Accuracy of orthodontic movement with nocturnal three-dimensionally printed and thermoformed aligners : Retrospective cohort study comparing two different treatments protocols.

PURPOSE: This study aimed to compare the accuracy of orthodontic tooth movements achieved with three-dimensionally (3D) printed aligners (Noxi, Sweden&Martina, Due Carrare, Padova, Italy) using a 12 h/day protocol with that of thermoformed aligners (F22 aligner, Sweden&Martina, Due Carrare, Padova, Italy) using a 22 h/day protocol.

METHODS

Of the 40 white adult patients (12 men and 28 women, mean age 30.1 years) undergoing orthodontic treatment with aligners selected based on specific inclusion criteria, 20 patients were treated with Noxi aligners using a 12 h/day protocol (study group), and the remaining 20 patients were treated with F22 aligners using a 22 h/day protocol (control group). Pretreatment, ideal posttreatment (as planned in the setup), and real posttreatment digital models were analyzed using VAM software (Vectra, Canfield Scientific, Fairfield, NJ, USA). Angular and linear measurements were evaluated to measure mesiodistal tipping, vestibulolingual tipping, and rotational movements for 1120 teeth. Data were compared to evaluate treatment accuracy for each tooth, with statistical analysis of the results.

RESULTS

No statistically significant differences in accuracy emerged between the study group (64.2%) and the control group (65.4%) for any type of tooth movement or tooth category. In the study group, vestibulolingual tipping showed the highest predictability (69.63%), followed by mesiodistal tipping (65.38%) and rotation (60.5%). In the control group, the vestibulolingual and mesiodistal movements showed the highest predictability, with a mean accuracy of about 67%, followed by rotation (62.3%).

CONCLUSION

Despite the reduced collaboration request, the group treated with Noxi aligners did not show any significant differences compared to the group treated with F22 aligners with regard to percentage accuracy for all analyzed orthodontic movements.