Comparison of Powered versus Manual Tooth Brushing for Safety and Efficacy in Patients with Gingivitis: A Randomised, Multicentre Clinical Trial in China.

OBJECTIVE: To evaluate the effects of powered and manual tooth brushing on gingival inflammation in a Chinese population with mild to moderate gingivitis. METHODS: The present randomised, single-blind, parallel clinical trial was conducted in five cities in China. Generally healthy participants aged 18 to 65 years, who were non-smokers and had at least 20 sites of gingival bleeding, were included as eligible subjects. The subjects were randomly assigned to either the powered tooth brushing (PTB) group or standard manual tooth brushing (MTB) group. All subjects were supplied with a fluoride-containing toothpaste, Gingival Bleeding Index (GBI), Modified Gingival Index (MGI) and the Turesky modification of the Quigley-Hein Plaque Index (MPI) were used to evaluate the outcomes. RESULTS: A total of 235 subjects completed the study, 118 in the PTB group and 117 in the MTB group. The mean age and sex distribution for the PTB and MTB groups were 34.40 ± 9.99 years, 89 women and 29 men, and 34.20 ± 10.14 years, 82 women and 35 men, respectively. After 6 months, the percentage decrease in MGI was 26.150% ± 26.897% for the PTB group and 14.768% ± 38.544% for the MTB group (P = 0.0092). Statistically significant differences between types of tooth brushing were also observed at 6 months for GBI, and at all time points for MPI. CONCLUSION: Tooth brushing with a powered toothbrush twice a day was shown to be more effective than use of a manual toothbrush in reducing gingival inflammation, gingival bleeding and surface plaque after a 6-month period. Both kinds of toothbrushes were safe for the oral tissues.

Determining the factors associated with oral health-related quality of life in Chinese elders: Findings from the fourth national survey.

OBJECTIVE: The purpose of this study was to assess the associations between the self-reported oral health-related quality of life (OHRQoL) of older Chinese people and their socio-economic status and oral health using data collected in the 4th National Oral Health Survey. METHODS: After multistage stratified cluster sampling, 4332 adults aged 65-74 years participated in the study. After a clinical examination, the participants completed a structured questionnaire. A Mandarin version of the General Oral Health Assessment Index (GOHAI) was included in the questionnaire. Clinical examinations were carried out using the criteria recommended by the World Health Organization. Multivariate analysis was used to evaluate the associations of the clinical and socio-demographic variables with the GOHAI scores of the participants. RESULTS: The weighted mean (SE) GOHAI score was 51.6 (0.0). Female sex and having more than 10 missing teeth, unrestored tooth spaces, more than 10 decayed teeth and a periodontal pocket ≥6 mm were negatively associated with the GOHAI score, while having a higher education level and living in the Eastern region of China were positively associated with the GOHAI score. CONCLUSION: After adjustment for confounders, the OHRQoL of older Chinese individuals was mainly affected by untreated dental caries and the loss of teeth. Older Chinese individuals who were male, had a higher education level, were from the Eastern region, had no unrestored tooth spaces or deep periodontal pockets and had fewer decayed or missing teeth had higher GOHAI scores, indicating better OHRQoL.

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.

Associated Factors of Oral Health-related Quality of Life in Chinese Adolescents Aged 12-15 Years.

adolescents aged 12 to 15 years based on the 4th National Oral Health Survey and to explore its associated factors. METHODS: Students aged 12 to 15 years were recruited using to a multistage stratified random sampling method. All the subjects received oral examination and completed a questionnaire. Information relating to OHRQoL was collected through a Mandarin version of the child oral impacts on daily performances (Child-OIDP) questionnaire. The relationship between the Child-OIDP scores and independent variables was assessed using a Mann-Whitney U-test, Kruskal-Wallis test and a multivariate Poisson regression. RESULTS: A total of 89,582 subjects were included in the analysis, of whom 76.6% reported oral impacts in the last 6 months. Eating was the most affected daily performance. The results of the regression analysis showed that factors associated with adolescents' OHRQoL included sex, location of residence, region, only child status, parents' level of education, frequency of sugar consumption, self-perception of general/oral health, dental appointments in the past 12 months, oral health knowledge status, age, decayed, missing and filled teeth (DMFT) index and number of teeth with gingival bleeding. CONCLUSION: Oral impacts were common among Chinese adolescents, although most were not so severe. Eating was the most commonly affected performance. Sex, location of residence, region, only child status, parents' level of education, frequency of sugar consumption, selfperception of general/oral health status, dental appointments in the previous 12 months, oral health knowledge status, age, DMFT index and number of teeth with gingival bleeding were found to be associated with OHRQoL.

