Epidemiology of plaque-induced gingivitis among 12-15-year-old Chinese schoolchildren: A study based on the 2018 case definition.

AIM: To explore the epidemiology of plaque-induced gingivitis and related factors among Chinese adolescents. MATERIALS AND METHODS: This cross-sectional survey comprised 118,601 schoolchildren in the 12-15-year age group. Data came from the National Oral Health Survey in mainland China. The field investigation was conducted according to the World Health Organization guidelines. The new 2018 case definition for plaque-induced gingivitis was used. Participants underwent clinical examinations and completed a structured questionnaire. Bleeding on probing (BOP) was performed on all teeth. Multinomial logistic regression was used to explore the factors related to the extent of gingivitis. RESULTS: Nearly half of the study population (47.3%) had plaque-induced gingivitis; 23.9% and 23.3% presented with localised and generalised gingivitis, respectively. The first molars were the most affected by BOP. Well-established factors, such as demographic characteristics, socioeconomic status, local factors and smoking habits, were significantly associated with the extent of gingivitis. Odds ratios for localised and generalised gingivitis increased with the decrease in frequency of toothbrushing with a fluoride dentifrice. CONCLUSIONS: The study population had high plaque-induced gingivitis prevalence. The extent of gingivitis appeared to have a dose-response relationship with the frequency of toothbrushing with a fluoride dentifrice.

Long-term exposure to ambient fine particulate matter and periodontitis: An observational study using nationally representative survey data.

AIM: The rising prevalence of periodontitis imposes substantial burdens on individuals and society. Identifying environmental risk factors for periodontitis may contribute to tackling the global public health burden of it. This study aimed to assess the association between long-term exposure to PM2.5 and periodontitis in a nationally representative population from China. MATERIALS AND METHODS: In this multi-centre cross-sectional study of 372 communities in 31 provinces of Mainland China, we used data from the Fourth National Oral Health Survey of China in 2015-2016, in combination with high-resolution gridded concentrations of fine particulate matter (PM2.5). Logistic regression was applied to assess the relationship between long-term PM2.5 exposure and the risk of periodontitis. In addition, we examined whether the association varied by individual characteristics, and estimated the exposure-response relationship and the risk of damaged tooth in each tooth quadrant. RESULTS: A total of 8391 participants from 96 cities were diagnosed with periodontitis, accounting for 60.04% (8391/13,459) of the participants. For each 10 µg/m3 increment in 1-, 3- and 5-year average concentrations of PM2.5, the risk of total periodontitis increased by 9.0% (95% confidence interval: 6.0%, 12.0%), 8.0% (6.0, 11·0) and 7.0% (5.0, 10.0), respectively. Mild periodontitis was more strongly associated with PM2.5 exposure than moderate and severe periodontitis. The teeth in the lower anterior, lower posterior or upper anterior are more susceptible to the effect of PM2.5 on the periodontal pocket, calculus and bleeding gums. CONCLUSIONS: Long-term exposure to PM2.5 is significantly associated with an increased risk of periodontitis in the nationally representative Chinese population. Considering the rising prevalence of periodontitis, considerable costs of treatment, and substantially adverse effects on individuals and society, these findings suggest that stricter air quality regulations may help ease the burden of periodontal disease.

Investigation of a novel biofilm model close to the original oral microbiome.

