Objectives: Dental caries is a multifactorial disease, and a sugary diet can generate an acidic plaque environment that advances its development. However, the specific effect of sugary drinks on the subsequent oral health of schoolchildren with mixed dentition is unclear. In this study, we investigated the association between the consumption of sugary drinks and 1 year incidence rate of caries in permanent teeth among Taiwanese schoolchildren with mixed dentition. Methods:A longitudinal 1 year follow-up study was conducted among Taiwanese schoolchildren aged 8-9 years. A questionnaire collected information regarding the parents' oral health status and their children's demographic background, oral healthrelated behaviours and consumption habits of sugary drinks, including handmade drinks (specifically bubble tea and pearl milk tea) and carbonated drinks. Dental caries was recorded through standardized oral examinations. The number of dental services received was retrieved from the Taiwan National Health Insurance Research Database. Multivariate Cox proportional hazards models and zero-inflated negative binomial models were used to estimate the association between the consumption of sugary drinks and the incidence rate of caries in permanent teeth after 1 year. Results:The study involved 494 children. During the 1 year follow-up period, 117 children developed new dental caries in their permanent teeth, yielding a caries incidence rate of 0.183 per person-year. After adjustments for confounding factors, children who preferred having sugar-rich beverages were associated with having a 4.3 times higher (95% confidence interval [CI] = 1.2-15.7) risk of developing caries than did those who preferred nonsugary drinks (P < .05). Additionally, children who often consumed handmade drinks were associated with having a 1.7 times higher (95% CI = 1.1-2.9) risk of developing caries than those who seldom consumed (P < .05). Conclusions:The findings suggest that the consumption of sugary drinks during the mixed dentition stage might be a major etiological factor for caries in permanent teeth. These findings could be valuable to paediatricians, dentists, nutritionists and policymakers.

AimTo investigate whether the timing of root canal treatment (primary aim) or other endodontic parameters (secondary aim) is associated with the survival probability of autotransplanted third molars, using a nationwide population‐based database.MethodologyA total of 1811 third molars autotransplanted between 2000 and 2013 met the inclusion criteria and were followed until the end of 2016. The teeth were classified into three groups on the basis of timing between root canal treatment and the autotransplantation: preoperative, extraoral and postoperative treatment groups. Univariate and multivariate Cox proportional hazards models were used to estimate the association between the timing of root canal treatment and the risk of tooth extraction after autotransplantation.ResultsOf the 1811 autotransplanted third molars, 462 were extracted, yielding a 17‐year survival probability of 0.578. The survival probability of autotransplanted teeth that received postoperative root fillings after 17 years was 0.583, which was significantly higher than the 0.434 and 0.566 for teeth that received preoperative and extraoral root fillings, respectively (P = 0.0013). After adjustment for potential confounding factors, teeth that received postoperative root fillings were associated with a significantly lower tooth extraction hazard ratio (HR) compared with those that received extraoral root fillings (adjusted HR, 1.43; 95% confidence interval [CI], 1.14–1.78) and those that received preoperative root fillings (adjusted HR, 2.13; 95% CI, 1.19–3.82). Furthermore, the use of a rubber dam during postoperative root filling was associated with a significantly lower extraction rate after autotransplantation (adjusted HR, 0.54; 95% CI, 0.43–0.69).ConclusionsPostoperative root canal treatment resulted in a significantly lower extraction rate than did preoperative or extraoral root canal treatment amongst autotransplanted third molars during a mean follow‐up period of 8.33 years. Rubber dam use is recommended during postoperative root canal treatment to improve the outcomes of autotransplantation.