Debridement ability of the WaveOne Gold and TruNatomy systems in the apical third of root canals: ex vivo assessment.

Cleaning and shaping the root canal system are essential steps for performing successful endodontic therapy, and are challenging procedures in the apical region. This study aimed to conduct an ex vivo assessment of the debridement ability of the WaveOne Gold (Medium 35/.06) and TruNatomy (Medium 36/.03) systems in the apical third of round root canals of mandibular premolars. Forty-eight teeth, extracted for orthodontic or periodontal reasons, were divided into three groups (n=16), as follows: Group C, control (without instrumentation or irrigation); Group WOG, instrumentation with WaveOne Gold; Group TN, instrumentation with TruNatomy. A total of 40 mL of 2.5% sodium hypochlorite and 5 mL of 17% ethylenediamine tetraacetic acid were used per root canal in all the groups. Ten 0.5-μm serial cross-sections per specimen were obtained every 0.2 mm from a 2-mm segment of the apical region, extending from 1 to 3 mm short of the root apex. The sections were stained with hematoxylin-eosin and analyzed under a digital microscope (100x). The percentages of unprepared walls and remaining debris were quantified using ImageJ software. Generalized linear models were used to analyze the results (α=5%). Groups WOG and TN had significantly lower percentages of unprepared walls and remaining debris than Group C (p<0.05). There was no significant difference between groups WOG and TN for either of the variables studied (p>0.05). Instrumentation with the WaveOne Gold Medium and TruNatomy Medium instruments was associated with equivalent percentages of unprepared walls and remaining debris in the apical third of round canals of mandibular premolars.