Accuracy of Orthodontic 3D Printed Retainers versus Thermoformed Retainers

Abstract

Background: The integration of the current technology of CBCT and 3D CAD/CAM technology has great potential in the field of orthodontics, which is not yet fully investigated. The purpose of this article is to evaluate the accuracy of 3D printed retainers in comparison to vacuum formed retainers. Methods: Alginate impressions were taken for ten patients who have a CBCT scan. A 3D printed retainer and vacuum formed retainer were fabricated. Linear measurements were measured by two assessors using digital caliper. Every measurement on the 3D printed retainer was compared to the corresponding measurement on the thermoformed retainer. The linear measurements were Inter-canine width, Inter-premolar width (first and second premolars), Inter-molar width, Canine-midline length (both sides) and Canine-molar length (both sides). Intra-observer, and inter-observer reliability measurements were done. Results: Results showed excellent intra-observer reliability for the thermoformed retainer and the 3D printed retainer. Inter-observer measurements showed strong agreement between the measurements of the two assessors, for both retainers. The comparison of the thermoformed retainer to the 3D printed retainer showed high statistical agreement, except for the canine-molar on the right side, but with no clinical significance,

Evaluation of fit for 3D-printed retainers compared with thermoform retainers

“…A few years later, the same authors evaluated the fit of the 3D-printed retainers. 21 In that study, digital calipers were used to measure the difference between the 3D-printed retainer and a vacuum-formed retainer. In the present study, software was used to superimpose the digital images of the printed retainers and their original models.…”

“…A recent study by the same investigators reported that the 3D-printed retainers were as accurate and reliable as the traditional vacuum-formed retainers. 21 However, comparisons between the 2 retainers were made based on the linear measurements performed manually with the use of digital calipers. Furthermore, the digital file used to fabricate the retainers was created from a CBCT image.…”

3D Printing Part 1 - A History and Literature Review Of 3D Printing in Dentistry

“…A recent study compared the accuracy between orthodontic 3D printed and thermoformed retainers, in which 3D printed retainers were reported as more accurate and reliable than the conventional vacuum formed retainer [35]. Based on this study, it is important to note that CBCT was used to create the digital file to fabricate the two retainers.…”

“…In 2014, a selective laser sintering (SLS) 3D printer was successfully used to fabricate a retainer directly from a digital model of cone-beam computed tomography (CBCT) without a physical model, as reported by Nasef, El-Beialy, and Mostafa. [35] Although the accuracy of fabricated retainer appliances was not assessed, the 3D printing technologies using CBCT provided simplicity, accuracy, speed, and patient satisfaction. The study results indicated 3D virtual retainer with user-friendly software seemed to be a promising technique that would eventually change the practices in present-day dentistry.…”

“…It would pave the way for designing and manufacturing custom orthodontic appliances, which matches with the new digital orthodontic era. [35] Figure 10. The IDDA Scan Method Training Model as given to the members of the International Digital Dental Academy to help with learning to use a 3D scanner.…”