Bond strength of 3D printed resin-composite resin using universal adhesives

Abstract

Aim or Purpose: The aim of this study was to evaluate the bond strength between a 3D printed resin and composite resin using universal adhesives, while examining the effect of surface roughening and aging on bond strength. Materials and Methods: Ninety-six cylinders (15mm diameter, 20mm height) were produced using a DLP printer (Carima) and a material developed for permanent restorations (Graphy). The cylinders were divided into eight groups of 12 based on surface roughening and thermocycling for each type of adhesive: Single Bond Universal (SBS) and All Bond Universal (ABU). After placing composite resin on the surface-treated 3D printed substrates, the shear bond strengths were measured after 24 hours of storage in water (n=12) and after 10,000 cycles of thermocycling (n=12). Statistical analyses were conducted at a significance level of 0.05. Results: Surface roughening significantly improved the bond strength in both adhesives. Aging reduced the bond strength of ABU when the surface was not roughened. However, there were no significant differences in bond strength between the two universal adhesives, irrespective of surface roughening and aging. Pre-test failures were more frequent in cases where the surface was not roughened after aging. Conclusion: Surface roughening is necessary to enhance the bond strength between the 3D printed resin and composite resin, regardless of the type of adhesive used. Further studies are required to explore the optimal surface treatment method for other types of 3D printed resin materials.