Relationship between periodontal disease and male infertility: A case-control study.

OBJECTIVES: To compare the prevalence of chronic periodontitis between men who had semen abnormalities and those who had normozoospermia through a case-control study. MATERIALS AND METHODS: Male patients who visited the assisted reproduction clinic of a large general hospital and were diagnosed with semen abnormalities were included in the case group. The control group was composed of patients of the same clinic with normozoospermia. The semen analysis included sperm concentration, count and progressive and total motility, which were measured in the laboratory. A questionnaire and clinical periodontal examination were conducted for all participants. Logistic regression was performed to explore the relationship between chronic periodontitis and male infertility. RESULTS: A total of 192 participants were included: 63 participants (32.8%) had some type of semen abnormality (case group), while 129 participants (67.2%) had normozoospermia (control group). The case group had a significantly higher prevalence of moderate/severe periodontitis than the control group (33.3% vs. 17.8%, p = .012). The logistic regression showed that participants who had moderate/severe periodontitis had a greater chance of having semen abnormalities after adjusting for other confounding factors (OR = 3.377, p = .005). CONCLUSIONS: Periodontitis is associated with semen abnormalities and sperm motility in men.

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.

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.

Efficacy of an anhydrous stannous fluoride toothpaste for relief of dentine hypersensitivity: A randomized clinical study.

AIM: To compare efficacy of an anhydrous 0.454% w/w stannous fluoride/sodium fluoride toothpaste (Test) versus a sodium monofluorophosphate toothpaste (Negative control) and a stannous chloride/sodium fluoride toothpaste (Positive control) for dentine hypersensitivity relief after 8 weeks' twice-daily use. MATERIALS AND METHODS: In this randomized, examiner-blind, stratified, parallel study, primary and secondary efficacy variables were mean changes in Schiff score (evaporative [air] sensitivity) and tactile threshold (Yeaple probe), respectively, from baseline to Week 8 between Test (n = 62) and Negative control (n = 62). Test and Positive control (n = 61) comparisons were exploratory objectives. RESULTS: All groups significantly improved from baseline on both dentine hypersensitivity measures (p < .0001). Difference between adjusted mean changes from baseline in Schiff sensitivity scores at Week 8 for Test versus Negative control groups was 0.19 (95% CI 0.002, 0.374), in favour of the Negative control (p = .0476; 12.57% difference). Difference in tactile threshold was -7.20 g (95% CI -16.376, 1.975), and this was not statistically significant (p = .3715; -21.83% difference). Test group showed no significant difference versus Positive control for either measure. Toothpastes were generally well tolerated. CONCLUSION: While twice-daily use of Test toothpaste significantly reduced dentine hypersensitivity from baseline, there was no significant advantage over negative or positive controls. STUDY REGISTRATION: Clinicaltrials.gov; NCT03310268.

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.

A novel phage from periodontal pockets associated with chronic periodontitis.

Bacteriophages often constitute the majority of periodontal viral communities, but phages that infect oral bacteria remain uncharacterized. Here, we present the genetic analysis of the genome of a novel siphovirus, named Siphoviridae_29632, which was isolated from a patient with periodontitis using a viral metagenomics-based approach. Among 43 predicted open reading frames (ORFs) in the genome, the viral genes encoding structural proteins were distinct from the counterparts of other viruses, although a distant homology is shared among viral morphogenesis proteins. A total of 28 predicted coding sequences had significant homology to other known phage ORF sequences. In addition, the prevalence of Siphoviridae_29632 in a cohort of patients with chronic periodontitis was 41.67%, which was significantly higher than that in the healthy group (4.55%, P < 0.001), suggesting that this virus as well as its hosts may contribute to the ecological environment favored for chronic periodontitis.

Detection of a new species of torque teno mini virus from the gingival epithelium of patients with periodontitis.

