Factors Affecting the Implant Supracrestal Complex: A Scoping Review as Part of a Global Consensus Meeting Organised by the Osstem Implant Community<b></b>

Aim: To map current evidence and identify key factors influencing peri-implant tissue stability related to abutment configuration, design, materials, and prosthetic protocols in implant-supported fixed prostheses. Methods: A comprehensive search of PubMed and Scopus was performed up to June 2025, supplemented by manual searches. Human studies in English with ≥1 year of follow-up were included. Two reviewers independently conducted screening, data extraction, and quality assessment using the Newcastle–Ottawa Scale. The review was carried out at the Universities of Sassari and Ferrara in collaboration with the Osstem Global Consensus Meeting. Results: From 974 records, 46 studies were included: 33 randomized clinical trials, 9 cohort, 2 case-control, and 2 cross-sectional studies. Thirty-nine were rated as good quality and five as fair. Concave abutment profiles and emergence angles &lt; 30° promoted peri-implant tissue stability, while convex designs and wider angles increased risks of bone loss and peri-implantitis. Titanium remains the reference abutment material in posterior sites, zirconia provides superior aesthetics anteriorly, and hybrid abutments balance strength and esthetics. Conclusions: Prosthetic design and abutment material selection critically affect peri-implant tissue stability and esthetic outcomes. Evidence supports screw-retained designs, platform switching, and the “one abutment–one time” approach for predictable long-term success.