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.

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.

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.

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.

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.

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.

Impact of COVID-19 on the oral health of adults in Wuhan and China: results of a nationwide online cross-sectional questionnaire survey.

BACKGROUND: COVID-19 has seriously threatened the health and lives of people. This study aimed to investigate the impact of COVID-19 on the oral health of adults in Wuhan and other places of China amid the epidemic and to evaluate attitudes towards dental care in the post-epidemic period. METHODS: An online cross-sectional survey based on a questionnaire of 22 questions was conducted. RESULTS: A total of 3352 valid questionnaires were collected. Participants from Wuhan tended to be relatively psychologically affected and more concerned about future dental treatment. Toothbrushing frequency did not differ significantly between participants from Wuhan and other places and was associated with the prevalence of oral problems people encountered. Gingival bleeding, bad breath and oral ulcers were the three most common oral problems amid the epidemic, and significantly more participants in Wuhan experienced oral problems than other places in China. CONCLUSION: The three most common oral problems amid the epidemic were gingival bleeding, bad breath and oral ulcers. Adults in Wuhan tended to be more seriously affected and suffered more oral problems than people from other places in China. Maintaining good oral health behaviours plays an important role in preventing dental problems. It is crucial to establish and to follow the standard guidelines for the provision of dental care during and after the epidemic.

The impact of coronavirus lockdown on oral healthcare and its associated issues of pre-schoolers in China: an online cross-sectional survey.

BACKGROUND: The sudden outbreak of coronavirus disease (COVID-19) epidemic influenced people's daily life. During lockdown of Wuhan city, the oral health and its associated issues of preschool children were investigated and guidance for dental clinics when the epidemic were controlled in the future were also provided. METHODS: A national online survey was conducted among preschool children and completed by their caregivers. The questionnaire related to children's oral health status and care behaviour, caregivers' attitudes. The information was statistically analyzed between Wuhan residents and others residents. RESULTS: 4495 valid questionnaires were collected. In oral health status, during Wuhan lockdown, 60.8%, 35.5% and 18.3% children had self-reported dental caries, toothache and halitosis respectively. In oral health attitudes, respondents who would increase attention to oral health was more than that would decrease. In oral hygiene behaviour, compared to non-Wuhan children, the children in Wuhan became more active in brushing their teeth. In utilization of dental services in the future, less Wuhan residents would choose to have dental visit directly, 28.5% Wuhan residents and 34.7% non-Wuhan residents agreed all of procedures could be done if proper protected. CONCLUSIONS: Oral health status and associated issues of preschool children in Wuhan were significantly different from that of others during lockdown of Wuhan city and in the future. Effective measures should be taken as early as possible to protect children's oral health.

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.

Prevalence and associated factors of periodontal conditions among 55- to 74-year-old adults in China: results from the 4th National Oral Health Survey.

