Overdentures in the edentulous mandible supported by implants and retained by a Dolder bar: a 5-year prospective study.

PURPOSE

This prospective study was performed to evaluate the outcomes of XiVE® S plus implants (Dentsply Friadent, Mannheim, Germany) following conventional restoration with bar structures and overdentures in the edentulous mandible.

MATERIALS AND METHODS

A total of 39 patients were treated with four interforaminal implants (n = 156) splinted by a Dolder bar. Overdentures were attached to the bars after 3 months of healing. As primary outcome measures, clinical and radiological parameters were evaluated at the time of implant placement (baseline) and once a year (1, 2, 3, 4, 5 years) after functional loading. Secondary outcome measures included (i) primary stability and surgical complications, as well as (ii) Periotest® (Medizintechnik Gulden, Modautal, Germany) values, implant survival, and prosthetic complications at baseline and follow-up.

RESULTS

A total of 156 implants were placed. The vast majority (n = 149) were tightened to >30 Ncm, while torques in the range of 20-30 Ncm were obtained in the remaining cases (n = 7). Mean crestal bone levels around the implants were 0.41 mm at baseline and 1.04/1.20/1.34/1.45/1.44 mm after 1/2/3/4/5 years respectively. The mean values of the plaque, calculus, bleeding, and mucosal indices remained low throughout this period. The reported follow-up periods involved one implant loss after 3 months (survival rate: 99.4%) and one implant failure after 4 years (success rate: 98.4%). Prosthetic complications included factures of bars (n = 3) and denture teeth (n = 7). Prosthetic survival was 100%.

CONCLUSIONS

Dolder bars to restore oral implants in the edentulous mandible appear to offer a high rate of implant survival, good stability of the peri-implant tissue, and a low rate of prosthetic complications.