Predictable casting for dimensional shrinkage of fast-cast post-and-cores

Area of Science:

• Dental materials science
• Prosthodontics
• Casting technology

Background:

• Dimensional variability in fast-cast post-and-cores necessitates improved casting methods.
• Inconsistent shrinkage can lead to lateral stresses on remaining tooth structure.

Purpose of the Study:

• To identify a reliable method for casting post-and-cores with consistent dimensional shrinkage.

Main Methods:

• Fabrication of 45 methyl methacrylate post-and-core patterns.
• Casting using three distinct methods with varying investment materials (Fast Fire 15, Beauty Cast gypsum) and burnout times.

Main Results:

• Statistical significance (p<0.05) observed between different investment materials.
• The accelerated casting technique yielded the most consistent results.
• All tested cast post-and-cores exhibited measurable shrinkage.

Conclusions:

• Phosphate investment combined with an accelerated technique ensures consistent and predictable shrinkage.
• This approach can improve the fit of cast post-and-cores and reduce tooth stress.