Effect of different frequencies of fluoride dentifrice and mouthrinse administration: an in situ study

Association between toothbrushing frequency and dental caries and tooth loss in adolescents: a cohort study

This cohort study assessed the association between toothbrushing frequency and the increment of dental caries and tooth loss in a population-based sample of southern Brazilian adolescents, to investigate whether there is any additional benefit in performing a third daily brushing. At baseline, 1,528 12-year-old schoolchildren attending 42 schools were examined for gingivitis and dental caries, and answered a questionnaire. After a mean period of 2.5 years, 801 schoolchildren were re-examined. Dental caries and tooth loss increment were outcomes of the study. The main predictor variable was toothbrushing frequency (≥3 times/day vs. twice/day or ≤1 time/day). Poisson regression models were used to estimate the risk for caries and tooth loss increment. Incidence risk ratios (IRR) and 95% confidence intervals (CI) were estimated. The final model adjusted for sociodemographic, behavioral, and clinical variables showed that brushing twice/day afforded 40% greater risk (IRR = 1.40; 95%CI: 1.02-1.92) for caries increment than ≥3 times/day. Regarding the tooth loss increment, adolescents who brushed their teeth twice/day had a fourfold greater risk (IRR = 3.92; 95%CI: 1.23-12.49) than those who brushed ≥ 3 times/day. Sex, school type, and gingivitis were found to act as effect modifiers, inasmuch as a third daily brushing presented advantages against tooth loss only for girls, public school attendees, and those with ≥ 50% of bleeding sites. This study suggests that adolescents benefit from a third daily toothbrushing. Increasing brushing frequency to 3 times/day may be a suitable strategy to control dental caries and tooth loss among high-risk adolescents.

Assessment of the effects of decontamination and storage methods on the structural integrity of human enamel

Abstract Introduction The storage of teeth for use in research is a controversial issue with no consensus on the most appropriate treatment method for this purpose. Objective The aim of this study was analyze the effectiveness and the influence of different methods of decontamination and storage of human enamel samples, in order to maintain their integrity. Material and method The sample consisted of 124 molars distributed randomly into three groups according to the method: control - distilled water, 0.1% thymol and 0.02% sodium azide. The tests performed were laser fluorescence, surface microhardness and profilometry analysis (0, 15 and 30 days) and Microbiological test (7, 15 and 30 days). Data were analyzed by the ANOVA and Tukey tests (P <0.05). Result In the laser fluorescence test, thymol proved to be more feasible for maintaining the integrity of the dental organ, since it did not show significant variations in values among the analyzed periods (P> 0.05). The surface microhardness analysis showed loss of tooth structure in all methods, and sodium azide led to a lower level of tooth loss. Profilometry analysis showed loss of mass in all groups whereas sodium azide showed the greatest loss. None of the methods was able to inhibit bacterial growth. Conclusion Among the processing methods analyzed none was able to combine effective decontamination and storage with maintenance of the structural integrity of the human enamel.

Tooth loss prevalence and risk indicators among 12-year-old schoolchildren from South Brazil

This population-based cross-sectional study aimed to assess the prevalence and risk indicators for tooth loss due to dental caries among 12-year-old schoolchildren from South Brazil. 1,528 out of 1,837 (participation rate = 83.17%) schoolchildren were included. Tooth loss prevalence was 5.81% (95% CI = 3.71-8.98) and 0.08 (95% CI = 0.04-0.12) teeth were missing. Schoolchildren with low socioeconomic status (OR = 2.28, 95% CI = 1.23-4.21), who repeated years in school (OR = 1.56, 95% CI = 1.01-2.42), and with gingivitis (OR = 1.81, 95% CI = 1.33-2.45) were more likely to have missing teeth. Schoolchildren brushing 2 times/day (OR = 0.78, 95% CI = 0.64-0.96) or more (OR = 0.49, 95% CI = 0.33-0.74), and those with dental insurance or private dentists (OR = 0.60, 95% CI = 0.39-0.93) were less likely to present missing teeth. © 2014 S. Karger AG, Basel.

Sodium fluoride mouthrinse used twice daily increased incipient caries lesion remineralization in an in situ model

OBJECTIVES

To investigate the remineralizing effects of fluoride mouthrinses used at different times and frequency in addition to fluoride toothpaste.

METHODS

A randomized crossover single blinded study comprised 4 experimental phases of 21 days each. Twelve orthodontic volunteers were fixed with an orthodontic bracket containing an artificial carious enamel slab, which was from the same tooth in all 4 phases, and were randomly assigned to the following groups: (1) brushing with F toothpaste 2× per day (F- brush), (2) F- brush+rinsing with 0.05% NaF (F- rinse) after lunch, (3) F- brush+F-rinse before bedtime, and (4) F- brush+F- rinse 2× per day. Mean mineral gain after each phase was determined from mineral density profiles obtained using Micro-CT.

RESULTS

The mean mineral gain in all treatments with F- brush and F-rinse were significantly greater than those in F- brush (p<0.05). Moreover F- rinse 2× per day increased lesion remineralization more than F- rinse once a day.

CONCLUSIONS

The twice-daily use of 0.05% NaF mouthrinse combined with twice-daily regular use of fluoride toothpaste resulted in the greatest remineralization of incipient caries. These data indicate that rinsing frequency is a factor affecting the effectiveness of fluoride mouthrinse.

CLINICAL SIGNIFICANCE

The rinsing frequency of NaF mouthrinse, when used with fluoride toothpaste, also affects the remineralization. This finding, if confirmed by a clinical study, would lead to a new recommendation for fluoride mouthrinse used in high caries risk patients who could benefit from using it twice a day.