Effect of Aging on the Antifungal Activity and Surface Roughness of Soft Lining Material Incorporated with Chitosan Nano-Particles

Abstract

Background: Chitosan is a natural bio-polymer, which has been utilized in different pharmaceutical and biomedical fields, and it has antimicrobial activities. Resilient liner, it’s a polymeric material, considered as a kind of "shock absorber". Purpose: The purpose of this study is to evaluate the effects of immersion in the artificial saliva on the antifungal activity and surface roughness of heat-polymerized soft lining material impregnated with CHs-NPs. Approach: 180 specimens were prepared. Divided into 3 groups according to the test: Sensitivity test, viable count test and surface roughness test. Then the specimens subdivided into 3groups depending on the Chitosan addition and the different pH of saliva. The sample’s dimensions for candida viability count test were (10×10×2.3mm) length, width, and thickness, while a plastic disc with dimensions (6 diameter ×0.5mm thickness) for disc diffusion test. For surface roughness test a disc with 30mm diameter and 3mm thickness. The data analyzed statistically using SPSS, (ANOVA) test with Games-Howell test to accept or reject the statistical hypothesis. Results: For viable count test, there was a significant decrease in CFU/ml of C. albicans after incorporation 3.5%CHs-NPs, the results also showed that the specimens’ group that was stored in acidic artificial saliva, recorded a significant increase in CFU/ml of C. albicans, followed by the specimens’ group that was stored in alkaline artificial saliva. While for disk diffusion test, results showed there was no inhibition zone around any PEMA disks except the experimental group that was stored in neutral artificial saliva. The results of surface roughness, showed no significant difference after incorporation in 3.5% of CHs-NPs into the soft denture liner and immersion in the artificial saliva with different pH levels. Conclusion: Acidic and alkaline artificial saliva encouraging the growth C. albicans, while the neutral artificial saliva had the least effect. Also, the result of the study concluded that vertex soft lining material impregnated with chitosan nano-particles aids in obtaining a lining material with the antifungal activity against C. albicans. While the aging process and the addition of CHs-NPs was not having a significantly effect on the surface roughness.