Micro-computed Tomography Evaluation of Film Thickness of Veneers Cemented with Heated Resin Composites and a Resin Cement

Objectives: The purpose of this in vitro study was to evaluate the film thickness (FT) of various cementation techniques through 3-dimensional (3D) microcomputed tomography (mCT).
Methods: Thirty 3D printed tooth maxillary central incisors specimens with standard preparations for veneers and used as testing models with 3D printed veneers.They were divided into 5 groups (n=6): Clearfill AP-X (APX); ENA Hri (ENA); Estelite Omega (EOM); Essentia (ESS); Calibra Esthetic (CES). The cementation was performed using pre-heated composite to 55 degrees C with a commercial compule heater (Ena Heat) and resin cement at room temperature, using standard procedures by one person. Specimens were scanned after polymerization using a mCT apparatus (mCT 40; Scanco Medical AG), and the resulting files were imported and analyzed with 3D rendering software to calculate the FT. Collected data from FT were submitted to 1-way ANOVA (a=.05).

Results: In general, film thickness of the light-curing resin cement was about half of the pre-heated resin composites tested, and it ranged from 0.29mm to 0.59mm.

Conclusions: Pre-heated resin composites promote thicker resin cements than light-curing resin cements when cementing veneers.