title: [Clinical analysis of caries status of the mandibular second molar].
abstract: OBJECTIVE
  To collect the cases which have caries on the mandibular second molar and analyze the caries status and correlative factors.
  
  
  METHODS
  Patients treated in the Department of Endodontics in West China Hospital of Stomatology were randomly collected. The baseline information, primary sites and severity of dental caries on the mandibular second molar, and eruption pattern of the mandibular third molar were recorded. The data was analyzed with SPSS13.0 software package.
  
  
  RESULTS
  Four hundred eighty-one patients including 227 males and 254 females were collected. Caries on the mandibular second molar starting from the occlusal, distal proximal and buccal surfaces accounted for 33.8%, 33.2% and 24.4%, respectively. Caries involving dental pulp (49.7%) were significantly more than deep and shallow to moderate caries (31.7% and 18.6%). Gender was not correlated with the site and severity of caries. However, impacted mandibular third molars and age were significantly related to both caries site and severity.
  
  
  CONCLUSIONS
  Occlusal and distal proximal surfaces are the most predisposed sites to have caries on mandibular second molar. Impacted mandibular third molar and age are significantly related to caries of mandibular second molar.
authors.affiliation: Department of Conservative Dentistry and Endodontics, West China School of Stomatology, Sichuan University. Chengdu 610041, Sichuan Province, China.E-mail:anny350080@hotmail.com.
authors.forename: Chun-an
authors.initials: CA
authors.lastname: You
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: Ning
authors.initials: N
authors.lastname: Hu
authors.forename: Qin
authors.initials: Q
authors.lastname: Su
mesh_terms: D002681:China; D003731:Dental Caries; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible; D008963:Molar; D008964:Molar, Third; D014078:Tooth Eruption; D014095:Tooth, Impacted