Comparison of shear bond strenght of porcelaın repair systems to various CAD/CAM restorative materials

Purpose: The aim of this&study&was to&evaluate and&compare&the shear bond strength (SBS) of different porcelain repair&systems&to various CAD/CAM& prosthetic materials. Materials&and&methods: Two hundred disc-shaped PEEK, Metal, Zirconia, Titanium and Glass-ceramic&samples were&prepared with the CAD/CAM&system (7 mm x 3 mm). After all samples were polished with silicon carbide sandpaper, the bonding surface was roughened with 120µm Al2O3. Then, all materials were÷d&into 2 groups &(n = 20) according to the repair system&used; Bredent and Clearfil repair sytsems. Following adherence to the guidelines provided by the manufacturer, the resin cements were applied. Subsequently, the specimens were divided into two subgroups (n=10) and exposed to varying storage conditions, namely short-term and long-term storage. Subsequently, all samples underwent SBS (Shear Bond Strength) testing, and the resultant fracture patterns were assessed. Statistical analysis was conducted utilizing both one-way and two-way ANOVA, in conjunction with the Tukey Honestly Significant Difference (HSD) test, with a significance threshold set at p < 0.05. Results: Long-term&storage&decreased&the&SBS values significantly&in all prosthetic materials and repair systems (p<0.05). Statistically&significant&differences&were&found& between the SBS values of different prosthetic materials according to repair systems (p<0.05). In short-term storage, when Clearfil repair system was evaluated, the lowest SBS values were recorded for glass-ceramic group (7.88 ± 1.63 MPa) and the highest SBS values were recorded for titanium group (14.92± 3.65 MPa) (p<0.05). In long-term storage, when Clearfil repair system was evaluated, the lowest SBS values were recorded for PEEK group (4.53 ± 1.14 MPa) and the highest SBS values were recorded for Co-Cr metal group (11.57± 2.35 MPa) (p<0.05). When Bredent repair system was evaluated in short-term storage, the lowest SBS values were recorded for zirconia group (8.33 ± 1.84 MPa) and the highest SBS values were recorded for titanium group (15.77± 5.79 MPa) (p<0.05). In long-term storage, when Bredent repair system was evaluated, the&lowest SBS values&were&recorded&for glass-ceramic&group (1.87±&0.43 MPa) and the highest SBS values were recorded for Co-Cr metal group (7.09± 1.05 MPa) (p<0.05). Conclusion: It&can&be&concluded&that all repair systems used in this study had different bonding values to various prosthetic materials. Long-term storage decreased the bonding between the materials and the repair systems. The new Bredent repair system seems promising and has similar bonding performance with the well-documented repair system. Future studies are needed to confirm the results of this study. Key words: PEEK, metal, zirconia, titanium, Glass-ceramic, CAD/CAM, repair system, shear bond strength.