A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal of this study is to develop a novel oral biofilm medium to restore the original oral microbiome. Firstly, we conducted a systematic literature review by searching PubMed and summarized the current reported culture media in vitro. Seven culture media were found. We used mixed saliva as the origin of oral species to compare the effects of the above media in culturing oral multispecies biofilms. Results indicated that among the seven media brain heart infusion containing 1% sucrose (BHIs) medium, PG medium, artificial saliva (AS) medium, and SHI medium could obviously gain large oral biofilm in vitro. The nutrients contained in different culture media may be suitable for the growth of different oral bacteria; therefore, we optimized several novel media accordingly. Notably, results of crystal violet staining showed that the biofilm cultured in our modified artificial saliva (MAS) medium had the highest amount of biofilm biomass. 16S rRNA gene sequencing showed that the operational taxonomic units (OTUs) and Shannon index of biofilm cultured in MAS medium were also the highest among all the tested media. More importantly, the 16S rRNA gene sequencing analysis indicated that the biofilm cultured in MAS medium was closer to the original saliva species. Besides, biofilm cultured by MAS was denser and produced more exopolysaccharides. MAS supported stable biofilm formation on different substrata. In conclusion, this study demonstrated a novel MAS medium that could culture oral biofilm in vitro closer to the original oral microbiome, showing a good application prospect. KEY POINTS: • We compare the effects of different media in culturing oral biofilms • A novel modified artificial saliva (MAS) medium was obtained in our study • The MAS medium could culture biofilm that was closer to oral microbiome.

An experiential service-learning project on oral health examination and education.

BACKGROUND: It has been demonstrated that experiential service-learning is effective in fields including public health and medicine. Preventive Dentistry is a practical course, and Oral Health Examination and Education is a topic that is suitable for teaching with experiential service-learning. This study describes an example of experiential service-learning in Preventive Dentistry named "Oral Health Examination and Education Project" and also evaluates its effectiveness among dental students. METHODS: A total of 108 dental students in their fourth year participated in this project in 2022. The project was composed of six sections: theoretical teaching, field investigation, data collection and analysis, investigation report writing and creating oral health education materials, oral health education and students' evaluation of the project. RESULTS: During this project, students learned how to perform surveys related to oral health, wrote an investigation report, created oral health education materials, and provided oral health education for children. Students were demonstrated an improvement in their academic performance for theoretical knowledge related to Oral Health Examination and Education in comparison with the students in the previous year. Over 90% of students expressed their preference for the learning method of experiential service and believed that it helped them to better understand the course material. They also recommended this teaching method for future classes. CONCLUSIONS: This study indicated that an experiential service-learning approach within this scope was highly beneficial to students because it provided them with the opportunity to understand the practical application of their coursework and obtain valuable experience in the field. This research suggests that oral epidemiology instructors in dental and oral public health programs should pay more attention to incorporate similar experiential projects into their curriculum with the aim of better preparing students for careers in oral public health.

Comparing the effectiveness of caries arrest by micro-operative treatment to operative treatment: A 2-year randomized controlled clinical trial.

OBJECTIVES: To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial. MATERIALS AND METHODS: A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05. RESULTS: After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026). CONCLUSION: Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years. CLINICAL RELEVANCE: To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn ; Feb 15th, 2020; No. ChiCTR2000029862.

Heavy metals in drinking water and periodontitis: evidence from the national oral health survey from China.

BACKGROUND: Periodontitis has become an increasingly important public health issue, coupled with a high economic burden for prevention and treatment. Exposure to essential trace heavy metals has been associated with various diseases; however, the relationships between essential trace heavy metals and periodontitis remain inconclusive. OBJECTIVES: To investigate the association between essential trace heavy metals in tap water and periodontitis in a nationally representative sample in China. METHODS: We conducted a nationwide study including 1348 participants from the Fourth National Oral Health Survey in the 2015-2016 period. The trace heavy metals concentration was measured in the local pipeline terminal tap water. Periodontitis was diagnosed according to the classification scheme proposed at the 2018 world workshop on the classification of periodontal and peri-implant diseases and conditions. We used weighted multivariable logistic regression to estimate the association between essential trace heavy metals and the risk of periodontitis. We additionally used spline analysis to explore the possible nonlinear dose-response associations. RESULTS: Periodontitis patients were exposed to higher concentrations of essential trace heavy metals. In adjusted models, for 1 SD increase in the concentration of iron, manganese, and copper in tap water, the risk of periodontitis increased by 30% (OR: 1.30, 95%CI: 1.12-1.50), 20% (OR: 1.20, 95%CI: 1.03-1.41), and 20% (OR: 1.20, 95%CI: 1.04-1.39), respectively. Stratified analyses demonstrated that the associations between essential trace heavy metals and periodontitis were higher in females, elders, and rural residents. Spline analysis revealed nonlinear exposure-response relationships between periodontitis and exposure to iron, manganese, and copper in tap water. CONCLUSIONS: Exposures to essential trace heavy metals in drinking water were associated with greater odds of periodontitis. Given the growing burden of periodontitis, our study sheds light on tailored public health policies for improving drinking water standards to alleviate periodontitis impairment.