The relationship between different types of caries and periodontal disease severity in middle-aged and elderly people: findings from the 4th National Oral Health Survey of China.

BACKGROUND: The relationship between dental caries and periodontal disease is still controversial. The objective of this study was to explore the relationship between different types of caries and periodontal disease severity in middle-aged and elderly people in China. METHODS: The study population consisted of 4407 middle-aged and 4117 elderly subjects. Caries were divided into the following three types: type A, crown caries; type B, lesions involving both the crown and root, representing mixed-type caries; and type C, root caries. These three types together represent the overall caries situation, which we call type ABC. Caries were quantitated by decayed and filled teeth (DFT index). Periodontitis was evaluated by clinical attachment loss. RESULTS: Middle-aged people with periodontitis had a significant association with DFT type B (OR: 1.21, 95% CI 1.17-1.25) and type C (OR: 1.40, 95% CI 1.24-1.56). Elderly people with periodontitis had a significant association with DFT type C (OR: 1.28, 95% CI 1.21-1.35). CONCLUSIONS: In China, caries types B/C were positively correlated with periodontitis in the middle-aged group, and only caries type C was positively correlated with periodontitis in the elderly group.

Dental expenditure, progressivity and horizontal inequality in Chinese adults: based on the 4th National Oral Health Epidemiology Survey.

BACKGROUND: The financial burden of oral diseases is a growing concern as the medical expenses rise worldwide. The aim of this study was to investigate the dental expenditure, analyze its progressivity and horizontal inequality under the general health finance and insurance system, and identify the key social determinants of the inequality for Chinese adults. METHODS: A secondary analysis used the data of 13,464 adults from the 4th National Oral Health Epidemiological Survey (NOHES) in China was undertaken. The dental expenditure was collected and divided into out-of-pocket and health insurance payments. Horizontal inequality index and Kakwani index were used to analyze the horizontal inequality and progressivity, respectively. The decomposition model of the concentration index was set up to explore the associated socioeconomic determinants. RESULTS: The results showed that a mean dental expenditure per capita of Chinese adults was $20.55 (95% Confidence Interval-CI: 18.83,22.26). Among those who actually used dental service, the cost was $100.95 (95%CI: 93.22,108.68). Over 90% of dental spending was due to out-of-pocket expenses. For self-reported oral health, the horizontal inequality index was - 0.1391 and for the decayed tooth (DT), it was - 0.2252. For out-of-pocket payment, the Kakwani index was - 0.3154 and for health insurance payment it was - 0.1598. Income, residential location, educational attainment, oral hygiene practice, self-reported oral health, age difference were the main contributors to the inequality of dental expenditure. CONCLUSION: Dental expenditure for Chinese adults was at a lower level due to underutilization. The ratio of payments of dental expenditure and utilization was disproportional, whether it was out-of-pocket or insurance payment. Individuals who were more in need of oral care showed less demand for service or not required service in time. For future policy making on oral health, it is worth the effort to further promote the awareness of the importance of oral health and utilization of dental service.

The Prevalence and Associated Factors of Periodontal Disease among 35 to 44-year-old Chinese Adults in the 4th National Oral Health Survey.

