Evaluation of fixed mandibular retainer using 3D printed positioning tray versus direct bonding technique a Randomized Clinical trial

Abstract

Objective: to compare the chairside time of fixed mandibular retainers when bonded using the conventional direct technique and the 3D printed positioning tray. Methods: A randomized clinical trial was performed using the two techniques to directly and indirectly bond the fixed lingual retainers, 20 subjects who in need of fixed retainers showing no signs of enamel defects or signs of gingival inflammation were recruited in this study. 20 retainers were bonded to the lower anterior teeth. Group I was the intervention group (3D positioning tray technique) and Group II was the comparative (the direct technique). In the intervention group, lower impression was taken and the cast produced was scanned using desktop scanner to produce the digital model on which the virtual retainer was placed using the OrthoAnalyzer software. The tray was designed by using Appliance Designer software and printed with rigid resin to allow ease of insertion and removal. The wire was placed inside the 3D positioning tray and then transferred inside the patients mouth the chairside time was recorded ,In the comparative group, same steps where done as intervention group, but with the exception of the bonding technique where the retainer was placed directly inside the patients mouth. Results: the Chairside time in group I (3D printed positioner) was (15:35 ± 0.03) minutes while in group II (Control) was (17:52 ± 0.05) minutes. Conclusion: The chairside time difference between the two bonding techniques was statistically significant, with the 3D positioning tray technique taking less chairside time than direct technique.