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Objective To evaluate the effect of surface pretreatment and adhesive strategies on the bond strength of resin-based materials to restorative 3D-printed resins for cementation and repair procedures. Methods This systematic review followed PRISMA 2020 guidelines and was prospectively registered in PROSPERO (CRD420261289076). Searches were performed in PubMed/MEDLINE, Scopus, Web of Science, and Embase (until November 25, 2025). In vitro and in situ studies evaluating bond strength of restorative 3D-printed resin materials after chemical and/or mechanical surface pretreatments were included. Outcomes comprised shear bond strength (SBS/μSBS), microtensile bond strength (μTBS), and tensile bond strength (TBS). Risk of bias was assessed using the QUIN tool. Meta-analyses were conducted using multilevel random-effects models (REML) with cluster-robust variance estimation (CR2) to account for non-independence of multiple comparisons within studies; single-study subgroups were narratively summarized. Results Seventeen studies were included. Risk of bias was low in four studies, moderate in ten, and high in three. For cementation, hydrofluoric acid etching showed no significant improvement in bond strength in the robust model (MD = 5.44 MPa; 95% CI: −12.6 to 23.5; p = 0.324; 2 independent studies). Chemical surface treatments excluding hydrofluoric acid (e.g., silane and phosphate-containing primers) were supported by a single study and showed inconsistent, heterogeneous effects (descriptive evidence only). Mechanical surface pretreatments significantly increased bond strength (MD = 1.60 MPa; 95% CI: 0.45 to 2.74; 4 independent studies; I 2 = 73.5%). Evidence regarding adhesive/primer strategies was limited to one study and was descriptively reported. For repair procedures, surface pretreatment significantly increased repair bond strength (MD = 5.07 MPa; 95% CI: 3.28 to 6.86; p = 0.0067; 3 independent studies), although heterogeneity was high. Conclusions Mechanical surface pretreatment is the most consistently effective strategy to enhance bond strength of restorative 3D-printed resin materials. Evidence supporting chemical treatments alone remains limited and inconsistent, while repair outcomes appear strongly dependent on pretreatment protocol. Overall, the certainty of evidence is constrained by heterogeneity and moderate-to-high risk of bias in several studies.
Dascanio et al. (Fri,) studied this question.