Exploration of the Main Antibiofilm Substance of Lactobacillus plantarum ATCC 14917 and Its Effect against Streptococcus mutans.

Dental plaque, a complex biofilm system established by cariogenic bacteria such as Streptococcus mutans (S. mutans), is the initiator of dental caries. Studies have found that the cell-free supernatant (CFS) of Lactobacilli could inhibit S. mutans biofilm formation. However, the main antibiofilm substance of the Lactobacilli CFS that acts against S. mutans is unclear. The present study found that the CFS of Lactobacillus plantarum (L. plantarum) ATCC 14917 had the strongest antibiofilm effect among the five tested oral Lactobacilli. Further bioassay-guided isolation was performed to identify the main antibiofilm substance. The antibiofilm effect of the end product, named 1-1-4-3, was observed and the structure of it was elucidated by using Q-TOF MS, 2D NMR and HPLC. The results showed that several components in the CFS had an antibiofilm effect; however, the effect of 1-1-4-3 was the strongest, as it could reduce the generation of exopolysaccharides and make the biofilm looser and thinner. After structure elucidation and validation, 1-1-4-3 was identified as a mixture of lactic acid (LA) and valine. Additionally, LA was shown to be the main antibiofilm substance in 1-1-4-3. In summary, this study found that the antibiofilm effect of the L. plantarum CFS against S. mutans was attributable to the comprehensive effect of multiple components, among which LA played a dominant role.

Tooth brushing with fluoridated toothpaste and associated factors among Chinese adolescents: a nationwide cross-sectional study.

BACKGROUND: Tooth brushing with fluoridated toothpaste has become the most important way to provide the anti-caries effect of fluoride around the world. China has promoted the use of fluoridated toothpaste since 1989. However, there are few studies on the national profile of use of fluoridated toothpaste and related factors in Chinese adolescents. We carried out this study to investigate oral hygiene behaviours, especially the status of tooth brushing with fluoridated toothpaste and its correlates among adolescents, based on data from the latest Nation Oral Health Survey in mainland China. METHODS: This cross-sectional study recruited 118,601 participants aged 12-15 years using multistage stratified sampling. Questionnaires were completed by students at school. Data employed in analyses were extracted from the questionnaire, including information on tooth brushing, fluoridated toothpaste, dental floss, sociodemographic factors, fluoride knowledge and attitude towards regular dental check-ups. A binary logistic regression was performed to compute the odds ratios (OR). Tooth brushing twice daily with fluoridated toothpaste was the dependent variable. Sociodemographic factors, fluoride knowledge, attitude towards regular dental check-ups, dental visit experience and perceived oral health were the independent variables. P < 0.05 was considered statistically significant. RESULTS: A total of 32.6% of participants brushed their teeth twice daily, 7.4% used fluoridated toothpaste, and 3.9% cleaned their teeth twice daily with fluoridated toothpaste. The logistic regression showed the probability of twice-a-day tooth brushing with fluoridated toothpaste was higher among these groups: females (OR: 1.141; 95%CI: 1.072-1.214), 15-year-olds (OR: 1.786; 95%CI: 1.634-1.952), from urban areas (OR: 1.389; 95%CI: 1.288-1.497), without siblings (OR: 1.351; 95%CI: 1.259-1.450), with an educated father (OR: 1. 605; 95%CI: 1.442-1.788) and mother (OR: 1.706; 95%CI: 1.530-1.903), having dental visit experiences (OR: 1.702; 95%CI: 1.589-1.823), rating one's oral health as good (OR: 2.341; 95%CI: 2.083-2.631), having fluoride knowledge (OR: 4.345; 95%CI: 4.034-4.678) and having a positive attitude towards regular dental check-ups (OR: 1.589; 95%CI: 1.460-1.729). CONCLUSIONS: The oral hygiene behaviours of Chinese adolescents were undesirable. Twice daily tooth brushing with fluoridated toothpaste was significantly associated with sociodemographic factors, fluoride knowledge, and attitudes towards regular dental check-ups.

