Introduction

Inappropriate mechanical treatment of root canals can result in unfavorable outcome of root canal treatment.

Objectives

The aim of this study was to compare rotational and reciprocal instrumentation techniques by measuring the degree of dentin removal and preserving the original root canal anatomy.

Material and methods

Twenty permanent mandibular molars extracted due to periodontal reasons were mechanically cleansed and randomly divided into two groups of ten teeth each. First group was instrumented with a rotational instrumentation technique, F360 system (Komet Dental, Lemgo, Germany), and second group was instrumented with Endo-Eze Genius reciprocating system (Ultradent Products, Utah, USA) according to manufacturers’ protocols. Measurements of canal diameter and canal curvature straightening were obtained using standardized X-ray images taken before and after instrumentation at four levels of the root canal by utilizing computer software Adobe Photoshop CC 2020 (Adobe Systems Incorporated, San Jose, California, USA).

Results

Rotational technique resulted in a statistically significant increase in the root canal diameter after instrumentation at all levels (all p < 0.05). The reciprocating technique significantly increased the canal diameter at all levels (all p < 0.05), except for the second level (p = 0.063). Regarding the maintenance of root canal anatomy, both techniques led to canal alignment. When compared to reciprocal technique, rotational instruments caused significantly greater straightening of the curve at the third level (p = 0.017).

Conclusions

Both instrumentation systems have similar degree of dentine removal; however, rotational technique is more prone to cause root canal straightening.