The effect of various surface treatments applied to denture base materials produced with different techniques on the bond strength of soft liner materials

The denture base is the structure that supports the artificial teeth and directly contacts the gum tissues. Although different manufacturing techniques and materials are used, the compatibility of these materials with tissues decreases over time, leading to the need for relining. Research emphasizes the importance of performing the relining process optimally in determining the lifespan of dentures. The aim of this study is to evaluate the effect of various surface treatments applied to denture base materials produced with different manufacturing techniques on the bond strength of soft liner materials. In this study, polymethyl methacrylate, polyamide, and 3D-printed resin materials were used, with each material prepared in two equal pieces of 7x12x36 mm dimensions, resulting in a total of 108 samples (n=36). These samples were fabricated in half-dumbbell form according to ASTM D412-16 standards and were randomly divided into groups to undergo different surface treatments (control group, Er:YAG laser treatment, Nd:YAG laser treatment, aluminum oxide sandblasting) (n=9). Afterward, a 3 mm thick soft liner was applied to the samples, and a tensile test was performed on each sample using a universal testing machine at a speed of 5 mm/min until failure. According to the results of the study, among the control group materials, 3D-printed resin showed the highest bond strength, while polyamide demonstrated the lowest bond strength. The Er:YAG laser treatment enhanced the surface properties of all materials, with the most significant effect observed in the 3D-printed resin. The Nd:YAG laser treatment had a significant effect only on polymethyl methacrylate, while it was not effective on the other materials.