Accuracy of stereolithographically printed digital models compared to plaster models

Area of Science:

• Dentistry
• Orthodontics
• Biomedical Engineering

Background:

• Traditional orthodontic treatment relies on plaster models derived from alginate impressions.
• Advancements in digital dentistry offer intraoral scanning and 3D printing as alternatives.

Purpose of the Study:

• To compare the dimensional accuracy of 3D printed models from intraoral scans with conventional plaster models.
• To evaluate the clinical relevance of discrepancies between model types for orthodontic applications.

Main Methods:

• Alginate impressions and intraoral scans were taken from 28 volunteers.
• Plaster models and stereolithography (SLA) 3D printed models were fabricated.
• Digital calipers were used to measure key dental and interarch dimensions on both model types.

Main Results:

• Significant differences were observed in tooth dimensions and interarch parameters between plaster and printed models.
• Transversal measurements, specifically upper and lower intermolar distances, were clinically relevant smaller on printed models.
• Overall accuracy was compromised by clinically relevant transversal contraction in 3D printed models.

Conclusions:

• 3D printed models using SLA technology exhibit clinically relevant transversal contraction.
• These printed models are not yet a suitable replacement for conventional plaster models in orthodontic diagnosis and treatment planning.
• Further research is needed to improve the accuracy of 3D printed dental models.