Microwave assisted urethane grafted nano-apatites for dental adhesives

Abstract

The objectives were to synthesize urethane grafted nano-apatite in shortest possible time duration using the microwave irradiation method and to utilize them for synthesis of experimental dental adhesives. The structural, morphological, thermal, and mechanical behavior of synthesized grafted nano-apatite were investigated. Then, these grafted nano-apatite particles were incorporated in various concentrations that is, 5wt.%, 10wt.%, and 15wt.% into dimethacrylate resins to develop bioactive adhesives. The weight measurement analysis in deionized water and phosphate buffer saline, Knoop micro-hardness, and degree of conversion were evaluated. The bacterial adhesion was investigated with Streptococcus mutans at 6h, 24h, and 48h. Statistical analysis was conducted using one-way ANOVA. The urethane dimethacrylate was successfully grafted on the nano-apatite surface and spectroscopic analysis confirmed the presence of urethane and phosphate peaks. An inverse relationship was found in both media between the concentration of grafted fillers and weight loss. No significant difference was observed in the micro-hardness and degree of conversion among the groups, whereby the degree of conversion for all groups was in the range of 83% to 86%. The mean number of bacterial colonies was significantly lower in the 15wt.% group compared to 5wt.% and 10wt.%. The grafted nano-apatite presented favorable results for adhesive resin incorporation, where 15wt.% group comparatively showed superior results than other groups.

Bibliometric Analysis of Literature Published on Antibacterial Dental Adhesive from 1996–2020

“…The United States of America, China, and Brazil were the major collaborators with other countries worldwide. The Table in Figure 6 indicated the top ten collaborations show that major two collaborations have been between China and the USA (56) and the USA and Brazil (18). The rest of the 54 collaboration entries are in a single digit.…”

“…Antibacterial agents can be leachable compounds, polymerizable monomers, and filler particles [15]. Several studies have been conducted to evaluate the effect of adding nanoparticles such as silver, calcium phosphate, zinc oxide, and titanium dioxide in various restorative materials, including glass ionomer cements, resin-based materials, and dental adhesives [16][17][18]. The quaternary ammonium compounds (QAC) have been used in composite restorations and impact the polymeric structure, degree of conversion, solvent sorption, shrinkage, and alter the biocompatibility behavior [19].…”

Low-temperature flow-synthesis-assisted urethane-grafted zinc oxide-based dental composites: physical, mechanical, and antibacterial responses

“…It is expected that grafting of urethane on ZnO surface led to formation of a monoblock system when incorporated as a filler in UDMA, bis-GMA, and TEGDMA-based resin matrices. Both bis-GMA and UDMA are large molecular weight monomers compared with TEGDMA, and during mixing of resin matrices, they underwent hydrogen bonding [35].…”

Analyses of Experimental Dental Adhesives Based on Zirconia/Silver Phosphate Nanoparticles

“…Imazato et al introduced the “immobilized bactericide” concept to inhibit bacteria that come into contact with dental resin materials [ 9 ]. With the emergence of nanotechnology in dentistry, nanoparticles of different origins such as silica [ 10 ], zirconia [ 11 ], amorphous calcium phosphate [ 12 ], hydroxyapatite [ 13 ], titanium dioxide [ 14 ], zinc oxide [ 15 ], nano-clay [ 16 ], silver [ 17 ], etc. have been added to improve the mechanical and antibacterial properties of the dental adhesives.…”