Shinan Zhang

Dental caries and erosion status of 12-year-old Hong Kong children

BackgroundThis study aimed to assess the dental caries and erosion status of 12-year-old Hong Kong children and study the determinants of dental caries and dental erosion of these children.MethodsThe survey was performed from 2011 to 2012 with ethics approval. Stratified random sampling was adopted to select 12-year-old children in 7 primary schools in Hong Kong. The participating parents were asked to complete a self-administered questionnaire concerning their children’s diet and oral health habits. The children were examined for caries status with WHO criteria by 3 calibrated examiners. Detection of dental erosion followed Basic Erosive Wear Examination (BEWE) criteria.ResultsA total of 704 children were recruited and 600 (316 boys, 53%) participated in the survey. There were 124 children (21%) with caries experience (DMFT > 0) and their DMFT was 0.34 ± 0.76. About half of their decay was unfilled (DT = 0.16 ± 0.52) The DMFT of girls and boys were 0.45 ± 0.89 and 0.23 ± 0.61, respectively (p = 0.001). Girls also had a higher DT (0.21 ± 0.62 compared with 0.11 ± 0.41, p = 0.013) and FT than boys (0.23 ± 0.63 compared with 0.12 ± 0.44, p = 0.016). Most children (75%) had at least some sign of erosion (BEWE > 0), but no severe erosion (BEWE = 3). Logistic regression showed girls who consumed soft drinks and took vitamin C supplements had higher caries risk. Dental erosion was more severe among the children who had caries experience and consumed fruit juice.ConclusionsThe 12-year-old Hong Kong children had low caries experience, and almost half of the decay was left untreated. Although severe erosion was not found, many children had early signs of erosion.

Dental caries status of Dai preschool children in Yunnan Province, China

BackgroundThe Dai people, one of the ethnic minorities in China, have a population of 1,260,000. They have the same origin as one of the main ethnic groups of Laos and Thailand. Most of the Dai live in Yunnan province, which is located in the less-developed southwestern part of China. This study aimed to describe the oral health status of Dai preschool children in China and the factors that influence their oral health status.MethodsAn oral health survey was performed between 2011 and 2012 to select Dai five-year-old children using multi-stage stratified sampling in Yunnan. Their dental caries experience was measured using the “dmft” index, and severe caries was assessed using the “pa” index, which is modified from the “pufa” index. Oral hygiene status was assessed using the visual plaque index (VPI). A questionnaire to study the children’s socio-demographic background and oral health-related behaviours was completed by the children’s parents.ResultsA total of 833 children were examined. Their caries prevalence was 89% and 49% of the children had carious tooth with pulp involvement. The mean (SD) dmft score was 7.0 (5.3). Higher dmft scores were found among children who were girls, were currently bottle-fed, took daily sweet snacks, had higher VPI scores, and had visited a dentist within the last year.ConclusionsThe caries prevalence and experience of the five-year-old Dai children in Yunnan, China was high, and almost half had severe caries. The caries experience was associated with gender, snack habits, dental visit habits, and oral hygiene status.

Dental caries status of Bulang preschool children in Southwest China

BackgroundBulang is one of the 55 ethnic minorities in China with a population of around 120,000. They live mainly in Yunnan, which is a less-developed province in southwestern China. Many Bulang people live in remote villages and have little access to dental care. They like hot and sour food and chew betel nut. This study examines the caries status of 5-year-old Bulang children and factors that influence their caries status.MethodsA sample of 5-year-old Bulang children in Yunnan was selected using a multi-stage cluster sampling method. One trained dentist examined the children using dental mirrors with intra-oral LED light and CPI probes. Caries experience was measured according to the dmft index. Oral hygiene status was recorded according to the visible plaque index (VPI). A parental questionnaire was used to study the children’s oral health-related behaviours.ResultsA total of 775 children were invited and 723 joined the survey. The caries prevalence was 85%, and 38% of them had caries involved in pulp. The mean dmft and dt score were 5.8 ± 4.9 and 5.6 ± 4.8, respectively. Visible plaque was found on 636 children (88%). Multi-factor ANCOVA analysis found that higher dmft scores were found among the children who snacked on sweets daily, had visited a dentist within the last year and had higher VPI scores.ConclusionsThe caries prevalence and experience among 5-year-old Bulang children in Yunnan was high, and most of the caries were left untreated. The caries experience was associated with snacking habits, dental visit habits and oral hygiene.

Dental and periodontal status of 12-year-old Bulang children in China

BackgroundBulang is an ethnic minority group living in Yunnan in the southwestern part of China. There is little information pertaining to the oral health of Bulang children. This study aims to examine the dental caries and periodontal status of 12-year-old Bulang children in China and the factors affecting their oral-health status.Methods12-year-old Bulang school children in Yunnan, China, were recruited through a multi-stage cluster sampling method. Following the recommendation of the World Health Organization, caries experiences were recorded using the DMFT index and periodontal status with the CPI index. A self-completed questionnaire was used to collect information on the background and oral health-related behaviours of the children.ResultsA total of 900 children in primary schools were invited, and 873 (97%) joined the survey. Their caries prevalence was 35%. Their caries experience in mean DMFT (±SD) score was 0.6 ± 1.1, and 94% of the carious teeth had no treatment. Most children (71%) had bleeding gums, and 58% of them had calculus. Girls and those who had visited a dentist in the previous year had higher caries risk.ConclusionsDental caries was common among the 12-year-old Bulang children in China. Most of the carious teeth were left untreated. Caries prevalence was associated with gender and dental attendance. Their periodontal condition was poor, and more than half of them had calculus.

