title: [Survey of the coverage and influencing factors of pit and fissure sealants in primary and middle school of Hangzhou city].
abstract: OBJECTIVE
  To investigate the coverage of pit and fissure sealants in primary and middle school students of Hangzhou city, and to explore the causes of unsealing students.
  
  
  METHODS
  An analysis of sealing rate and unsealing causes of eligible children in Hangzhou city was carried out, using 3-year data of pit and fissure sealants program sponsored by the government. Based on the results, the validity of pit and fissure sealants as a government-sponsored public health program was evaluated.
  
  
  RESULTS
  The sealing rate was 52.89%. The main reasons of unsealing were uneruption and incomplete eruption of teeth when the medical teams went to school for pit and fissure sealing.
  
  
  CONCLUSIONS
  The main reason of unsealing is eruption issue, which can be controllable. Some scientific adjustments need to be made to improve the coverage, such as increasing sealing times considering the difference of teeth eruption.
authors.affiliation: The Clinic for Prevention and Defence of Hangzhou City. Hangzhou 310014;China.E-mail:fdf6378@163.com.
authors.forename: Da-feng
authors.initials: DF
authors.lastname: Fang
authors.forename: Yan-juan
authors.initials: YJ
authors.lastname: Chen
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
mesh_terms: D002648:Child; D003731:Dental Caries; D005500:Follow-Up Studies; D006801:Humans; D010895:Pit and Fissure Sealants; D012574:Schools; D013334:Students
chemical_list: D010895:Pit and Fissure Sealants