title: [The experimental study of the relationship between preparation height and retention of complete crowns].
abstract: OBJECTIVE
  This study was to discuss the influence of preparation height on retention of complete crown.
  
  
  METHODS
  In this study we measured the retention of complete crown with the preparation height 2 mm, 3 mm, 4 mm and 5 mm. All crowns had no preparation taper and no bonding agent was used. The retention of crowns was measured and the data was statistically analyzed by t test.
  
  
  RESULTS
  The preparation height was directly proportional to the retention of complete crown. And the crown with the height of 2 mm had enough retention when the crown had no preparation taper.
  
  
  CONCLUSIONS
  In order to get enough retention of short height molar, we should induce the preparation taper.
authors.affiliation: Department of Prosthodontics, Ninth People's Hospital, School of Stomatology, Shanghai Second Medical University, Shanghai 200011, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Chen
authors.forename: Nan
authors.initials: N
authors.lastname: Hua
authors.forename: Yan
authors.initials: Y
authors.lastname: Ge
authors.forename: Jing
authors.initials: J
authors.lastname: Zhuang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Qian
mesh_terms: D003442:Crowns; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D006801:Humans; D019231:Tooth Preparation, Prosthodontic