State Key Laboratory of Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University, Chengdu, 610041, China; Department of Endodontics, Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China.
State Key Laboratory of Oral Diseases, Department of Cariology and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University, Chengdu, 610041, China.
J Dent. 2020 Jun;97:103355. doi: 10.1016/j.jdent.2020.103355. Epub 2020 May 4.
Resin infiltrant is used in early enamel caries. However, commercial resin infiltrant lacks persistent antibacterial activity. Dimethylaminododecyl methacrylate (DMADDM) was added to resin infiltrant to give it sustainable antibacterial properties and inhibit demineralization.
After the application of resin infiltrant to bovine enamel, cytotoxicity, surface roughness, and aesthetics were assessed. A multi-species biofilm was incubated on the enamel disk before and one month after microbial-aging. After a 48-h anaerobic incubation, biomass accumulation, metabolic activity, and lactic acid were analyzed using a crystal violet assay, an MTT (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and a lactic acid assay. Biofilm structure and composition were determined by live/dead staining, exopolysaccharide (EPS) staining, scanning electron microscopy (SEM), and quantitative polymerase chain reaction (qPCR). The depth and content of demineralization were tested by transverse microradiography (TMR).
Incorporating DMADDM did not increase the cytotoxicity or change the physical properties when the mass fraction of the DMADDM was 2.5-10 %. The modification decreased the amount of bacterial biofilm, metabolic activity, lactic acid production, EPS, and the proportion of Streptococcus mutans in the biofilms. It also provided anti-demineralization effects. The surface roughness and antibacterial ability were not changed after one month of microbial-aging.
The incorporation of DMADDM improved the antibacterial and anti-demineralization effects of the material. It demonstrated a sustained antibacterial effect.
The antibacterial modification might be a potential choice for future clinical applications to inhibit early enamel caries.
树脂渗透剂用于早期釉质龋。然而，商业用树脂渗透剂缺乏持久的抗菌活性。二甲氨基十二烷基甲基丙烯酸酯（DMADDM）被添加到树脂渗透剂中，使其具有可持续的抗菌性能并抑制脱矿。
在牛牙釉质上应用树脂渗透剂后，评估其细胞毒性、表面粗糙度和美学效果。在微生物老化之前和之后一个月，在牙釉质圆盘上孵育多物种生物膜。经过 48 小时的厌氧孵育，使用结晶紫测定法、MTT（3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴盐）测定法和乳酸测定法分析生物膜的生物量积累、代谢活性和乳酸。通过活/死染色、胞外多糖（EPS）染色、扫描电子显微镜（SEM）和定量聚合酶链反应（qPCR）来确定生物膜的结构和组成。通过横向显微放射照相术（TMR）测试脱矿的深度和含量。
当 DMADDM 的质量分数为 2.5-10%时，加入 DMADDM 不会增加细胞毒性或改变物理性质。修饰降低了细菌生物膜、代谢活性、乳酸产生、EPS 和生物膜中变形链球菌的比例。它还提供了抗脱矿作用。微生物老化一个月后，表面粗糙度和抗菌能力没有变化。
DMADDM 的掺入提高了材料的抗菌和抗脱矿作用。它表现出持久的抗菌效果。
抗菌修饰可能是未来临床应用中抑制早期釉质龋的一种潜在选择。
