Final Prosthetic Abutment Insertion Time (One-Time Abutment Insertion Protocol Versus Conventional Protocol) and Related Outcomes: A Systematic Review of Randomized Controlled Trials with Meta-analysis

Purpose: To verify whether the use of a “one abutment one time” (OAOT) insertion technique in dental implant treatment protocols significantly impacts clinical outcomes (ie, survival rates and success rates) and peri-implant indices (ie, survival rate, success rate, bleeding on probing, and marginal bone changes [MBC]) compared to conventional protocols. Materialsand Methods: The protocol used in this review was developed according to PRISMA guidelines. The focus question was “In patients that are receiving a rehabilitation using dental implants, does the use of a OAOT technique have a better clinical performance compared to using provisional abutments?” The risk of bias (RoB) was performed using a modified version of the Cochrane RoB tool for randomized trials (RoB2, Cochrane Methods). A total of 554 articles were found in three databases (MEDLINE/PubMed, Scopus, and b-on). After screening them, 32 full-text articles were assessed for eligibility, and 11 randomized controlled studies (RCTs) published between 2010 and 2024 in the English language were included (κ = 0.98). Results: A total of 505 patients were included, with a mean age of 54 years; overall, there were more women than men (~ 58%). A total of 821 implants were included, with 397 implants in the test group (definitive abutment) and 424 implants in the control group (healing/provisional abutment). Follow-up periods ranged from 4 to 36 months. Five studies placed the implant shoulder at bone level, four studies placed it 0.5 to 2.0 mm below the bone crest, one admitted both placements, and another study did not disclose that information. The meta-analysis included 10 studies. The results showed a decrease in peri-implant vertical bone loss with the OAOT protocol compared to the conventional protocol at 6 and 12 months postoperative. Only one study exhibited a high RoB. Conclusions: Implementing the OAOT protocol with platform switching (PS) and higher abutments led to a decrease in bone loss compared to the conventional protocol; however, this reduction may not be clinically significant and might not improve esthetics.