Accuracy of Impression Techniques with Maxillary Angled Implants Using Trays and Multifunctional Guides

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials Engineering

Background:

• Accurate dental impressions are crucial for fabricating passive implant-supported frameworks.
• Various splinting techniques and tray types influence impression accuracy.

Purpose of the Study:

• To compare the in vitro accuracy of different splinting techniques using transfers with various tray types for dental impressions.
• To evaluate the dimensional stability and accuracy of polyvinyl siloxane impressions.

Main Methods:

• Fabricated a maxillary master cast with four implants and a passive metallic bar.
• Utilized six impression techniques with polyvinyl siloxane material (n=8 per group).
• Measured 2D and 3D malalignments between framework analogs using a contact scanner and a passive metallic bar.

Main Results:

• No significant differences in 2D vertical malalignments were observed across groups.
• In 3D analysis, plastic trays with metal and resin splinted transfers showed significantly less deviation on the z-axis and xz-axis compared to multifunctional guides with resin splinted transfers.
• Specific analogs showed significant differences, with multifunctional guides using metal and resin splinted transfers demonstrating better accuracy.

Conclusions:

• Impression accuracy differs between 2D and 3D evaluations.
• Splinting transfers with both metal and acrylic resin generally yields superior 3D accuracy compared to acrylic resin alone, particularly with plastic trays and multifunctional guides.
• The bonding technique of transfers significantly impacts 3D accuracy in multifunctional guide impressions.