Farklı kinematiklerin kök kanal preparasyonu sırasında dentin çatlağı oluşması üzerine etkilerinin karşılaştırmalı olarak incelenmesi

GÖZDE UYSALCAN

Farklı kinematiklerin kök kanal preparasyonu sırasında dentin çatlağı oluşması üzerine etkilerinin karşılaştırmalı olarak incelenmesi

Thesis Type: Dental Specialty

Institution Of The Thesis: Sivas Cumhuriyet University, Diş Hekimliği Fakültesi, Klinik Bilimler Bölümü, Turkey

Approval Date: 2021

Thesis Language: Turkish

Student: GÖZDE UYSALCAN

Supervisor: Demet Altunbaş

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In our study, the effects of the rotary file system used with different kinematics on the formation of dentin cracks during the shaping of the mesial root canals of the mandibular first molars were examined. In the present study, the mesial roots of 100 newly extracted mandibular first molars with two root canals and two apical foramina were used. The crowns and distal roots of the teeth were removed under water cooling with a diamond bur. Teeth were randomly divided into 10 groups, and no preparation was applied to the teeth in the control group (Group 1). ProGlider files were used to form a glide path in the experimental groups, and ProTaper Next files were used with different kinematics for shaping. In the first experimental group (Group 2), glide path formation and shaping processes were performed with continuous rotation movement using the Tri Auto ZX2 endodontic motor. Glide path formation and shaping processes were completed using an E-connect S endodontic motor with 150° CW- 30° CCW reciprocation movement in Group 3, an Elements™ motor with adaptive movement in Group 4, in the 180° mode of the Optimum Torque Reverse (OTR) function of a Tri Auto ZX2 endodontic motor in Group 5, in the OTR 240° mode of a Tri Auto ZX2 endodontic motor in Group 6, with the Optimum Glide Path (OGP) 240° and OTR 240° functions using a Tri Auto ZX2 endodontic motor in Group 7, with the OGP 90° and OTR 240° functions in Group 8, with the OGP 240° and OTR 180° functions in Group 9, and finally with the OGP 90° and OTR 180° functions in Group 10. After the root canal shaping, the samples were cut in the horizontal direction using a low-speed saw under water cooling, at a distance of 3, 6, and 9 mm from the apex. To observe cracks more clearly, each section was dyed with a caries-detector dye, and photographs were obtained from the sections under a stereomicroscope at 12.5x magnification. The sections were examined for the presence of dentin cracks, and two different evaluations were made. In the first evaluation, the samples were examined in terms of the presence/absence of cracks, and in the second evaluation, in terms of the absence of cracks, the presence of complete cracks and other defects (incomplete cracks and craze line). The data obtained were statistically analyzed using the chi-square test. There was no dentin crack formation in the control group. In our study, the most defects were determined in the groups in which the reciprocal and continuous rotation movements were used, but no significant difference was found between these two groups. The most complete cracks were found in reciprocal and continuous rotation kinematics, while the most incomplete cracks and craze lines were found in the OGP 240° OTR 180° group. As a result of the preparation made with rotary files, when the sections were evaluated by ignoring the groups, the most dentin defects were observed in the coronal third, although it was not statistically significant. Although not statistically significant, the most complete cracks were observed in the coronal section, while the most incomplete cracks and craze lines were observed in the middle third. Considering the limitations of in-vitro studies, crack formation was observed in root dentin in all groups in which different rotary system kinematics used in our study. Continuous rotation and reciprocation movements caused more defects in dentin.