Permanent crown caries in 12 – 15 years-old students in Shenzhen city: a sampling survey

  Objective  To examine the prevalence of crown caries among 12 – 15 years old students in Shenzhen city and to provide evidences for oral health care in the city.

  Methods  Using stratified multistage proportional to size sampling in Shenzhen city, we recruited 5 509 students aged 12 – 15 years in 12 high schools in 4 districts with different gross domestic production (GDP) per capita; an oral health survey was conducted among the students based on the method recommended by World Health Organization (WHO) during September – October 2018. WHO community periodontal index (CPI) probe was used to check crown caries of all permanent teeth. Caries prevalence rate, mean decayed, missing, and filled teeth (DMFT), and filling rate among the students were calculated.

  Results  For the students aged 12 to 15 years, the caries prevalence rate was 39.98%, 43.44%, 44.77%, and 49.91%; the mean DMFT was 1.03, 1.26, 1.39, and 1.62; and the filling rate was 30.97%, 33.52%, 35.45%, and 31.5%, respectively. Both the caries prevalence rate and the mean DMFT increased significantly with the increment of age (both P < 0.001). Compared with those in boy students, caries prevalence rate and mean DMFT were significantly higher in the girl students (both P < 0.05). In comparison with those in 1997, significantly decreased caries prevalence rate (39.98% vs. 56.72%) and the mean DMFT (1.03 vs. 1.53) but increased filling rate (30.97% vs. 7.60%) were detected among the students aged 12 years (P < 0.001 for all). Compared with the results of the Fourth National Oral Health Epidemiological Survey, the filling rate (30.97%) is higher than the average national level (16.5%) and the average level of Guangdong province (20.19%) for the 12-year-old students in Shenzhen city.

  Conclusion  Among the students aged 12 – 15 years in Shenzhen city, the caries prevalence rate and mean DMFT increase with age. Both the caries prevalence rate and mean DMFT are higher in girl students than in boy students; the filling rate of the students is significantly higher than the average national level and the average level of Guangdong province.