Evaluation of the bond strength of various denture teeth materials to conventional, CAD/CAM, and 3D printed denture bases

OBJECTIVES: The aim of this in vitro study is to investigate the bond strength of recently introduced commercial denture teeth to denture base materials that are fabricated in different methods. The effect of thermocycling on shear bond strength was investigated. MATERIALS AND METHODS: From high-impact pourable acrylic HIPA (Dentsply Sirona), Ivotion Base (Ivoclar Vivadent), Lucitone Digital Print (Dentsply Sirona), and Formlabs Denture Base (Formlabs) denture base materials, plate specimens were fabricated (15 mm × 15 mm × 2 mm). These base materials were bonded to Portrait IPN (Dentsply Sirona), Ivotion Dent (Ivoclar Vivadent), Lucitone Digital Value (Dentsply Sirona), and Formlabs Denture Tooth (Formlabs) tooth rods (3.5 mm × 6 mm) according to manufacturer instructions, respectively. For each material combination, 24 specimens were prepared and divided into 2 groups including control and aged. Bond strength was determined using shear bond test. Data were analyzed using two-way ANOVA followed by Tukey’s HSD test and Student’s t test (α=0.05). RESULTS: Lucitone Digital Print (Dentsply Sirona) bonded to Lucitone Digital Value (Dentsply Sirona) and Ivotion Base (Ivoclar Vivadent) bonded to Ivotion Dent (Ivoclar Vivadent) exhibited significantly higher bond strength to high-impact pourable acrylic HIPA (Dentsply Sirona) bonded to Portrait IPN (Dentsply Sirona) and Formlabs Denture Base (Formlabs) bonded to Formlabs Denture Tooth (Formlabs) (p < 0.0001). Each paired Student’s t-test showed that thermocycling treatment decreased the shear bond strength of the Formlabs materials significantly (p < 0.0001). CONCLUSION: The application of monomer and conditioning agents improved bond strength between denture base and denture tooth material regardless of the fabrication method. Thermocycling had an adverse effect on bond strength for all materials