Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Nov 29;23(1):49.
doi: 10.1186/s40510-022-00443-2.

Force profile assessment of direct-printed aligners versus thermoformed aligners and the effects of non-engaged surface patterns

Evan Hertan  1 , Julie McCray  1 , Brent Bankhead  1 , Ki Beom Kim  2
Affiliations

Force profile assessment of direct-printed aligners versus thermoformed aligners and the effects of non-engaged surface patterns

Evan Hertan et al. Prog Orthod. .

Abstract

Background: The purpose of the study was to measure the forces delivered by direct-printed aligners (DPA) in the vertical dimension and compare the force profile with traditional thermoformed aligners (TFA) and to investigate the impact of non-engaged surface patterns to the properties of DPA and TFA.

Methods: A force-measuring appliance was fabricated capable of displacing the aligner in 0.10 mm increments and measuring the resultant force. Polyethylene terephthalate glycol (ATMOS 0.030″ American Orthodontics) and TC-85DAC resin (Graphy Inc) were used to create TFA and DPA, respectively. Aligners were temperature-controlled prior to and during testing to simulate the oral environment. The resultant forces from displacements ranging from 0.10 to 0.30 mm were measured.

Results: At intraoral temperatures, DPA demonstrated significantly less force than TFA. TFA demonstrated a substantial statistically significant increase in force with each 0.10 mm increase in vertical displacement. DPA demonstrated a much more consistent force profile across the range of displacements. The effects of surface patterns in both DPA and TFA were generally a decrease in force. Statistical significance of surface patterns was detected for TFA at displacements of 0.30 mm and greater and significant for DPA only at a displacement of 0.10 mm. Surface patterns in both DPA and the TFA did not show any statistical difference when assessing force proprieties.

Conclusions: Forces delivered by aligners in the vertical dimension by DPA are more consistent and of lower magnitude than those of TFA aligners. Surface patterns were not capable of altering the force properties of both DPA and TFA.

PubMed Disclaimer

Conflict of interest statement

We declare that we have no competing interests.

Figures

Fig. 1
Fig. 1
Design of the YA Master Model with attachments as designed in uDesign
Fig. 2
Fig. 2
Design of the test model, note no attachments are present on the model
Fig. 3
Fig. 3
Experimental Test Stand with dynamometer and integrated caliper prior to initializing displacement test of TFA aligner on the test model
Fig. 4
Fig. 4
Comparison of Peak Forces of TFA versus DPA
Fig. 5
Fig. 5
Comparison of Stabilized Forces of TFA versus DPA
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Christensen L, Luther F. Adults seeking orthodontic treatment: expectations, periodontal and TMD issues. Br Dent J. 2015;218(3):111–117. doi: 10.1038/sj.bdj.2015.46. - DOI - PubMed
    1. Thai JK, Araujo E, McCray J, Schneider PP, Kim KB. Esthetic perception of clear aligner therapy attachments using eye-tracking technology. Am J Orthod Dentofacial Orthop. 2020;158(3):400–409. doi: 10.1016/j.ajodo.2019.09.014. - DOI - PubMed
    1. Dawood A, Marti Marti B, Sauret-Jackson V, Darwood A. 3D printing in dentistry. Br Dent J. 2015;219(11):521–529. doi: 10.1038/sj.bdj.2015.914. - DOI - PubMed
    1. Tartaglia GM, Mapelli A, Maspero C, et al. Direct 3D printing of clear orthodontic aligners: current state and future possibilities. Materials (Basel) 2021;14(7):1799. doi: 10.3390/ma14071799. - DOI - PMC - PubMed
    1. Voet VSD, Guit J, Loos K. Sustainable photopolymers in 3D printing: a review on biobased, biodegradable, and recyclable alternatives. Macromol Rapid Commun. 2021;42(3):e2000475. doi: 10.1002/marc.202000475. - DOI - PubMed

LinkOut - more resources