We describe a novel species of torque teno mini virus called TTMV-204, which was isolated from the gingival epithelium of patients with periodontitis and characterized using viral metagenomics. The sequence of the full genome is 2824 nt in length. Phylogenetic analysis and genetic analyses show classic Betatorquevirus species organization with less than 40% amino acid similarity in ORF1. The prevalence of TTMV-204 in the periodontitis patient population was 18.75% (15/80), which was higher than in periodontally healthy individuals (10.00%, 10/80). However, the difference of the TTMV-204 prevalence between two groups was not statistically significant (p = 0.115). Further investigation is required to determine whether this new virus is associated with inflammation.

Statistical inference for extended or shortened phase II studies based on Simon's two-stage designs.

BACKGROUND: Simon's two-stage designs are popular choices for conducting phase II clinical trials, especially in the oncology trials to reduce the number of patients placed on ineffective experimental therapies. Recently Koyama and Chen (2008) discussed how to conduct proper inference for such studies because they found that inference procedures used with Simon's designs almost always ignore the actual sampling plan used. In particular, they proposed an inference method for studies when the actual second stage sample sizes differ from planned ones. METHODS: We consider an alternative inference method based on likelihood ratio. In particular, we order permissible sample paths under Simon's two-stage designs using their corresponding conditional likelihood. In this way, we can calculate p-values using the common definition: the probability of obtaining a test statistic value at least as extreme as that observed under the null hypothesis. RESULTS: In addition to providing inference for a couple of scenarios where Koyama and Chen's method can be difficult to apply, the resulting estimate based on our method appears to have certain advantage in terms of inference properties in many numerical simulations. It generally led to smaller biases and narrower confidence intervals while maintaining similar coverages. We also illustrated the two methods in a real data setting. CONCLUSIONS: Inference procedures used with Simon's designs almost always ignore the actual sampling plan. Reported P-values, point estimates and confidence intervals for the response rate are not usually adjusted for the design's adaptiveness. Proper statistical inference procedures should be used.

Impact of periodontal conditions on the quality of life of pregnant women: a cross-sectional study.

BACKGROUND: Studies have been rarely conducted to provide a comprehensive perspective of pregnant women with the intention to investigate the relationships between periodontal conditions and oral health-related quality of life (OHRQoL). As such, this study aimed to describe the OHRQoL of pregnant women in Shanghai, China and to investigate the relationships between periodontal conditions and OHRQoL of pregnant women. METHODS: A cross-sectional study was conducted amongst pregnant women in all stages of pregnancy in Shanghai, China. Clinical examinations were performed to assess periodontal conditions, including tooth loss, visible plaque index, bleeding on probing, probing pocket depth and clinical attachment level. The OHRQoL of pregnant women was determined using the Oral Health Impact Profile (OHIP-14, Chinese version). Information regarding maternal characteristics, socio-demographic background and health-related behaviours was also obtained from the participants through the structured questionnaires. RESULTS: A total of 512 pregnant women (mean age = 27.3 ± 4.0 years)participated in the survey,giving a response rate of 91.4 %. The mean gestational age was 19 weeks (SD = 8.2). The mean and the median OHIP-14 scores were 7.92 (SD = 6.84) and 6, respectively. The mean number of negative impact items (extent) was 0.20 (SD = 0.82). Approximately 10 % of pregnant women reported at least one item with 'fairly often' or 'very often' (prevalence). Results of multivariable analyses showed that periodontal conditions was not significantly associated with three scoring formats of OHRQoL (severity, extent and prevalence of impact) after adjustment for pregnancy-related variables and possible confounders (all p > 0.05). However, frequency of nausea-vomiting was found to be significantly associated with severity of impacts (p = 0.012). Utilization of dental services, age and tooth loss were the significant variables to the extent of negative impacts (all p < 0.05). While no significant variable was related with prevalence of negative impacts (p > 0.05). CONCLUSION: Pregnant women with different trimesters showed similar impact of oral disease on their OHRQoL in Shanghai, China. Periodontal health status have no impact on their OHRQoL in the fully adjusted models. Their OHRQoL was associated with early pregnancy reaction, utilisation of dental services, age and tooth loss.

Factors associated with black tooth stain in Chinese preschool children.

