Accuracy of digital models generated by conventional impression/plaster-model methods and intraoral scanning

Area of Science:

• Digital Dentistry
• Dental Materials Science
• Metrology in Dentistry

Background:

• Accurate digital models are crucial for modern digital dentistry workflows.
• Traditional methods involve physical impressions and model fabrication, followed by scanning.
• Intraoral scanning offers a direct digital capture alternative.

Purpose of the Study:

• To compare the accuracy of digital models generated via intraoral scanning versus desktop scanning of conventional impression/plaster models.
• To evaluate the impact of different impression materials on the accuracy of scanned models.

Main Methods:

• Eight ceramic spheres were affixed to epoxy dental models for precise measurements.
• Conventional impressions (alginate and silicone) were taken, cast into dental stone models, and then scanned using a desktop scanner.
• Direct digital models were generated using an intraoral scanner.
• Twelve linear distance measurements between sphere centers were calculated for all digital models.

Main Results:

• No significant accuracy differences were found among the three groups for six specific linear distance measurements.
• The intraoral scanning group (IOS) demonstrated significantly higher accuracy compared to the alginate (AI) and silicone (SI) impression groups when considering five specific linear distance measurements.
• Desktop scanning of conventional impression/plaster models showed comparable accuracy to intraoral scans in some measurements.

Conclusions:

• Intraoral scanning may provide superior accuracy for generating digital dental models compared to scanning conventional impression/plaster models.
• The choice of impression material can influence the accuracy of the final digital model when using conventional methods.
• Intraoral scanning presents a potentially more precise method for digital impression acquisition in restorative dentistry.