In Vitro evaluation of the effect of crowding on the aplication success in interproximal enamel reduction carried out with different methods through 3D scanners

OBJECTIVE: It was aimed to determine the effect of crowding on the success of interproximal enamel reduction (IPR) using a three-dimensional (3D) scanner. MATERIALS AND METHODS: In this study, 264 thermoplastic mandibular incisors (Frasaco GmbH, Tettnang, Germany) were divided into twenty-four subgroups according to the abrasive material properties, to be abraded at two different abrasion amounts (0.3 mm and 0.5 mm). Single and double-sided diamond discs, manual abrasives, and motor-assisted abrasives have been used in abrasion applications. Thermoplastic teeth were scanned and recorded using a 3D scanner before and after IPR. The recorded 3D models were superimposed on the Geomagic Control X. RESULTS: The amount of achieving the planned IPR does not show a statistically significant difference depending on the material (p>0.05). The amount of reaching the planned IPR according to the placement shows a statistically significant difference, which is higher in crowded teeth (p=0.001; p<0.01). No statistically significant relationship was found between the amount of error and the amount of IPR (p>0.05). Error amounts according to one-sided/double-sided were found to be statistically significantly higher in double-sided appliances (p=0.001; p<0.01). According to the material, it was found significant that the amount of buccal overflow of manual abrasive material was higher than that of diamond disc and motor-assisted abrasive materials. There was no statistically significant difference between other materials (p>0.01). In crowded teeth; depending on the sides, the amount of buccal overflow was found to be higher in one-sided materials (p=0.001; p<0.01). Motor-assisted abrasive material for crowded teeth; depending on the direction, the amount of buccal overflow was found to be higher in one-sided materials (p=0.001; p<0.01). The amount of buccal overflow did not differ significantly depending on the sides in diamond disc and manual abrasives. According to the placement, the top reduction area is located in the middle region with a rate of 92.43% in aligned teeth and 87.11% in crowded teeth. According to the planned IPR amount, 86.37% of the teeth with a reduction peak area of 0.3 mm; For those planned IPR 0.5 mm, 93.19% of the time it is in the middle region. Error peak for aligned teeth is 100%; In crowded teeth, 94.85% of the time it is in the middle region. The error peak area is located lingually in 5.15% of crowded teeth. CONCLUSION: Crowding increases the rate of achieving the targeted amount of IPR, but it moves the reduction area away from the ideal depending on the position of the crowded teeth. The use of double-sided abrasive material in IPR on crowded teeth increases the amount of error. There is no superiority between materials in IPR effectiveness, but the amount of IPR applied to crowded teeth varies depending on the type of material used and whether it is one-sided or not.