Clinical and radiographic assessment of circular versus triangular cross-section neck implants in the posterior maxilla: Five-year follow-up of a randomized controlled trial.

OBJECTIVES: Dental implants with a triangular neck design have been developed in order to maintain peri-implant bone. The primary aim of this randomized controlled trial (RCT) was to assess after 5 years the peri-implant bone stability and the peri-implant soft tissue conditions with this new triangular implant neck design compared to a conventional round neck implant design.

MATERIAL AND METHODS: This is a secondary evaluation of a RCT including 34 patients. Patients were recalled after 1, 3, and finally 5 years to assess implant survival and peri-implant bone levels using standardized radiographs. Peri-implant soft tissue health was also evaluated by recording probing depth, plaque index and Bleeding on Probing. Patient Reported Outcome Measures (PROMs) and the Pink Esthetic Score were also assessed.

RESULTS: No implant loss occurred during the 5-year follow up period. The mean ± SD proximal bone remodeling after 5 years reached 0.38 ± 0.39 mm for the circular design and 0.29 ± 0.58 mm for the triangular design (p = .49). Peri-implant soft tissue health parameters and PROMs were found to be comparable. Altogether, 80% of implants presented peri-implant mucositis whereas one implant (4%) displayed sings of peri-implantitis.

CONCLUSION: The 5-year evaluation of the triangular neck implants showed similar results to the circular neck implants.