Zhang Ning, Chen Chen, Melo Mary As, Bai Yu-Xing, Cheng Lei, Xu Hockin Hk
1] Biomaterials and Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, USA [2] Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, China.
1] Biomaterials and Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, USA [2] State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Int J Oral Sci. 2015 Jun 26;7(2):103-9. doi: 10.1038/ijos.2014.77.
Secondary caries due to biofilm acids is a primary cause of dental composite restoration failure. To date, there have been no reports of dental composites that can repel protein adsorption and inhibit bacteria attachment. The objectives of this study were to develop a protein-repellent dental composite by incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC) and to investigate for the first time the effects of MPC mass fraction on protein adsorption, bacteria attachment, biofilm growth, and mechanical properties. Composites were synthesized with 0 (control), 0.75%, 1.5%, 2.25%, 3%, 4.5% and 6% of MPC by mass. A commercial composite was also tested as a control. Mechanical properties were measured in three-point flexure. Protein adsorption onto the composite was determined by the microbicinchoninic acid method. A human saliva microcosm biofilm model was used. Early attachment at 4 h, biofilm at 2 days, live/dead staining and colony-forming units (CFUs) of biofilms grown on the composites were investigated. Composites with MPC of up to 3% had mechanical properties similar to those without MPC and those of the commercial control, whereas 4.5% and 6% MPC decreased the mechanical properties (P<0.05). Increasing MPC from 0 to 3% reduced the protein adsorption on composites (P<0.05). The composite with 3% MPC had protein adsorption that was 1/12 that of the control (P<0.05). Oral bacteria early attachment and biofilm growth were also greatly reduced on the composite with 3% MPC, compared to the control (P<0.05). In conclusion, incorporation of MPC into composites at 3% greatly reduced protein adsorption, bacteria attachment and biofilm CFUs, without compromising mechanical properties. Protein-repellent composites could help to repel bacteria attachment and plaque build-up to reduce secondary caries. The protein-repellent method might be applicable to other dental materials.
由生物膜酸导致的继发龋是牙科复合树脂修复失败的主要原因。迄今为止，尚无能够排斥蛋白质吸附并抑制细菌黏附的牙科复合树脂的相关报道。本研究的目的是通过掺入2-甲基丙烯酰氧基乙基磷酰胆碱（MPC）来开发一种具有蛋白质排斥性的牙科复合树脂，并首次研究MPC质量分数对蛋白质吸附、细菌黏附、生物膜生长及力学性能的影响。通过质量分数为0（对照）、0.75%、1.5%、2.25%、3%、4.5%和6%的MPC合成复合树脂。还测试了一种市售复合树脂作为对照。通过三点弯曲测量力学性能。采用微生物辛可宁酸法测定复合树脂上的蛋白质吸附情况。使用人体唾液微生态生物膜模型。研究了在复合树脂上生长的生物膜在4小时时的早期黏附、2天时的生物膜、活/死染色及菌落形成单位（CFU）。MPC含量高达3%的复合树脂的力学性能与不含MPC的复合树脂及市售对照的力学性能相似，而MPC含量为4.5%和6%时则降低了力学性能（P<0.05）。将MPC从0增加到3%可降低复合树脂上的蛋白质吸附（P<0.05）。含3%MPC的复合树脂的蛋白质吸附量是对照的1/12（P<0.05）。与对照相比，含3%MPC的复合树脂上口腔细菌的早期黏附和生物膜生长也显著减少（P<0.05）。总之，在复合树脂中掺入3%的MPC可显著降低蛋白质吸附、细菌黏附和生物膜CFU，且不影响力学性能。具有蛋白质排斥性的复合树脂有助于排斥细菌黏附和牙菌斑形成，以减少继发龋。蛋白质排斥方法可能适用于其他牙科材料。