OBJECTIVE: To assess the current periodontal status of 35 to 44-year-olds from the Chinese population and to analyse potential influence factors on periodontal disease. METHODS: The data of subjects were collected from both urban and rural areas of all 31 provinces, autonomous regions and municipalities of the mainland of China, as part of the 4th National Oral Health Survey. All subjects were aged 35 to 44 years old. In total, 4,410 subjects were enrolled in the present study. Each subject was asked to undergo a professional oral examination and to fill in a questionnaire. Periodontal health status was evaluated by probe bleeding, calculus, periodontal pocket depth and clinical attachment loss. The data were analysed using the chi-square test and binary logistic regression analysis. RESULTS: The prevalence of probe bleeding and calculus was 87.4% and 96.7% respectively among the 35 to 44-year-old population. Prevalence of shallow pockets (4 mm ≤ PD < 6 mm) and deep pockets (PD ≥ 6 mm) was 45.8% and 6.9% respectively among 35 to 44-year-old people. In addition, prevalence of clinical attachment loss (CAL > 3 mm) was 33.2%. Gender, educational level, smoking, teeth brushing frequency, dental floss and toothpick use were found relevant to periodontal condition. CONCLUSION: Periodontal disease was highly prevalent among 35 to 44-year-old Chinese adults. Gender, educational level, smoking, teeth brushing frequency, toothpick and dental floss use could be potential influence factors of periodontal health status.

Factors Impacting the Oral Health-related Quality of Life in Chinese Adults: Results from the 4th National Oral Health Survey.

OBJECTIVE: To explore the clinical and socio-demographic factors influencing oral health-related quality of life (OHRQoL) of Chinese adults in the 4th National Oral Health Survey. METHODS: Multistage stratified cluster sampling and PPS method were used in sampling and 4720 adults aged 35 to 44 years were recruited. The study subjects completed a structured questionnaire in an interview and underwent a clinical examination. The questionnaire was a Putonghua version of the General Oral Health Assessment Index (GOHAI) and was completed by the interviewer on the site of the 4th National Oral Health Survey. Clinical examination was performed using the criteria recommended by the World Health Organization (WHO). RESULTS: The mean GOHAI score of the subjects was 54.42 (SD 6.01). Result of Poisson regression showed that subjects with a higher household income per capita, had lower DMFT, fewer missing teeth, had no unrepaired missing teeth, or not wearing a partial denture had higher GOHAI scores indicating better OHRQoL. CONCLUSION: The OHRQoL of the adults in China was fair and was mainly influenced by dental caries, integrity of dentition and restoration of lost teeth. With limited resources and dental manpower in China, higher priority should be given to the prevention and treatment of the main cause leading to losing teeth.

Report of the National Investigation of Resources for Oral Health in China.

OBJECTIVE: To investigate the current status and distribution of resources for oral health in China, by means of analysing national data from the National Investigation of Resources for Oral Health. METHODS: The National Investigation of Resources for Oral Health in China was performed in 2015, in parallel with the 4th National Oral Health Survey of China (2015 to 2016). A structured questionnaire on resources for oral health was used to collect the data of professional institutions and stomatological/dental workforce in each province. For each province, the local Investigation Group was responsible to summarise the status and distribution of institutions with stomatological/dental departments and stomatological/dental workforce. Descriptive analysis of resources for oral health was performed to learn about the number and percentage of each category both for each province and nationally. The ratio of number of stomatological/dental workforce to population was also calculated and compared with the criteria of the World Health Organisation (WHO). RESULTS: There were totally 75,399 stomatological/dental departments nationally in all professional institutions in the mainland of China, most of which were set in institutions of primary health care services. Institutions of private sectors accounted for a higher proportion (69.8%) which was over two-fold compared to that of public ones (30.2%). General hospitals were the major part of hospitals with stomatological/dental departments compared with stomatological/dental specialised hospitals. Stomatological/dental clinics were the majority of institutions of primary health care services, compared to community health care service centres/stations and township health care services. Amongst all professional institutions of public health with stomatological/dental departments, 35.0% were maternal and child health care services and 11.2% were institutions for prevention and control of oral diseases. The total number of stomatological/dental workforce in the country was 314,347, among whom 171,587 (54.6%) were stomatologists/dentists. The ratio of number of stomatologists/dentists to population was 1:7,768 nationally, which was lower than the WHO standard of 1:5,000. CONCLUSION: The National Investigation of Resources for Oral Health in China exhibited the current status and distribution of resources for oral health over the country, whereas insufficiencies of stomatological/dental workforce and institutions and inequalities of their distribution were found nationally. This could provide some policy suggestions for the health authorities in China to promote oral health in the Chinese population in the future.

