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

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.