Purpose: The aim is to determine the effect of different lengths of post-space preparation on the incidence of root crack formation using micro-computed tomography (micro-CT).
Methods: Forty-two single and straight-rooted human mandibular premolar teeth were used. Teeth were randomly divided into two groups (n = 21). All teeth were scanned using micro-CT before and after the canal shaping, followed by filling with gutta-percha and a resin-based root canal sealer. Different lengths of post-space (1/2 [Group 1] and 2/3 [Group 2] of the canal length) were prepared for the teeth in Group 1 and Group 2. Teeth were again scanned with micro-CT.
Results: After the post-space preparation, no new microcrack formation was observed. As a result of the propagation of microcracks detected in the first scan, completed fractures were detected in 3 teeth in Group 1 and 2 teeth in Group 2.
Conclusion: It can be concluded that the different lengths of post-space preparation did not affect the incidence of microcrack formation in root dentin.