Comparison and Accuracy of Different Impression Procedures Utilizing Hex and Non-Hex Impression Copings

Area of Science:

• Dental prosthetics
• Implant dentistry
• Impression techniques

Background:

• Accurate impressions are critical for passive fit in implant-supported prostheses.
• Impression accuracy can be significantly affected by factors like coping design and implant angulation.

Purpose of the Study:

• To compare the accuracy of different impression procedures using Hex and Non-Hex impression copings.
• To evaluate these procedures in multiple implant conditions with varying angulations.

Main Methods:

• An in vitro study utilized three mandibular edentulous acrylic models with implant angulations of 0°, 5°, and 10°.
• Hex and Non-Hex copings were tested in Hex-Hex, Hex-Non-Hex, and Non-Hex-Non-Hex configurations using the open-tray technique.
• Deviations were measured on master casts and reference models scanned with a Medit T300 scanner.

Main Results:

• The Non-Hex-Non-Hex configuration demonstrated the least deviation across all axes in 5° and 10° angulated models.
• The Hex-Hex combination consistently showed the highest deviation values.
• Statistically significant differences (P < 0.05) in impression accuracy were observed, particularly in angulated conditions.

Conclusions:

• Non-Hex impression copings yield superior accuracy for multiple and angulated implant impressions.
• Clinical recommendation for Non-Hex copings in nonparallel implant conditions to enhance prosthetic fit.