Zargar Nazanin, Naseri Mandana, Gholizadeh Zeynab, Mehrabinia Pegah
Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences. Tehran, Iran.
Dentist, Private Practice, Tehran, Iran.
Iran Endod J. 2022 Summer;17(3):138-145. doi: 10.22037/iej.v17i3.36525.
This study investigated the amount of debris and smear layer remaining followed chemomechanical preparation using three systems: ProTaper Universal, reciprocating SafeSider, and hand K-Flexofiles with scanning electron microscope (SEM).
Sixty-five mandibular molars with mesiobuccal canal curvature (25 to 40) were extracted and divided into one control group (=5), and three experimental groups (=20) according to the preparation method; K-Flexofile, ProTaper Universal and SafeSider instruments. All canals were irrigated with 3 ml of 5.25% sodium hypochlorite solution and 3 mL of 17% EDTA. Subsequently, the canals were irrigated with 5 ml of normal saline. Then the teeth were examined under the scanning electron microscope (SEM). Kruskal-Wallis, Dunn-Q Bonferroni, and Friedman tests were used for statistical analysis of results.
To assess the accumulation of debris, statistically significant differences were observed only in the coronal area among ProTaper Universal, SafeSider, K-Flexofile, and the control group. (=0.029). To evaluate the residual smear layer amount, statistically significant differences were observed only in the coronal and middle areas, following the preparation of the canals using ProTaper Universal, SafeSider, and hand K-Flexofiles and control groups (=0.019).
Based on the present study, we can declare that the canals were utterly cleaned of debris and smear layer in none of the groups. Manual Flexofile and ProTaper Universal groups result in cleaner canal walls than reciprocal SafeSider, in the coronal and middle thirds.
本研究使用扫描电子显微镜（SEM）研究了使用三种系统进行化学机械预备后残留的碎屑和玷污层的量：ProTaper Universal、往复式SafeSider和手动K-Flex锉。
拔除65颗近中颊根管弯曲度为25至40的下颌磨牙，并根据预备方法分为1个对照组（n = 5）和3个试验组（n = 20）；K-Flex锉、ProTaper Universal和SafeSider器械。所有根管均用3 ml 5.25%次氯酸钠溶液和3 ml 17%乙二胺四乙酸（EDTA）冲洗。随后，用5 ml生理盐水冲洗根管。然后在扫描电子显微镜（SEM）下检查牙齿。采用Kruskal-Wallis检验、Dunn-Q Bonferroni检验和Friedman检验对结果进行统计学分析。
为评估碎屑的堆积情况，仅在ProTaper Universal、SafeSider、K-Flex锉和对照组的冠部区域观察到统计学上的显著差异（P = 0.029）。为评估残留玷污层的量，在使用ProTaper Universal、SafeSider和手动K-Flex锉预备根管后，仅在冠部和中部区域观察到与对照组相比有统计学上的显著差异（P = 0.019）。
基于本研究，我们可以宣称，在所有组中，根管均未完全清除碎屑和玷污层。在冠部和中三分之一区域，手动Flex锉组和ProTaper Universal组的根管壁比往复式SafeSider组更清洁。
