title: Prospective clinical evaluation of 307 single-tooth morse taper-connection implants: a multicenter study.
abstract: OBJECTIVE
  This prospective clinical study evaluated the incidence of abutment loosening of Morse taper-connection implants used for single-tooth replacement. In addition, the cumulative survival rate and the implant/crown success were evaluated.
  
  
  METHODS
  Implants were evaluated 12, 24, 36, and 48 months after insertion. The incidence of abutment loosening, modified Plaque Index, modified Sulcus Bleeding Index, probing depth, distance from the implant-crown margin to the coronal border of the peri-implant mucosa, width of keratinized mucosa, and the distance between implant shoulder and first bone-implant contact (DIB) were assessed. The cumulative survival rates were calculated with Kaplan-Meier estimates. Implant/crown success criteria included absence of abutment loosening, absence of suppuration and mobility, probing depth < 5.0 mm, and DIB < 1.5 mm after 12 months and not exceeding 0.2 mm for each following year.
  
  
  RESULTS
  Over a 4-year period (2003-2007; mean follow-up per implant: 30.79 months), 307 implants (162 maxillary, 145 mandibular) were inserted in 295 patients (125 men and 170 women aged between 24 and 79 years) at six different clinical centers. The sites included anterior (n = 115) and posterior (n = 192) teeth. At the end of the study, a very low percentage of implant-abutment loosening (0.66%) was found, with only two loosened abutments. The cumulative implant survival rate was 98.4%. Mean DIB was 1.14 mm (48 months). Only four surviving implants did not meet the criteria for success, and the implant/crown success rate was 97.07%.
  
  
  CONCLUSIONS
  Based upon this study of 307 implants observed during a 4-year period, Morse taper-connection implants represent a good solution for single-tooth restorations, with a very low incidence of abutment loosening (0.66%).
authors.affiliation: Biomaterials Science, Dental School, University of Varese, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Mangano
authors.forename: Francesco
authors.initials: F
authors.lastname: Mangano
authors.forename: Adriano
authors.initials: A
authors.lastname: Piattelli
authors.forename: Giovanna
authors.initials: G
authors.lastname: Iezzi
authors.forename: Alberto
authors.initials: A
authors.lastname: Mangano
authors.forename: Luca
authors.initials: L
authors.lastname: La Colla
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000145:classification; D003442:Crowns; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods; D019250:Dental Implants, Single-Tooth; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D005884:Gingival Hemorrhage / Q000145:classification; D006801:Humans; D007633:Keratins; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification; D011446:Prospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007633:Keratins