State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, MD 21201, USA.
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
Mater Sci Eng C Mater Biol Appl. 2019 Jan 1;94:587-596. doi: 10.1016/j.msec.2018.10.004. Epub 2018 Oct 2.
Recurrent caries often occurs and is a primary reason for the failure of dental composite restorations. The objectives of this study were to: (1) develop a bioactive composite containing dimethylaminohexadecyl methacrylate (DMAHDM), (2) investigate its antibacterial effects and suppression on biofilm growth, and (3) investigate its ability to modulate biofilm species composition for the first time. DMAHDM was incorporated into a composite at mass% of 0%, 0.75%, 1.5%, 2.25% and 3%. A commercial composite Heliomolar served as a comparative control. A biofilm model consisting of Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis) and Streptococcus gordonii (S. gordonii) was tested by growing biofilms for 48 h and 72 h on composites. Colony-forming units (CFUs), metabolic activity and live/dead staining were evaluated. Lactic acid and polysaccharide productions were measured to assess biofilm cariogenicity. TaqMan real-time polymerase chain reaction was used to determine the proportion of each species in the biofilm. DMAHDM-containing composite had a strong anti-biofilm function, reducing biofilm CFU by 2-3 orders of magnitude, compared to control composite. Biofilm metabolic activity, lactic acid and polysaccharides were decreased substantially, compared to control (p < 0.05). At 72 h, the cariogenic S. mutans proportion in the biofilm on the composite with 3% DMAHDM was 19.9%. In contrast, an overwhelming S. mutans proportion of 92.2% and 91.2% existed in biofilms on commercial control and 0% DMAHDM, respectively. In conclusion, incorporating DMAHDM into dental composite: (1) yielded potent anti-biofilm properties; (2) modulated the biofilm species composition toward a non-cariogenic tendency. The new DMAHDM composite is promising for applications in a wide range of tooth cavity restorations to modulate oral biofilm species and combat caries.
龋齿经常复发，是牙科复合树脂修复失败的主要原因。本研究的目的是：（1）开发一种含有二甲氨基十六烷基甲基丙烯酸酯（DMAHDM）的生物活性复合材料，（2）研究其抗菌作用和对生物膜生长的抑制作用，（3）首次研究其调节生物膜物种组成的能力。DMAHDM 以 0%、0.75%、1.5%、2.25%和 3%的质量比掺入复合材料中。以商业复合材料 Heliomolar 作为对照。通过在复合材料上培养 48 小时和 72 小时，建立了由变形链球菌（S. mutans）、血链球菌（S. sanguinis）和戈登链球菌（S. gordonii）组成的生物膜模型。通过菌落形成单位（CFU）、代谢活性和死活染色评估来评估生物膜。测量乳酸和多糖的产生来评估生物膜致龋性。使用 TaqMan 实时聚合酶链反应来确定生物膜中每种物种的比例。与对照复合材料相比，含有 DMAHDM 的复合材料具有很强的抗生物膜功能，将生物膜 CFU 减少了 2-3 个数量级。与对照相比，生物膜代谢活性、乳酸和多糖均显著降低（p<0.05）。在 72 小时时，含有 3% DMAHDM 的复合材料上生物膜中致龋性 S. mutans 的比例为 19.9%。相比之下，商业对照和 0% DMAHDM 上的生物膜中 S. mutans 的比例分别为 92.2%和 91.2%。总之，将 DMAHDM 掺入牙科复合材料中：（1）产生了强大的抗生物膜性能；（2）调节了生物膜的物种组成，使其向非致龋倾向发展。新型 DMAHDM 复合材料有望广泛应用于牙齿腔隙修复，以调节口腔生物膜物种并防治龋齿。
