Physicomechanical and cytotoxic effects of a newly developed dental hybrid composite adhesive cement reinforced with zirconia and alumina

Dental cement made from silica rice husks, reinforced with zirconia and alumina, may carry improved physical and mechanical properties. This study aimed to investigate the physical and mechanical properties and the cytotoxicity of an experimental dental hybrid composite adhesive cement (DCAC), made from silica rice husk and containing different amounts of zirconia and alumina. Five groups were included, namely a control group with DCAC comprising only silica (CTR); groups containing either 3 wt.% zirconia (Zr3), 3 wt.% alumina (AL3), or 10 wt.% alumina (AL10); and a positive control group (Rely-X U200). The DCACs were characterised based on the degree of conversion (DC) and void volumes, then tested for compressive strength (CS) and cytotoxicity. In all groups, DC was higher than 60% and there was no significant difference between groups, except for CTR. Void content significantly decreased when the hybrid fillers were used (p < 0.05). The CS of group AL10, with a higher alumina weight fraction, was significantly different from CTR (p < 0.05). At concentration < 100 mg mL(-1), cytotoxicity of DCAC was comparable to Rely-X U200. Reinforcement of DCAC with zirconia and alumina may, thus, improve its physical and mechanical properties. Hybridisation of different filler particle sizes is one way to improve both physical and mechanical properties. All DCACs showed no or minimal cytotoxicity.

Automated summary

This study investigated the physical and mechanical properties and cytotoxicity of a dental hybrid composite adhesive cement (DCAC) made from silica rice husk and different amounts of zirconia and alumina. The results showed that the addition of zirconia and alumina improved the physical and mechanical properties of DCAC, and the cytotoxicity was minimal.