Evaluation of the Biocompatibility of Novel BPA-free, Fluorinated Fiber-reinforced Composites

Objectives: Bis-phenol A (BPA) as a precursor to bis-phenol A-glycidyl methacrylate (bis-GMA) has garnered substantial controversy due to the potential toxicity on human health. As such, it is highly warranted to develop new materials to replace bis-GMA in fiber-reinforced composites (FRCs) to fulfill a long-term clinical usage. Herein, this study aims to evaluate the cytotoxicity and biocompatibility of the newly manufactured BPA-free, fluorinated urethane dimethacrylate (FUDMA)-based and fiber-reinforced composites for dental application.
Methods: The composites were prepared by the varying types and the weight ratios of monomers and then classified into 5 groups. Briefly, the BPA groups comprised two bis-GMA/triethyleneglycol dimethacrylate (TEGDMA) based FRCs with the weight ratio of 49%/49wt% and 70%/28wt%, respectively; and the fluorinated FRCs groups comprised three different FUDMA/TEGDMA ratios (28%/70wt%, 49%/49wt%, and 70%/28wt%). After polymerization, MC3TC-E1 cells were cultured on the different FRCs for one, three, and five days. Their viability, proliferation, morphology, and differentiation were assessed using MTT, LIVE/DEAD staining, scanning electron microscopy (SEM) and alkaline phosphatase (ALP) level test, respectively.
Results: The cell viability in all fluorinated FRCs was higher than those in the BPA groups after five days, while the fluorine amount in the FRCs showed a positive effect on the cell proliferation. Together with the SEM assessment, the confocal scanning laser microscopy indicated that the fluorine in the FRCs might effectively facilitate the cell proliferation and distribution compared to bis-GMA. It was notable that ALP activities in fluorinated FRCs groups were significantly higher than bis-GMA groups (p < 0.05) after five days, with maximal ALP activities observed with the 70wt% FUDMA-FRCs group, whilst 70wt% bis-GMA-FRCs showed the lowest values.
Conclusions: FUDMA-based FRCs are innovative dental materials possessing superior cytocompatibility properties compared to the conventional bis-GMA-FRCs. Our findings might strongly support the use of this biocompatible material to formulating the next generation of dental composites.