In vitro evaluation of composite containing DMAHDM and calcium phosphate nanoparticles on recurrent caries inhibition at bovine enamel-restoration margins. Issue 10 (October 2020)

• Record Type: Journal Article
• Authors: Zhou, Wen; Peng, Xian; Zhou, Xuedong; Weir, Michael D.; Melo, Mary Anne S.; Tay, Franklin R.; Imazato, Satoshi; Oates, Thomas W.; Cheng, Lei; Xu, Hockin H.K.
• Is Part Of: Dental materials. Volume 36:Issue 10(2020)
• Page Start: 1343
• Page End: 1355
• Publication Date: 2020-10
• Subjects: Recurrent caries -- Demineralizaiton and remineralization -- Antibacterial -- Nanocomposite -- Biofilms -- Enamel hardness.; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2020.07.007
• Languages: English
• ISSNs: 0109-5641

Abstract

Abstract: Objective: Recurrent caries is a primary reason for restoration failure caused by biofilm acids. The objectives of this study were to: (1) develop a novel multifunctional composite with antibacterial function and calcium (Ca) and phosphate (P) ion release, and (2) investigate the effects on enamel demineralization and hardness at the margins under biofilms. Methods: Dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP) were incorporated into composite. Four groups were tested: (1) Commercial control (Heliomolar), (2) Experimental control (0% DMAHDM + 0% NACP), (3) antibacterial group (3% DMAHDM + 0% NACP), (D) antibacterial and remineralizing group (3% DMAHDM + 30% NACP). Mechanical properties and Ca and P ion release were measured. Colony-forming units (CFU), lactic acid and polysaccharide of Streptococcus mutans ( S. mutans ) biofilms were evaluated. Demineralization of bovine enamel with restorations was induced via S. mutans, and enamel hardness was measured. Data were analyzed via one-way and two-way analyses of variance and Tukey's multiple comparison tests. Results: Adding DMAHDM and NACP into composite did not compromise the mechanical properties ( P > 0.05). Ca and P ion release of 3% DMAHDM + 30% NACP was increased at cariogenic low pH. Biofilm lactic acid and polysaccharides were greatly decreased via DMAHDM, and CFU was reduced by 4 logs ( P < 0.05). Under biofilm acids, enamel hardness at the margins was decreased to about 0.5 GPa for control; it was about 1 GPa for antibacterial group, and 1.3 GPa for antibacterial and remineralizing group ( P < 0.05). Conclusions: The novel 3% DMAHDM + 30% NACP composite had strong antibacterial effects. It substantially reduced enamel demineralization adjacent to restorations under biofilm acid attacks, yielding enamel hardness that was 2-fold greater than that of control composites. The novel multifunctional composite is promising to inhibit recurrent caries.