OBJECTIVES: The objective of this study was to investigate the prevalence of black tooth stain and associated factors in primary dentition in Shanghai, China. MATERIALS AND METHODS: Through a cross-sectional design, preschool children were randomly recruited from 12 kindergartens. Children's dental caries were assessed on the number of decayed, missing, and filled teeth (dmft) and surfaces (dmfs). The presence of black tooth stain was examined, and the visible plaque index was calculated. Questionnaires were completed by the children's parents or guardians. Negative binomial regression was used to investigate the associated factors. RESULTS: A total of 2,023 children were invited, and 1,397 examined participants with questionnaire data were included in final analysis. The rate of black tooth stain was 9.9 % with mean age of 4.55 years. Compared to children without black stain, children with black stain had a significant lower prevalence and experience of dental caries (P < 0.01). Factors for black stain were age, born in Shanghai, parents' higher education level, lower visible plaque index and mean dmfs, less use of nursing bottle, food with more soy sauce, and history of pneumonia. CONCLUSIONS: Preschool children with black tooth stain had fewer dental caries. Further studies are warranted to explore the microbiologic risk factors for black tooth stain and to evaluate the causal-effect factors using prospective study design. CLINICAL RELEVANCE: In clinics, dentists should pay more attention to this aesthetic problem for the relative high prevalence of black tooth stain in primary dentition. Also, the related factors can be explained to parents for the prevention of black tooth stain in children.

A randomized trial on the inhibitory effect of chewing gum containing tea polyphenol on caries.

OBJECTIVE: The purpose of the study was to determine the cariostatic potential of a chewing gum containing tea polyphenol. STUDY DESIGN: A total of 157 schoolchildren aged 8-9 years were randomly allocated into three groups. Two groups received chewing gum with or without tea polyphenol. A third group did not receive any chewing gum. A single examiner assessed the caries status for all participates at baseline, 12 months and 24 months. A one-way analysis of variance (ANOVA) was performed to evaluate differences among the groups at each interval The Chi-square test was used to compare the caries-free rate among the three groups. RESULTS: The mean DMFT increment was 0.17 for the polyphenol gum group, 0.60 for the control gum group, and 1.15 for the no gum group. Children who chewed gum containing tea polyphenol had a significantly lower mean DMFS increment over the 24-month period than did the other two groups (p < 0.05). The caries-free rate in the polyphenol gum group was significantly higher than that in the other two groups (p < 0.05) after two years. CONCLUSION: These findings indicated that the oral application of chewing gum with tea polyphenol has an inhibitory effect on dental caries.

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.

Status of the dental health care workforce in Shanghai, China.

OBJECTIVES: The status of the dental health care workforce in Shanghai was investigated in order to support and improve regional planning of this workforce. METHODS: Questionnaires were used to survey all dental medical units in Shanghai. Data were collected on the quantity, structure and levels of dental health personnel. RESULTS: A total of 852 dental medical units and 3,218 dentists were identified in Shanghai. The ratio of dentists to population is 1 : 5,201. CONCLUSIONS: Presently, the total dental health workforce in Shanghai is relatively sufficient, but its distribution is inequitable because there are fewer dental health personnel employed in the suburbs. Moreover, the structure of the dental health workforce in Shanghai is inequitable and specialists in preventive dentistry are lacking. The results of this study can be applied to help Shanghai achieve the rational distribution and efficient utilisation of the dental health workforce available.

Epidemiological and Microbiome Characterization of Black Tooth Stain in Preschool Children.

