In Vitro Cytotoxicity of Provisional Resin Materials on Human Dental Pulp Cells

Objectives: The purpose of this study was to determine the effects that provisional resins have on cell toxicity from primary human dental pulp stem cell (DPSCs). Despite being commonly used in contact with dentin as temporary prosthesis, there is a lack of studies regarding the cytotoxicity of provisional resin to DPSCs.
Methods: The materials used in this study were chemically activated bis-acryl composite (Chem-Bis), chemically activated polyethyl metacrylate (Chem-PEMA), chemically activated polymethyl metacrylate (Chem-PMMA), urethane dimethacrylate (UDMA) resins and PMMA resin fabricated by CAD/CAM process (CAD/CAM-PMMA). Extraction was performed with distilled water in a ratio of 3cm²/mL. After quantitative analysis was performed with extraction from Chem-PEMA by liquid chromatography–mass spectrometry, cytotoxicity from extraction or dilution of the extraction from five provisional resins was analyzed by MTS and live and dead assays. Data were statistically analyzed by one-way ANOVA and Tukey HSD post hoc test (p<0.05).
Results: The results showed that there was a significant difference in cell viability depending on types of material and time on start of extracting (p<0.05). Generally, Chem-PEMA and Chem-PMMA showed relatively low cell viability on DPSCs compared to UDMA and CAD/CAM-PMMA. In addition, there was a significant lower cell viability in the early extracting group compared to set-group (p<0.05, n=5). Such results were confirmed by live and dead images. N,N-Dimethyl-p-toluidine, benzophenone-3 and several surfactants were detected in extract from Chem-PEMA.
Conclusions: Careful consideration on interpreting the results for cytotoxicity evaluation of five provisional resins is needed when different components and extracting time are used. The results demonstrated that extract from provisional resins during setting, especially Chem-PEMA and Chem-PMMA, cause cytotoxic reactions due to extracted cytotoxic-component. This cytotoxicity of provisional resins to DPSCs should be considered, particularly in use for deep cavities, in order to preserve the regenerative capacity of the pulp.