Effect of different access cavity designs on the quality of root canal filling: a micro-computed tomography study

Effect of Different Access Cavity Designs on the Quality of Root Canal Filling: A Micro-Computed Tomography Study Aim: The aim of this study is to evaluate the effect of different access cavity designs on the quality of root canal filling with micro-computed tomography in extracted human mandibular molars. Material and Method: 24 extracted human mandibular molar teeth were randomly divided into three different groups (n=8) as follows: group 1, teeth prepared with traditional endodontic access cavity (GEGK); group 2, teeth prepared with conservative endodontic access cavity (KEGK); group 3, teeth prepared with truss endodontic access cavity (TEGK). First micro-ct scans of the teeth performed before dental procedures. Root canals were cleaned and shaped with Reciproc (VDW, GmbH, Munich, Germany) instruments. The second micro-CT scan of the samples was performed. Groups were divided into two subgroups in terms of root canal filling method (n=4) as Lateral Condensation (LK) and Single Cone (TK) techniques. The access cavities were filled with Cavit G (3M ESPE, Seefeld, Germany) and samples were stored at 37 °C for 24 hours in a 100% humidity. The third screening of the samples was performed. Results: In the TEGK group when the percentage of the sealer volume in the mesial root canals filled with the lateral compaction technique were compared with the mesial root canals filled with the single-cone method the difference was statistically significant (p <0.05). Between the GEGK, KEGK and TEGK groups, when the volumetric changes in root dentin (p˃0.05), the percentages of 0-4 mm filling material (p˃0.05), 0-8 mm filling material (p˃0.05), gutta-percha (p˃0.05) and void (p˃0.05) volumes were compared there were no statistically significant difference. The TEGK was the group in which root canal preparation was completed in the longest time (p <0.05). Teeth with GEGK were the group in which cavity cleaning was completed in the shortest time (p <0.05). Conclusion: Micro-CT analysis revealed no difference between the GEGK, KEGK and TEGK groups when the quality of root canal filling was evaluated. Key Words: Conservative endodontic access cavity, micro-computed tomography, root canal filling, truss endodontic access cavity