Comparative Analysis of Three Different Impression Techniques for Impression Defects and Dimensional Accuracy Using a...

Area of Science:

• Dental Materials Science
• Prosthodontics
• Digital Dentistry

Background:

• Accurate impressions are vital for fabricating well-fitting fixed partial dentures.
• Digital intraoral scanners are increasingly used for dental impressions.
• Evaluating traditional impression techniques against digital methods is essential.

Purpose of the Study:

• To assess impression defects and dimensional accuracy of three techniques: single-step, two-step without spacer, and two-step with spacer.
• To compare these techniques for fixed partial dentures in the anterior maxillary region using a digital intraoral scanner.

Main Methods:

• Thirty subjects requiring fixed prostheses for maxillary incisors were included.
• Impressions were evaluated for defects using loupes.
• Dimensional accuracy was compared using an intraoral scanner and digital calipers.

Main Results:

• The single-step double mix technique exhibited the fewest defects (40%), followed by two-step without spacer (56.7%), and two-step with spacer (80%).
• The two-step with spacer technique demonstrated the highest dimensional accuracy, closest to the intraoral scanner control.

Conclusions:

• All techniques produced defects, primarily voids and bubbles.
• Single-step and two-step without spacer techniques showed more favorable defect profiles.
• The two-step with spacer technique provided superior dimensional accuracy for fixed partial dentures.