Transportation of curved canals instrumented with manual and mechanical techniques

The purpose of this study was to compare the effect of manual and mechanical instrumentation techniques in curved root canals using area of dentine removed and canal axis movement as the end-points. Sixty mandibular molars with curved root canals with angulations ranging from 15 degrees to 45 degrees were selected. The teeth were embedded in transparent resin in a grilon key-like muffle using Bramante's procedure. The roots were horizontally sectioned at three levels and pre and post instrumentation photographs were taken. The sections were reassembled in the muffle and the canals were instrumented with manual and mechanical techniques using Cursor (W&H). Anatomic measurements of transportation were made employing pre and post instrumentation photographs and Macintosh Image 1.45 Software. Statistical analysis of the data was performed by ANOVA. There were no significant differences in canal center axis movement among the groups. Differences in area of dentine removed between manual and mechanical instrumentation techniques were observed at the apical level only.