Decomposing socioeconomic inequalities in dental caries among Chinese adults: findings from the 4th national oral health survey.

OBJECTIVE: This cross-sectional study aimed to investigate socioeconomic inequalities in dental caries among adults (35 years and older) in China and explore the contributions of various factors to these inequalities. METHODS: This study included 10,983 adults (3,674 aged 35-44 years, 3,769 aged 55-64 years and 3,540 aged 65-74 years) who participated in the 4th National Oral Health Survey (2015-2016) in China. Dental caries status was evaluated by the decayed, missing and filled teeth (DMFT) index. Concentration indices (CIs) were applied to quantify the different degrees of socioeconomic-related inequality in DMFT, decayed teeth with crown or root caries (DT), missing teeth due to caries or other reasons (MT), and filled teeth without any primary or secondary caries (FT) among adults of different age groups. Decomposition analyses were conducted to identify the determinants and their associations with inequalities in DMFT. RESULTS: The significant negative CI indicated that DMFT for the total sample were concentrated among socioeconomically disadvantaged adults (CI = - 0.06; 95% confidence interval [CI], - 0.073 to - 0.047). The CIs for DMFT for adults aged 55-64 and 65-74 years were - 0.038 (95% CI, - 0.057 to - 0.018) and - 0.039 (95% CI, - 0.056 to - 0.023), respectively, while the CI for DMFT for adults aged 35-44 years was not statistically significant (CI = - 0.002; 95% CI, - 0.022 to 0.018). The concentration indices of DT were negative and concentrated in disadvantaged populations, while FT showed pro-rich inequalities in all age groups. Decomposition analyses showed that age, education level, toothbrushing frequency, income and type of insurance contributed substantially to socioeconomic inequalities, accounting for 47.9%, 29.9%, 24.5%,19.1%, and 15.3%, respectively. CONCLUSION: Dental caries was disproportionately concentrated among socioeconomically disadvantaged adults in China. The results of these decomposition analyses are informative for policy-makers attempting to develop targeted health policy recommendations to reduce dental caries inequalities in China.

The association between low birth weight and/or preterm birth and dental caries -A systematic review and meta-analysis.

BACKGROUND: Studies on the association between adverse birth outcomes and dental caries in children have shown conflicting results, so the aim of this systematic review and meta-analysis was to investigate the association between adverse birth outcomes and dental caries in children. METHODS: We systematically searched articles in four electronic databases (Web of Science, PubMed, Cochrane Library and Embase) published prior to August 2021. The odds ratio (OR) (or converted OR) and the corresponding 95% confidence intervals (95% CI) were processed. The certainty of evidence was assessed using GRADE's risk bias assessment tool. Random effects model was used for this meta-analysis. RESULTS: A total of thirty-one observational studies met the inclusion criteria. The pooled estimates indicated that children exposed to low birth weight (LBW)/preterm birth (PTB) did not experience higher dental caries in primary teeth. Subgroup analyses showed that children with LBW (OR: 1.30, 95% CI: 1.03-1.63) were prone to have dental caries in primary teeth for cross-sectional studies, but no significant differences for prospective studies. PTB children experienced more primary caries in high-income countries (OR: 1.31, 95% CI: 1.00-1.70) than in low- and middle-income countries. CONCLUSIONS: The current evidence did not suggest a significant association between LBW and dental caries in children for primary teeth. Children with PTB in high-income countries had a higher prevalence of primary dental caries. Further prospective studies should adjust for confounding factors (age, oral health and family finances) to determine the definitive association between LBW/PTB and dental caries.

