An in vitro study on the bond strength between composite resin and porcelain using different surface treatment and bonding methods

The study aimed to determine the effect of different surface treatments and bonding methods on bond strength between composite resin and feldspar ceramic, focusing on the interplay between these variables for enhanced clinical outcomes of chipping repair. Two surface treatments (hydrofluoric acid [HF] etching and surface roughening using a diamond disc) were investigated alongside two bonding methods utilizing either a universal adhesive (Scotchbond Universal, 3M) or a separate silane primer and adhesive (Intraoral Repair Kit, BISCO). Bond strength was measured using shear forces, and light microscopy was used to analyse the fracture mode. The findings indicate that the bonding method plays a more significant role than surface treatment for increasing bond strength since bond strength was similar following either roughening or HF acid etching. The separate silane primer and adhesive demonstrated superior bond strength over the universal adhesive, despite both containing silane, and this was attributed to differences in silane monomer stability. Selecting an appropriate bonding method, specifically using separate silane primer, enhances bond strength in composite repairs. This approach may mitigate the known risks associated with HF and addresses clinical challenges by optimizing the bond stability between feldspathic porcelain and composite resin.