Can transfer type and implant angulation affect impression accuracy? A 3D in vitro evaluation.

Area of Science:

• Dental Implantology
• Prosthodontics
• Biomaterials Science

Background:

• Passive fit of dental prostheses is essential for long-term success.
• Impression accuracy directly influences the passive fit of implant-supported superstructures.
• Understanding factors affecting impression accuracy is critical for predictable clinical outcomes.

Purpose of the Study:

• To evaluate the impact of different impression coping types on accuracy.
• To assess the influence of varying implant angles on impression accuracy.
• To determine the combined effect of coping type and implant divergence on impression accuracy.

Main Methods:

• Three impression coping types were tested: closed tray (CT), open tray (COT), and telescopic open tray (TOT).
• Impressions were made on a master model with implants at 0°, 15°, and 35°.
• Digital models were created, and linear/angular discrepancies were measured and analyzed using ANOVA.

Main Results:

• Significant discrepancies in linear (Δx, Δy, Δz) and angular measurements were observed.
• Both impression coping type and implant divergence angle significantly affected impression accuracy (p ≤ 0.001).
• Specific coping types and greater implant angulations led to reduced accuracy.

Conclusions:

• Coping type is a significant parameter influencing dental impression accuracy.
• Implant divergence angle is a significant parameter influencing dental impression accuracy.
• Clinical choices of impression techniques and consideration of implant angulation are critical for achieving passive fit.