OBJECTIVE: The purpose of this study was to assess periodontal health conditions among 55- to 74-year-old Chinese people and to analyze the factors associated with periodontal diseases. MATERIALS AND METHODS: In total, 9054 subjects aged 55-74 years were enrolled from all 31 provinces using a stratified multistage probability sampling method, autonomous regions and municipalities of the Chinese mainland, the response rate was 86.9%. All subjects underwent clinical examinations on the severest site for every tooth and completed a questionnaire that collected information on their sociodemographic characteristics and oral habits. T tests, chi-square tests and binary logistic regression analysis were performed to analyze the data. RESULTS: The percentage of people without bleeding on probing, probing depth ≥ 4 mm and attachment loss > 3 mm was 5.0 and 9.3% in the 55- to 64-year-old and the 65- to 74-year-old age group. The prevalence of bleeding on probing was 88.4% among 55 to 64 years old and 82.6% among 65 to 74 years old. Mean number of teeth with bleeding on probing were 13.87 among 55 to 64 years old and 11.25 among 65 to 74 years old. The prevalence of probing depth ≥ 4 mm and attachment loss > 3 mm were 69.3 and 69.9% in people aged 55-64 years and were 64.6 and 74.2% in people aged 65-74 years. Mean number of teeth with probing depth = 4-5 mm and probing depth ≥ 6 mm were 4.48 and 0.36 in 55-64 age group and 3.70 and 0.33 in 65-74 age group. And mean number of teeth with attachment loss > 3 mm were 5.17 among 55 to 64 years old and 5.63 among 65 to 74 years old. Besides, attachment loss > 3 mm was associated with age, gender, smoking, toothbrushing frequency and toothpick use. CONCLUSIONS: Periodontitis was not highly prevalent among 55- to 74-year-old Chinese adults. Age, gender, smoking, toothbrushing frequency and toothpick use could be risk factors. CLINICAL RELEVANCE: Scientific rationale for the study: The periodontal conditions among 55 to 64 and 65 to 74 years old Chinese population were not highly serious, but prevalence of bleeding on probing, periodontal pockets and attachment loss should be drawn enough attention by relevant public health administrations. PRINCIPAL FINDINGS: The prevalence of periodontal diseases was evaluated in 55- to 64-year-old and 65- to 74-year-old subjects in a nationally representative Chinese sample population. The prevalence of probing depth ≥ 4 mm and AL > 3 mm were high; these values were 69.3% and 69.9%, respectively, in the 55-64 age group and 64.6% and 74.2%, respectively, in the 65-74 age group. In addition, case percentage of AL = 4-5 mm combined with PD < 6 mm were 23.1 and 19.4% among 55- to 64-year-old and 65- to 74-year-old people. And case percentage of AL> 5 mm combined with PD ≥ 6 mm were 11.1% and 12.1% among 55- to 64-year-old and 65- to 74-year-old people, respectively. PRACTICAL IMPLICATIONS: The present study provides a reference for the epidemiological analysis of periodontal diseases. To reduce widespread inadequate treatment of periodontal diseases, clinical management should be performed in dental practices. Furthermore, oral health recommendations should be made at multiple levels.

Utilization of dental services and associated factors among preschool children in China.

BACKGROUND: This study sought to evaluate dental utilization among 3-,4-, and 5-year-old children in China and to use Andersen's behavioural model to explore influencing factors, thereby providing a reference for future policy making. METHODS: This study is a cross-sectional study. Data of 40,305 children aged 3-5 years were extracted from the Fourth National Oral Health Survey, which was performed from August 2015 to December 2016. Patient data were collected using a questionnaire, which was answered by the child's parents, and clinical data were collected during a clinical examination. Stratification and survey weighting were incorporated into the complex survey design. Descriptive statistics, bivariate correlations and hierarchical logistic regression results were then analysed to find the factors associated with oral health service utilization. RESULTS: The oral health service utilization prevalence during the prior 12 months were 9.5% (95%CI: 8.1-11.1%) among 3-year-old children, 12.1% (95%CI: 10.8-13.5%) among 4-year-old children, and 17.5% (95%CI: 15.6-19.4%) among 5-year-old children. "No dental diseases" (71.3%) and "dental disease was not severe" (12.4%) were the principal reasons why children had not attended a dental visit in the past 12 months. The children whose parents had a bachelor's degree or higher (OR: 2.29, 95%CI: 1.97-2.67, p < 0.001), a better oral health attitude ranging from 5 to 8(OR: 1.64, 95%CI: 1.43-1.89, p < 0.001), annual per capital income more than 25,000 CNY (OR: 1.40, 95%CI: 1.18-1.65, p < 0.001),think their child have worse or bad oral health (OR: 3.54, 95%CI: 2.84-4.40, p < 0.001), and children who often have toothaches (OR: 9.72, 95%CI: 7.81-12.09, p < 0.001) were more likely to go to the dentist in the past year. CONCLUSION: The prevalence of dental service utilization was relatively low among preschool children. It is necessary to strengthen oral health education for parents and children, thereby improving oral health knowledge as well as attitude, and promoting dental utilization.

The prevalence and risk indicators of tooth wear in 12- and 15-year-old adolescents in Central China.

