Genetic approaches have shown that several genes could modify caries susceptibility; AmelogeninX (AMELX) has been repeatedly designated. Here, we hypothesized that AMELX mutations resulting in discrete changes of enamel microstructure may be found in children with a severe caries phenotype. In parallel, possible AMELX mutations that could explain resistance to caries may be found in caries-free patients. In this study, coding exons of AMELX and exon-intron boundaries were sequenced in 399 individuals with extensive caries (250) or caries-free (149) individuals from nine French hospital groups. No mutation responsible for a direct change of amelogenin function was identified. Seven single-nucleotide polymorphisms (SNPs) were found, 3 presenting a high allele frequency, and 1 being detected for the first time. Three SNPs were located in coding regions, 2 of them being non-synonymous. Both evolutionary and statistical analyses showed that none of these SNPs was associated with caries susceptibility, suggesting that AMELX is not a gene candidate in our studied population.

In the literature, the enamelin gene ENAM has been repeatedly designated as a possible candidate for caries susceptibility. Here, we checked whether ENAM variants could increase caries susceptibility. To this aim, we sequenced coding exons and exon-intron boundaries of ENAM in 250 children with a severe caries phenotype and in 149 caries-free patients from 9 French hospital groups. In total, 23 single-nucleotide polymorphisms (SNPs) were found, but none appeared to be responsible for a direct change of ENAM function. Six SNPs had a high minor allele frequency (MAF) and 6 others were identified for the first time. Statistical and evolutionary analyses showed that none of these SNPs was associated with caries susceptibility or caries protection when studied separately and challenged with environmental factors. However, haplotype interaction analysis showed that the presence, in a same variant, of 2 exonic SNPs (rs7671281 and rs3796704; MAF 0.12 and 0.10, respectively), both changing an amino acid in the protein region encoded by exon 10 (p.I648T and p.R763Q, respectively), increased caries susceptibility 2.66-fold independent of the environmental risk factors. These findings support ENAM as a gene candidate for caries susceptibility in the studied population.

Gingival bleeding (GB) is a common sign of gingival inflammation which indicates the presence of periodontal diseases. This cross-sectional multicenter survey aimed to assess the prevalence of self-reported gingival bleeding (SRGB) in French adults and identify the main associated factors. A questionnaire-based interview was randomly proposed to 794 individuals in four French cities (Nancy, Montpellier, Paris, and Rennes). Subjects were recruited in preventive medicine centers (50%), railway stations, and malls (50%). The questionnaire comprised 25 items: SRGB characteristics, socioeconomic variables, oral hygiene habits, use of drugs, and anxiety level. The overall prevalence of SRGB was 63.2% [59.8%; 66.6%], with 58.7% bleeding after toothbrushing and 4.5% spontaneous bleeding. Males reported significantly lower SRGB prevalence than females (p = 0.04). The distribution of SRGB frequency was inversely proportional to age (p < 0.0001). No association between drug use and SRGB was found. The people interviewed in the preventive medicine centers reported the highest frequency of SRGB (p < 0.0001). In the multivariate logistic model, SRGB was significantly related to occupation, smoking status, brushing frequency, and anxiety level. In conclusion, SRGB was prevalent in more than half of the sample and was mainly associated with age, toothbrushing frequency, and anxiety level. Thus, providing information to patients about the importance of this oral manifestation may play an important role in preventing periodontal diseases.

Background: Despite extensive prevention programs, dental hygiene remains inadequate, particularly among children under the age of six, and early childhood caries (ECC) are still a concern. Oral hygiene behavior and preventive practices seem difficult to change at a family level. Aim. The present study aimed to better understand the reasons behind this behavior and to identify the different barriers to the implementation of adequate preventive measures. Methods: A qualitative study was conducted in the pediatric dentistry service of the Montpellier University Hospital (France) in 2019. A thematic analysis concerning three domains was performed: family environment, dental literacy, and oral hygiene. Results. The main barriers encountered by the parents were, respectively, (1) a weakness in the organization of familial life, together with a low-medium family income and a lack of authority, (2) ignorance of the necessity of treating carious primary teeth, and (3) a lack of time for brushing or supervising their children’s teeth. Conclusion: These results showed that oral hygiene and primary teeth care could not be easily achieved in the family environment of the participants, and oral health strategies should be focused not only on children but also on their parents.

The primary objective of this study was to evaluate the effects of sealants in preventing pit and fissure caries in primary molars. The secondary objective was to assess the sealant retention during a 2‐yr study period. A 2‐yr split‐mouth randomized clinical trial including 90 3–7‐yr‐old children was conducted in the paediatric dental department of Montpellier hospital. The dentition of each included patient was divided into an experimental side and a control side, with annual follow‐up visits. Caries increments, measured as the number of new occlusal cavitated lesions, were not different between the sealed (mean 0.23) and the control primary molars (mean 0.29). A multiple mixed‐effects logistic regression showed that male gender, moderate/high caries risk, and a higher oral hygiene index score, had a statistically significant effect resulting in higher caries increments in the primary molars, than did female gender, low caries risk, and lower oral hygiene index scores. Sealing showed no statistically significant influence on the development of new caries lesions. After 2 yr, the percentages of partially or totally lost sealants were 22.7% and 32.0%, respectively. In this sample of children, the caries increment was not significantly different between the sealed and the unsealed molars. At the end of this 2‐yr study, more than half of the sealants were totally or partially lost, which could explain the low sealant effectiveness.

The first aim of this study was to investigate the recreational use of nitrous oxide (N2O) among health profession students at Montpellier University (France). The second aim was to identify the factors associated with N2O use. All students in medicine, dentistry, pharmacy and midwifery of the Montpellier University were contacted by email to participate in the survey. The students answered directly online by filling out anonymously a questionnaire including demographic information and questions about N2O, illicit drugs and alcohol use. Ethical approval was granted by the ethics committee of the Montpellier University. The sample comprised 593 students (mean age = 22.3 ± 2.6 yr), with 68.6% of females. Lifetime N2O use was reported by 76.6% and frequent alcohol use by 30.5% of the respondents. The lifetime use of cannabis, ‘poppers’, cocaine, ecstasy and LSD was 26.8%, 54.6%, 9.6%, 10.1% and 2.0% respectively. In multivariate analysis, the substances significantly associated with lifetime N2O were alcohol drinking and ‘poppers’ use. With respect to this self-nominated sample, our results indicate that respondents who were alcohol drinkers, were poppers users, follow longer studies, divert medical products for recreational use or were members of a students’ corporation had higher odds of lifetime N2O use.

The present study focuses on the use of a metaproteomic approach to analyze Black Extrinsic Tooth Stains, a specific type of pigmented extrinsic substance. Metaproteomics is a powerful emerging technology that successfully enabled human protein and bacterial identification of this specific dental biofilm using high-resolution tandem mass spectrometry. A total of 1600 bacterial proteins were identified in black stain (BS) samples and 2058 proteins in dental plaque (DP) samples, whereas 607 and 582 human proteins were identified in BS and DP samples, respectively. A large diversity of bacteria genera (142) in BS and DP was identified, showing a high prevalence of Rothia, Kingella, Neisseria, and Pseudopropionibacterium in black stain samples. In this work, the high diversity of the dental microbiota and its proteome is highlighted, including significant differences between black stain and dental plaque samples.

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