Developing Novel Antibacterial Dental Filling Composite Restoratives

Abstract

A novel antimicrobial dental composite system has been developed and evaluated.Both alumina and zirconia filler particles were covalently coated with an antibacterial resin and blended into a composite formulation, respectively. Surface hardness and bacterial viability were used to evaluate the coated alumina filler-modified composite.Compressive strength and bacterial viability were used to evaluate the coated zirconia filler-modified composite. Commercial composite Kerr was used as control. The specimens were conditioned in distilled water at 37°C for 24 h prior to testing. Four bacterial species Streptococcus mutans, Staphylococcus aureus, Pseudomon asaeruginosa and Escherichia coli were used to assess the bacterial viability. Effects of antibacterial moiety content, modified particle size and loading, and total filler content were investigated.Chapter 2 describes how we studied and evaluated the composite modified with antibacterial resin-coated alumina fillers. The results showed that almost all the modified composites exhibited higher antibacterial activity along with improved surface hardness, as compared to unmodified one. Increasing antibacterial moiety content, particle size and loading, and total filler content generally increased surface hardness. Increasing antibacterial moiety, filler loading, and total filler content increased antibacterial activity. On the other hand, increasing particle size showed a negative impact on antibacterial activity. The leaching tests indicate that the modified experimental composite showed no leachable antibacterial component to bacteria.Chapter 3 describes how we studied and evaluated the composite modified with antibacterial resin-coated zirconia fillers. The results showed that almost all the modified composites exhibited higher antibacterial activity along with decreased compressive strength, as compared to the unmodified control. It was found that with increasing antibacterial moiety content and modified filler loading, yield strength,modulus and compressive strength of the composite were decreased. In addition,the strengths of the composite were increased with increasing powder/liquid ratio.On the other hand, with increasing antibacterial moiety content, filler loading and powder/liquid ratio, antibacterial activity was enhanced.In summary, we have developed a novel antibacterial dental composite system for improved dental restoratives. Both composites modified with the antibacterial resin-coated alumina and zirconia fillers have demonstrated significant antibacterial activities.The composite modified with the alumina fillers showed improved hardness values, but the composite modified with the zirconia fillers showed decreased compressive strength values. It appears that the developed system is a non-leaching antibacterial dental composite.