BACKGROUND: Tooth wear has been investigated in numerous countries, and the prevalence has varied. However, the data on tooth wear in China are scarce. The aim of this study was to describe the prevalence of tooth wear and to investigate the relative indicators associated with tooth wear in 12- and 15-year-old adolescents in Wuhan City, Hubei Province, Central China. METHODS: A cross-sectional descriptive study was undertaken among 720 adolescents in Hubei Province, Central China. The age groups in this study were 12- and 15-year-old, and each group consisted of 360 participants in which females and males represented 50 % each. A modified version of the Basic Erosive Wear Examination (BEWE) tooth wear index was used for the buccal, cervical, occlusal/incisal and lingual surfaces of all of the teeth in the 720 adolescents. All of the participants were asked to answer a questionnaire consisting of questions about their current and historical dietary habits and oral hygiene. RESULTS: The prevalence of tooth wear was 18.6 and 89.4 % in 12- and 15-year-old adolescents, respectively. The prevalence rates of dentin exposure were 1.9 and 5.6 %, respectively. A significantly higher prevalence of tooth wear and dentin exposure in 15-year-old adolescents was found than in 12-year-old adolescents (p < 0.001 and p = 0.011). Several factors such as drinking soft drinks and fruit juices immediately after sports, taking aspirin, reflux, unilateral chewing, tooth brushing once daily or less often, duration of brushing less than 2 min and swimming in the summer were found to be associated with tooth wear. CONCLUSIONS: Tooth wear in 12- and 15-year-old adolescents in Central China is a significant problem and should receive greater attention. The prevalence of tooth wear increases with age and associated with socio-behavioral risk factors.

Decomposing Socioeconomic Inequality in Early Childhood Caries Among 3 to 5-Year-Old Children in China.

INTRODUCTION AND AIMS: Early childhood caries (ECC) is a widespread oral disease that harms children's health in China. Although previous studies have linked ECC prevalence to socioeconomic status, few have measured the degree of socioeconomic inequality. This study aimed to evaluate the socioeconomic inequality of ECC in children aged 3 to 5 years in China and identify the contributor to the inequality. METHODS: We extracted data on 3 to 5-year-old children from the fourth National Oral Health Survey. We measured the inequality of ECC by the average household income per capita. We used the average household income per capita to measure the inequality of ECC. To describe inequality both qualitatively and quantitatively, we used the following methods: concentration curve, Erreygers-corrected concentration index, relative index of inequality and slope index of inequality. We also applied a decomposition based on the probit model to identify the factors that contributed to inequality. RESULTS: The prevalence of ECC in Chinese preschool children was 63.11% (95% CIs: 60.54%, 65.61%). The negative value of the Erreygers-corrected concentration index (-0.0459; 95% CIs: -0.0594, -0.0324), slope index of inequality (-0.0674; 95% CIs: -0.0876, -0.0471) and the positive value of relative index of inequality (0.7484; 95% CIs: 0.6856, 0.8169) all indicated that ECC prevalence was higher among children from low-income families. The main factors contributing to inequality were average household income, parents' educational level and living areas. CONCLUSION: There is a pro-poor inequality in ECC among 3 to 5-year-old children in China. CLINICAL RELEVANCE: To improve oral health equality, policymakers should focus more on children from low-income families, with less educated parents and living in rural areas.

Association between periodontitis and hypertension: cross-sectional survey from the Fourth National Oral Health Survey of China (2015-2016).

OBJECTIVES: To evaluate the association between periodontitis severity and hypertension based on Chinese epidemiological data. DESIGN: This cross-sectional survey enrolled adults from the Fourth National Oral Health Survey of China (2015-2016). SETTING: The data were obtained from the Fourth National Oral Health Survey of China (2015-2016). PARTICIPANTS: The study included individuals aged 35-44 years (n=4409), 55-64 years (n=4568) and 65-74 years (n=4218). PRIMARY AND SECONDARY OUTCOME MEASURES: Periodontal status, defined on the basis of the 2017 classification scheme, and periodontal parameters (eg, bleeding on probing (BOP)) were compared between individuals with hypertension and individuals with normotension. Smoothed scatterplots were constructed to demonstrate the associations of periodontal parameters and periodontal status with hypertension. RESULTS: Severe periodontitis (stages III and IV) was present in 41.4% of individuals with hypertension and 28.0% of individuals with normotension, respectively (p<0.001). The prevalence of severe periodontitis was higher in individuals with hypertension than that in individuals with normotension among participants aged 35-44 years (18.0% vs 10.1%, p<0.001) and 55-64 years (40.2% vs 36.7%, p=0.035), but not in participants aged 65-74 years (46.4% vs 45.1%, p=0.429). Therefore, the difference in periodontal status between individuals with hypertension and individuals with normotension decreased with age. There were higher prevalences of BOP, probing depth (PD) ≥4 mm and PD ≥6 mm in individuals with hypertension than in individuals with normotension (52.1% vs 49.2%, 19.6% vs 14.7% and 1.8% vs 1.1%, respectively). Periodontitis severity and the proportion of teeth with PD ≥4 or ≥6 mm were positively associated with hypertension. CONCLUSION: Periodontitis is associated with hypertension in Chinese adults. Hypertension prevalence increased with periodontitis severity, particularly among young participants. Accordingly, it is necessary to improve the education, awareness of periodontal treatment and preventive management among individuals at risk of hypertension, particularly in the younger population.

