Apical periodontitis (AP) is essentially an inflammatory disease of microbial etiology primarily caused by infection of the pulp and root canal system. Variation of the bacterial communities caused by AP, as well as their changes responding to dental therapy, are of utmost importance to understand the pathogensis of the apical periodontitis and establishing effective antimicrobial therapeutic strategies. This study aims to uncover the composition and diversity of microbiota associated to the root apex to identify the relevant bacteria highly involved in AP, with the consideration of root apex samples from the infected teeth (with/without root canal treatment), healthy teeth as well as the healthy oral. Four groups of specimens are considered, the apical part of root from diseased teeth with and without root canal treatment, and wisdom teeth extracted to avoid being impacted (tooth healthy control), as well as an additional healthy oral control from biofilm of the buccal mucosa. DNA was extracted from these specimens and the microbiome was examined through focusing on the V3-V4 hypervariable region of the 16S rRNA gene using sequencing on Illumina MiSeq platform. Composition and diversity of the bacterial community were tested for individual samples, and between-group comparisons were done through differential analysis to identify the significant changes. We observed reduced community richness and diversity in microbiota samples from diseased teeth compared to healthy controls. Through differential analysis between AP teeth and healthy teeth, we identified 49 OTUs significantly down-regulated as well as 40 up-regulated OTUs for AP. This study provides a global view of the microbial community of the AP associated cohorts, and revealed that AP involved not only bacteria accumulated with a high abundance, but also those significantly reduced ones due to microbial infection.

This study aims to understand the deciduous dental caries status of preschool children in Xuhui District of Shanghai, China and to analyze the associated risk factors. In January of 2016, a cross-sectional investigation was conducted to examine the oral health of all the kindergarten children in Xuihui District of Shanghai, China. Meanwhile, a field questionnaire survey was conducted with the children’s guardians to ascertain the potential risk factors associated with deciduous dental caries. Among 11,153 children, the prevalence of deciduous dental caries was 47.02%, and the mean dmft score was 2.21. The first three predilection sites were maxillary central primary incisors, mandible second primary molars, and mandible first primary molars. There were statistically significant differences in caries prevalence and dmft among different age groups and different household registration (Hukou) types (P < 0.001). Multivariate Logistic regression suggested that the possible risk factors for deciduous caries included: older age, drinking sweetened beverages frequently, often or usually eating sweets before sleep compared to rarely/never eat them at this time, exclusive or predominant breastfeeding compared to exclusive or predominant artificial feeding and latter introduction of toothbrushing. On the other hand, Shanghai Hukou families, high educational level of guardians (high school or college education), regular parental support for children’s toothbrushing, guardians’ oral health knowledge, and a good perception about children’s oral health conditions were shown as potential protective factors for deciduous dental caries. The deciduous dental caries status of preschool children in Xuhui District of Shanghai was still serious. The caries prevalence in Xuhui, China, is associated with children’s age, household registration type, oral health habits, feeding habits, guardians’ education level, parental perception about children’s oral health and knowledge about oral health.

Vital pulp therapy (VPT) is recommended as an alternative treatment to root canal therapy (RCT) for management of teeth with carious pulp exposure. This randomized clinical trial aimed to compare the outcomes and postoperative pain, and to evaluate the time and cost after full pulpotomy (FP) and RCT in mature molar teeth with irreversible pulpitis (IP). A total of 160 mature molar teeth with IP were randomly divided into two treatment groups. The FP group (test group) was treated with FP using iRoot BP Plus by an endodontist, the RCT group (control group) was treated with RCT using iRoot SP as sealer by the same endodontist. Pain was recorded preoperatively and daily until day 7 postoperatively. The treatment time and cost were recorded. Clinical and radiographic assessments were collected, and pulp sensibility tests were done by electric pulp test (EPT) at 3-, 6-, 12- month postoperatively. Data were analyzed through chi-square test, Mann-Whitney U test, Fisher exact and independent t test. FP and RCT had comparable success rates (Clinical, 97.3% vs. 98.6%; radiographic, 93.3% vs. 94.6%) (P > 0.05). Pain levels decreased over time from day 1 to day 7 postoperative in both groups, and the FP group had larger reductions in pain intensity than RCT at day 1 (P < 0.05). In the FP group, there were 5, 3 and 3 unresponsive teeth with EPT at 3-, 6- and 12- month follow-ups, respectively. The treatment time and cost in the FP group were significantly lower than in the RCT group (P < 0.05). FP could be an appropriate alternative treatment for management of mature teeth with IP in short follow-up. The trial was registered in Chinese Clinical Trial Registry (ChiCTR2200063380 at 05/09/2022).