OBJECTIVE: To assess the epidemiologic attributes and microbial variations associated with extrinsic black tooth stain (BTS) among Chinese preschool children. METHODS: This cross-sectional study included 250 preschool children (3-4 years) from three kindergartens in Shanghai, China. Following clinical examination, and using a case-control design, saliva and dental plaque specimens were collected from caries-free participants with (n = 21, BTS group) and without (n = 48, control group) BTS. The chi-square test and logistic regression model were used to evaluate factors associated with BTS. 16S rRNA sequencing were used to characterize the associated microbial communities. RESULTS: BTS was detected in 12.4% of participants, with a mean of 13.7 black-stained teeth. Participants with BTS had a lower caries burden and better oral hygiene (P = 0.003). Children with less frequent intake of marmalade or honey (P = 0.033) and regular application of fluoride (P = 0.007) had a lower likelihood of having BTS. Microbiota analysis revealed 14 phyla, 35 classes, 63 orders, 113 families, 221 genera, 452 species, and 1,771 operational taxonomic units (OTUs). In terms of microbial diversity, no significant differences were observed in the saliva of the two groups (P > 0.05). Dental plaque from the BTS group exhibited higher OTU richness but lower evenness than that from the control group (Chao P = 0.006, Shannon P = 0.007, respectively) and showed a significant difference in ß diversity (P = 0.002). The microbiome in the two groups was characterized by various microbial biomarkers, such as Pseudomonas fluorescens, Leptotrichia sp._HMT_212, Actinomyces sp._HMT_169, and Aggregatibacter sp._HMT_898 in plaques from the BTS group. Functional analysis of the microbial species suggested the existence of a hyperactive metabolic state on teeth surfaces with BTS plaques and revealed that ferric iron, the iron complex transport system, and the iron (III) transport system were more abundant in BTS plaque samples. CONCLUSIONS: This study provides insights into the epidemiologic and microbial features of BTS in preschool children. The microbiome in BTS is characterized by various microbial biomarkers, which can serve as indicators for BTS diagnosis and prognosis.

Microbiota of preterm infant develops over time along with the first teeth eruption.

Objective: The temporal growth of the infant microbiome in the early years of life influences short- and long-term infant health. The aim of this longitudinal study was to investigate bacterial dynamics in the microbiome of preterm infants during tooth eruption. Methods: Saliva samples from normally delivered (n = 24) and preterm infants (n = 31) were collected 30 days after birth and after the eruption of two primary mandibular incisors. Based on Illumina MiSeq Sequencing of the 16S rRNA gene, the dynamic microbial changes of newborns at two-time points were investigated. Meanwhile, the Human Oral Microbiome Database was adopted for assigning taxonomy. Results: Using alpha and beta diversity analyses, different shift patterns of microbiome structures in preterm and healthy participants and bacterial diversity over time were observed. The relative abundance and shifts trend, along with the two lower primary central incisors eruption, of core oral flora varies in full-term and preterm groups, including Gemella spp., Rothia mucilaginosa, Veillonella atypica, etc. Several microorganisms colonize later in the oral microbiome development of premature babies, such as Gemella spp. In addition to teeth eruption, the growth of the saliva microbiome in preterm infants could be influenced by breastfeeding durations and birth weight. Conclusion: This study provided insights into how the oral microbiota changes during tooth eruption in preterm infants and how the colonization of the oral cavity with bacteria in preterm infants differs significantly from that in full-term infants.

[Prevalence of torque teno mini virus (TTMV) and epstein-barr virus (EBV) in gingival tissues in 80 patients with periodontitis].

PURPOSE: To study the prevalence of torque teno mini virus (TTMV) and epstein-barr virus(EBV) in patients with periodontitis. METHODS: Gingival tissue samples were collected from 80 patients with periodontitis and 40 periodontal healthy volunteers. The presence of EBV and TTMV-222 were detected by nested PCR, and the virus loads were detected by real-time PCR. Statistical analysis was performed by SPSS 16.0 software package. RESULTS: The detection rates and virus loads of EBV and TTMV-222 in periodontitis group were significantly higher than those in periodontal health group (P＜0.05), and the detection rate of TTMV-222 in EBV positive group was significantly higher than that in EBV negative group (P＜0.01). There was a positive correlation between EBV and TTMV-222 in gingival tissues(P＜0.01). CONCLUSIONS: TTMV infection and co-infection of EBV and TTMV may be related to periodontal disease, but the pathogenic mechanism of the interaction between the two viruses needs further studies.

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.

[The effect of chronic kidney disease on periodontitis-related microorganisms in mice].