Amyloid peptides with antimicrobial and/or microbial agglutination activity.

Microbe (including bacteria, fungi, and virus) infection in brains is associated with amyloid fibril deposit and neurodegeneration. Increasing findings suggest that amyloid proteins, like Abeta (Aß), are important innate immune effectors in preventing infections. In some previous studies, amyloid peptides have been linked to antimicrobial peptides due to their common mechanisms in membrane-disruption ability, while the other mechanisms of bactericidal protein aggregation and protein function knockdown are less discussed. Besides, another important function of amyloid peptides in pathogen agglutination is rarely illustrated. In this review, we summarized and divided the different roles and mechanisms of amyloid peptides against microbes in antimicrobial activity and microbe agglutination activity. Besides, the range of amyloids' antimicrobial spectrum, the effectiveness of amyloid peptide states (monomers, oligomers, and fibrils), and cytotoxicity are discussed. The good properties of amyloid peptides against microbes might provide implications for the development of novel antimicrobial drug. KEY POINTS: • Antimicrobial and/or microbial agglutination is a characteristic of amyloid peptides. • Various mechanisms of amyloid peptides against microbes are discovered recently. • Amyloid peptides might be developed into novel antimicrobial drugs.

The rs35874116 single nucleotide polymorphism increases sweet intake and the risk of severe early childhood caries: a case-control study.

BACKGROUND: Dental caries is one of the most prevalent chronic diseases worldwide among children. The rs35874116 single nucleotide polymorphism (SNP) in the sweet receptor gene TAS1R2 has been associated with dental caries at a high risk in permanent teeth among school children and adults. To date, little is known about the association of this SNP with sweet intake and caries risk in the primary school children. METHODS: Total of 236 children were included, namely 118 subjects in the non-caries (NC) group and severe early childhood caries (S-ECC) group, respectively. Oral mucosa cells were collected from all the selected children, and the full length of exon 3 in TAS1R2 was sequenced to analyse rs35874116 polymorphism. A questionnaire was used to collect information about socio-demographic information, frequency of sweet intake and oral hygiene habits. Multiple logistic regression models were applied to assess the relationship of rs35874116 polymorphism with frequency of sweet intake and S-ECC among the five-year-old children. RESULTS: Children with the TT genotype of rs35874116 had a higher frequency of sweet intake than CT/CC carriers (51.3% vs. 32.7%; x2 = 5.436, p = 0.020), and S-ECC individuals were more likely to be TT genotype carriers than NC individuals (53.5% vs. 46.5%; x2 = 4.353, p = 0.037). Multiple logistic regression analyses showed that the TT genotype of rs35874116 was not only significantly related to the frequency of sweet intake (OR = 2.25, 95% CI = 1.14-4.44) but also significantly associated with S-ECC (OR = 2.11, 95% CI = 1.01 ~ 4.42). CONCLUSIONS: The rs35874116 polymorphism might increase sweet intake and the risk of S-ECC among five-year-old children in Nanning, China.

Income-related inequality and decomposition of edentulism among aged people in China.