Status of Tooth Loss and Denture Restoration in Chinese Adult Population: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the status of tooth loss and denture restoration in Chinese adults, analyse the changing trend and provide fundamental data for oral health policy. METHODS: According to the protocol of the 4th National Oral Health Survey, a multistage stratified random cluster-sampling method was used to enrol adult subjects aged 35 to 44, 55 to 64 and 65 to 74 years in all 31 provinces, municipalities and autonomous regions of the mainland of China. The status of tooth loss and denture restoration was investigated. SPSS20.0 software was used for statistics analysis. RESULTS: Among the 13,464 subjects investigated, 13.8% had complete dentition, 84.4% had dentition defects, and 1.8% was edentulous. Urban subjects showed a significantly higher proportion of complete dentition than those in rural (P = 0.02), and males showed the statistically higher proportion of complete dentition than females (P = 0.01). The mean of remaining teeth was 26.1 ± 6.90, which in urban areas was significantly higher than in rural areas (P < 0.01). The means of remaining teeth were 29.6 ± 2.3, 26.3 ± 6.1, and 22.5 ± 8.7 in the 35 to 44, 55 to 64 and 65 to 74 age groups, respectively. The detection rate of fixed partial dentures (FPD) was statistically higher in urban than in rural areas and in males than that in females (P < 0.01). The detection rate of removable partial dentures (RPD) was statistically higher in urban areas than in rural locations (P < 0.01). However, the detection rates of irregular denture and unrepair of tooth loss were both significantly lower in urban than in rural areas (P < 0.01). The rate of restoration of tooth loss was 41.6% in Chinese adults. CONCLUSION: Although the tooth loss and denture restoration status recorded in the survey was improved compared with the results of 10 years ago, more efforts need to be made on strengthening oral health promotion, particularly for elderly people and those living in rural areas.

Oral Health Status of 12-year-olds from Regions with and without Coverage of the National Oral Health Comprehensive Intervention Program for Children in China.

OBJECTIVE: To investigate the oral health status and related factors of 12-year-olds from regions with and without coverage of the National Oral Health Comprehensive Intervention Program in China by means of analysing national data from the 4th National Oral Health Survey. METHODS: Data of 12-year-olds participating in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Oral health status, pit-and-fissure sealant history, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and oral health knowledge were compared between children from regions with and without coverage of the national programme. For the number of decayed, missing and filled permanent teeth (DMFT) and its components, as well as the number of teeth with pit-and-fissure sealants, mean values were statistically tested to see if significance existed between regions covered by the national programme and uncovered regions, whereas caries prevalence and percentage of pit-and-fissure sealants presented were also compared. RESULTS: Data from 27,821 12-year-old children were analysed, among whom 7,726 were from regions covered by the national programme and 20,095 were from uncovered regions. Statistical significance was found in caries experience and activity, pit-and-fissure sealant history, sugar consumption habits, utilisation of dental services and oral health knowledge when compared between the covered and uncovered regions. Prevalence of dental caries and indices for caries experience and activity was lower in regions covered by the national programme than those not covered, while the percentage of pit-and-fissure sealants presented and the number of teeth with pit-and-fissure sealants exhibited higher in the covered regions. This remained the same even if we focused only on the first molars instead of the full dentition. CONCLUSION: The National Oral Health Comprehensive Intervention Program for Children in China potentially contributed to better oral health status, behaviour and knowledge in 12-year-old children. The expansion and extension of coverage of the national programme was expected to be beneficial for improving oral health status in children, as well as constructing teams of oral and dental workforce and working mechanisms in some underdeveloped regions.

Oral Health Knowledge, Attitudes, Behaviour and Oral Health Status of Chinese Diabetic Patients Aged 55 to 74 Years.

