Effect of xylitol varnishes on remineralization of artificial enamel caries lesions in situ.

OBJECTIVES: Analyze the effect of varnishes containing xylitol compared to commercial fluoridated varnishes on the remineralization of artificial enamel caries lesions in situ. METHODS: Twenty subjects took part in this crossover, double-blind study performed in four phases of 5days each. Each subject worn palatal appliances containing four predemineralized bovine enamel specimens. Artificial caries lesions were produced by immersion in 30ml of lactic acid buffer containing 3mM CaCl2·2H2O, 3mM KH2PO4, 6µM tetraetil metil diphosphanate (pH 5.0) for 6days. The specimens in each subject were treated once with the following varnishes: 20% xylitol (experimental); Duofluorid™ (6% NaF, 6% CaF2), Duraphat™ (5% NaF, positive control) and placebo (no-F/xylitol, negative control). The varnishes were applied in a thin layer and removed after 6h. Fifteen subjects were able to finish all phases. The enamel alterations were quantified by surface hardness and transversal microradiography. The percentage of surface hardness recovery (%SHR), the integrated mineral loss and lesion depth were statistically analyzed by Friedmann and Dunn's tests test (p<0.05). RESULTS: Enamel surface remineralization was significantly increased by Duraphat™, Duofluorid™ and 20% xylitol formulations. Significant subsurface mineral remineralization could also be seen for the experimental and commercial varnishes, except for Duraphat™, when the parameter "lesion depth" was considered. CONCLUSIONS: 20% xylitol varnish seem to be a promising alternative to increase surface and subsurface remineralization of artificial caries lesions in situ. CLINICAL SIGNIFICANCE: effective vehicles are desirable for caries control. Xylitol varnishes seem to be promising alternatives to increase enamel remineralization in situ, which should be confirmed by clinical studies.

Distribution and prevalence of dental caries in Bauru, Brazil, 1976-2006.

AIMS: To compare caries prevalence and severity, as well as the disease distribution in the permanent dentition of 12-year-old schoolchildren in Bauru, Brazil, from 1976 to 2006. METHODS: Probabilistic samples were obtained in six surveys, from 1976 to 2006, which were conducted by calibrated examiners, following the same protocol. For data analysis, the DMFT (decayed, missing and filled teeth), Significant Caries Index (SiC Index), percentage of caries-free children, Gini Coefficient and Care Index were determined. RESULTS: The means (SD) for DMFT were 9.89 (3.96), 6.98 (3.80), 4.30 (3.11), 4.29(3.44), 1.53(2.07), and 0.90(1.53) in 1976, 1984, 1990, 1995, 2001 and 2006, respectively. Except for years 1990 and 1995 and also for 2001 and 2006, there were statistically significant differences in mean DMFT among the surveys (p < 0.05). The number of caries-free children (DMFT=0), which has significantly increased over the years (p < 0.001), ranged from 0.4% in 1976 to 63.8% in 2006. The SiC Indexes were 14.34, 11.42, 7.74, 8.06, 3.89, and 2.63; the Care Index were 31.9%, 57.4%, 68.7%, 50.5%, 66.4%, and 56.3%; and the Gini Coefficients were 0.23, 0.30, 0.39, 0.43, 0.66, and 0.76 in the surveys. CONCLUSION: Dental caries experience and prevalence in 12-year-old schoolchildren have declined significantly during the last 30 years in Bauru.

Low-fluoride dentifrices with reduced pH: fluoride concentration in whole saliva and bioavailability.

