Evaluation of gap width and fit in two types of thermoformed clear aligner materials

Document Type : Original Article

Authors

1 Orthodontic Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt

2 Department of Orthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.

3 Orthodontic department, Faculty of Dentistry, Ain Shams University.

Abstract

Objective: To evaluate the difference in overall fit and fit percentage in two different aligner materials.
Materials and methods: A series of clear aligners made of two types of orthodontic aligner thermoplastic materials, including polyethylene terephthalate glycol (PETG) films (n = 11) and thermoplastic polyurethane (TPU) films (n = 11) of 0.75 and 0.76 mm in thickness, respectively, were manufactured from the same standard tessellation language (STL) file via a positive pressure thermoforming process and trimmed to a straight 2 mm long border. The samples were sprayed with opaque spray, scanned with a desktop scanner, imported to Geomagic Control X metrology software, and superimposed on the reference STL file by the best-fit algorithm. Then root mean square (overall fit) and fit percentage were measured.
Results: Root mean square values, representing the overall trueness, ranged from 0.2718 ± 0.0314 mm for Zendura FLX and 0.3162 ± 0.017 mm for Duran. Fit percentage ranged from 71.2 ± 5.4% for Zendura and 65.8 ± 3.7% for Duran.
Conclusions: Multi-layered thermoplastic polyurethane (TPU) material has superior fit compared to single-layered polyethylene terephthalate glycol (PET-G) material.

Keywords

Files

Share

How to cite

Statistics