title: Long-term outcomes of short dental implants supporting single crowns in posterior region: a clinical retrospective study of 5-10 years.
abstract: OBJECTIVE
  Aimed to evaluate the long-term clinical and radiographic outcomes of short implants supporting single crowns in the posterior regions.
  
  
  METHODS
  A retrospective study design was adopted. The clinical and radiographic data of 231 short implants (intra-bony length ≤8 mm) supporting single crowns in 168 patients, were collected after 5-10 (mean 7.22) years' follow-up. Implant and prosthesis failures, peri-implant marginal bone loss, biological and technical complications were evaluated. The influence factors on implant failure were studied.
  
  
  RESULTS
  In total 4 implants and 11 prostheses failed. The 10-year (5-year) cumulative survival rate was 98.3% (98.7%) for implant-based analysis and 97.6% (98.2%) for patient-based analysis. The short implants placed in type IV bone yielded more failures than in type I-III and presented a survival rate of 94.0%. The 10-year survival rate of the prostheses was 95.2%. The mean marginal bone loss between implant installation and the 10 years' follow-up visit was 0.63 ± 0.68 mm. The marginal bone loss between the first and 5th year was minimal (0.05 ± 0.10mm and not statistically significant). 18 (7.8%) implants were exposed to biological complications, whereas 29 (12.6%) implants were involved in technical complications.
  
  
  CONCLUSIONS
  High survival rates for both the implants and the prostheses could be achieved after 5-10 years for short implants supporting single crowns, without severe marginal bone loss and complications. One may conclude that a single crown supported by a short implant is a predictable treatment modality. However, short implants in type IV bone sites should be applied with caution.
authors.affiliation: Department of Oral and Maxillo-facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China. lhc9@hotmail.com
authors.forename: Hong-Chang
authors.initials: HC
authors.lastname: Lai
authors.forename: Mi-Si
authors.initials: MS
authors.lastname: Si
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Zhuang
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.forename: Yue-Lian
authors.initials: YL
authors.lastname: Liu
authors.forename: Daniel
authors.initials: D
authors.lastname: Wismeijer
mesh_terms: D000328:Adult; D000368:Aged; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014945:Wound Healing
chemical_list: D015921:Dental Implants