Stereomicroscopic evaluation of dentinal microcracks after instrumentation with rotary and reciprocating file systems: An in vitro observational study

TL;DR

This study found that different root canal file systems create similar dentinal microcracks, but with variations in location and type.

Contribution

The study highlights that file design and material, not just motion, influence microcrack formation during root canal treatment.

Findings

All instrumentation methods caused dentinal microcracks without significant overall differences.

Reciprocating files caused fewer apical cracks but more coronal fractures.

Rotary files showed better performance at the coronal level but more apical defects.

Abstract

Root canal instrumentation was associated with dentinal microcrack formation in all groups, with no statistically significant
differences observed. The single-file reciprocating system showed fewer apical microcracks, while the rotary system demonstrated more
apical defects but performed better at the coronal level. Complete fractures were relatively uncommon but occurred more frequently with
reciprocating files at the coronal level. These variations suggest that factors beyond instrumentation kinematics, including file design
and metallurgy, contribute to microcrack development. Further studies with advanced imaging are needed to validate these findings and
assess their clinical implications.