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.

AIM: The study was conducted to assess the changes in bone density before and after performing accelerated orthodontic maxillary canine retraction by microosteoperforations (MOPs). MATERIALS AND METHODS: Forty patients (120 cone-beam computed tomography [CBCT] images) within the age group of 15 to 25 years undergoing fixed orthodontic treatment with bilateral maxillary first premolar extraction were enrolled in this study. The right and left sides of the maxillary jaw in the same patients were selected as experimental and control sites. To accelerate the tooth movement, MOPs were performed distal to the canine root in the extraction space under local anesthesia with a miniscrew. Thereafter, the maxillary canine retraction was initiated using a NiTi closed coil spring. The CBCT images were taken and evaluated at the following time intervals: 1 week before MOPs(T0);1 week after MOPs(T1);3 weeks after MOPs(T2). RESULTS: A statistically significant reduction in bone density was observed at the center of resistance of canine on the experimental site (after MOPs) at 1 week and 3 weeks (T0-T1 = 0.000,0.115; T1-T2 = 0.0025,0.0117), whereas a statistically non-significant difference was found 1 week before and 3 weeks later in the control group. CONCLUSION: Accelerated orthodontics by MOPscan result in a substantial reduction in bone density during canine retraction, leading to an increase in the tooth movement rate, hence lowering the overall orthodontic treatment time.