The Effect of Different Surface Treatments of Shear Bond Strength of Repaired Polymer-infiltrated Ceramic Network Materials

Objectives: This study aimed to determine the alternative surface treatment method for repairing aged polymer-infiltrated ceramic network materials (PICNs) utilizing a shear bond strength (SBS) test. Methods: APICNs block (VITAEnamic®) was cut into 5x5x5 mm3 followed by thermocycling for 10,000 cycles. The specimens were then randomly divided into four groups (n=12), based on different surface treatments. Group HF+Si: treated with a 9.5% hydrofluoric acid and silane application, Group HF+Si+He: treated with a 9.5% hydrofluoric acid and silane application followed by an application of a hydrophobic resin monomer,Group MEP: treated with a self-etching ceramic primer, Group MEP+He: treated with a self-etching ceramic primer followed by an application of a hydrophobic resin monomer. All specimens were repaired with a resin composite and underwent a thermocycling aging process for 10,000 cycles before measuring shear bond strength. Results: One-way ANOVA revealed a significant difference in SBS among all groups. Group MEP exhibited a significantly lowest mean SBS value (p<0.05), while, mean SBS values from groups HF+Si, HF+Si+He, and MEP+He did not show statistically significant differences. Conclusions: Treating aged PICNs with only self-etching ceramic primer group provided an insufficient shear bond strength. However, when a hydrophobic resin monomer was applied after conditioning with self-etching ceramic primer, shear bond strength was distinctly improved to a comparable level to those treated with 9.5% hydrofluoric acid and silane primer.