Anti-biofilm effect of denture base resin containing dimethylaminododecyl methacrylate on multi-species biofilm

摘要

Introduction: The increased denture stomatitis due to unbalanced interactions between oral microbiota requires novel denture materials with antimicrobial ability. Objectives: The objectives of this study were to investigate the mechanical properties and antimicrobial effect of a new denture base resin containing dimethylaminododecyl methacrylate (DMADDM) on multi-species biofilms and the biocompatibility of this material for the first time. Materials and Methods: DMADDM was mixed with one third of the specimen, at a mass fraction of 0% (control group), 1.65 %, 3.3% and 6.6 %. Candida albicans, Streptococcus mutans, Actinomyces naeslundii and Streptococcus sanguinis were chosen to form multi-species biofilms on denture base resin with DMADDM. Scanning electron microscope (SEM) imaging, colony-forming unit (CFU) counts, confocal laser scanning microscopy (CLSM) imaging analysis as well as XTT assays were used to quantify the biomass and metabolic activies change of biofilms. The effects on morphological change of C. albicans were observed by CLSM and the virulence genes expressions were quantified using real-time PCR. LDH array were used to determine the damage of epithelial cells co-cultured with the biofilm while real-time PCR were performed to quantify the gene expressions of cells responding to the biofilms. Animal experiment was performed and followed by hematoxylin-eosin (HE) staining and histological evaluation to study the biocompatibility of denture base resin in vivo. Flexure strength was measured to evaluate the mechanical properties of resin containing DMADDM. Results and Discussion: The denture base resin containing DMADDM reduced both the biomass and the metabolic activity of biofilms (p ＜ 0.05). In DMADDM-containing groups, the hyphal form of C. albicans was less prevalent while the virulence genes ALS3 and HWP1 gene were also down-regulated (p ＜ 0.05). The reduced C. albicans virulence factors in these modified groups were consistent with the down-regulation of cell IL-18 gene and lower LDH activity when the biofilm was co-cultured with TR-146 cells (p ＜ 0.05). In vivo histological evaluations proved that the addition of DMADDM at less than 6.6% in denture material did not increase the inflammatory response (p ＞ 0.05). The denture base resin with DMADDM had ftexural strength similar to that of the control group. Conclusion: The new antibacterial denture base resin with DMADDM had strong inhibition against multi-species biofilms, without compromising the mechanical properties. The novel anti-biofilm denture base resin is a new promising therapeutic system for denture stomatitis applications.