STATEMENT OF PROBLEM: Displacement of zirconia restorations is among the most frequent failures. Airborne-particle abrasion (APA) with aluminum oxide (Al₂O₃) has been studied to increase surface roughness, energy, and wettability, thereby improving bond strength. Therefore, a systematic review is needed.
PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate how APA with Al₂O₃ affects the bond strength of zirconia ceramics.
MATERIAL AND METHODS: Following the population, intervention, control, outcome, and study design (PICOS) framework, searches were conducted in the MEDLINE (via PubMed), Web of Science, Scopus, and Embase databases through December 2024, without language restrictions. Included studies involved flat zirconia specimens bonded to composite resin, dentin, or enamel, with APA as the intervention and untreated surfaces as controls. Outcomes were shear, microshear, tensile, or microtensile bond strength. Two authors independently screened titles, abstracts, and full texts. Risk of bias was assessed, and data were analyzed using Cochrane Review Manager. Core Grading of Recommendations Assessment, Development and Evaluation (CORE GRADE); certainty assessment was performed with adaptations for in vitro studies.
RESULTS: Thirty-four studies met the inclusion criteria. Common biases involved lack of sample size calculation and operator blinding. Most APA protocols significantly improved bond strength to dentin, enamel, or composite resin. However, microshear tests on dentin showed no significant difference. High heterogeneity was found. Funnel plots for shear and microtensile tests showed no asymmetry, but microshear results suggested publication bias. Publication bias analysis was not possible for tensile bond strength because of limited data. Certainty of evidence ranged from moderate to very low.
CONCLUSIONS: APA significantly increased bond strength compared with no treatment, especially when bonding zirconia to enamel or composite resin. APA after sintering proved more effective than before sintering.