BACKGROUND: The aim of this study was to assess the income-related inequality of edentulism among the aged in China and identify the contributing factors. METHODS: A secondary analysis of data from the 4th National Oral Health Epidemiology Survey in China was conducted, and 65-74 years old were selected for the analysis of income-related inequality of edentulism. The concentration curve, Concentration index (CI) and Erreygers-corrected concentration index (EI) were used to represent inequality and its degree qualitatively and quantitatively, respectively. A decomposition method based on probit model was employed to determine the contributors of inequality, including demographic factors, income status, oral health-related knowledge, attitude and practices and self-perceived general health status. RESULTS: In China, aged people with edentulism were concentrated in the poor. The CI was - 0.2337 (95% CIs: - 0.3503, - 0.1170). The EI was - 0.0413 (95% CIs: - 0.0619, - 0.0207). The decomposition results showed that income (75.02%) and oral health-related knowledge, attitude and practices (15.52%) were the main contributors to the inequality. CONCLUSION: This study showed that pro-poor inequality among the elderly with edentulism existed in China. Corresponding policies against the contributors could be considered to promote the health equality of the elders.

[Research Updates: Cariogenic Mechanism of Streptococcus mutans].

The prevalence of dental caries remains high, posing a major burden on the public health of the global society. Microorganisms are the main cause of dental caries, among which Streptococcus mutans ( S. mutans) is one of the most widely recognized cariogenic bacteria. In recent years, the progress in research technology enabled the academic circle to conduct more in-depth research into caries-inducing S. mutans at the DNA, RNA and protein levels, and to gain thereby a new understanding of the surface structure and extracellular matrix composition of S. mutans. In this paper, we summarized recent findings on the cariogenic mechanism of S. mutans in order to help reveal more targets and potential approaches for the future development of caries prevention agents that target S. mutans, and to promote the development of dental caries prevention campaign.

The prevalence and severity of periodontal disease in Mainland China: Data from the Fourth National Oral Health Survey (2015-2016).

AIM: To evaluate periodontal conditions in adults in mainland China based on data from the 4th National Oral Health Survey. MATERIALS AND METHODS: Data of adult subjects (35- to 44-year-old group [N = 4409], 55- to 64-year-old group [N = 4622], and 65- to 74-year-old group [N = 4428]) were analysed. Demographic, socio-economic, personal habit, dental history, and health attitude data were obtained using a questionnaire. Periodontal condition was assessed using the standardized case definitions of the 2018 classification scheme. A multivariate analysis was performed to investigate the relationship between periodontitis severity and age, smoking status, gender, and region using generalized additive models after adjusting for confounders. RESULTS: The frequency of subjects with periodontitis was 52.8%, 69.3%, and 64.6% in the three age groups, respectively. The frequency of subjects with severe periodontitis (stage III or IV) was 10.6%, 37.3%, and 43.5% in the three age groups, respectively. The severity of periodontal disease was positively associated with age. Current and former smokers exhibited significantly greater disease severity than non-smokers after adjustment for confounders. No significant difference of severity was found between males and females. CONCLUSION: Within the limitations of the study, the prevalence of periodontitis is very high among adults in mainland China. Periodontal status is associated with age and smoking status.

Characterization and function of membrane vesicles in Gram-positive bacteria.

In recent years, extracellular vesicles have gained more attention. However, studies on membrane vesicles in Gram-positive bacteria were carried out relatively late because of the thick bacterial wall and the low production of membrane vesicles. Thanks to the research in recent years, the cognition of the composition and function of the membrane vesicles of Gram-positive bacteria has made significant progress. Membrane vesicles are spherical in shape comprising bilayer membranous structures with a diameter of 20-400 nm. Components of membrane vesicles are diverse, including proteins, nucleic acids, lipids, and metabolites. It also has been reported that membrane vesicles are involved in various pathophysiological processes and serve as communication tools in pathophysiological activities between the bacteria and the host. This review provided the current understanding of components and functions of membrane vesicles in Gram-positive bacteria. The findings might facilitate further research in the emerging field of membrane vesicles in Gram-positive bacteria. KEY POINTS: • Membrane vesicles in Gram-positive bacteria contain proteins, nucleic acids, lipids, and metabolites, suggesting their biological significance. • Membrane vesicles in Gram-positive bacteria are thought to be involved in stress response, biofilm formation, immune regulation, and so on.

