Additive manufacturing is an emerging technology that has been successfully used in dentistry for denture fabrication. However, the conventional issue of tooth debonding exists in additively manufactured dentures. In this study, we investigated the physical properties of conventional teeth attached to a heat-cured denture base material compared to additively manufactured tooth-coloured materials attached to denture base-coloured materials in a printed monolithic unit. We designed a model consisting of a tooth attached to a cylindrical base to fabricate the additively manufactured group and the conventional group. All groups were tested for fracture load before and after thermocycling, water sorption, solubility, and shape accuracy. The Mann-Whitney U test was used for statistical analysis. The fracture load of the additively manufactured group was significantly higher than that of the conventional group after thermocycling (p = 0.019). The water sorption of the conventional group was significantly lower than that of the additively manufactured group (p = 0.000), whereas there was no significant difference in the water solubility between them (p = 0.192). The shape accuracy of the additively manufactured group was significantly better than that of the conventional group (p < 0.05). In conclusion, additive monolithic manufacturing technology may provide an alternative way to enhance the fracture load between the teeth and denture bases.
Keywords: 3D printing; CAD/CAM; PMMA denture base; additive manufacturing; bond strength; material jetting; monolithic; polyjet printing; water solubility; water sorption.