 months (P ≥ 0.1). There was a non-significant increase in mineral loss in the plaque-covered specimens (P = 0.08). However, the total mineral content of specimens subjected to plaque removal and topical fluoride did not change. This treatment resulted in an increased mineral content in the surface layer (P < 0.01) and formation of a zone of higher mineral content within the body of the lesion. The sound root surfaces which had been cleaned for a three-month period showed mineral uptake in the surface layer, occasionally associated with subsurface demineralization extending 20 to 70 pm into the tissue. The mineral loss of these specimens was significantly smaller than that of plaque-covered surfaces (P < 0.001). It is concluded that daily plaque removal and topical fluoride use influence the distribution of mineral in sound and carious root surfaces and may arrest lesion progression without affecting the total mineral content. [ABSTRACT FROM AUTHOR]

Demineralization of dentin specimens proceeds at a faster rate than that of enamel. Although this is generally accepted, aquantification of the rate of formation of root lesions is hampered by the shrinkage of the lesions when these are dried prior to microradiographic analysis. This leads to a significant underestimation of the lesion depth and total mineral loss. The aim of this paper was to quantitate the rate of mineral loss during root lesion formation in vitro and to determine the shrinkage of root specimens as a result of drying. Unerupted roots of human teeth were subjected to a demineralizing system of 0.1 mol/L lactate buffer (pH = 4.8) with 0.2 mmol/L methanehydroxydiphosphonate during four, 11, 22, and 44 days. The root lesions were assessed by quantitative microradiography. The demineralizing solutions were analyzed to determine the amounts of root tissue dissolved. A comparison of these two sets of data showed that, with the demineralizing system used, root lesions may shrink up to 62%. Fixation of the specimens in fixative did not affect this shrinkage. Chemical analysis showed that mineral loss proceeded linearly with time. From the data-sets of this study, a model was developed to compensate for the shrinkage in the dentin specimens. In this way, it was possible to calculate the lesion depth at four demineralization times as being 130, 220, 320, and 530PM, respectively. These values were in agreement with a microscopic determination of the lesion depth. [ABSTRACT FROM AUTHOR]

This study describes the structural features of the interface between microbial deposits and root cementum in actively progressing root-surface caries lesions developed experimentally in six elderly individuals. A total of 18 specimens was examined by microradiography, and a further 18 by light and transmission electron microscopy after intra-oral periods of one, two, and three months. All specimens showed various degrees of subsurface dissolution of mineral and bacterial invasion of the cementum. Although the microradiographic pattern of mineral loss was subsurface in nature, transmission electron microscopy showed dissolution of crystals in the outermost layers of the cementum, with a distinct gradient inward. Bacterial invasion occurred along the borders between bundles of relatively well-mineralized extrinsic collagen fibers in which the characteristic cross-banding remained intact. The pattern of bacterial invasion was influenced by the incremental lines and the cemento-dentinal junction. The invading bacteria were almost exclusively Gram-positive, of various shapes, and possessed thick, moderately electron-dense cell walls and electron-lucent "vacuoles" in the cytoplasm. It is concluded that because of pronounced mineral loss of the outermost cementum, accompanied by bacterial invasion, the surface of an active cementum caries lesion, as observed by transmission electron microscopy, is not identical to that seen in micro-radiograms. [ABSTRACT FROM AUTHOR]