Akademik Veri Yönetim Sistemi
Journal of Prosthetic Dentistry, 2025 (SCI-Expanded, Scopus)
Statement of problem: Although minimally invasive repair of existing resin-based restorations is clinically advantageous, the effects of different surface pretreatments on additively and subtractively manufactured resins remain insufficiently studied. This lack of evidence hinders the development of a standardized and reliable protocol for the repair of such materials. Purpose: This in vitro study aimed to evaluate the impact of different mechanical and chemical surface pretreatments (airborne-particle abrasion, grinding, universal adhesive application, or no treatment) on the shear bond strength (SBS) of composite resin repairs on hydrothermally aged resin-based materials, used either additively or subtractively for definitive fixed dental prostheses. Material and methods: A total of 240 resin disks (Ø10×2 mm) were fabricated using 3 additive manufacturing resins (C&B Permanent; Tera Harz TC-80DP; and Crowntec); and 1 subtractive manufacturing resin (Brillant Crios) (n=60 each). All specimens underwent hydrothermal aging through 5000 thermal cycles between 5 °C and 55 °C. Disks were randomly assigned into 3 mechanical pretreatment groups: airborne-particle abrasion with 50 µm Al₂O₃ particles, grinding with a diamond rotary instrument, or no treatment (control) (n=20 each). Each group was then randomly divided into 2 chemical surface pretreatment subgroups: application of a universal adhesive (Clearfil Universal Bond Quick) or no treatment (control) (n=10 each) and then composite resin (Clearfil Majesty ES-2 Classic) was bonded in the center of the surface-treated area. SBS was assessed using a universal testing machine at a crosshead speed of 1 mm/minute. Failure modes were analyzed under a microscope at ×12.5 magnification. Statistical analysis included a 3-way ANOVA and chi-squared test to evaluate the effects of material, mechanical pretreatment, and adhesive on SBS (α=.05). Results: The application of an adhesive substantially increased the SBS (Mean difference (MD): 6.91 ±3.30 MPa; P<.001). When adhesive was used, no differences were observed between resin materials or mechanical surface pretreatments (airborne-particle abrasion or grinding) in either SBS or failure mode (chi-squared test). In contrast, in the absence of adhesive, significant differences were found between materials (P<.001) and mechanical pretreatment (P=.001) for both outcomes. Conclusions: Repair bond strength depended on the application of an adhesive. When applied, the impact of resin material and mechanical pretreatment remained minimal.