Kumaran Ponnuswamy, Sivapriya Elangovan, Indhramohan Jamuna, Gopikrishna Velayutham, Savadamoorthi K Subramani, Pradeepkumar Angambakkam Rajasekharan
Department of Conservative Dentistry and Endodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
J Conserv Dent. 2013 Nov;16(6):522-6. doi: 10.4103/0972-0707.120968.
To evaluate the role of rotary root canal instrumentation followed by obturation with three different techniques and two different materials on the incidence of dentinal defects.
One hundred and sixty mandibular premolars were divided into eight groups (n = 20). Group I was left untreated and served as control. The other seven groups were prepared with profile rotary instruments till #40.06 taper. After preparation, group II was left unfilled, groups III, IV, and V were obturated with Gutta-percha and AH Plus sealer using passive technique, lateral compaction and warm vertical compaction, respectively. Groups VI, VII, and VIII were obturated with Resilon and Realseal sealer using passive technique, lateral compaction, and warm vertical compaction, respectively. Roots were then sectioned at 3, 6, and 9 mm from the apex and inspected under a stereomicroscope (50×) for dentinal defects. Chi-square test was performed to compare the incidence of dentinal defects between the groups (P < 0.05).
The unprepared control group had no dentinal defects. The instrumentation group (group II) and the obturation group (groups III-VIII) showed significantly more defects than the uninstrumented control group (group I) (P < 0.001). There was no significant difference between the root canal obturating techniques (group III-VIII) when compared with the instrumentation group (group II). On inter group comparison among the obturation groups the number of defects after lateral compaction with Gutta-percha (group IV) was significantly larger than passive Gutta-percha obturation (group III) (P < 0.05).
The results suggest that root canal instrumentation significantly influenced the incidence of dentinal defects or fracture. Dentinal defects were more significantly attributed to the role of root canal instrumentation rather than the type of obturation technique or material. Lateral compaction with Gutta-percha significantly produces more defects than passive Gutta-percha obturation.
评估采用三种不同技术和两种不同材料进行根管预备后充填对牙本质缺陷发生率的影响。
160颗下颌前磨牙分为八组（n = 20）。第一组不做处理作为对照组。其他七组用Profile旋转器械预备至#40.06锥度。预备后，第二组不充填，第三、四、五组分别采用被动技术、侧向加压和热垂直加压技术用牙胶尖和AH Plus封闭剂充填。第六、七、八组分别采用被动技术、侧向加压和热垂直加压技术用Resilon和Realseal封闭剂充填。然后将牙根从根尖处3、6和9 mm处截断，在体视显微镜（50倍）下检查牙本质缺陷情况。采用卡方检验比较各组间牙本质缺陷的发生率（P < 0.05）。
未预备的对照组无牙本质缺陷。预备组（第二组）和充填组（第三至八组）的缺陷明显多于未预备的对照组（第一组）（P < 0.001）。与预备组（第二组）相比，根管充填技术（第三至八组）之间无显著差异。在充填组之间进行组间比较时，用牙胶尖侧向加压充填后的缺陷数（第四组）明显多于被动牙胶尖充填（第三组）（P < 0.05）。
结果表明根管预备显著影响牙本质缺陷或折断的发生率。牙本质缺陷更主要归因于根管预备的作用，而非充填技术或材料的类型。与被动牙胶尖充填相比，牙胶尖侧向加压明显产生更多的缺陷。
