Evaluation of the Consistency of Two Interproximal Reduction Methods in Clear Aligner Therapy: A Preliminary Study.

Objective: To compare the consistency of two interproximal reduction (IPR) methods in terms of the amount of planned and performed IPR during clear aligner therapy (CAT). Methods: Thirty-four patients who received IPR using hand-operated abrasive strips (Group 1, 20 patients, 162 teeth) and motor-driven 3/4 oscillating segmental disks (Group 2, 14 patients, 134 teeth) during CAT were included in this preliminary study. The consistency between the planned and performed IPR amounts was evaluated within and between groups for teeth and quadrants. Results: In Group 1, the amount of IPR performed on teeth numbers 22 and 43 and in the upper left quadrant was found to be statistically less than that of planned. On the other hand, the amount of performed IPR was statistically higher on tooth number 44 and in the upper right quadrant, whereas it was statistically less on tooth number 33 when compared with the planned amount in Group 2. The inconsistency between the planned and performed IPR amounts were statistically significant only in Group 1 and for teeth numbers 11, 21, 32, 33, and 43. No significant difference was found when the same parameter was compared between the groups. Conclusion: The consistency of IPR was found to be better with the motor-driven oscillating disk system than with the hand-operated IPR strip system.

Comparison of the accuracy of three interproximal reduction methods used in clear aligner treatment.

OBJECTIVES: To comparatively assess 3 interproximal reduction (IPR) methods used in clear aligner treatment with regard to accuracy, and patient perception of discomfort and anxiety. MATERIALS AND METHODS: A total of 42 patients, treated with the Invisalign® system, were included in this prospective trial and received one of the following IPR methods: hand-operated abrasive strips (group 1; 14 patients, 150 teeth), motor-driven 3/4 oscillating segmental discs (group 2; 14 patients, 134 teeth), or motor-driven abrasive strips (group 3; 14 patients, 133 teeth). Accuracy was evaluated using the difference between planned and executed IPR. Anxiety and discomfort levels experienced by the patients were evaluated using a questionnaire of 17 questions. RESULTS: The accuracy of IPR was high in groups 2 and 3; however, it was low in group 1 with the executed IPR significantly less than the planned amount. On quadrant-level, executed IPR was significantly less in the upper left quadrant in group 1, and significantly more in the upper right quadrant in group 2. The difference between planned IPR and executed IPR was significant for teeth 11, 21, 32, 33, and 43 in group 1, indicating deficiency. The average difference between planned IPR and executed IPR was 0.08 mm for group 1, 0.09 mm for group 2, and 0.1 mm for group 3. Anxiety and discomfort levels did not differ between the methods, but a negative correlation was observed between age and discomfort and anxiety levels. CONCLUSIONS: The overall accuracy of the 2 motor-driven IPR methods was found to be better than the hand-operated system. Maxillary central incisors and mandibular canines were more prone to IPR deficiency when hand-operated abrasive strips were utilized. Patients were similarly comfortable with all 3 methods, and discomfort and anxiety levels decreased with age. CLINICAL RELEVANCE: Motor-driven methods have proven to be more effective when compared to the hand-operated ones by means of precision, speed, and patient comfort. If the clinician favors a hand-operated method, it may be advised to perform slightly more IPR especially on mandibular canines and maxillary central incisors.