OBJECTIVE: To understand the oral health knowledge, attitude, behaviour and oral health status of Chinese diabetic patients so as to facilitate the development of oral health education programmes for diabetic patients in China. METHOD: A face-to-face questionnaire was conducted for 1,024 diabetic patients and 8,030 non-diabetic people aged 55 to 74 years old in order to understand their oral health knowledge, attitudes, and behaviour. Oral health examination was implemented including caries, gingival bleeding, dental calculus, periodontal attachment loss, etc. according to the Oral Health Surveys Basic Methods 5th Edition. RESULTS: Compared with non-diabetic patients, those with diabetes had more oral health knowledge and more positive attitudes. The proportion of people who formed toothbrushing habits was higher in diabetic patients, but that of regular scaling and flossing is as low as that in non-diabetic people. The detection rate of deep periodontal pockets in diabetic patients was higher than that in non-patients, while the caries situation was better than that in non-patients. CONCLUSION: This study has shown that the oral health knowledge, attitude, behaviour and oral health status of the 55 to 64-year-old diabetic population are not optimistic. There is a great need for a systematic oral health education programme in China. The contradiction between a large number of diabetes patients and limited health resources requires us to give priority to the improvement of oral health behaviours, such as educating patients to develop toothbrushing and flossing habits.

Utilisation of Oral Health Services and Economic Burden of Oral Diseases in China.

OBJECTIVE: To evaluate the use of oral health services, the economic burden of oral diseases and related influential factors in China. METHOD: Using the multistage, stratified, equal proportion, random sampling method in the 4th National Oral Health Survey of China conducted in 2015 to 2016, residents aged 3 to 5 years, 12 to 15 years, 35 to 44 years, 55 to 64 years, and 65 to 74 years respectively were recruited, clinically examined and answered a questionnaire. Utilisation of oral health services were assessed in all the age groups and the economic burden of oral diseases in the past 12 months were assessed in the 3 to 5 years and 35 to 74 year-old groups. Chi-squared tests, t tests, correlation analysis and a one-way ANOVA were used to determine the relationships of different factors with utilisation of oral health services and the economic burden of oral diseases. RESULTS: In the subject groups - 3 to 5 years, 12 to 15 years and 35 to 74 years - the prevalence of the utilisation of oral health services in the past 12 months was 14.6% (5,876/40,353), 23.6% (27,936/118,592), and 20.1% (2,708/13,461), respectively. In all three groups, receiving dental treatment was the most common reason for subjects' recent dental visit. The average dental cost in the past 12 months was 403.43 CNY (median = 100) for 3 to 5-year-old children and 850.83 CNY (median = 300) for adults aged 35 to 74 years old. Area, education and annual household income per person were the socio-economic influential factors. Oral health status, oral hygiene and attitudes to and knowledge of oral health affected the utilisation of oral health services and the economic burden of oral diseases. CONCLUSION: The percentage of dental service utilisation was relatively low, and the economic burden was high. The related factors for both utilisation of oral health services and the economic burden of oral diseases included living in area, educational attainment, household income, perceived oral health status, and oral hygiene.

The 4th National Oral Health Survey in the Mainland of China: Background and Methodology.

Oral disease patterns change over time and it is important to conduct epidemiological surveillance population surveys regularly to monitor the situation. The overall objectives of the present survey were: (1) to describe the oral health status of Chinese children and adults in the 2015-2016 4th National Oral Health Survey; (2) to investigate the oral health knowledge, attitudes, and behaviours among children and adults; (3) to explore the association among sociodemographic characteristics, oral health behaviours, and the oral health status of Chinese children and adults. A national oral health survey was conducted among a representative sample of Chinese children and adults. Local residents from the five age groups - 3 to 5 years, 12 to 15 years, 35 to 44 years, 55 to 64 years, and 65 to 74 years - were selected. A multi-stage cluster sampling method was adopted for the identification of participants. All 31 provinces, autonomous regions and municipalities of the mainland of China were included. All participants were clinically examined and information on their oral health status, including oral mucosal lesions, dental caries experience, periodontal health status, dental fluorosis, and dental prosthesis status, was collected according to the procedures and criteria recommended by the World Health Organization (WHO). A calibration training programme and quality control procedures were conducted to ensure the reliability of the findings. Information on sociodemographic background, oral health behaviours, knowledge and attitude was also collected from all five age groups through a questionnaire survey.

Dental Caries Status and its Associated Factors among 3- to 5-year-old Children in China: A National Survey.

