Saleh A A, Ettman W M
Conservative Dentistry Department, Faculty of Dentistry, Tanta University, Egypt.
J Dent. 1999 Jan;27(1):43-6. doi: 10.1016/s0300-5712(98)00018-9.
This study was undertaken to evaluate the effect of several endodontic irrigation solutions on the microhardness of root canal dentine.
Eighteen freshly extracted maxillary incisors were used in this experiment. The crowns of teeth were sectioned at the cemento-enamel junction. The root canals were instrumented to an apical size #50 file, and irrigated with saline solution. The prepared roots were divided equally into two groups each of nine roots. Each root was sectioned transversely into cervical, middle and apical segments. The three sections of each root were separately mounted in a metal chuck with acrylic resin. The coronal dentine surfaces of the root segments were polished. The microhardness of the dentine was measured for the purposes of control data at 500 microns and 1 mm from the pulpo-dentinal interface. The canal portions in the root segments included in the first group were irrigated with 3% H2O2 and 5% NaOCl solutions used alternatively, while 17% EDTA solution was the irrigation used in the second group. One millilitre of each solution/segment was applied for 60 s exposure time. After irrigation, dentine microhardness was re-assessed and compared with the control values obtained before the irrigation treatment. Data were statistically analysed using ANOVA and Scheffe's test.
The results showed that, irrigation with either H2O2/NaOCl or EDTA decreased the microhardness value of root dentine. Irrigation with EDTA gave more reduction of dentine hardness compared to H2O2/NaOCl irrigation. The reduction of KHN of dentine following the irrigation treatment was statistically significant (p < 0.05) at both levels of hardness measurement.
Both H2O2/NaOCl and EDTA irrigating solutions significantly reduced the microhardness of root canal dentine.
本研究旨在评估几种根管冲洗液对根管牙本质显微硬度的影响。
本实验使用了18颗新鲜拔除的上颌切牙。将牙齿的冠部在牙骨质 - 釉质界处截断。根管预备至根尖尺寸#50锉，并使用生理盐水冲洗。将预备好的牙根平均分为两组，每组9根。每根牙根横向分为颈部、中部和根尖段。每根牙根的三个切片分别用丙烯酸树脂固定在金属夹头中。对牙根段的冠部牙本质表面进行抛光。为了获得对照数据，在距牙髓 - 牙本质界面500微米和1毫米处测量牙本质的显微硬度。第一组牙根段中的根管部分交替使用3%过氧化氢和5%次氯酸钠溶液冲洗，而第二组使用17%乙二胺四乙酸溶液冲洗。每段使用1毫升每种溶液，暴露时间为60秒。冲洗后，重新评估牙本质显微硬度，并与冲洗治疗前获得的对照值进行比较。数据采用方差分析和谢费检验进行统计学分析。
结果表明，用过氧化氢/次氯酸钠或乙二胺四乙酸冲洗均会降低牙根牙本质的显微硬度值。与过氧化氢/次氯酸钠冲洗相比，用乙二胺四乙酸冲洗使牙本质硬度降低得更多。在两个硬度测量水平上，冲洗治疗后牙本质努氏硬度值的降低均具有统计学意义（p < 0.05）。
过氧化氢/次氯酸钠和乙二胺四乙酸冲洗液均显著降低了根管牙本质的显微硬度。
