A comparison of impression materials for complete-arch fixed partial dentures.

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials Engineering

Background:

• Accurate marginal fit of complete-arch fixed prostheses is crucial for long-term clinical success.
• Impression material selection significantly impacts the precision of dental restorations.
• Previous research indicates variability in the dimensional stability of different impression materials.

Purpose of the Study:

• To compare the marginal fit of complete-arch fixed prostheses fabricated using different common impression materials.
• To evaluate the clinical acceptability of prostheses based on impression material accuracy.
• To determine the influence of luting procedures on the marginal integrity of multi-unit restorations.

Main Methods:

• Fabrication of complete-arch fixed prostheses on master casts created from polyether, polyvinyl siloxane (medium-viscosity and putty-wash), and reversible hydrocolloid impressions.
• Measurement of marginal fit of individual abutment castings before and after luting on the master cast.
• Utilized a maxillary dentoform with four abutment teeth for simulated clinical conditions.

Main Results:

• Polyether and addition silicone (medium-viscosity and putty-wash) impression materials demonstrated significantly higher accuracy than reversible hydrocolloid.
• All individual castings exhibited clinically acceptable marginal fit.
• Complete-arch fixed partial dentures fabricated using reversible hydrocolloid impression materials showed unacceptable marginal fit after luting.

Conclusions:

• Polyether and addition silicone impression materials are recommended for fabricating accurate complete-arch fixed prostheses.
• Reversible hydrocolloid is less suitable for achieving precise marginal fit in complex, multi-unit fixed restorations.
• Material selection is a critical factor influencing the success of complete-arch fixed prosthodontics.