Comparison of linear transverse measures between plaster and resin printed digital models

Area of Science:

• Dentistry
• Digital Dentistry
• Prosthodontics

Background:

• Traditional alginate impressions are a cornerstone of dental diagnostics and prosthetics.
• Intraoral scanners offer a digital alternative, enabling 3D model creation via .stl files.
• Evaluating dimensional accuracy between conventional and digital impression techniques is crucial for clinical application.

Purpose of the Study:

• To compare dimensional variations between plaster models from alginate impressions and 3D printed replicas derived from intraoral scans.
• To assess the clinical significance of any measured differences in intercanine and intermolar distances.

Main Methods:

• Eighty maxillary and mandibular arches from 40 patients were analyzed.
• Alginate impressions and intraoral scans were taken for each arch.
• Digital scans were 3D printed into resin models; linear intercanine (IC) and intermolar (IM) distances were measured using a caliper and compared.

Main Results:

• High repeatability was confirmed, with intraclass correlation coefficient (ICC) values exceeding 0.98.
• Statistically significant differences were observed in IC and IM lengths between alginate and 3D printed models.
• These differences were less than 0.1 mm, deemed not clinically significant.

Conclusions:

• Both alginate impressions and 3D printed replicas from intraoral scans demonstrate high repeatability.
• While statistically significant, the dimensional variations between the two methods are below the threshold for clinical relevance.
• 3D printed models from intraoral scans are a viable alternative to traditional alginate impressions for dental applications.