Randomized controlled trial on fluoride varnish application for treatment of white spot lesion after fixed orthodontic treatment.

The purpose of this study was to determine the efficacy of fluoride varnish (5% sodium fluoride, Duraphat(®), Colgate) in reverting white spot lesions (WSLs) after fixed orthodontic treatment. This study was a randomized, parallel group, controlled clinical trial. Using saline solution as control, 110 participants (mean age ± standard deviation: 16.6 ± 3.2 years) ranging from 12 to 22 years old were randomly assigned to either the test group (group 1) or the control group (group 2). Application of fluoride varnish or saline was applied onto tooth surfaces with WSLs every month during the first 6 months after debonding. The labial (buccal) surfaces of the teeth were assessed by the use of a DIAGNOdent pen (DD) at the baseline, 3- and 6-month follow-up visits. After 6 months, 96 subjects with a total of 209 study teeth (47 subjects, 104 teeth in group 1; 49 subjects, 105 teeth in group 2) remained. The WSLs had a mean DD reading at baseline of 17.66 ± 5.36 in group 1 and 16.19 ± 5.70 in group 2, which decreased by 5.78 and 2.44, respectively, at the 3-month follow-up visit and decreased by 7.56 and 3.09, respectively, at the 6-month follow-up visit. The mean baseline DD readings in the two groups were similar (t test, P > 0.05). There was statistically significant differences between the mean DD readings of the two groups at the 3-month (P < 0.05) and at the 6-month follow-up visits (P < 0.01). Topical fluoride varnish application is effective in reversing WSLs after debonding and should be advocated as a routine caries prevention measure after orthodontic treatment.

Socioeconomic-related inequality in dental care utilization among preschool children in China.

OBJECTIVES: This study aimed to investigate socioeconomic-related inequality in dental care service utilization in the past 12 months among Chinese preschool children and to explore the contribution of various factors to this inequality. METHOD: A total of 40 305 children aged 3-5 years from 372 kindergartens who participated in the Fourth National Oral Health Survey in China were included in the final analysis. The method of data weighting in complex sampling was adopted to make the samples more representative. Erreygers-corrected concentration index (EI) was used to measure socioeconomic-related inequality in dental care service utilization. The horizontal inequality index (HI) was employed to analyse horizontal inequality. Decomposition analyses were conducted to explore the contributions of income level, need variables (dmft, caregiver-evaluated oral health status and toothache experience) and nonneed variables (caregiver education level, residential location, age, and sex) to the inequality of health service utilization. RESULT: The utilization of oral health services within the past 12 months among the high-, middle- and low-income groups was 17.4% (95% CI: 15.6-19.3), 13.6% (95% CI: 12.2-15.1) and 9.4% (95% CI: 8.1-11.0) respectively. The concentration curve was below the line of equality, and the EI and HI were 0.072 and 0.078, respectively, indicating that dental care utilization in children aged 3-5 years was concentrated in those who were better off. The contribution of the need variables to socioeconomic-related inequality in dental services was minimal, and most dental care utilization inequality could be explained by household income, caregiver education attainment and urban-rural disparities, accounting for 32.0%, 49.4% and 20.4% respectively. CONCLUSION: This study reveals the existence of pro-rich inequality in dental care utilization among preschool children in China. The decomposition analysis suggests that income, caregiver education background and urban-rural disparities are the main factors contributing to this outcome. Equity-oriented policies and programmes are needed to achieve equitable dental care utilization.

Measuring and decomposing socioeconomic-related inequality in the use of oral health services among Chinese adults.

