Comparison of consistency and effectiveness of THREE interproximal reduction methods in CLEAR aligner treatment

Interproximal reduction in orthodontic treatment has a critical importance in the full realization of the planned tooth movements in the treatment of clear aligners and, on this occasion, in determining the quality of the treatment results. Interproximal reduction is a frequently preferred application in orthodontic treatment in order to remove mild and moderate crowding, remove black triangles, eliminate Bolton tooth size discrepancies, shape interproximal contact points and stabilize the dental arch. The aim of this study is to evaluate the consistency of 3 different interproximal reduction methods frequently used in clear aligner (Invisalign®) treatment and to reveal the most effective interproximal stripping method in clear aligner treatments. In addition, it is aimed to compare the pain and anxiety levels of patients who underwent interproximal reduction with these methods. A total of 42 patients who received IPR with hand-operated abrasive strips (ContacEZ) (Group 1; 14 patients, 150 teeth), motor-driven 3/4 oscillating segmental discs (KOMET) (Group 2; 14 patients, 134 teeth) and motor-driven abrasive strips (SWISS) (Group 3; 14 patients, 133 teeth) were included in this prospective study. All teeth to which interproximal reduction was applied were polished with a Sof-Lex disc to remove the rough surfaces that occurred after the reduction process. A metal interproximal gauge was then used to quantify the amount of stripping. The difference between planned and executed IPR was comparatively evaluated on tooth- and quadrant-level. Furthermore, a questionnaire was conducted to evaluate anxiety and pain levels of the patients. It was observed that the overall consistency of the interproximal reduction procedure was significantly lower in Group 1 (p<0.05), and higher in Groups 2 and 3 (p>0.05). It was determined that the mean amount of interproximal reduction executed on the quadrant-level was significantly less in the upper left quadrant in Group 1 (p<0.05) and more in the upper right quadrant in Group 2 (p<0.05) compared to the planned amount. The mean difference between planned and executed interproximal reductions for teeth 11, 21, 32, 33 and 43 in group 1 was significant (p<0.05). According to the questionnaire data, anxiety and pain levels did not differ between the methods, while a negative correlation was observed between age, and anxiety and pain levels. It was determined that patients were similarly comfortable in all 3 methods. It is thought that this study will be beneficial for clinicians applying clear aligner treatment in choosing the interproximal reduction method.