Three-Dimensional Assessment of Internal and Marginal Fit of Provisional Crowns Fabricated Using 3D-Printing Technology

To evaluate the effect of silanized filler particles and blue light-sensitive photoinitiator system on the internal and marginal fit of 3D printed resin crowns as well as the volume of provisional cement space. This study evaluated three commercially available 3D-printing resins (Smart Print Temp/SP, Resilab 3D Temp/RL, and Cosmos Temp/CT). The experimental groups consisted of the addition of 30% by weight (30 wt%) of silanized filler particles and a blue light-sensitive Ternary Photoinitiator System (TPS). Samples were printed for each group (n = 10) and evaluated for internal and marginal fit and volume of cement space using a micro-computed tomography (μCT). The obtained data were analyzed by Generalized Linear Models (α = 0.05). The incorporation of TPS and filler particles to the 3D printing resins altered the internal fit and the marginal fit, increasing the cement space at the occlusal face and decreasing the cement space of the axial walls for all tested materials. The volume was significantly affected too, especially for RL and CT. Internal misfit was significantly higher with the addition of TPS, and marginal misfit with the addition of filler particles. In general, the incorporation of TPS and 30 wt% of filler particles promoted an increase in the volume of cement space, as well as an increase in occlusal space and marginal space and a decrease in the axial walls' spaces.