OBJECTIVES: This study aimed to measure socioeconomic-related inequality and horizontal inequity in the use of oral health services and decompose this inequality among adults of different age groups in China. METHODS: In total, 10 973 adults (3669 aged 35-44 years, 3767 aged 55-64 years and 3537 aged 65-74 years) who participated in the 4th National Oral Health Survey (2015-2016) in China were included. Concentration curves and the Erreygers-corrected concentration index (EI) were employed to measure socioeconomic-related inequality in the use of oral health services. Then, inequity in this utilization was measured by the horizontal inequity index (HI). Furthermore, decomposition analyses were conducted for the three groups to explain the contributions of income level, need factors (ie self-assessed oral health and evaluated oral health status), other factors (ie sex, residential location, educational attainment level and type of basic insurance) and a residual term to overall inequality in oral health service utilization. RESULTS: The significant positive EI and HI values indicated that pro-rich inequality and inequity in oral health service utilization exist among Chinese adults. Income and type of basic medical insurance contributed the most to socioeconomic-related inequality in the use of oral health services among adults aged 55-64 and 65-74 years. However, the main driving factors of socioeconomic inequality among adults aged 35-44 years in dental care use included income, educational achievement, type of basic medical insurance and residential location. The need variables accounted for a very small proportion of overall socioeconomic-related inequality in oral health service use in all three groups. CONCLUSIONS: Oral healthcare service utilization was disproportionately concentrated among better-off Chinese adults. The primary determinants of inequality in dental care use in different age groups provide information for policymakers to create more targeted policies to achieve equity in the oral healthcare system in China.

Factors associated with oral health service utilization among adults and older adults in China, 2015-2016.

OBJECTIVES: To explore the factors associated with utilization of oral health services among Chinese adults and older adults according to the Andersen Behavior Model. METHODS: Data from the 4th National Oral Health Survey (2015-2016) in China were used. A total of 7206 people (3669 adults aged 35-44 years and 3537 older adults aged 65-74 years) were included in our analysis. Oral health service utilization in the past 12 months was the outcome variable. Explanatory variables were selected according to the Andersen Behavior Model. Descriptive statistics and bivariate associations (chi-square tests) were analysed, followed by hierarchical Poisson regression models, which were conducted to determine the factors associated with oral health service utilization. RESULTS: In total, 21.4% (95% CI: 19.4%-23.7%) of adults (35-44 years old) and 20.7% (95% CI: 18.6%-22.9%) of older adults (65-74 years old) utilized oral health services in the past 12 months. Nearly 80% of adults (78.7%, 95% CI: 74.0%-82.7%) and more than 90% of older adults (93.7%, 95% CI: 91.0%-95.6%) visited a dentist for treatment. Adults aged 35-44 years old who were female (IRR: 1.15, 95% CI: 1.00-1.33, P = .047), had good oral health knowledge and attitudes (IRR: 1.30, 95% CI: 1.06-1.59, P = .011), perceived their oral health status as fair (IRR:1.51, 95% CI:1.24-1.85, P < .001) or poor/very poor (IRR:2.52, 95% CI:2.01-3.18, P < .001) and had a decayed, missing and filled teeth (DMFT) index >0 (IRR: 1.52, 95% CI: 1.11-2.09, P = .009) were more likely to report dental visits in the past 12 months. Older adults who utilized oral health services tended to be female (IRR: 1.32, 95% CI: 1.09-1.59, P = .004); to be covered by Urban Resident Basic Medical Insurance (URBMI) (IRR: 1.56, 95% CI: 1.18-2.05, P = .002), Urban Employee Basic Medical Insurance (UEBMI) (IRR: 1.69, 95% CI: 1.32-2.16, P < .001) or government medical insurance (GMI) (IRR: 1.03, 95% CI:1.01-2.16, P = .044); to have a high education level (IRR: 1.37, 95% CI: 1.08-1.74, P = .010); to have an income level in the 2nd tertile (IRR: 1.44, 95% CI: 1.13-1.84, P = .003) or 3rd tertile (IRR:1.52, 95% CI:1.18-1.95, P = .001); and to perceive their oral health status as poor or very poor (IRR: 1.53, 95% CI: 1.21-1.95, P = .001). CONCLUSIONS: Sex and self-perceived oral health status were associated with oral health utilization among Chinese population. Additionally, for older adults, education level, household income and insurance coverage were determinants of dental service use. These findings can aid in creating more targeted policies to increase the use of dental services by Chinese adults.