Comparison of dimensional accuracy between direct-printed and thermoformed aligners
- Author:
Nickolas KOENIG
1
;
Jin-Young CHOI
;
Julie MCCRAY
;
Andrew HAYES
;
Patricia SCHNEIDER
;
Ki Beom KIM
Author Information
- Publication Type:Original Article
- From:The Korean Journal of Orthodontics 2022;52(4):249-257
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:The purpose of this study was to evaluate and compare the dimensional accuracy between thermoformed and direct-printed aligners.
Methods:Three types of aligners were manufactured from the same reference standard tessellation language (STL) file: thermoformed aligners were manufactured using Zendura FLX TM (n = 12) and Essix ACETM (n = 12), and direct-printed aligners were printed using Tera HarzTM TC-85DAP 3D Printer UV Resin (n = 12). The teeth were not manipulated with any tooth-moving software in this study. The samples were sprayed with an opaque scanning spray, scanned, imported to Geomagic® Control XTM metrology software, and superimposed on the reference STL file by using the best-fit alignment algorithm. Distances between the aligner meshes and the reference STL file were measured at nine anatomical landmarks.
Results:Mean absolute discrepancies in the Zendura FLXTM aligners ranged from 0.076 ± 0.057 mm to 0.260 ± 0.089 mm and those in the Essix ACETM aligners ranged from 0.188 ± 0.271 mm to 0.457 ± 0.350 mm, while in the direct-printed aligners, they ranged from 0.079 ± 0.054 mm to 0.224 ± 0.041 mm. Root mean square values, representing the overall trueness, ranged from 0.209 ± 0.094 mm for Essix ACETM , 0.188 ± 0.074 mm for Zendura FLXTM , and 0.140 ± 0.020 mm for the direct-printed aligners.
Conclusions:This study showed greater trueness and precision of direct-printed aligners than thermoformed aligners.
