Einfluss verschiedener Präparationstechniken bei geraden und gekrümmten Wurzelkanälen auf die Entstehung von Mikrorissen im Dentin Eine Mikro-Computertomografie-Studie
Incidence of microcracks after preparation of straight and curved root canals with three different NiTi instrumentation techniques assessed by micro-CT
von Juliane Krämer
Datum der mündl. Prüfung:2022-01-27
Erschienen:2022-01-14
Betreuer:Prof. Dr. Tina Rödig
Gutachter:Prof. Dr. Tina Rödig
Gutachter:PD Dr. Wolfram Hahn
Dateien
Name:eDiss.pdf
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Format:PDF
Zusammenfassung
Englisch
This study aimed to evaluate the cause-effect relationship between canal preparation with three different NiTi instrumentation techniques and dentinal microcracks in straight and curved root canals using micro-computed tomography (micro-CT) analysis. After radiographic determination of angle and radius of root canal curvature, 33 roots from mandibular premolars and 33 maxillary molars (n = 66) were assigned to three groups with the same mean canal curvature and radius. All roots were dried for 2 hours before the pre- and postoperative scans. After preoperative micro-CT scans and simulation of a periodontal ligament, root canals were prepared with either Reciproc, OneShape or ProTaper NEXT to size 25. This was followed by the postoperative micro-CT scan with the same parameters. Postoperative cross-sectional images were screened by two calibrated observers. 40290 cross-sections of straight root canals and 34973 of curved root canals were analyzed (n = 75263). The presence of dentinal microcracks cracks on postoperative images was compared with the preoperative micro-CT scans. Overall, dentinal microcracks were identified in 2.79 % (n = 2236) of the micro-CT images. Cracks were visible in all three groups of straight and curved root canals. All dentinal microcracks in postoperative cross-sectional images were already present in preoperative images. In addition, the kinematic and the number of NiTi instruments did not influence the development of new dentinal microcracks. No causal relationship between canal curvature and the development of dentinal microcracks because of root canal intrumentation with Reciproc, OneShape and ProTaper NEXT was observed.
Keywords: dentinal microcracks, micro-CT, curvature, Reciproc, OneShape, ProTaper NEXT