Akademik Veri Yönetim Sistemi
BMC ORAL HEALTH, cilt.25, sa.1, 2025 (SCI-Expanded)
Statement of problemDetermining the effect of additive and subtractive manufacturing on marginal and internal fit in restorations with more than one unit is important, which are less discussed in the literature.PurposeThis in vitro study aims to evaluate the effect of subtractive and additive manufacturing on the marginal and internal fit of provisional fixed dental prostheses (FDPs) using Micro-CT.Materials and methodsModel teeth were prepared with 2 mm occlusal, 1.5 mm axial reduction, and chamfer finish line. After digital impressions with laboratory scanner, provisional crown and bridge restorations were designed with Exo-CAD software. All restorations were produced using 2 different production methods (n = 10). Marginal and internal fit of restorations were evaluated micrometrically and volumetrically with Micro-CT. Shapiro Wilk normality test and Levene test for variance homogeneity were used for data distributions. The Independent Sample T Test was used for normally distributed data, and the Mann Whitney-U Test was used for those not normally distributed to compare the independent groups. The two-way ANOVA test was used to examine the difference between normally distributed independent groups with the interaction effect, and the Scheirer Ray Hare test was used for non-normally distributed groups. Post-hoc Corrected Bonferroni tests were performed to reveal the group or groups that made the difference (alpha = 0.05).ResultsThe fabrication method affected marginal and internal fit for both resin crowns and bridges (alpha = 0.05). The additive method showed a better fit for crowns than the subtractive method. For bridges, it was found that a better fit was generally achieved with the subtractive method.ConclusionsIn both crown and bridge restorations, the marginal fit was higher than the internal fit in both production techniques. The additive technique provided a better fit for crown restoration, and the subtractive technique provided a better fit for bridge restoration. The production method significantly affected marginal fit.Clinical significanceWhile almost any type of restoration can be produced with subtractive manufacturing, additive manufacturing is mostly seen in single-unit treatments. Predicting that additive manufacturing will also achieve this goal is not difficult. Hence, examining additive manufacturing in study protocols where the units are increased is important.