Evaluation of dentinal crack formation during post space preparation using different fiber post systems with micro-computed tomography

Completed and advanced cracks were observed in all groups, while no newly formed cracks were detected in the RelyX-1/2 group. The type of post drill and the preparation length are crucial factors in preventing the development of root dentinal cracks. Preparing 1/2 of the canal length may be a safer preparation length, and the RelyX drill may pose less risk of inducing root dentinal cracks.