Clinical Outcome of Root-Shaped Dental Implants of Various Diameters: 5-Year Results

Purpose: The aim of this retrospective study was to evaluate the long-term survival and success rates of screw-type root-shaped (Camlog) implants of various diameters and their implant-prosthodontic reconstructions for more than 5 years of clinical use. Materials and Methods: A retrospective study of patients receiving root-shaped screw-type dental implants placed between May 2001 and July 2003 was conducted. The cumulative implant survival and success rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index) as well as the prosthodontic maintenance requirements were evaluated. Results: In all, 541 implants (3.8 mm: 237 implants; 4.3 mm: 211 implants, 5/6 mm: 93 implants) were placed and restored for implant prosthodontic rehabilitation in 216 patients (134 women, 82 men; mean age 54.3 ± 9.1 years). Of the original 216 patients enrolled, 198 (91.6%; 510/541 implants [94.2%]) were available for a follow-up evaluation after 5 to 7 years (mean follow-up, 68.8 ± 7.4 months). The overall cumulative 5-year survival and success rates were 98.3% and 97.3%, respectively. A failure rate of 3.7% (9/237) was seen for 3.8-mmdiameter implants; the corresponding figures for the 4.3-mm and wide-diameter (5.0/6.0-mm) implants were 1.4% (3/211) and 1.0% (1/93), respectively. For implants classified as successful, the average peri-implant marginal bone resorption value was 1.8 ± 0.4 mm, with no differences among the different implant diameters evaluated. Peri-implant soft tissue conditions such as plaque, bleeding, and pocket depth were also satisfactory. All prostheses were functional throughout the observation period, with no fractures of implants, abutments, or screws. Abutment screw (4.5%) or isolated crown loosening (9.8%) for single-tooth restorations requiring recementation, retightening of screws, and adaptation of removable prostheses were the most frequent prosthodontic maintenance needs. Conclusion: The rootshaped implants and the associated prosthetic constructions used in this study showed excellent survival and success rates. Keywords: dental implants, root-form implants, root-shaped implants, screw-type implants