Comparative Evaluation of Compressive Bond Strength between Acrylic Denture Base and Teeth with Various Combinations of Mechanical and Chemical Treatments

Debonding and detachment of artificial teeth from the denture base is frequently encountered in prosthodontic practice. This study aims to assess the effect of modifications in the ridge-lap surface of denture teeth with various combinations of mechanical and chemical surface treatments with hydrofluoric acid on bond strength with the acrylic denture base resin and to identify the failure modes (adhesive, cohesive, or mixed). Seventy acrylic resin teeth samples were randomly divided into seven groups (n = 10): a control group (unmodified) and six treatment groups, in which various combinations of mechanical and chemical surface treatments were performed. Then, these teeth were attached to a heat-cured denture base resin block at 45° angulation. The acrylized test samples were thermocycled, and the compressive bond strength was evaluated using a universal mechanical testing machine. The results suggest that roughening with diamond burs yields the highest bond strength, whereas etching/grooving and air abrasion result in the lowest bond strength. Acid etching complemented air abrasion to improve bond strength, while negative effects were noted with acid etching in other groups. Furthermore, roughening at the neck portion of the acrylic teeth can be used by the manufacturing companies as a standard to provide higher bond strength while maintaining the esthetics of the anterior teeth.