OBJECTIVE: To investigate the prevalence and severity of dental caries among pre-school children in China as part of the 4th National Oral Health Survey. METHODS: The sampling process was conducted with a multistage stratified cluster method. A total of 40,360 children aged between 3 and 5 years were recruited for this study. Each participant was clinically assessed according to the 5th edition of the oral health survey's basic methods recommended by the World Health Organization (WHO) and their parents or grandparents completed a questionnaire at a face-to-face interview. The status of dental caries was shown in the form of the mean dmft and the prevalence of dental caries. The logistic regression analysis was performed to study the relationships between the prevalence of dental caries and the selected variables. RESULTS: The prevalence of dental caries was 50.8%, 63.6% and 71.9% for 3-, 4- and 5-year-olds, respectively. The mean dmft was 2.28, 3.40 and 4.24, respectively. Logistic regression analysis showed that children who were mixed-fed had a higher chance of staying free of dental caries; children who had dessert before going to bed were associated with a higher probability of caries. CONCLUSION: The status of dental caries among preschool children in China is on the increase. The preschoolers' dental caries status related to their breastfeeding conditions within the first 6 months of life and their snacking habits.

Dental Caries in Chinese Elderly People: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the dental caries status and related factors in Chinese elderly people, using data from the 4th National Oral Health Survey of China. METHODS: In this cross-sectional study, a multistage, cluster strategy was used to recruit 4,431participants (2,222 male and 2,209 female) aged 65 to 74 years from all 31 provinces, autonomous regions and municipalities of the mainland of China. The survey was performed according to the diagnostic standard proposed by the World Health Organization (WHO). Socio-demographic information was collected with a closed questionnaire. RESULTS: The caries prevalence in 65 to 74-year-olds was rather high; the report shows it was 98.0% (DMFT ≥ 1) among elderly people in China. The mean DMFT, DT, MT and FT was 13.33 ± 9.32, 3.33 ± 4.17, 9.50 ± 8.66 and 0.49 ± 1.41, respectively. The filling rate was very low, assessed as 12.8%. The number of DMFT related to gender, residential district type, educational level, level of annual household income, toothbrushing frequency, consumption frequency of desserts, attitudes to oral health and oral health-related knowledge. CONCLUSION: The prevalence of dental caries in Chinese elderly people is rather high and a lot of decayed teeth still need to be filled and suitable prevention and treatment for this group is urgently needed.

The Prevalence and Associated Risk Indicators of Dental Fluorosis in China: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To explore the prevalence and associated risk indicators of dental fluorosis in the mainland of China. METHODS: Data for this study was obtained from the 4th National Oral Health Survey in China, conducted from 2015 to 2016. The sample population was 12-year-old school students. Study participants were selected using a multi-stage, stratified random sample selection procedure using a sampling frame compiled from geographical distribution of China. The level of dental fluorosis was determined using the Dean index recommended by the World Health Organization (WHO). A structured questionnaire was distributed to all the subjects in schools. Participants completed a questionnaire with assistance from staff. A bivariate analysis was performed using the chi-square test. Logistic regression was performed to evaluate the association between dental fluorosis and the independent variables. RESULTS: A total of 27,495 students were evaluated, of which 13,650 (49.6%) were male. Overall, dental fluorosis was found in 13.4% of participants; 6.3% had very mild fluorosis, 4.3% had mild fluorosis, 2.3% had moderate fluorosis, and 0.5% had severe fluorosis. The community fluorosis index was 0.28. In the final logistic regression model students from rural areas (RR:1.582, 95%CI 1.473-1.700), students whose fathers had low education (RR:1.429, 95%CI 1.230-1.661 & 1.184, 95%CI 1.026-1.365), and those students with sibling (RR:1.537, 95%CI 1.414-1.671) were more significantly associated with dental fluorosis. CONCLUSION: As a whole, China has a low dental fluorosis prevalence. Rural areas were the key places for the prevention of dental fluorosis. More prevention measures should be conducted on the children whose fathers were of lower education and who were not an only child.

