Evaluation of the shear bond strength between 3D printed acrylic denture base resin and teeth with surface modifications - An in-vitro study

Aim: This study aimed to assess the shear bond strength between three-dimensional (3D)-printed acrylic denture base resin and 3D-printed teeth with and without ridge lap surface modifications. Materials and Methods: The investigation included three groups: A control group with unmodified surfaces, a group with macromechanical modification using a vertical slot, and a group with micromechanical modification using Erbium, Chromium: Ytrrrium Scandium Gallium Garnet laser irradiation. Standardized test samples were fabricated using computer-aided designing software and printed using 3D printing resins. The bonding was carried out using a light-curing adhesive, and the assembled specimens were subjected to controlled UV curing. Statistical Analysis Used: Shear bond strength was measured using a universal testing machine, and data were statistically analyzed using analysis of variance and post hoc tests. Results: The control group had significantly higher shear bond strength compared to both experimental groups. No statistically significant difference was observed between the macro-and micromechanically modified groups. Conclusion: These findings suggest that surface modifications to the ridge lap of 3D-printed acrylic teeth and resin may not improve and could potentially reduce bond strength when compared to unmodified surfaces. The study highlights the importance of exploring alternative methods, particularly chemical surface treatments, to enhance the adhesion between 3D-printed denture bases and teeth.