Biomechanical preparation in primary molars using manual and three NiTi instruments: a cone-beam-computed tomographic...

Area of Science:

• Endodontics
• Pediatric Dentistry
• Dental Materials Science

Background:

• Deciduous root canal preparation requires specialized techniques to preserve thin dentinal walls.
• Evaluating the shaping ability of different rotary and hand instruments is crucial for effective endodontic treatment in primary teeth.

Purpose of the Study:

• To compare the shaping ability, dentine removal, canal transportation, untouched canal surface area, and preparation time of ProTaper Universal (PTU), ProTaper Next (PTN), self-adjusting file (SAF), and stainless steel hand K files in deciduous root canals.
• To assess the suitability of these systems for primary root canal preparation using 3D reconstruction.

Main Methods:

• Primary molars were shaped and cleaned using PTU, PTN, SAF, and hand K files.
• Cone-beam computed tomography (CBCT) and specialized software were used for 3D reconstruction and analysis of pre- and post-operative scans.
• Evaluation parameters included shaping properties, transportation, dentine removal, untouched canal surface area, and preparation time.

Main Results:

• No instrument failures or canal stripping occurred.
• SAF resulted in significantly less dentine removal compared to other systems.
• Hand K files left a larger untouched canal surface area; SAF demonstrated the least.
• Rotary files were faster than hand files, with PTN being the fastest rotary system.
• Canal transportation was similar across all groups in the cervical and apical thirds.

Conclusions:

• SAF offers a more conservative dentine removal, preserving the integrity of thin-walled primary root canals.
• SAF provides better contact with primary canal walls, indicated by less untouched surface area.
• Rotary systems, especially PTN, significantly reduce preparation time, a key advantage in pediatric endodontics.