This double-blind study assessed the fluoride (F) concentration in whole saliva and F bioavailability after the use of low-F dentifrices with reduced pH. Whole saliva was collected from 10 volunteers after brushing with: experimental dentifrices (pH 5.5) 275, 550 and 1,100 ppm F; commercial 500 ppm F, pH 6.9 and a 'gold standard' 1,100 ppm F, pH 6.5. To analyze F bioavailability, 9 volunteers ingested weights of four dentifrices equivalent to 2 mg F: 1,500 ppm F/MFP/CaCO3, pH 9.5; 1,100 ppm F/NaF/silica, pH 5.5; 1,100 ppm F/NaF/silica, pH 7.0 and 1,100 ppm F/NaF/silica, pH 6.5 ('gold standard'). Ductal saliva and urine were collected. F was analyzed by electrode. Data were tested using ANOVA and Tukey's post hoc test (p < 0.05). The 550 ppm F/pH 5.5 dentifrice was similar to the 'gold standard' in its effect on whole saliva F concentration. The area under the curve of ductal saliva F concentration x time and urinary F excretion rates did not differ among the dentifrices. The results show that acidic low-F dentifrices are effective in increasing salivary F concentration and pH reduction does not seem to affect their F bioavailability.

Effectiveness of a chlorhexidine dentifrice in orthodontic patients: a randomized-controlled trial.

This blind and randomized-controlled trial analysed chlorhexidine dentifrices in relation to dental plaque, gingivitis, bleeding, calculus and enamel extrinsic staining development. Volunteers in fixed orthodontic therapy used the following dentifrices: 1100 ppmF, NaF (group A, n=27); experimental, 1100 ppmF, NaF and chlorhexidine 0.95% (group B, n=28); and experimental, chlorhexidine 0.95% (group C, n=28). At baseline, after 6, 12 and 24 weeks, clinical examinations were carried out. The gingivitis, bleeding and plaque data were tested by anova and Tukey's post hoc tests. Stain and calculus data were analysed by Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Plaque, gingivitis and bleeding scores improved in all three groups, but up to the 6 and 12 weeks examination the products containing chlorhexidine were statistically better. The chlorhexidine dentifrices significantly increased the mean of the stain index, although most of the patients did not notice the stains. The calculus index was not significantly modified. In summary, this study suggests that the use of dentifrices containing chlorhexidine seems to be effective for the treatment of gingivitis in orthodontic patients, although the intense motivating contact that the volunteers had with the researchers may have also played a role.

Trends in dental caries prevalence in 12-year-old schoolchildren between 1976 and 2001 in Bauru, Brazil.

OBJECTIVE: To evaluate the trends in dental caries prevalence in 12-year-old schoolchildren between 1976 and 2001 in Bauru, Brazil. Study design. An epidemiological survey was performed by trained, calibrated examiners by the same research group in 1976, 1984, 1990, 1995 and 2001, using the decayed, missing and filled teeth (DMFT) index. METHODS: Urban elementary schools were chosen because they provide a fair representation of the city's population in terms of socio-economic status. The study included 261, 321, 253, 377 and 211 subjects from the same regions in 1976, 1984, 1990, 1995 and 2001, respectively. The prevalence of caries and the DMFT index were used. RESULTS: A remarkable decrease was seen in the DMFT index at age 12 (84.53%) between 1976 and 2001. The DMFT indices at age 12 were 9.89, 7.01, 3.97, 4.13 and 1.53 in 1976, 1984, 1990, 1995 and 2001, respectively. The percentage of schoolchildren presenting with sound permanent teeth (DMFT = 0) increased from 0.40 to 45.50% between 1976 and 2001. Over the same period, the percentage of schoolchildren with six or more decayed teeth decreased from 86.99% to 5.21%. CONCLUSIONS: The phenomenon of dental caries polarization is already perceptible in Bauru, Brazil. The increase in the number of schoolchildren with sound permanent teeth (DMFT = 0) suggests that the dental health policy in Bauru has had a positive effect in children's dental health, and should therefore be considered for other cities.

[Severity of dental caries in children and relationship with social and behavioral aspects]. / Severidade de cárie em crianças e relação com aspectos sociais e comportamentais.

