Optimization of the synthesis of novel alginate-manganese oxide bionanocomposite by Taguchi design as antimicrobial dental impression material

Abstract

Control of the infection transmission cycle in clinics and increase of drug resistance are among the current problems of the dental community. In this study, the optimization synthesis of the dental impression material of alginate-manganese oxide with the highest level of antibacterial activity was studied. For this purpose, alginate biopolymer and manganese oxide nanoparticles were synthesized by green synthesis using Azotobacter vinelandii and Bacillus sp, respectively. The in situ method was applied to synthesize alginate-manganese oxide nanocomposite. Nine experiments were designed to determine the antibacterial effects of the synthesized nanocomposites against Streptococcus mutans biofilm by the Taguchi method. Antibacterial activity of nanocomposite and its components were performed by the colony-forming unit (CFU) test. The results indicated that the synthesized nanocomposite by experiment 3 (50 mg/ml alginate, 4 mg/ml manganese oxide, and 90 min of stirring time) had the highest antibacterial activity (2.10 CFU/ml). The highest effect on streptococcus muntas bacteria survival was related to manganese oxide with an effect of 84.66%, stirring time of 6.58%, and alginate of 5.82%, respectively. Alginate at the first level and stirring time at the third level had the strongest interaction with each other and on the survival rate of streptococcus muntas bacteria at the amount 46.57%. Manganese oxide and stirring time at the third level showed a significant interaction on the survival rate of streptococcus muntas bacteria at the amount 13.68%. The lowest interaction intensity index was related to alginate at the first level and manganese oxide at the third level at the amount 2.85%. Characteristics of alginate-manganese oxide nanocomposite and its components evaluated by ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), and thermogravimetric analysis (TGA) confirmed the formation of the nanocomposite and the improvement of its properties.