A 10-year prospective study of ITI dental implants placed in the posterior region. II: Influence of the crown-to-implant ratio and different prosthetic treatment modalities on crestal bone loss

Clin Oral Implants Res. 2007 Dec;18(6):707-14. doi: 10.1111/j.1600-0501.2006.01307.x. Epub 2007 Aug 13.


Objective: To evaluate the influence of the crown-to-implant ratio (C/I) ratio and different implant prosthetic treatment modalities on crestal bone loss around dental implants placed in the posterior region.

Material and methods: A total of 192 ITI dental implants were consecutively placed in premolars and molars of 83 partially edentulous patients. All implants were restored by means of ceramic-to-metal fused fixed partial dentures or a single crown. Patients were followed as part of a prospective longitudinal study focusing on implant success. Surgical, radiographic and clinical variables were collected at the 1-year recall after implant placement and at the most recent clinical evaluation. Radiographic parameters were evaluated on periapical radiographs taken with a standardized long-cone paralleling technique. Implant restorations were divided into three groups according to their respective clinical C/I ratios: (a) 0-0.99, (b) 1-1.99 and (c) >or=2.

Results: The mean clinical C/I ratio was 1.77+/-0.56 mm. A total of 51 implants (26.5%) showed a clinical C/I ratio equal to or greater than 2. In this group, three implants failed, giving a cumulative survival rate of 94.1%. Crestal bone loss was -0.34+/-0.27 mm in group a, -0.03+/-0.15 mm in group b and -0.02+/-0.26 mm in group c. Differences among groups were statistically significant (P=0.009). Mode of retention, splinting or presence of cantilever extensions did not have an effect on crestal bone loss around ITI dental implants.

Conclusions: Implant restorations with C/I ratios between 2 and 3 may be successfully used in the posterior areas of the jaw.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Alveolar Bone Loss / diagnostic imaging
  • Alveolar Bone Loss / etiology
  • Analysis of Variance
  • Bicuspid
  • Crowns*
  • Dental Implantation, Endosseous / instrumentation
  • Dental Implantation, Endosseous / methods*
  • Dental Implants, Single-Tooth / adverse effects*
  • Dental Implants, Single-Tooth / statistics & numerical data
  • Dental Prosthesis Design*
  • Dental Prosthesis Retention*
  • Dental Prosthesis, Implant-Supported
  • Dental Restoration Failure
  • Female
  • Follow-Up Studies
  • Humans
  • Jaw, Edentulous, Partially / diagnostic imaging
  • Jaw, Edentulous, Partially / rehabilitation
  • Jaw, Edentulous, Partially / surgery
  • Male
  • Middle Aged
  • Molar
  • Periodontal Index
  • Prospective Studies
  • Radiography
  • Sex Factors
  • Treatment Outcome
  • Weight-Bearing