Palazzi Flavio, Sadile Gennaro, Mohammadi Zahed, Del Fabbro Massimo, Riccitiello Francesco
Department of Neuroscience, Reproductive and Odontostomatological Sciences, Federico II, University of Naples, Naples, Italy -
Minerva Stomatol. 2016 Dec;65(6):368-377. Epub 2016 Jul 14.
The purpose of the present study was to assess the effect of concentration and temperature of sodium hypochlorite (NaOCl) with added surfactants and time of exposure on its penetration into human dentine.
Seventy-five extracted permanent maxillary anterior teeth with single canals were shaped by using ProTaper SX hand-operated instruments. Then teeth were sectioned perpendicular to their long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred fifty stained blocks were further split into halves and treated by six NaOCl-based solutions from different brands: three solutions added with surfactants (Hypoclean, H6, Chlor-Xtra) and their regular counterparts (5.25%, 6%, <%6NaOCl). The dentine blocks were exposed to the solutions for 2, 5, and 20 minutes at 20° C, 37° C, and 45° C, respectively. The depth of penetration of NaOCl was determined by bleaching of the stain and measured by light microscopy at magnifications of 20x and 40x. Statistical analysis was made by using two way ANOVA and by comparing groups two by two with t-test.
The shortest penetration (130.80±1.92μm) was measured after incubation with 5.25%NaOCl for 2 minutes at 20° C; the highest penetration (375.40±3.05μm) was obtained with Chlor-Xtra for 20 minutes at 45° C. Temperature and exposure time had a significant direct relationship with penetration of sodium hypochlorites with lowered surface tension into dentinal tubules.
The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules.
本研究的目的是评估添加表面活性剂的次氯酸钠（NaOCl）的浓度、温度以及暴露时间对其渗入人牙本质的影响。
使用ProTaper SX手动器械对75颗拔除的单根管上颌恒前牙进行预备。然后将牙齿垂直于其长轴进行切片。去除所有牙齿的冠部和根尖三分之一。将剩余的牙根加工成4毫米长的块状，并在结晶紫中染色过夜。将150个染色的块状物进一步切成两半，并用来自不同品牌的六种基于NaOCl的溶液进行处理：三种添加了表面活性剂的溶液（Hypoclean、H6、Chlor-Xtra）及其常规对应溶液（5.25%、6%、<%6NaOCl）。牙本质块分别在20°C、37°C和45°C下暴露于溶液中2、5和20分钟。通过污渍的漂白来确定NaOCl的渗透深度，并在20倍和40倍放大倍数下通过光学显微镜进行测量。使用双向方差分析并通过t检验两两比较组间差异进行统计分析。
在20°C下用5.25%NaOCl孵育2分钟后测得最短渗透深度（130.80±1.92μm）；在45°C下用Chlor-Xtra处理20分钟获得最高渗透深度（375.40±3.05μm）。温度和暴露时间与表面张力降低的次氯酸钠渗入牙本质小管的深度有显著的直接关系。
次氯酸钠的暴露时间、温度以及表面活性剂的添加可能会影响冲洗液渗入牙本质小管的深度。
