Biocompatibility of New CAD/CAM-Machinable Materials for Provisional Long-Term Restorations

CAD/CAM manufacturing in dentistry offers new possibilities for easy and quick preparation and replication of temporary restorations until the requirements for a final prosthetic solution are established with clinical and prosthetically acceptable parameters. These new provisional materials combine flexural strength with improved esthetics and lasting color stability. Objective: The aim of this in-vitro study was to investigate the biocompatibility of these new CAD/CAM-machinable materials for provisional restorations compared to established provisional resins. Materials and Methods: Specimens from three different polymers for CAD/CAM use (Artbloc-Temp, Merz Dental; CAD-Temp, Vita; C-Temp, Kavo) and three different established materials for provisional fixed restorations (Luxatemp, DMG; Prevision, Hereaus; Protemp, 3MEspe) were prepared and tested on human oral epithelial cells. Biocompatibility was tested by evaluating the cytotoxicity using the agar-overlay-test, measuring succinic dehydrogenases activity (MTT-Assay) and detecting adenosine triphosphate (Cell-Titer-Glo-Assay). Two methods were applied: Indirect contact between cell cultures and specimens by setting up eluates (method 1), and direct incubation of the specimens in the cell culture and in an agar-overlay-test (method 2). Untreated cell culture for method 1 and a ceramic specimen for method 2 served as a positive control, liquid PMMA for both methods was used as a negative control. Results: All CAD/CAM-machinable materials tested with the agar-overlay were found to be “non-toxic”, whereas the established provisional materials ranked from ”non-toxic” to “mild-toxic”. For the MTT-Assay and the ATP-Assay no significant toxicity was observed between the ceramic specimen and the CAD/CAM-machinable materials. The established materials for provisional restorations showed slightly lower levels of cell-viability but no significant cytotoxicity. Conclusion: CAD/CAM-machinable materials for provisional restorations showed no cytotoxic effects with all test methods used to assess biocompatibility.

This study was supported by the Forschungsgemeinschaft Dental e.V.