Saito Kayo, Hayakawa Tohru, Kawabata Rihito, Meguro Daijiro, Kasai Kazutaka
Department of Orthodontics, Nihon University School of Dentistry, Japan.
Angle Orthod. 2009 Mar;79(2):331-7. doi: 10.2319/120907-578.1.
To assess the antibacterial activity and cytotoxicity of an orthodontic bonding material containing an antibacterial agent.
Superbond C&B (4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane [4-META/MMA-TBB]) resin was mixed with benzalkonium chloride (BAC) to obtain final BAC concentrations of 0.25%, 0.75%, 1.25%, 1.75%, 2.5%, and 5.0% (wt/ wt). Antibacterial activity against Streptococcus mutans and Streptococcus sobrinus was evaluated by soaking the BAC-resin in distilled water at 37 degrees C for periods of 30, 90, and 180 days. Antibacterial activity of the BAC-resin was measured by the disk diffusion method, and the inhibition zone around each sample was measured and recorded. For evaluation of cytotoxicity, BAC-resin samples were put into cell culture inserts placed above human gingival cells and were incubated at 37 degrees C for 1, 3, and 6 days. Cytotoxicity was assessed with a tetrazolium bromide reduction assay.
The antibacterial activity of BAC-incorporated resin samples decreased significantly after immersion in water for 180 days, regardless of BAC concentration. The antibacterial activity of nonimmersed resin containing 0.25% or 1.75% BAC was comparable with that of 5.0% BAC-resin immersed for 180 days. In cytotoxicity tests, most cells died when exposed to resins containing 1.75%, 2.5%, and 5% BAC. No difference was observed between resins containing 0.25% and 0.75% BAC at 1, 3, and 6 days of culture.
The addition of BAC to 4-META/MMA-TBB resin confers an antibacterial effect even after immersion in water, and 4-META/MMA-TBB resin containing 0.25% to 0.75% BAC has no significant cytotoxic effect.
评估含抗菌剂的正畸粘结材料的抗菌活性和细胞毒性。
将Superbond C&B（偏苯三酸三（4-甲基丙烯酰氧基乙酯）/甲基丙烯酸甲酯-三正丁基硼烷[4-META/MMA-TBB]）树脂与苯扎氯铵（BAC）混合，使最终BAC浓度分别为0.25%、0.75%、1.25%、1.75%、2.5%和5.0%（重量/重量）。通过将含BAC的树脂在37℃蒸馏水中浸泡30、90和180天，评估其对变形链球菌和远缘链球菌的抗菌活性。采用纸片扩散法测定含BAC树脂的抗菌活性，测量并记录每个样品周围的抑菌圈。为评估细胞毒性，将含BAC树脂样品放入置于人牙龈细胞上方的细胞培养插入物中，在37℃孵育1、3和6天。采用溴化四氮唑还原试验评估细胞毒性。
无论BAC浓度如何，含BAC的树脂样品在水中浸泡180天后抗菌活性均显著降低。含0.25%或1.75%BAC的未浸泡树脂的抗菌活性与浸泡180天的含5.0%BAC树脂相当。在细胞毒性试验中，大多数细胞在接触含1.75%、2.5%和5%BAC树脂时死亡。在培养1、3和6天时，含0.25%和0.75%BAC的树脂之间未观察到差异。
向4-META/MMA-TBB树脂中添加BAC即使在水中浸泡后仍具有抗菌作用，含0.25%至0.75%BAC的4-META/MMA-TBB树脂无明显细胞毒性作用。