Antibiofilm peptides as a promising strategy: comparative research.

Biofilms lead to approximately 65% of infections, and these infections are hard to treat. Thus, it is crucial to identify effective antibiofilm agents with low cytotoxicity. Peptides with antibiofilm activity have been regarded as promising solutions, and peptides with MBICs (minimal biofilm inhibitory concentrations) that are lower than their minimal inhibitory concentration (MICs) (minimal inhibitory concentrations) are appealing. Therefore, we systematically summarized and classified previously reported peptides with antibiofilm activity. A total of 51 peptides with antibiofilm activity were classified into 14 categories. The MICs and MBICs of these fourteen representative peptides, one selected from each category, were compared against the Gram-positive bacterium Streptococcus mutans, the Gram-negative bacterium Pseudomonas aeruginosa, and the fungus Candida albicans. Six representative peptides (C5-pleurocidin, C6-Pac-525, C9-protegrin-1, C11-TetraF2W-RR, C13-WLBU2, and C14-melittin) showed antibiofilm activity against both bacteria and fungi, and among these 6 representative peptides, 4 peptides (C9-protegrin-1, C11-TetraF2W-RR, C13-WLBU2, and C14-melittin) could prevent biofilm formation with lower MBIC values than their MICs. CLSM (confocal laser scanning microscopy), SEM (scanning electron microscopy), and TEM (transmission electron microscopy) were further used to observe the morphologies of the biofilms after treatment with the peptides. Among the above 4 peptides, WLBU2 and melittin sparsely scattered the biofilms without destroying the bacteria. In conclusion, the currently reported peptides with antibiofilm activity are limited in number, but peptides with lower MBICs than MICs exist as promising candidates against biofilm-related infections and need further study. KEY POINTS: • Antibiofilm peptides could inhibit biofilm formation with MBICs that are lower than MICs. • The mechanism of antibiofilm peptides is not only due to antimicrobial activity.

Trend on dental caries status and its risk indicators in children aged 12 years in China: a multilevel analysis based on the repeated national cross-sectional surveys in 2005 and 2015.

BACKGROUND: This study aimed to explore the trend and risk indicators for dental caries of children aged 12 years in China based on national oral health survey data in 2005 and 2015. METHODS: Research data were from the two latest national oral health surveys conducted in mainland China, including 30 and 31 provinces, autonomous regions, and municipalities in 2005 and 2015, respectively. Children aged 12 years were clinically examined for dental caries and dental fluorosis according to the World Health Organization criteria. Sociodemographic characteristics and oral health-related behaviours were collected using questionnaires. Multilevel zero-inflated negative binomial regression model was used to investigate the association between dental caries severity and dental fluorosis, sociodemographic characteristics, and oral health-related behaviours. RESULTS: The final analyses included 12,350 and 27,818 children surveyed in 2005 and 2015, respectively. The standardized prevalence of dental caries increased from 27.05% (95% confidence interval [CI], 24.25-28.85) in 2005 to 37.92% (95% CI, 34.94-40.90) in 2015, and the respective standardized mean decayed, missing, filled teeth (DMFT) index scores increased from 0.50 (standard deviation [SD], 1.04) to 0.83 (SD, 1.45) (P < 0.001). Fujian province had the highest increase in dental caries, followed by Liaoning, Heilongjiang, Hainan, and Yunnan. Results revealed that children who were girls, more frequently experienced dental pain, and had more recent dental visits, had significantly higher DMFT scores after adjusting for the survey year and other variables (all P < 0.05). CONCLUSIONS: Dental caries of 12-year-old children in China deteriorated from 2005 to 2015, particularly in the northeast and southwest regions. Dental caries was associated with sex, dental pain, and dental service utilization.

