Abstract:
Ensuring an effective endodontic therapy, requires free dentinal walls from any smear layer. Smear layers formed during canal debridement, any remanent of this layer may reduce the overall efficacy of therapy. Aims: This study aims to evaluate the clearance of smear layer by using three different systems with different tapers, namely, Materials and Methods: Protaper Next (PTN) :(X1=17/04& X2=25/06) (Dentsply Maillefer, Ballaigues, Switzerland),Hyflex CM (HCM)(20/04&25/06) (Coltene-Whaledent AG, Allstetten, Switzerland) , Aurum Blue™ (Meta Biomed, Korea) (20/04&25/06%). Ninety extracted mandibular premolars with a single canal were chosen for each taper. The teeth were randomly grouped evenly to three groups of 15 specimens. Analysing samples was runs out by using a Scanning Electron Microscope (SEM) at a magnification of 2000x at the centre of the three thirds: coronal, middle, and apical areas. Statistical analysis: of the data was conducted using the Kruskal-Wallis and Mann-Whitney tests. Results:. The study revealed a lower mean of the smear layer across all groups in the coronal region. No significant differences were found among the coronal thirds of the various groups. Despite some minor differences, all instruments removed smear layer produced during instrumentation. The significant difference was found between the coronal third and the middle as well as the apical thirds among the tested groups. Conclusion: Root canal preparation with Aurum blue and ProTaper Next instruments resulted in better canal cleanliness in the apical and middle thirds compared with HyFlex CM instruments.