OBJECTIVE: To identify social and behavioral conditions that could act as risk factors to the severity of dental caries in 12-year-old children. METHODS: Based on the oral health survey data obtained in Florianópolis, Brazil, in 1995, social and behavior conditions were compared between two 12-year-old children groups with dental caries with different severity: high and very high severity, and very low severity. In the interview, there were questions about each family were part of the interview, besides social-economic conditions and behavior aspects. RESULTS/CONCLUSIONS: The multivariate logistic regression analysis showed that the risk factors for dental caries with high severity were candy intake and family income. Children who consumes cariogenic products 2 or 3 times a day on a daily basis has 4.41 more chance of having dental caries with high severity when compared to children who consumes these same products only once a day - CI (OR) = [1.18; 16.43] ). Family income was the most important socialeconomic factor. Children whose family income is lower than five minimum wages has 4.18 more chance of having high severity dental caries when compared to children whose family income is higher than five minimum wages - CI (OR) = [1.16; 15.03]. The purpose of this study was to have a a better knowledge of dental caries occurrence in 12-year-old children who, in most cases, have a complete permanent dentition that showed the illness history.

Urinary fluoride levels and prevalence of dental fluorosis in three Brazilian cities with different fluoride concentrations in the drinking water.

Urine samples from three daytime periods were collected from 545 5-50-year-old residents of three different Brazilian cities: Garça had fluoridated drinking water since 1973, Bauru since 1975 and Itápolis was not fluoridated. Dental fluorosis was examined in 985 5-24-year-olds using the Thylstrup-Fejerskov index (TF). The subjects were asked to estimate their daily intake of liquids and frequency of beverage consumption. The analysis of 94 water samples showed high variations in the fluoride content of the drinking water. The mean fluoride concentration of the water samples in Garça was 0.9 mg/L (range 0.75-1.2), in Bauru 0.64 mg/L (range 0.01-1.3), and in Itápolis 0.02 mg/L. Mean urinary fluoride concentration was 1.31 mg/L (s 0.61) in Garça, 0.88 mg/L (s 0.49) in Bauru, and 0.39 mg/L (s 0.21) in Itápolis. Self-reported daily liquid intake was not related to urinary fluoride concentration. The mean prevalence of fluorosis was 13.3% in Garça, 6.8% in Bauru, and 1.7% in Itápolis, with mainly categories TF 1 and TF 2 being recorded. Subjects with dental fluorosis tended to show a higher mean urinary fluoride concentration but the difference was not statistically significant. The study showed that fluoride exposure measured by urinary fluoride excretion was within the range expected for the level of fluoride concentration in the drinking water. However, enamel fluorosis tended to be markedly lower than expected. This study revealed that fluoride levels in the two cities with fluoridated drinking water were variable. To optimise anticaries benefits and minimise the risk of fluorosis greater control of the fluoride dosing of the drinking water is required.

Drinking water fluoride levels, dental fluorosis, and caries experience in Brazil.

OBJECTIVES: The main aim of this study was to consider the association between water fluoride levels and caries prevalence in three Brazilian populations. METHODS: A total of 457 6-12-year-old lifetime residents from three economically deprived groups with 2-3, 0.7, and less than 0.01 ppm F in their water supplies were examined. Dental caries was recorded on permanent upper central incisors and first molars and all primary teeth (dmft). RESULTS: There was a significant trend (P < 01) for the mean dmft to decrease with increasing levels of fluoride in the drinking water. Caries experience in the six permanent teeth was significantly lower (P < 01) in the area with 0.7 ppm F than in the other two groups For the 2-3 ppm F group significantly more caries was found in subjects with higher TF scores (P < 05). CONCLUSION: Optimization of fluoride levels in the drinking water remains a valuable dental public health measure in Brazil.

Comparison of dental prophylaxis and toothbrushing prior to topical APF applications.

This study was conducted to evaluate the effect of dental prophylaxis prior to the topical application of acidulated phosphate fluoride solution applied twice a year in schoolchildren. Experimental groups were: Group I--control group, had no treatment. Group II--twice yearly topical application of acidulated phosphate fluoride solution with prior professional prophylaxis with rubber cup and non fluoride paste. Group III--twice yearly topical application of acidulated phosphate fluoride solution with prior toothbrushing with a non-fluoridated prophy paste. After 18 months analysis of 160 children in each study group led to the following conclusions: 1. Acidulated phosphate fluoride topical applications are effective in the prevention of dental caries. 2. The omission of a professional prophylaxis prior to topical fluoride application does not affect significantly the caries preventive effect.