PURPOSE: To explore the effect of chronic kidney disease on the composition of oral microbial community in mice and find the significant species. METHODS: Twenty C57BL/6 male mice were randomly divided into 4 groups: healthy control group (HC), periodontitis group (PD), chronic kidney disease group (CKD) and chronic kidney disease and periodontitis group (CKD+PD). The periodontitis model was created in the fourth week when the chronic kidney disease model was established, and then the mice were sacrificed in the sixth week. Histopathological analysis of the kidney was performed by H-E staining and Masson's trichrome staining. Alveolar bone resorption of maxilla was analyzed by micro-CT analysis. The third-generation full-length sequencing of 16SrRNA gene was used to analyze the composition of oral microbial community among groups. Statistical analysis was performed using SPSS 24.0 software package. RESULTS: There were significant differences in alveolar bone resorption, the richness of species and the overall composition of the microbial community among the four groups (P＜0.001). In CKD group, Streptococcus azizii had the most significant abundance. Escherichia coli was the most significantly different species among identifiable bacteria in CKD+PD group, while Staphylococcus lentus and Lactobacillus murinus were species with the most significant differences in HC group and PD group, respectively. CONCLUSIONS: The composition of the oral microbial community was significantly different among four groups with significant species.

Prevalence and Associated Factors of Tooth Wear in Shanghai.

OBJECTIVE: To estimate the prevalence and distribution of tooth wear among groups of adolescents and adults in Shanghai, China through an epidemiological survey, and explore the associated factors. METHODS: Multistage, stratified, constant volume and cluster sampling methods were used in an epidemiological survey conducted in Shanghai in 2014. The basic erosive wear examination (BEWE) index was used to screen for tooth wear in different age groups: 12 years, 15 years, 18 to 35 years, 36 to 49 years and 50 to 74 years. A previously published questionnaire collected information including dietary habits, oral hygiene habits and general conditions. RESULTS: This survey reports the results for 1806 participants in Shanghai. The prevalence of tooth wear was 59.7% in adolescents (BEWE ≥ 1) and 93.1% in adults (BEWE ≥ 2). The prevalence and severity of disease increased with age (P < 0.01). The teeth most susceptible to wear were the central incisors and first molars. Multivariate analysis of covariance (ANCOVA) results showed that soft drinks, alcoholic drinks, pickled vegetables and hard food, gastroesophageal reflux disease (GERD), xerostomia and poor tooth brushing habits were statistically correlated with tooth wear in different age groups. CONCLUSION: The prevalence of tooth wear appears to be high in adolescents and adults in Shanghai. Frequent consumption of soft or alcoholic drinks, GERD, xerostomia and poor tooth brushing habits were positively associated with tooth wear in different age groups.

[Risk factors of dental caries among young children in Pudong New District, Shanghai].

PORPOSE: To establish a prospective cohort of kindergarten children and longitudinally study the causes of early childhood caries. METHODS: Cluster random sampling was used to select a kindergarten in the urban and suburban areas of Pudong New District of Shanghai, a total of 240 small-class children joined the study. Chi-square test, analysis of variance, binomial logistic regression model and general linear regression model was used to analyze caries of the cohort children at baseline and 1 year after follow-up with SPSS 21.0 software package. RESULTS: In the first two years of this cohort study, the follow-up rate was 88.3%, the caries rate in the first year of baseline and follow-up were 58.3% and 69.8%, and the mean dmft values were 3.1±4.2 and 4.5±4.9, respectively. 56.1% of children had new caries. Logistic regression results showed that children who lived in the suburbs (P=0.010) and ate candy more frequently (P=0.036) had higher rates of new caries. The results of general linear regression equation showed that children in the suburbs (P<0.001), those who did not use fluoridated toothpaste (P=0.003) and those who ate candy more frequently (P=0.002) had higher new mean dmft values. CONCLUSIONS: Living in the suburbs, not using fluoride toothpaste and eating candy more frequently are important risk factors for new caries in preschool children in Pudong New District of Shanghai.