Accuracy of the second pour casts using dual-arch trays

Area of Science:

• Dental Materials Science
• Prosthodontics
• Casting Technology

Background:

• Accurate dental stone casts are crucial for fabricating precise prosthetics.
• Dual-arch trays are commonly used for impression taking in fixed prosthodontics.
• The accuracy of repeated pours from the same impression is a critical factor in cast quality.

Purpose of the Study:

• To compare the in vitro accuracy of dental stone casts from first and second pours.
• To evaluate the influence of metallic (Smart) versus plastic (Triple Tray) dual-arch trays on cast accuracy.
• To determine if tray material affects the dimensional stability of repeated dental stone pours.

Main Methods:

• Impressions of a prepared typodont molar were made using vinyl polysiloxane material.
• Ten impressions were taken with both metallic and plastic dual-arch trays.
• Type IV die stone was used for first and second pours, with measurements taken after 1-hour intervals. Dimensional accuracy was assessed using a profile projector and analyzed with Student's t-test.

Main Results:

• A statistically significant difference in mesio-distal width was observed between the first and second pours using the plastic tray.
• No significant difference was found for the metallic tray between the first and second pours in mesio-distal width.
• The buccal-lingual width showed no statistically significant differences for either tray type between pours.

Conclusions:

• Repeated pours using metallic dual-arch trays exhibit higher accuracy than those made with plastic trays.
• The choice of dual-arch tray material can influence the dimensional accuracy of subsequent dental stone casts.
• Metallic trays may be preferable when multiple pours are required to ensure optimal cast precision.