title: [The accuracy of probing depth measurements of undergraduate students and associated factors analysis].
abstract: OBJECTIVE
  To investigate the accuracy of probing depth measurements of undergraduate students in department of periodontology and analyze the cause of measurement errors.
  
  
  METHODS
  Thirty-eight dental students from Peking Universty School and Hospital of Stomatology who began their periodontal clinical practice for the first time were recruited. According to principle of clinical teaching, after the students recorded the probing depth of 1-2 periodontitis patients using Williams periodontol probe, an experienced teacher checked the probing depth. The measurements of interproximal sites of Ramfjord index teeth (6 14 41 6) were used as the data of this study. According to the probing depth discrepancies between teacher and the students, all the probing sites were divided in three levels: absolutely consistent sites (probing depth measured by teacher and by student was completely consistent), almost consistent sites (the depth discrepancy between teacher and student was 1 mm), inconsistent sites (the depth discrepancies between teacher and student ≥ 2 mm).
  
  
  RESULTS
  The accuracy of probing depth measurements of students decreased with the deepening of probing depth, and the accuracy of probing depth measurements in molar teeth was significantly lower than incisor teeth [58.8% (261/444) vs.73.1% (339/464), P < 0.01]. The main factor associated with the accuracy of probing depth measurements in interproximal sites was the probe's inability to get into gingival col, which accounted for 70.7% (87/123) of the total inconsistent sites.
  
  
  CONCLUSIONS
  The correct angle of insertion of the probe in interproximal sites should be reinforced during the course of pre-clinical education of periodontal probing. More attention should be paid to check the probing depth of deep pockets and molar teeth during the clinical practice of undergraduate students.
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xiang-hui
authors.initials: XH
authors.lastname: Feng
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Wen-jie
authors.initials: WJ
authors.lastname: Hu
authors.forename: Huan-xin
authors.initials: HX
authors.lastname: Meng
mesh_terms: D001641:Bicuspid / Q000473:pathology; D055113:Chronic Periodontitis / Q000473:pathology*; D002983:Clinical Competence; D003762:Dental Instruments; D006801:Humans; D007180:Incisor / Q000473:pathology; D008963:Molar / Q000473:pathology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000473:pathology*; D013335:Students, Dental