Attitude and awareness of medical and dental students towards collaboration between medical and dental practice in Hong Kong

BackgroundMedical-dental collaboration is essential for improving resource efficiency and standards of care. However, few studies have been conducted on it. This study aimed to investigate the attitude and awareness of medical and dental students about collaboration between medical and dental practices in Hong Kong.MethodsAll medical and dental students in Hong Kong were invited to complete a questionnaire survey at their universities, hospitals and residential halls. It contained 8 questions designed to elicit their attitudes about the collaboration between medical and dental practice. Students were also asked about their awareness of the collaboration between dentistry and medicine. The questionnaires were directly distributed to medical and dental students. The finished questionnaires were immediately collected by research assistants on site.ResultsA total of 1,857 questionnaires were distributed and 809 (44%) were returned. Their mean attitude score (SD) towards medical-dental collaboration was 6.37 (1.44). Most students (77%) were aware of the collaboration between medical and dental practice in Hong Kong. They considered that Ear, Nose & Throat, General Surgery and Family Medicine were the 3 most common medical disciplines which entailed collaboration between medical and dental practice.ConclusionIn this study, the medical and dental students in general demonstrated a good attitude and awareness of the collaboration between medical and dental practice in Hong Kong. This established an essential foundation for fostering medical-dental collaboration, which is vital to improving resource efficiency and standards of care.

Traditional oral health beliefs and practices of Bulang people in Yunnan, China

AIM The aim of the present study was to explore traditional oral health beliefs among the Bulang ethnic minority group in China. METHODS Eighteen village leaders, chiefs, elders, and seniors in Yunnan, China were assigned to three focus groups for discussion of traditional oral health beliefs. The discussions were led by a facilitator. Transcripts were made, and data were extracted. RESULTS The focus group discussions on traditional oral health beliefs addressed three themes: (a) the perception of oral health; (b) the impact of healthy teeth (oral health), in that healthy teeth essentially have an impact on physical health, emotions, and social status; and (c) toothache management, which was regarded as tooth decay (dental caries). Blackening teeth was a pain relief method. Blackened teeth were reported to be part of ethnic identity, and considered esthetically pleasing. It also indicated the marital status of women. CONCLUSION Some Bulang people believed that healthy dentition has no spacing, pain, or functioning problems. Well-aligned dentition was associated with higher social status. Toothaches were considered to be caused by tooth worms. Consulting a monk was another way to manage a toothache. Tooth blackening was considered traditional, and effective for caries prevention.

Occlusal Features and Caries Experience of Hong Kong Chinese Preschool Children: A Cross-Sectional Study

Objective: To study occlusal features and their relation to caries experience in Hong Kong Chinese preschool children. Methods: Seven kindergarten classes in Hong Kong were selected using a stratified random sampling method, and the 4- and 5-year-old Chinese kindergarten children were invited to join the survey. Two calibrated dentists performed the clinical examinations in the kindergartens. Occlusion features, including incisal overjet; canine and molar relationship; median diastema; and primate space as well as malocclusion features, including crossbite; anterior open bite; and scissor bite, were recorded. Caries experience was recorded with the dmft index. Results: A total of 538 children were invited to participate in the study, and finally 495 children were examined (92%). Approximately half (52%) had a normal incisor relationship. Most children had a class I canine relationship (left-79%; right-75%). Approximately two-thirds had a flush terminal plane (left-64%; right-65%). Most children (76%) had a maxillary primate space, and 47% had a mandibular primate space. The prevalence of median diastema, anterior crossbite, and unilateral posterior crossbite was 30%, 12% and 1%, respectively. No bilateral posterior crossbite or scissor bite was found. Approximately half (49%) had caries experience. The mean dmft score was 2.1. Gender and age were not associated with either the studied occlusal features or the mean dmft score (p > 0.05). Conclusion: Approximately half of the Hong Kong preschool children studied had a normal occlusion, and two-thirds of them had a flush terminal plane. About three-quarters of them had a maxillary primate space, and half of them had a mandibular primate space. Their occlusal traits were not associated with caries experience and prevalence.

Clinical studies on core-carrier obturation: a systematic review and meta-analysis

BackgroundThis systematic review aimed to evaluate the clinical performance of core-carrier obturation in endodontic treatment.MethodsKeywords of “(core carrier OR Thermafil) OR (cold lateral condensation OR lateral condensation) OR (warm vertical condensation OR vertical condensation) AND (obturation OR root canal filling) AND clinical study” were searched for all obtainable publications up to year 2017 in the databases of PubMed, ScienceDirect, EMBASE, Scopus and Web of Science. The success rate, short-term postoperative pain, overfilling and adaptation of core-carrier obturation from clinical studies were selected. Reviews, laboratory studies, animal studies and irrelevant reports were excluded.Results1349 relevant articles were identified with 149 duplicated articles removed and 1173 irrelevant articles were excluded after screening. The titles and abstracts of the 19 identified articles were screened in the systematic review. The full texts of remaining articles were retrieved with data extracted for meta-analysis on the success rate, postoperative pain, overfilling and adaptation of obturation. The pooled success rate of core-carrier obturation was 83% (95% CI: 69%-91%). The pooled incidence of 1-day and 7-day short-term postoperative pain were 35% (95% CI: 15%-62%) and 6% (95% CI: 1-35%). The pooled proportion of teeth with overfilling and adequate adaptation of the obturation material were 31% (95% CI: 18%-50%) and 85% (95% CI: 75%-91%), respectively.ConclusionsThe success rate of endodontic treatment using core-carrier obturation was 83%. Short-term postoperative pain was not uncommon (24%). Most teeth (85%) had adequate adaptation using core-carrier obturation material, but a considerable amount of teeth (31%) had overfilling.