Clinical Performance of Template-assisted Monochromatic Structural Colored Versus Universal Multishade Direct Composite Veneers Over 3 Years: A Randomized Clinical Trial

Background: We conducted a clinical trial using a modified split-mouth, double-blind, randomized approach to clinically assess template-assisted monochromatic structural colored versus universal multishade direct composite veneers over a 36-month period. Materials and Methods: A total of 88 direct composite veneers from 20 participants were included per the inclusion criteria. Each patient received at least one pair of the two types of direct veneers in two equal groups (n = 44): (group I): monochromatic structural colored veneer (OMNICHROMA) with palfique adhesive and (group II): uni versal multishade veneer (Ceram.x spectra) with Prime & Bond adhesive using U-veneer templates. Window-type veneer preparations were performed on the labial surface of anterior teeth (depth: 0.3–0.5 mm). Clinical assessment was conducted per modified United States Public Health Service (USPHS) criteria. The marginal integrity criterion was evaluated by scanning electron microscopy of an inverse replica of 32 randomly selected veneer restorations. Results: The Friedman and Wilcoxon signed-rank tests revealed significant differences between group I and group II in marginal adaptation, marginal discoloration, surface texture, and color match (p <0.05). However, there no significant differences in fracture type or anatomical form existed between the two groups (p?>0.05). The Mann Whitney U test indicated no significant differences between the groups across USPHS criteria (p?>0.05). No secon dary caries or hypersensitivity cases were reported during any evaluation period. The unpaired t test revealed no significant difference in the mean gap width between the two groups (p = 0.218 and 0.236, respectively). Spearman’s correlation test, conducted on the related criteria in groups I and II after 12, 18, and 36 months of follow-up, revealed a positive relationship between the evaluated criteria. Conclusions: Monochromatic structurally colored and universal multishade direct composite resin veneers demonstra ted comparable satisfactory clinical performance by the end of the study period.