Clinical And Radiographic Performance Of Self-Locking Conical Connection Implants In The Posterior Mandible: Five-Year Results Of A Two-Centre Prospective Study

Objective This prospective study aims to assess the 5-year clinical performance of implants with internal conical connection and platform-switched abutments in the posterior mandible. Material and Methods Healthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform-switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60-months post-loading. Results Twenty-four patients received 52 implants. Bone remodelling took place between surgery and loading (mean:-0.5, SD:+/- 0.4 mm). From loading to 60 months, there was a mean bone change of 0.27 (SD:+/- 0.47 mm) which stabilized 24 months after prosthesis delivery (mean:0.2, SD:+/- 0.46 mm). 71.7% of all implants presented bone preservation at 60 months irrespective of the initial insertion depth. Two implants were lost after 5 years and the success rate was 95.1%. Patient enquiry revealed high satisfaction. Conclusion Internal conical connection implants with platform-switched abutments presented a high success rate and preservation of marginal bone levels at the implant shoulder after 5 years of loading.