Effect of saliva and beverages on the surface roughness and hardnessof acrylic resin modified with nanomaterial.

Purpose: To evaluate the surface roughness and hardness of thermopolymerized acrylic resin incorporated with nanostructured silver vanadate (AgVO3) subjected to saliva and beverages.

Methods: The 128 specimens (5×5×2 mm) were prepared in thermopolymerized acrylic resin, according to the AgVO3 concentrations (n=32): 0%, 2.5%, 5% and 10%. The roughness and hardness were analyzed before and after immersion in saliva, Coca-Cola, orange juice and red wine, for 12 and 24 days. 2-way ANOVA and Bonferroni test (α= 0.05) were performed.

Results: After 12 days, Coca-Cola caused the highest roughness increase in the 2.5% group. The 10% group with saliva presented a higher roughness increase (P= 0.009). The control presented a decrease in roughness when in beverages (P< 0.05). After 24 days, orange juice and Coca-Cola produced a higher decrease in roughness in the control group (P< 0.05). After 12 days, saliva and wine produced a higher decrease in hardness of the 2.5% group (P< 0.05). Coca-Cola produced a decrease in hardness and wine an increase in hardness in the group with 10% AgVO3 concentration (P< 0.05). After 24 days, the group with 2.5% presented the highest decrease in hardness (P< 0.05). The immersions produced decreased hardness in the acrylic resin. Initially, there was an increase in roughness, however, over time, it decreased.

Clinical Significance: The control of oral biofilm is fundamental for the maintenance of the patient's oral health; however the incorporation of antimicrobial nanomaterial into prosthetic materials frequently exposed to saliva and beverages in the oral cavity interfered with the physical-mechanical properties of the products tested.