Three-dimensional assessment of dental casts' occlusal surfaces using two impression materials

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Digital Dentistry

Background:

• Accurate dental cast replication is crucial for diagnostics and research.
• Impression materials can influence the dimensional accuracy of resulting casts.
• Understanding these differences is vital for reliable dental research, particularly in wear studies.

Purpose of the Study:

• To compare the occlusal surface characteristics of dental casts produced from alginate and polyvinyl siloxane impression materials.
• To quantify volumetric differences in teeth replicated from these two impression materials using 3D computed tomography.
• To assess the impact of impression material choice on the dimensional fidelity of dental casts.

Main Methods:

• Two impression materials (alginate and polyvinyl siloxane) were used to create 40 dental casts from 20 students.
• Three-dimensional computed tomography (FlashCT scanner) was employed to digitize the dental casts.
• Geomagic Studio software was used to process digital images, separate 464 teeth, and compare their volumes.

Main Results:

• Teeth from alginate casts exhibited significantly larger volume measurements compared to those from polyvinyl siloxane casts (P = 0.005).
• This significant difference was most pronounced in the premolar and molar groups (P = 0.00).
• The mean volumetric difference across all analyzed teeth was 0.041 mm³.

Conclusions:

• The choice of impression material significantly affects the occlusal surface characteristics and volumetric accuracy of dental casts.
• Alginate impression materials may lead to overestimation of tooth volume compared to polyvinyl siloxane.
• Caution is advised when using dental casts derived from different impression materials in research, especially for dental wear analysis.