Estrela Cyntia Rde A, de Oliveira Jefferson D, Tirintan Fabio C, Guapo-Pavarina Rodrigo, Pereira Thiago M, Bandeca Matheus C, Tonetto Mateus R, Lima Suellen L, Pedro Fábio Lm, Borges Álvaro H
Department of Post-Graduate Program in Integrated Dental Science, University of Cuiaba, Cuiaba, Mato Grosso Brazil.
Department of Post-Graduate Program in Dentistry, CEUMA University, Sao Luis, Maranhao, Brazil.
J Contemp Dent Pract. 2018 Aug 1;19(8):904-909.
To evaluate the antibacterial effect of diode laser, associated or not with 2.5% sodium hypochlorite (NaOCl), against Enterococcus faecalis.
Eighty dentin blocks were obtained from single-rooted human teeth and sterilized. Seventy were inoculated with 0.01 mL of fresh bacterial inoculum (within 24 hours of preparation from pure culture) standardized to 1 McFarland turbidity. Contaminated blocks were incubated for 7 days at 37°C in humid conditions. Ten uncontaminated samples were incubated at 37°C during the contamination period to serve as a negative control group, while 10 of the infected specimens served as a positive control group. The dentin blocks were randomly divided into eight experimental groups (n = 10 each) according to the method of decontamination: 2.5% NaOCl alone; 2.5% NaOCl + photodynamic therapy (PDT) with methylene blue/660 nm laser at 18 J for 180 seconds; 2.5% NaOCl + PDT with methylene blue/660 nm laser at 8 J for 80 seconds; methylene blue alone; PDT alone with methylene blue/660 nm laser at 18 J for 180 seconds; PDT alone with methylene blue/660 nm laser at 8 J laser for 80 seconds; positive control group; and negative control group. Microbial growth was evaluated by culture medium turbidity and microbial concentration was analyzed by UV spectrophotometry (adjusted to read at wavelength l = 600 nM).
Root canals treated with laser alone at 18 J for 180 seconds had higher bacterial contamination compared with groups in which NaOCl was used, with or without laser irradiation at 18 J for 180 seconds (p < 0.05).
Photodynamic therapy with a 660 nm diode laser effectively reduced E. faecalis contamination. These findings can guide development of further studies in search of better alternatives for endodontic treatment.
Chemical and mechanical root canal preparation plays an essential role in reducing microbial burden. However, microorganisms present in areas not mechanically reachable by endodontic instruments. As an alternative to fix this problem, the laser can be applied.
评估二极管激光联合或不联合2.5%次氯酸钠（NaOCl）对粪肠球菌的抗菌效果。
从单根人牙获取80个牙本质块并进行灭菌处理。70个牙本质块接种0.01 mL新鲜细菌接种物（纯培养物制备后24小时内），标准化至1麦氏浊度。污染的牙本质块在37°C潮湿条件下孵育7天。10个未污染的样本在污染期于37°C孵育作为阴性对照组，10个感染样本作为阳性对照组。根据去污方法将牙本质块随机分为8个实验组（每组n = 10）：单独使用2.5% NaOCl；2.5% NaOCl + 用亚甲蓝/660 nm激光进行光动力疗法（PDT），能量为18 J，持续180秒；2.5% NaOCl + 用亚甲蓝/660 nm激光进行PDT，能量为8 J，持续80秒；单独使用亚甲蓝；单独用亚甲蓝/660 nm激光进行PDT，能量为18 J，持续180秒；单独用亚甲蓝/660 nm激光进行PDT，能量为8 J，持续80秒；阳性对照组；阴性对照组。通过培养基浊度评估微生物生长情况，并用紫外分光光度法（调整至波长λ = 600 nM读取）分析微生物浓度。
与使用NaOCl的组相比，单独用18 J激光照射180秒处理的根管细菌污染程度更高，无论是否联合18 J激光照射180秒（p < 0.05）。
660 nm二极管激光光动力疗法有效降低了粪肠球菌污染。这些发现可为进一步研究寻找更好的牙髓治疗替代方法提供指导。
化学和机械根管预备在减轻微生物负荷方面起着重要作用。然而，牙髓器械无法机械到达的区域存在微生物。作为解决这一问题的替代方法，可应用激光。
