Marginal bone loss in screw-retained zirconia fixed prostheses supported by Ti-base or multi-unit abutments: A systematic review and meta-analysis.

This systematic review aimed to evaluate the marginal bone loss (MBL) associated with screw-retained zirconia fixed dental prostheses (FDP) supported by either titanium-base (Ti-base) or multi-unit abutments.A comprehensive literature search was conducted in accordance with the PRISMA 2020 guidelines, using PubMed, Scopus, Web of Science, and the Cochrane Library, covering publications up to May 2024. The inclusion criteria focused on clinical trials and cohort studies reporting quantitative MBL outcomes for zirconia screw-retained prostheses supported by either Ti-base or multi-unit abutments, with a minimum follow-up of 6 months. Data extraction and risk-of-bias assessments were performed independently by 2 reviewers. A meta-analysis was conducted using a random-effects model to pool the MBL values.Of the 752 articles screened, 10 studies met the inclusion criteria, comprising 684 implants in 412 patients. The mean MBL ranged from 0.19 to 1.26 mm over follow-up periods of 12 to 60 months. The pooled mean MBL was 0.68 mm (95% CI: 0.54-0.81 mm; I2 = 47%). Subgroup analyses revealed no significant differences between the Ti-baseand multi-unit-supported restorations.Screw-retained zirconia FDP supported by Ti-base or multi-unit abutments are associated with minimal MBL within clinically acceptable thresholds. Long-term prospective studies are warranted to confirm these findings and further assess biological and technical complication rates.