Deflection Values As A Result Of Thermoforming Of 3D-Printed Dental Models Of Varying Wall Thicknesses During Clear Aligner Fabrication: 3D Deformation Analysis
DOI:
https://doi.org/10.64252/r9hhmq38Keywords:
Clear aligner fabrication, Thermoforming3D-printed dental models, Deformation resistance, MSLA 3D Printer, Model resin, Bio Star, 3D comparison software, Accuracy, Shell thickness, Cost savings, Environmental benefitsAbstract
Introduction: Clear aligner fabrication demands a very high level of accuracy. Thermoforming is done at aheavy pressure of 4-6 bars; which makes the 3D-printed dental models easily prone to deformation. This study employs three-dimensional printed models with varying wall thicknesses to investigate how these variations impact their resistance to deformation during aligner fabrication.
Aims & Objectives: The primary objective of the study was to analyzedeformation as a result of thermoforming of 3D-printed dental models of varying wall thicknesses.
Material & Methods: A total of hundred models of varying wall thicknesses (10 each of 1.0mm,1.25mm, 1.5mm,1.75 mm, 2.0mm,2.25mm, 2.5mm, 2.75mm, 3.0mm and solid) were printed using a MSLA 3D Printer (Saturn 3 12K, Elegoo, Shenzhen, China) using model resin (Elegoo Standard LCD Light-curing UV resin, Shenzhen, China).Printing was followed by cleaning and curing of the models according to the manufacturers’ guidelines. Aligners when then fabricated using Bio Star (Scheu Dental, Iserlohn, Germany) utilizing a 30sec cycle for a 0.8mm aligner sheet (Erkodent-AL, Erkodur, Pfalzgrafenweiler, Germany). Each model was then scanned with a lab scanner (T710, Medit Corp., Seoul, South Korea) and compared with the original 3D model using 3D comparison software (CloudCompare v2.13.1, Santry, Dublin, Ireland) and results were quantified.
Results: Models with 1mm and 1.25mm showed visible deformation, hence were not considered for deformation analysis. The average post deformation accuracy ranged from 83.529% for 1.50mm thick models to 99.1495% for solid models.The results show that model with wall thickness of 2.75mm or greater showed negligible deformation and can be used for clear aligner fabrication.
Conclusion: Hollow models with a shell thickness exceeding 2.75 mm are suggested for aligner production due to their ability to withstand stresses during thermoforming, while using less resin per unit compared to solid models. This approach,also offers cost savings, time efficiency, and environmental benefits, making it a more viable option for aligner fabrication.
