Deyu Hu

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.

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.

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.

To study the anti-halitosis effect of sugar-free chewing gum through their influence on odor induced by cysteine. Ten volunteers were randomly divided into the treatment group and the untreated group; each group consisted of five volunteers. All volunteers consented to participate in a test in which breath odor was induced by cysteine. After the test, the treatment group chewed sugar-free chewing gum for 1 min, whereas the untreated group did not undergo any treatment. The effectiveness was determined by the percent reduction of H2S, CH3SH, and (CH3)2S response after the volunteers chewed gum for 1, 10, and 20 min. At 1, 10, and 20 min, H2S of the treatment group was reduced by 82.68%, 92.27%, 97.47%, respectively, CH3SH was reduced by 65.49%, 73.79%, and 82.89%, respectively, and (CH3)2S was reduced by 60.45%, 73.82%, and 59.72%, respectively. The differences between the two groups at different times were significant (P < 0.05). Chewing gum can effectively inhibit cysteine-induced odor.

To determine whether sugar-free gum can provide remineralization and caries control of active enamel caries lesions compared to baseline (before gum chewing) and to a no-gum group, following daily chewing for 12 weeks by school children; to determine whether chewing frequency can affect the extent of remineralization. A pragmatic cluster-randomized controlled clinical trial with schools as the unit of randomization was employed. Three schools in Chengdu, PR China comprised the clusters. The study was approved by the Internal Review Board of Sichuan University. 177 school children, 8-13 years old, with at least one visible white-spot lesion were enrolled in the study. Each of the three clusters was randomly assigned to one of three groups: (1) no gum; (2) chew 2 pieces of sugar-free gum for 20 minutes, 3x per day; (3) chew 2 pieces of sugar-free gum for 12 minutes, 5x per day. White-spot lesions were examined by quantitative light-induced fluorescence (QLF) at baseline and after 4, 8, and 12 weeks of treatment. 155 subjects completed the study. Of them, the mean values of fluorescence loss at baseline were 9.52, 9.83 and 9.17 for no-gum group, 3x per day group and 5x per day group, respectively. For the area, the mean values at baseline were 2.52, 2.61 and 2.57 mm2 for no-gum group, 3x per day group and 5x per day group, respectively. For AQ, the mean values at baseline were -27.91, -28.29 and -29.67 for no-gum group, 3x per day group and 5x per day group, respectively. To adjust for differences in groups at baseline, ANCOVA was used. After 12-weeks, for all QLF metrics, the absolute values of 5x per day group were the lowest and the no gum group was the highest; the differences among three groups were statistically significant (P < 0.05). For AQ, which was accepted as the most useful metrics of QLF system, the adjusted mean values at 12 weeks were -26.35, -19.81 and -17.58 for no-gum group, 3x per day group and 5x per day group, respectively. There were significant differences between groups.

To investigate whether the long term use of two dentifrices containing arginine, an insoluble calcium compound, and fluoride: (1) 1.5% arginine and 1450 ppm F as sodium monofluorophosphate (NaMFP) in a dicalcium phosphate dihydrate (dical) base, and (2) 8.0% arginine and 1450 ppm F as NaMFP in a calcium carbonate base, results in an increase in oral malodor potentially associated with increased ammonia production from breakdown of arginine, as compared to a commercially available fluoride dentifrice without arginine (1450 ppm F as NaMFP in a dical base), after 6 months of product use. A 6-month clinical study, with 119 subjects, was conducted in Chengdu, China, using a double blind, randomized, parallel, three-treatment design. A panel of four expert judges used a nine-point hedonic scale to evaluate breath odor using a protocol designed in concordance with the ADA Acceptance Program Guidelines for Product Used in the Management of Oral Malodor. After a baseline evaluation, study subjects who scored above the threshold value for unpleasant breath odor were stratified by score and randomized into one of three treatment groups. Subjects were provided with a soft-bristled manual toothbrush (Colgate Classic Clean Toothbrush) and brushed their teeth thoroughly in their regular and customary manner for 1 minute with their assigned dentifrice, twice daily. Before breath-odor evaluations, the subjects refrained from eating odorigenic foods and did not use dental hygiene procedures, breath mints, or mouth rinses for 48 hours and 12 hours, respectively. There was no statistically significant difference in oral malodor levels among subjects using the three dentifrices after 1, 3 and 6 months of product use.

To assess the oral debris removal efficacy of two commercial sugar-free chewing gums, based on a newly developed oral debris scoring system. A randomized, examiner-blinded, three-arm crossover study was conducted, with a 1-week washout period between the crossover phases. 42 healthy adults were randomly assigned to sugar-free stick gum (Wrigley's Extra Freshmint), sugar-free pellet gum (Wrigley's Extra Fruit) or no-gum chewing groups. Subjects consumed a single chocolate cookie, and were examined at baseline, and at 2-, 5-, and 10-minute time points with or without gum-chewing treatment. Primary outcome measures were oral debris scores on the occlusal surface, interproximal and gingival margin areas. The entire test procedure was repeated on two subsequent visits. The baseline conditions in the three groups did not differ significantly. Chewing either stick gum or pellet gum resulted in significantly lower oral debris scores (P < 0.0001) compared to the control (no-gum) treatment for all intraoral sites, while no significant difference was observed between the two chewing gum groups. Intra-examiner repeatability of the new scoring criteria was high throughout the study (Kappa > 0.90).

To investigate the clinical characteristics and risk factors of dentine hypersensitivity in smaller cities and rural area in Sichuan province. The examinee aged 20 - 69 years old were interviewed and divided into five age groups (20 - 29, 30 - 39, 40 - 49, 50 - 59 and 60 - 69). The random sampling methods were performed in this study. A total of eight spots were survied, including 4 communities and 4 spots in rural area of Sichuan province. The information about the examinee's age, gender, occupation, education level, tooth brushing methods, the frequencies of eating fresh fruits and fruit juices and so on, were asked and recorded. All subjects were further diagnosed by a blast of air from a triple syringe connected to an air compressor at a pressure of 4 atm under room temperature of about 19 - 24°C. The premolars were the most commonly affected, followed by the first molar. The exposed root surface was the most commonly affected position [63.87% (663/1038)]. The first premolar had the greatest number of teeth with dentine hypersensitivity [29.96% (311/1038)]. Different tooth had different sensitive position. Female, too much time of using a tooth brush, and hydrochloric acid in gastric juice were risk factors for dentine hypersensitivity (OR value = 2.175, 1.157, 1.760). Dentine hypersensitivity is influenced by multiple factors. Prevention and treatment need be performed by improving general oral health and periodontal conditions.