Investigation of physical, chemical and mechanical behaviour of nano-ZrO <sub>2</sub> -based dental composite
Shiv Ranjan Kumar, Shiv Ranjan Kumar, Hari Om Sharma, Sachin Kumar, Sachin Kumar, Dinesh Kumar Patel
Abstract
The incorporation of glass fibre in dental composite improves mechanical properties but doesn’t improves physical and chemical properties. Hence, in this paper, it has attempted to investigate the effect of nano-ZrO 2 with varying content (0, 3, 6 and 9 weight percentage) on physical properties (water sorption behaviour, solubility), chemical properties (degree of conversion, polymerization shrinkage) as well as mechanical properties (compressive strength, flexural strength). The finding of the result indicated that polymerization shrinkage was decreased with the addition of nano-ZrO 2 . However, water sorption indicated varying trends in which it initially increased at 6 wt.% and later decreased at 9 wt.% nano-ZrO 2 . On the other hand, mechanical properties such as flexural strength and compressive strength were increased by 28.5% and 27.2%, respectively with the addition of 3 wt.% of nano-ZrO 2 despite an increase in water sorption at 3 wt.% of nano-ZrO 2 by 31%. Therefore, it can be concluded that the hygroscopic compensation due to water sorption in nano-ZrO 2 -based dental composite relieves the undesirable polymerization shrinkage but on the other side, the extensive amount of water sorption of nano-ZrO 2 -based dental composite results in degradation, softening, colour instability and decrease in mechanical properties.