title: Early loading of single crowns supported by 6-mm-long implants with a moderately rough surface: a prospective 2-year follow-up cohort study.
abstract: OBJECTIVE
  To evaluate prospectively the clinical and radiographic outcomes after 2 years of loading of 6 mm long moderately rough implants supporting single crowns in the posterior regions.
  
  
  METHODS
  Forty SLActive Straumann short (6 mm) implants were placed in 35 consecutively treated patients. Nineteen implants, 4.1 mm in diameter, and 21 implants, 4.8 mm in diameter, were installed. Implants were loaded after 6 weeks of healing. Implant survival rate, marginal bone loss and resonance frequency analysis (RFA) were evaluated at different intervals. The clinical crown/implant ratio was also calculated.
  
  
  RESULTS
  Two out of 40 implants were lost before loading. Hence, the survival rate before loading was 95%. No further technical or biological complications were encountered during the 2-year follow-up. The mean marginal bone loss before loading was 0.34+/-0.38 mm. After loading, the mean marginal bone loss was 0.23+/-0.33 and 0.21+/-0.39 mm at the 1- and 2-year follow-ups. The RFA values increased between insertion (70.2+/-9) and the 6-week evaluation (74.8+/-6.1). The clinical crown/implant ratio increased with time from 1.5 at the delivery of the prosthesis to 1.8 after 2 years of loading.
  
  
  CONCLUSIONS
  Short implants (6 mm) with a moderately rough surface loaded early (after 6 weeks) during healing yielded high implant survival rates and moderate loss of bone after 2 years of loading. Longer observation periods are needed to draw more definite conclusions on the reliability of short implants supporting single crowns.
authors.affiliation: Faculty of Dentistry of Araçatuba, UNESP - São Paulo State University, São Paulo, Brazil.
authors.forename: Fabio
authors.initials: F
authors.lastname: Rossi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Ricci
authors.forename: Claudio
authors.initials: C
authors.lastname: Marchetti
authors.forename: Niklaus P
authors.initials: NP
authors.lastname: Lang
authors.forename: Daniele
authors.initials: D
authors.lastname: Botticelli
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000145:classification / Q000000981:diagnostic imaging; D001732:Bite Force; D015331:Cohort Studies; D003442:Crowns; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D054459:Elasticity Imaging Techniques; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010512:Periodontal Index; D011446:Prospective Studies; D011859:Radiography; D013499:Surface Properties; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants