Clinical Evaluation of Intraoral, In-Lab Scanners and PVS Impression Materials Using STL Superimposition.

Area of Science:

• Dental Materials Science
• Digital Dentistry
• Prosthodontics

Background:

• Accurate impressions are crucial for fabricating removable complete dentures (RCD).
• The accuracy of digital impressions using intraoral scanners (IOS) versus traditional in-lab scanning of polyvinyl siloxane (PVS) impressions is an area of ongoing research.
• Understanding the dimensional stability of different PVS impression materials is vital for clinical success.

Purpose of the Study:

• To compare the accuracy of intraoral scanners (IOS) against in-lab scanners for RCD.
• To evaluate the accuracy differences between two types of PVS impression materials.
• To assess the accuracy of PVS impression materials compared to IOS.

Main Methods:

• Fourteen subjects received maxillary and mandibular RCD.
• Impressions were made using heavy/light (HL) or medium/light (ML) body PVS materials.
• Impressions were scanned using IOS (Trios, Omnicam) and an in-lab scanner; STL files were analyzed for gap measurements at 60 points.

Main Results:

• No significant difference in accuracy between Trios and Omnicam IOS (44 ± 10 μm).
• Significant differences were found between Trios and in-lab scans (62 ± 21 μm), and between ML and Trios (66 ± 24 μm) and HL and ML PVS groups (50 ± 21 μm).
• No significant difference was observed between HL PVS and Trios IOS (37 ± 10 μm).

Conclusions:

• Intraoral scanners demonstrate comparable scan quality.
• The choice of PVS impression material significantly impacts the accuracy of in-lab scans.
• Heavy and light body PVS materials provide accurate and dimensionally stable impressions for complete dentures, comparable to IOS.