Comparison of dimensional accuracy of elastomeric impression materials using 3D laser scanner

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Digital Dentistry

Background:

• Dimensional accuracy of elastomeric impression materials is crucial for prosthodontic restorations.
• Previous evaluation methods for material reliability remain questionable.
• Advancements in 3D scanning offer new possibilities for precise dimensional analysis.

Purpose of the Study:

• To evaluate the dimensional accuracy of three common elastomeric impression materials.
• To assess the reliability of 3D laser scanning for measuring volumetric changes in dental impressions.
• To compare the dimensional stability of addition silicone, condensation silicone, and polyether impression materials.

Main Methods:

• Ten impressions each of addition silicone, condensation silicone, and polyether were made using a custom tray and metal die.
• Die replicas were fabricated using Type IV die stone.
• Volumetric changes were measured using a Picza 3D laser scanner and CAD-CAM software, with statistical analysis via ANOVA and Tukey HSD.

Main Results:

• All tested elastomeric impression materials exhibited dimensional shrinkage from the master die.
• Condensation silicone demonstrated the highest mean percentage dimensional change (-319.02 ±15.50%).
• Polyether (-122.59 ± 0.64%) and addition silicone (-23.83 ± 0.43%) showed significantly less shrinkage, with addition silicone being the most dimensionally stable.

Conclusions:

• The Picza 3D laser scanner accurately measures volumetric changes in elastomeric impression materials.
• Significant differences in dimensional stability exist among addition silicone, condensation silicone, and polyether.
• Addition silicone offers superior dimensional accuracy compared to condensation silicone and polyether for dental impressions.