title: [An assessment of different crown-to-implant ratio for implant teeth in the posterior region over 5 years].
abstract: OBJECTIVE
  To evaluate the influence of crown-to-implant ratio (C/I ratio) on the results of restoration in the posterior region.
  
  
  METHODS
  From January 2007 to January 2012,119 patients with 208 ITI implants in the posterior region were followed up for 6-66 months. Implant restorations were divided into three groups according to their respective clinical C/I ratios after noble porcelain-fused-to-mental crown restoration: C/I ≤1,1<C/I≤1.5,C/I>1.5. Cumulative survival rate was calculated by life-table analysis. SPSS 13.0 software package was used for statistical analysis.
  
  
  RESULTS
  The mean clinical C/I ratio of 208 implants was 1.07±0.24, with maximum C/I of 1.8 and C/I of 0.6, 9.6 percent; of 208 implants had biomechanical complications. Differences among three groups were not statistically significant in annual crestal bone loss and biomechanical complications. In addition,implant cumulative survival rate in C/I ratio>1 was 97.6 percent;,and 98.8 percent; in C/I≤ 1.
  
  
  CONCLUSIONS
  Clinical C/I ratio does not significantly influence peri-implant crestal bone loss and biomechanical complications, implant restorations with C/I ratios>1 is successfully used in the posterior areas in this study.
authors.affiliation: School of Stomatology, China Medical University, Liaoning Province,China. zhao_baohong@vip.sohu.com
authors.forename: Bao-hong
authors.initials: BH
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.forename: Dan-ning
authors.initials: DN
authors.lastname: Wang
authors.forename: Lu-lu
authors.initials: LL
authors.lastname: Jang
authors.forename: Chun-fu
authors.initials: CF
authors.lastname: Deng
authors.forename: De-hao
authors.initials: DH
authors.lastname: Shang
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
mesh_terms: D016301:Alveolar Bone Loss; D003442:Crowns; D015921:Dental Implants; D019250:Dental Implants, Single-Tooth; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005500:Follow-Up Studies; D006801:Humans; D019228:Tooth Crown
chemical_list: D015921:Dental Implants; D003776:Dental Porcelain