Can CAD/CAM resin blocks be considered as substitute for conventional resins?

Abstract

Objective: Dentists are facing a myriad of new CAD/CAM product for dental filling therapies. Are the new materials any worthwhile using? Are they succeeding the standard filling materials? Here we compare for the first time the new resin-composite blocks (RCBs) with conventional materials (Filtek Z250 and Tetric EvoCeram).

Methods: The material were tested for residual monomer elution by HPLC, thermogravimetric analysis (TG) was used to determine the percentage of fillers by weight, hardness was evaluated by Vickers method, morphology of fillers and distribution in the matrix were examined by scanning electron microscopy (SEM), elemental analysis for elemental determination of the filler particles was performed by energy-dispersive X-ray spectroscopy (EDX) cytotoxicity using human gingival fibroblasts and an epithelial cell line.

Results: The RBC outperformed conventional composite regarding mechanical characteristics (hardness) and monomer eluation, but showed some worrisome results regarding cytotoxicity.

Significance: The cost benefit is not in favour of RBCs in comparison to conventional composites, as the cytotoxicity was found higher for RBCs.

Keywords: Biocompatibility; CAD/CAM resin blocks; Composites; Cytotoxicity; Dental filling materials; Hardness.