Permanent Teeth Caries Status of 12- to 15-year-olds in China: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the dental caries status of teenagers in China by means of analysing national data from the 4th National Oral Health Survey of China. METHODS: Data for 12- to 15-year-olds participated in the 4th National Oral Health Survey of China were used for statistical analysis. Children who were recruited in the survey completed a dental examination and filled in a questionnaire. Social demographic factors, oral hygiene behaviours, sugar consumption habits, status of dental service utilisation, and pit-and-fissure sealant history were compared between adolescents with caries experiences and those without. For decayed, missing and filled permanent teeth (DMFT) and each of its components, mean values were statistically tested to see if significance existed between or among different categories of all involved variables. RESULTS: In total, data from 27,821, 30,961, 30,691 and 29,128 Chinese 12-, 13-, 14-, and 15-year-olds respectively, were analysed. Social demographic factors, sugar consumption and dental service utilisation showed statistical significance when compared between those with and without dental caries experience in the 12- and 15-year-old groups. Certain categories of these factors above also had important influence on the mean value of the number of decayed teeth (DT), filled teeth (FT) and DMFT, and they might be potential determinants of dental caries experience of permanent teeth for teenagers. CONCLUSION: Dental caries in 12- and 15-year-old Chinese adolescents was impacted by certain social demographic and dental behavioural factors, which could provide some implications for policy makers and dental public health professionals when attempting to enhance oral health status for those teenagers in the early stages of permanent dentition.

Periodontal Status of Chinese Adolescents: Findings from the 4th National Oral Health Survey.

OBJECTIVE: To investigate the periodontal health status and associated factors of adolescents aged 12 to 15 years old in China. METHODS: A cross-sectional national oral health survey was conducted in 2015-2016. The multi-stage stratified cluster sampling was used to select participants in all 31 provinces, autonomous regions and municipalities in the mainland of China. Each participant received a clinical assessment including periodontal bleeding and calculus, and 15-year-old adolescents received additional examinations including for periodontal pocket depth and attachment loss, using the latest criteria from the Oral Health Survey Basic Methods, as recommended by the World Health Organization (WHO). A self-answered structured questionnaire was designed to collect the data of background information and associated risk factors. RESULTS: A total of 118,514 adolescents (14.0 ± 1.09 years old) completed all the oral examinations and the questionnaire. The prevalence of periodontal bleeding and calculus was 61.0% and 67.3% respectively. In the group of 15 year olds, 6.5% adolescents had periodontal pocket and 0.5% had attachment loss. Molars were often involved and, furthermore, calculus also occurred on lower incisors. The periodontal status of adolescents became worse as they grew up. The condition of girls was significantly better than boys. CONCLUSION: This survey illustrated a brief picture of periodontal status of adolescents in China showing that gingival bleeding and calculus were very common and frequent. Further actions on oral health education were necessary, especially for those in lower socio-economic classes.

How Root Caries Differs between Middle-aged People and the Elderly: Findings from the 4th National Oral Health Survey of China.

OBJECTIVE: To investigate the differences in distribution of root caries and related factors between middle-aged and elderly people in China. METHODS: In this cross-sectional study, a multistage, cluster strategy was used to recruit 4,410 participants (2,197 males and 2,213 females) aged 35 to 44 years and 4,431 participants (2,222 males and 2,209 females) aged 65 to 74 years from all 31 provinces, autonomous regions and municipalities of the mainland of China. The survey was conducted according to the basic methods proposed by the World Health Organization (WHO). Sociodemographic information, oral health behaviour, attitude and knowledge, history of dental prophylaxis and general health condition were collected with a closed questionnaire. RESULTS: A great increase in the occurrence of root caries in Chinese adults from 35 to 44-year-old to 65 to 74-year-olds, with the prevalence (DFR ≥ 1) from 25.4% to 61.9% and with the mean DFR score from 0.54 ± 1.34 to 2.63 ± 3.75. Filling rates were also very low, only 1.8% and 3.0%, respectively. Females and residents of rural areas were more likely to suffer from root caries. In both the middle-aged group and the elderly group, root caries related to gender, education level, sweet food/drinks consumption, oral health knowledge and status of root surface explosion. In 35 to 44 year olds, toothbrushing is a significant protection factor (OR = 0.88, 95%CI 0.81 ~ 0.96), while using toothpicks is a risk factor (OR = 1.06, 95%CI 1.02 ~ 1.10). In 65 to 74 year olds, not having dental had scaling in the past 12 months is a risk factor (OR = 1.66, 95%CI 1.09 ~ 2.53). CONCLUSION: Root caries among middle-aged people and elderly people in China have different risk factors and need more attention in future research to develop proper prevention.