Antimicrobial dental composites with K18-methyl methacrylate and K18-filler

Objective: To determine the effects of using K18-methyl methacrylate (K18-MMA) and K18-Filler on composite cure, esthetic, mechanical, polymerization shrinkage, and antimicrobial properties. Methods: K18-MMA (0–20% w/w) was used to replace TEGDMA in a 70:30 Bis-GMA:TEGDMA composite filled to 70% w/w with barium glass or K18-Filler. Composite degree of cure (Rockwell_15T hardness and near Infrared FTIR), hydrophilicity (contact angle measurements), translucency (transparency parameter measurements, TP), mechanical (3-point bend test), polymerization shrinkage (volumetric shrinkage and shrinkage stress), and antimicrobial properties (colony counting assay) against Streptococcus mutans, Streptococcus sanguinis, and Candida albicans were determined. Results: All experimental groups had comparable degrees of cure (near Infrared FTIR and Rockwell_15T Hardness), TP, moduli, polymerization volumetric shrinkages and shrinkage stresses to those of controls (Bonferroni corrected p > 0.0018). Only one group (15% K18-MMA+K18-Filler) had significantly different (lower) contact angles as compared to that of controls (Bonferroni corrected p < 0.0018). Most of the K18-Filler-containing composites had significantly lower ultimate transverse strengths (UTS) than controls (Bonferroni corrected p < 0.0018). Controls had significantly greater S mutans colony counts than 15% and 20% w/w K18-MMA+K18-Filler groups, and greater S sanguinis and C albicans colony counts than K18-containing groups. Of the composites with that provided significant antimicrobial properties against S. mutans, S. sanguinis, and C. albicans, only the 20% K18-MMA+K18-Filler group had significantly lower UTS than controls. Significance: Composites with K18-MMA and K18-Filler with comparable physical properties to control composites and significant antimicrobial properties have been developed. K18-MMA and K18-Filler seem to be suitable for incorporation into commercial dental resins.