Dimensional accuracy of stone casts made from silicone-based impression materials and three impression techniques

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials

Background:

• Accurate dental impressions are crucial for fabricating well-fitting prostheses.
• Condensation and addition silicones are common impression materials, each with distinct properties.
• Impression techniques can influence the dimensional stability of the final cast.

Purpose of the Study:

• To compare the dimensional accuracy of stone casts made from condensation and addition silicones.
• To evaluate the impact of three different impression techniques on cast accuracy.
• To determine the optimal material and technique for precise mandibular arch impressions.

Main Methods:

• Dimensional accuracy of stone casts from partially edentulous mandibular arches was assessed.
• Two condensation silicones and two addition silicones were used with three impression techniques (1-step, 2-step putty/light-body, monophase).
• Measurements of anteroposterior and transverse distances were taken using a microscope and compared to a stainless steel reference cast.

Main Results:

• All stone casts exhibited significant negative linear dimensional changes (shrinkage) compared to the reference cast.
• Stone casts produced using addition silicones demonstrated superior dimensional accuracy.
• No statistically significant differences in accuracy were observed among the 1-step, 2-step, and monophase impression techniques.

Conclusions:

• Addition silicones are recommended for achieving higher dimensional accuracy in stone casts for partially edentulous mandibular arches.
• The choice of impression technique (1-step, 2-step, or monophase) did not significantly impact the dimensional accuracy of the resulting stone casts.
• Material selection plays a more critical role than technique in ensuring the precision of dental casts.