Influence of Implant-Prosthetic Connection on Peri-implant Bone Loss: A Prospective Clinical Trial with 2-Year Follow-up

Purpose: To analyze peri-implant bone loss around six different types of implant-prosthetic connections over a 2-year follow-up period. Materials and Methods: A total of 120 implants were divided into six groups (n = 20), three with crestally and three with supracrestally placed implants, with different internal connections, placed in posterior sectors (molar and premolar), and bearing one-piece computer-aided design/computer-aided manufacturing (CAD/CAM) restorations screwed directly to each implant's prosthetic platform. Bone height was measured from parallelized periapical radiographs taken at the moment of loading and 2 years later. Results: The patient sample included 61 subjects, 36 men and 25 women. Significant differences were found in bone loss between groups, with the implant with internal hex and convergent transmucosal collar showing the least bone loss (P .001) in comparison with the other designs. Supracrestally placed implants underwent less bone loss than crestally placed implants (P = .025). Conclusion: Peri-implant bone loss is influenced by the level of implant placement in relation to the bone crest (crestal or supracrestal) and by the morphology of the prosthetic platform. Keywords: crestal bone loss, dental implants, internal connection, prosthetic platform, supracrestal