Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.
Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Int Endod J. 2020 Dec;53(12):1705-1714. doi: 10.1111/iej.13342. Epub 2020 Aug 27.
To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates.
A dual-species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96 h in plug inserts with anatomical features resembling an isthmus or lateral canal-like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1 mL s . The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15 min. A three-way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions.
For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (P = 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (P = 0.018 and P = 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1 mL s flow rate and one or two refreshments removed significant more biofilm (P = 0.04, 0.034 and 0.003, <0.001, respectively).
In this model, refreshment did not improve biofilm removal from simulated lateral root canal spaces. NaOCl removed more biofilm from the lateral canal- and isthmus-like structure. A higher flow rate removed significantly more biofilm from the isthmus-like structure. There was always remaining biofilm left after the irrigation procedures.
评估在模拟侧根管间隙中使用两种不同流速的 2%次氯酸钠（NaOCl）冲洗液的更新和暴露时间对生物膜清除效果。
通过恒深膜发酵器（CDFF）在具有类似峡部或侧管样结构的插塞中形成双物种生物膜，培养 96 小时。将插件放置在根管模型中，面向主通道。使用 2%次氯酸钠和去离子水（对照组）作为冲洗液。两种物质均以 0.05 和 0.1 mL/s 的流速应用。样品分为三组，在 15 分钟的总暴露时间内进行零、一次或两次冲洗。采用三因素方差分析（anova）研究独立变量之间的相互作用以及连续冲洗液对生物膜清除率的影响。采用 Tukey 事后检验评估在不存在统计学显著相互作用的情况下，每个独立变量对生物膜清除率的影响。
对于侧管，无论冲洗次数和暴露时间如何，NaOCl 去除的生物膜明显更多（P=0.005）。在同一生物膜中测量的连续冲洗液之间，生物膜清除率没有显著差异。对于峡部，无论冲洗次数和暴露时间如何，NaOCl 去除的生物膜明显更多；当分析暴露时间时，NaOCl 和高流速去除的生物膜明显更多（P=0.018 和 P=0.029）。评估连续冲洗液对同一生物膜的影响时，2%次氯酸钠、0.1 mL/s 流速和一次或两次冲洗去除的生物膜明显更多（P=0.04、0.034 和 0.003，均<0.001）。
在该模型中，冲洗并不能改善模拟侧根管间隙的生物膜清除效果。NaOCl 从侧管样结构中去除更多的生物膜。更高的流速从峡部样结构中去除更多的生物膜。冲洗后总会残留生物膜。