Infiltration and sealing for managing non-cavitated proximal lesions: a systematic review and meta-analysis.

BACKGROUND: Infiltration and sealing are micro-invasive treatments for arresting proximal non-cavitated caries lesions; however, their efficacies under different conditions remain unknown. This systematic review and meta-analysis aimed to evaluate the caries-arresting effectiveness of infiltration and sealing and to further analyse their efficacies across different dentition types and caries risk levels. METHODS: Six electronic databases were searched for published literature, and references were manually searched. Split-mouth randomised controlled trials (RCTs) to compare the effectiveness between infiltration/sealing and non-invasive treatments in proximal lesions were included. The primary outcome was obtained from radiographical readings. RESULTS: In total, 1033 citations were identified, and 17 RCTs (22 articles) were included. Infiltration and sealing reduced the odds of lesion progression (infiltration vs. non-invasive: OR = 0.21, 95% CI 0.15-0.30; sealing vs. placebo: OR = 0.27, 95% CI 0.18-0.42). For both the primary and permanent dentitions, infiltration and sealing were more effective than non-invasive treatments (primary dentition: OR = 0.30, 95% CI 0.20-0.45; permanent dentition: OR = 0.20, 95% CI 0.14-0.28). The overall effects of infiltration and sealing were significantly different from the control effects based on different caries risk levels (OR = 0.20, 95% CI 0.14-0.28). Except for caries risk at moderate levels (moderate risk: OR = 0.32, 95% CI 0.01-8.27), there were significant differences between micro-invasive and non-invasive treatments (low risk: OR = 0.24, 95% CI 0.08-0.72; low to moderate risk: OR = 0.38, 95% CI 0.18-0.81; moderate to high risk: OR = 0.17, 95% CI 0.10-0.29; and high risk: OR = 0.14, 95% CI 0.07-0.28). Except for caries risk at moderate levels (moderate risk: OR = 0.32, 95% CI 0.01-8.27), infiltration was superior (low risk: OR = 0.24, 95% CI 0.08-0.72; low to moderate risk: OR = 0.38, 95% CI 0.18-0.81; moderate to high risk: OR = 0.20, 95% CI 0.10-0.39; and high risk: OR = 0.14, 95% CI 0.05-0.37). CONCLUSION: Infiltration and sealing were more efficacious than non-invasive treatments for halting non-cavitated proximal lesions.

Related factors of periodontal health among Chinese middle school students, findings from a national cross-sectional survey.

BACKGROUND: To investigate the related risk factors of periodontal health status among Chinese middle school students. METHODS: This study is a part of the Fourth National Oral Health Epidemiological Survey, which is by far the largest oral epidemiological survey in China, including all provinces, municipalities and autonomous regions in mainland China. A multi-stage stratified sampling method was used to select middle school students aged 12-15 from the sampled middle school for investigation. The survey consisted of two parts: oral examination and questionnaire survey. The oral examination included gingival bleeding and calculus. The questionnaire included sociodemographic information, oral health knowledge, attitudes and behaviors. Logistic regression and generalized linear mixed model were used to investigate the risk factors of gingival bleeding and calculus. RESULTS: A total of 118,514 middle-school students has been examined. Less gingival bleeding (OR = 0.746, CI 0.718-0.774) and calculus (OR = 0.550, CI 0.529-0.527) were found in 12-year-old group compared to 15-year-old group. The periodontal health status of males was worse than that of females (gingival bleeding OR = 1.102, CI 1.074-1.132, calculus OR = 1.258, CI 1.223-1.295). Besides age and gender, region, living place, ethnic groups, family structure, parent's education level, oral health knowledge and behavior were also related to gingival bleeding and calculus. CONCLUSIONS: Gingival bleeding and calculus occurred most of 12-15 years old adolescents in China. Several related factors, such as gender, age, ethnicity, father's education level, oral health knowledge and behavior, were found in multi-factorial models. The impact of province should arouse people's attention.