Single-Tooth Rehabilitations Supported by Dental Implants Used in an Immediate-Provisionalization Protocol: Report on Long-Term Outcome with Retrospective Follow-Up

Background: There is a need for long-term studies evaluating the outcome of single-tooth rehabilitations supported by dental implants in immediate loading.

Purpose: To report the long-term outcome (in excess of 5 years) of single-tooth rehabilitations supported by dental implants in an immediate-provisionalization protocol.

Materials and methods: This retrospective cohort study included 332 consecutive patients (189 females and 143 males) with an average age of 47 years (range: 16 to 82 years) who were rehabilitated between 1996 and 2006 with 594 single crowns supported by dental implants in immediate loading. Implant success rates were calculated based on implant function and using life tables. Marginal bone levels were measured at 5 and 10 years. Mechanical and biological complications were calculated for the follow-up period between implant insertion and 5 years and every 6 months thereafter.

Results: Fifty-four patients dropped out of the study (16.5%). Nineteen patients lost a total of 25 implants (n = 23 in the maxilla; n = 2 in the mandible), rendering a cumulative survival rate of 95.7% at both 5 and 10 years of follow-up. The mean marginal bone levels were 1.56 mm (standard deviation 0.78 mm) and 1.75 mm (standard deviation 0.29 mm) at 5 and 10 years of follow-up. Mechanical complications occurred in 83 patients and 116 implants (19.5%) up to the 10-year follow-up, namely prosthetic screw loosening (2.4%), abutment complications (4.4%), fracture of provisional crowns (9.6%), and fracture of definitive ceramic crowns (3.5%). Biological complications occurred in 58 patients and 79 implants (13.3%) up to the 10-year follow-up, with the majority consisting in peri-implant pathology.

Conclusions: Considering the high survival rates and stable marginal bone levels after 10 years, it can be concluded within the limitations of the present study that replacement of single teeth with dental implants in an immediate-provisionalization protocol is a viable and safe treatment option for both maxilla and mandible.