Comparison of thickness and homogeneity of the cementation layer in indirect veneers, made with fluid resin vs. light-cure resin cement: in vitro study

Abstract

Objective: Compare the thickness and homogeneity of the cementing layer between a light-cure resin cement and a flowable resin. Materials and methods: To obtain the sample, the preparation was carved in a replica of tooth 1.1 (EWL model teeth, Kavo), which was scanned and then replicated 92 times in an ABS polymer by 3D printing. The sample was divided into 2 groups with 46 samples each. The cementation of the veneers was performed with Tetric N-Flow flowable resin in the G1 group, and with Variolink Esthetic light-cure resin cement in the G2 group. Each sample was previously washed with 70° alcohol, then dried and a layer of Tetric N-Bond was applied. Digital pressure was used to achieve the final settlement of the veneers. Finally, a medial and a paramedial section were made to obtain approximately 2 mm thick samples. The cementation layer was observed with an optical microscope. Results: The average thickness for Tetric N-Flow was 119μm in incisal, 113μm in medium and 107μm in cervical. For Variolink Esthetic the average was 117μm, 112μm and 110μm in incisal, middle and cervical respectively. The homogeneity was 93.3% for G1 and 91.3% for G2. Conclusion: There is no significant difference in the thickness and homogeneity of the cementing layer made with flowable resin and with light-cure resin cement.