An in vitro Comparative Assessment of Manual Hand File, Rotary ProTaper Ni-Ti, Erbium: Yttrium–Aluminum–Garnet Laser, Canal Brush, and Ultrasound Methods for Smear Layer Removal

BACKGROUND: Selection of instruments is important to prevent any complications such as ledge formation and instrument breakage. The main drawback linked with instrumentation is smear layer formation. OBJECTIVES: This study was done for comparison of manual hand file, rotary ProTaper Ni-Ti, erbium:yttrium–aluminum–garnet (Er:YAG) laser, ultrasound, and CanalBrush (CB) methods for smear layer removal. METHODOLOGY: Sixty freshly extracted single-rooted mandibular first premolars extracted for orthodontic treatment purpose were selected and classified into six groups. Group I was negative control in which no final agitation of irrigant was performed. In Group II, solution activation was performed with ProTaper Universal System, in Group III, solution activation was done with canal brush, in Group IV, ultrasound activation was done, in Group V, solution agitation was performed with Er:YAG laser agitation, and in Group VI, canal preparation with hand files was performed. Smear layer score was evaluated after canal preparation with each method. RESULTS: Score 1 was seen in 3 (30%) in Group IV and 6 (60%) in Group V, score 2 was seen in 3 (30%) in Group I, 8 (80%) in Group II, 7 (70%) in Group III, 5 (50%) in Group IV, 3 (30%) in Group V, and 4 (40%) in Group VI. Score 3 was observed in 7 (70%) in Group I, 2 (20%) in Group II, 3 (70%) in Group III, 2 (20%) in Group IV, 1 (10%) in Group V, and 6 (60%) in Group VI. A statistically significant difference was found in smear layer removal score in all groups (P < 0.05) except between Group I versus VI (P > 0.05). CONCLUSION: Complete removal of the smear layer was not observed in any of the methods used in the study; however, Er: YAG laser was found to be better as compared to other methods.