Comparison of the Internal and Marginal Adaptation of Implant-Supported Restorations on Titanium Base Using Various Materials: An In Vitro Study

The adaptation of restorations to the titanium base (TiBase) abutments varies depending on the materials and methods used, playing a crucial role in implant and prosthetic success. This in vitro study aims to compare the internal and marginal fit of a titanium interface among three different milled materials: doped graphene PMMA, single-density zirconia, and dual-density zirconia, used for the rehabilitation of CAD-CAM implant-supported single crowns. A digital method based on the silicone replica technique was employed. The silicone reproduction of each fabricated restoration's inner and basal parts was digitally aligned to the titanium base, measuring the space between them at three predetermined planes: basal, middle, and superior. The material with the worst overall adaptation was dual-density zirconia (0.1 ± 0.03 mm), followed by single-density zirconia (0.09 ± 0.03 mm), and doped graphene PMMA (0.06 ± 0.02 mm). No statistical differences were found in the internal fit, represented by the measurements made at the middle and superior plane, among the materials used (<i>p</i> > 0.05). However, the marginal fit of doped graphene PMMA restorations was statistically better than zirconia restorations (<i>p</i> < 0.05). No significant differences were observed between the marginal fit of both types of zirconia (<i>p</i> > 0.05). Across all three materials, the superior plane showed the best fit, while the marginal plane exhibited the worst.