Biocompatible CaCO3 Nanoparticles for Improving the Antibacterial and Antibiofilm activity of Dental Acrylic Resins

Abstract

Most of the products used for dental restorations are made of polymethylmethacrylate (PMMA) due to its sufficient mechanical strength and thermal properties however its poor antibacterial properties lead towards the development of secondary dental caries which compromised the quality of available dental composites. Methods to inhibit bacterial growth and reduce biofilms on resin based dental composites have been searched for many decades. The purpose of this study was to evaluate standard PMMA films incorporated with CaCO3 nanoparticles (synthesized from algal extracts) sand chitosan in terms of antimicrobial activity, biofilm inhibition, nanomechanical behavior. Antibacterial effects were mainly attributed to biocompatible CaCO3 nanoparticles, which were synthesized through green approach using microalgae strain (Dictyosphaerium DHM1 (LC159305). Microalgae strain was screened through GCMS and FTIR for its bio-constituents involved in the reduction if nanoparticles. Structure, average size, size distribution and morphology of hence prepared nano sized particles were investigated through UV-Vis, XRD, SEM, FTIR which confirmed synthesis of less than 100nm sized spherical nanoparticles. Biological properties such as antibacterial, antibiofilm and biocompatibility were determined against varying concentrations of CaCO3 nanoparticles. Antibacterial and antibiofilm effectiveness of nanoparticles was evaluated against Escherichia coli and Staphylococcus aureus and the results exhibited strong bacterial and biofilm inhibitions against both strains. Nanoparticles and chitosan were included in the polymer matrix of Polymethyl methacrylate (PMMA) after polymerization through physical mixing for uniform distribution which was confirmed through XRD and FTIR whereas surface morphology of synthesized nanocomposite PMMA films was studied using SEM and AFM. Further addition of CaCO3 nanoparticles along with chitosan to standard PMMA resulted in an increased hydrophobicity with improved thermal, mechanical and biological properties and reduced porosity, water sorption and solubility. Thus, the results of this study strongly suggest that nanocomposite PMMA films can be effectively used as antibacterial and biocompatible dental acrylic resins and provide a suitable source for the improvement of traditionally used dental acrylic resins.