Efficacy of root end cavity preparation techniques on gap formation of different mineral trioxide aggregate based root end filling materials: micro-computed tomography study.

Background: Endodontic surgery is conducted when previous endodontic treatment has not succeeded, requiring a high level of technical precision. The success of these procedures is crucial for tooth prognosis. Sealing the root end cavity is one of the most important factors for the success of the procedure. The main factors affecting the sealing of the root end cavity are the technique of cavity preparation and the selection of root end filling material. The aim of this study was to compare the gap and void formations of two different MTA-based filling materials during different root end cavity preparation techniques.

Methods: Forty-eight extracted human maxillary incisor teeth were selected. The root canals were prepared with ProTaper Next files to the #X3 file and obturated using single-cone technique. The teeth were randomly divided into two groups ( = 24 each) based on root end cavity preparation techniques (Er: YAG laser and ultrasonic). All root end cavities were prepared to 3 mm depth. Subsequently, they were divided into 2 subgroups ( = 12 each) based on the type of MTA-based root end filling material (MTA Angelus and MTA Flow). The samples were scanned with micro-CT. The volume of filling, total space, void, and gap in root end cavities were calculated. These volumes were saved as percentages. The Mann-Whitney U test was used for comparison. Significance level was taken as  < 0.05.

Results: In terms of filling, total space, void, and gap volume percentage, there was no significant difference between the laser and ultrasonic preparation techniques ( > 0.05). MTA Flow demonstrated significantly lower percentages in terms of filling, total space, and void volume than MTA-Angelus ( < 0.05). Root end preparation techniques and root end filling materials did not show a significant difference in terms of gap area percentage ( > 0.05).

Conclusion: The recently developed MTA Flow with fluid consistency revealed promising and comparable findings with conventional MTA in terms of production of void formation and filling quality in apical surgery.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12903-025-06503-3.