Complications in partially edentulous implant patients: a 5-year retrospective follow-up study of 133 patients supplied with unilateral maxillary prostheses.

BACKGROUND

Numerous studies have reported successful outcomes for restoration of fully edentulous patients with Brånemark implants. However, some studies indicate more mechanical problems in restored partially edentulous situations.

PURPOSE: The objective was to study patients with potential risk for mechanical complications after implant treatment.

MATERIALS AND

METHODS

Patients were retrospectively evaluated 5 years after implant treatment in upper jaw Appelgate-Kennedy Class II situations. Altogether 422 implants ad modum Brånemark were installed in 137 consecutively treated patients. One hundred thirty-three prostheses were placed and followed-up for 5 years, according to routine clinical protocols.

RESULTS

The overall 5-year implant cumulative survival rate (CSR) was 94.0%. The corresponding CSR for loaded implants and prostheses was 97.7% and 98.4%, respectively, and the overall marginal bone loss was 0.8 mm (+/- 0.6 mm) after 5 years. Sixteen abutment screws fractured in seven patients (5%) and 17 prostheses (13%) presented loose abutment or gold screws during the follow-up period. Significantly more problems were reported in association with prostheses that included the canine (p < .05), and significantly more gold screws were working loose when only two implants were supporting the frameworks (p < .01).

CONCLUSIONS

Upper jaw implant treatment in unilateral free-end situations seems to involve more mechanical problems than other implant treatment groups when only two implants can be installed and when the canine tooth is missing. However, most of these complications are easily adjusted, and the clinical survival of implants and prostheses is the same for these groups compared to other groups of partially edentulous implant patients.