Objective: This investigation aimed to develop a novel antibacterial dental adhesive containing nanoantibacterial inorganic fillers and measure the dentin bonding strength, mechanical properties, and antibacterial property of the novel adhesive in vitro.
Methods: Novel nanoantibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were synthesized on the basis of previous research. These novel nanoantibacterial inorganic fillers were added into the dental adhesive to prepare novel nanoantibacterial dental resin composite at mass fractions of 0%, 2.5%, 5.0%, 7.5%, and 10%; 0% was used as control. Dentin shear bonding test was used to evaluate the bonding strength. Flexural test was utilized to measure the novel resin composite flexural strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony forming unit, lactic acid production, and live/dead assay of the biofilm on novel dental adhesive were calculated to assess the effect of novel dental adhesive on human dental plaque microcosm biofilm.
Results: The dentin shear bond strength, flexural strength, and elastic modulus were 28.9 MPa, 86.6 MPa, and 4.2 GPa, respectively, when the nanoantibacterial inorganic filler mass fraction in the dental adhesive reached approximately 5.0%. Consequently, the dentin shear bond strength and mechanical properties significantly increased. Addition of 2.5% nanoantibacterial inorganic fillers into the dental adhesive exerted no adverse effect on the mechanical properties significantly (P>0.05). Dental adhesive containing 5% or more nanoantibacterial inorganic fillers inhibited the metabolic activity of the dental plaque microcosm biofilm significantly, thereby displaying a strong antibacterial potency (P<0.05).
Conclusions: This novel antibacterial dental adhesive, which contained 5.0% nanoantibacterial inorganic filler, exhibited promising bonding strength, mechanical property, and antibacterial ability. Hence, this adhesive can be potentially used in caries inhibition in dental application.
目的 合成含纳米抗菌无机填料的新型树脂粘接剂，并探讨其粘接强度、力学性能、体外抗菌性能等。方法 制备长链烷基季铵盐修饰的纳米抗菌二氧化硅填料，并以0%、2.5%、5.0%、7.5%及10%的质量分数添加到树脂粘接剂中，生成新型纳米抗菌树脂粘接剂。以0%组作为对照组，用牙本质剪切试验来测试粘接强度；用三点弯曲试验来测试力学性能；建立人牙菌斑生物膜体外模型，通过菌落计数、乳酸代谢分析及活/死细菌染色等手段来评价新型树脂粘接剂对牙菌斑生物膜的影响。结果 加入5.0%的纳米抗菌无机填料时，树脂粘接剂的牙本质粘接强度为28.9 MPa，弯曲强度及弹性模量分别为86.6 MPa和4.2 GPa，与对照组比较，粘接强度及力学性能明显提高（P< 0.05）；当抗菌无机填料含量达到2.5%时，新型抗菌树脂粘接剂对牙菌斑生物膜代谢产生明显抑制作用，显示了良好的抗菌性能（P<0.05）。结论 含一定质量分数（5.0%）新型纳米抗菌无机填料的树脂粘接剂具有较强的粘接强度、力学性能及抗菌功能，为进一步临床应用打下基础。.
Keywords: antibacterial property; dental adhesive; dental plaque microcosm biofilm; inorganic fillers; quaternary ammonium salt.