title: Clinical outcomes of single dental implants with external connections: results after 2 to 13 years.
abstract: OBJECTIVE
  The aim of this retrospective study was to evaluate the long-term survival rates and the frequency of complications associated with single implants and their associated restorations.
  
  
  METHODS
  A retrospective cohort study was performed in patients who received dental implants between 1997 and 2007. The cohort included patients who had a single implant restored with a cemented or screwed restoration that had been in function for more than 2 years. The cumulative implant survival rates and peri-implant conditions (marginal bone loss, pocket depth, and plaque, gingival, and bleeding indices), as well as prosthodontic maintenance requirements, were evaluated. Descriptive statistics, the chi-square test, and regression models were used.
  
  
  RESULTS
  Seventy-three implants were placed in 44 patients (32 women, 12 men; mean age, 48 years). All implants were available for follow-up after 2 to 13 years (mean follow-up, 60 months). The overall cumulative 5-year survival rates for implants were 95.9%, and most of the prostheses (98.6%) remained functional throughout the observation period. The overall frequency of complications was 29.6% (4.3% inflammatory, 22.5% prosthetic, 2.8% operative). The average peri-implant marginal bone loss was 1.8 mm. Peri-implant soft tissue conditions such as plaque and bleeding indices and pocket depths were also satisfactory. However, the presence of inflammation was significantly associated with pocket depth and gingival keratinized mucosa. The need to retighten loose abutment screws (21%) was the most frequent prosthodontic maintenance performed. However, all loose abutment screws occurred in prostheses retained with titanium screws, and 92.9% of the prostheses had a UCLA-type abutment.
  
  
  CONCLUSIONS
  The implants and the associated prosthetic constructions used in this study showed excellent survival rates. However, there was a high frequency of prosthetic complications associated with titanium screws and UCLA cast abutments. Other prosthetic components may have yielded different results.
authors: Department of Occlusion, Fixed Prostheses and Dental Materials, School of Dentistry, Federal University of Uberlandia, Minas Gerais, Brazil. germana_camargos@hotmail.com
authors: Germana De Villa
authors: Gde V
authors: Camargos
authors: Célio Jesus
authors: CJ
authors: do Prado
authors: Flavio Domingues
authors: FD
authors: das Neves
authors: Ivete Aparecida de Mattias
authors: IA
authors: Sartori
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D019250:Dental Implants, Single-Tooth / Q000009:adverse effects*; D003774:Dental Plaque Index; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000209:etiology*; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult