The effect of different types of oral mouth rinses on the hardness of Silorane-based and Nano-hybrid composites

Background:
The restorative materials used in dentistry are required to have long-term durability in the oral cavity. Effect of various fluids in the oral environment can affect the hardness of these restorations. This study was carried out to evaluate the effect of different mouth rinses on the hardness of Silorane and Nano-hybrid resin composites.


Materials and Methods:
Thirty specimens were prepared from each type of composite and stored in artificial saliva for 24 h at 37°C. They were then divided into six experimental groups based on the test solution and were immersed and stored for 24 h at 37°C. Thereafter, the specimens were washed, dried and the hardness was measured for each specimen by Vickers microhardness tester.


Results:
Nano-hybrid resin composite showed higher Vickers hardness number (VHN) than Silorane composite in any test solution. There was only a mildly significant difference in the mean VHN of Silorane composite immersed in alcohol-containing mouthwash compared with artificial saliva. However, there was a significant difference in the mean VHN of Nano-hybrid composite when immersed in different mouthwashes.


Conclusion:
The microhardness values of Silorane-based and Nano-hybrid resin composites were decreased after immersion in the mouthwashes. The hardness of Nano-hybrid composite immersed in artificial saliva showed the highest VHN and was significantly affected when immersed in other test solutions. Silorane-based composite is more resistant to alcohol-containing mouthwash than Nano-hybrid composite.