Crenelated versus Conventional Ceramic Dental Veneers: Microscopy and Micro-CT Evaluations of Marginal and Internal Fit to Tooth Surface

Aesthetic dentistry is in high demand today due to the various prosthetic options that enhance patients' smile design and self-esteem, consequently. The aim of our in vitro studies was to assess the effect of our patented, crenelated veneers design compared to conventional ones on their marginal and internal gap to the prepared tooth surface [Maroiu, A.C., Sinescu, C., Duma, et al., Medicina 57, 772 (2021)]. Twenty-four lithium disilicate ceramic veneers were obtained using CAD/CAM technology. The samples were divided into two groups: twelve veneers with a linear marginal contour - conventional (CO), and twelve veneers with the novel sinusoidal marginal design - crenelated (CR). All veneers were subsequetly luted to the dental surface by using a specific dental cement. The marginal gaps along the adhesive interfaces were analyzed using optical microscopy. Micro-Computed Tomography (CT) was used to investigate both the internal fit of the veneers and the homogeneity of the luting cement. Significant differences between CO and CR veneers were determined by using STATA and one-way ANOVA tests: (i) the marginal gap was larger for CO than for CR veneers; (ii) the internal adaptation was better for CR veneers; (iii) the porosity mean within the cement was not significantly different for CO and CR veneers, with a smaller standard deviation for the CR group. The internal gaps were modelled using the micro-CT results. Characteristic functions were obtained to compare volumes of luting cement for these two veneers. The novel veneers' design triggered better marginal and internal fit of the restorations to the prepared dental surface.