Cytotoxicity of dental ceramic materials on human gingival fibroblasts

This study aimed to evaluate the effect of new computer-aided design/computer-aided manufacturing all-ceramic materials on the viability and adhesion properties of human gingival fibroblasts (HGFs).

In this experimental study, the proliferation and adhesion potential of the cells were evaluated by seeding the HGF cells on rectangular samples (n = 18 for each group). The studied groups were tetragonal zirconia (TZr), cubic zirconia (CZr), lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and hybrid ceramic (HyC) (n = 6 for each studied time). The cell viability (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was conducted at determined times (24 h, 72 h, and 168 h) to evaluate the cell proliferation. Subsequently, the cultured cells were processed for scanning electron microscope (SEM) observation at each time interval. The surface roughness and wettability of studied ceramics were assessed using a surface profilometer and water contact angle. Differences in the cellular viability, surface roughness (Ra), and wet ability (wetting angle) of studied groups were compared by one-way analysis of variance and the Tukey multiple comparisons test (á = 0.05).

The highest percentage of cell viability after 24 h, 72 h, and 168 h cultures was related to ZLS, LDS, and CZr, respectively. The lowest proliferation of fibroblast cells was shown in ZLS compared to other groups. SEM analysis showed that the CZr and LDS groups have better adhesion patterns and morphology. The surface of HyC groups was significantly less rough than other groups. Regarding the water wetting angle (wettability), the TZr and CZr showed significantly larger angles.

Within the limitation of this study, it can be concluded that CZr and LDS ceramics had better adhesion patterns and typical morphology. On the other hand, zirconia with a larger wetting angle can reduce the chance of bacteria adhesion to the surface.