Evaluation of a two-piece post and core fabrication technique

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials Engineering

Background:

• Prefabricated posts are commonly used in post-and-core restorations.
• Casting a core directly to a prefit post aims to minimize adjustments during cementation.
• The mechanical integrity of one-piece versus two-piece post and core castings requires comparative analysis.

Purpose of the Study:

• To compare the tensile bond strength and failure modes of one-piece versus two-piece post and core castings.
• To evaluate the influence of casting technique on the structural integrity of post-and-core restorations.

Main Methods:

• Specimens were fabricated using Whaledent laboratory burnout posts and phosphate investment.
• Three dental casting alloys (Midas, Sturdicast, Rexillium III) were utilized.
• Tensile testing was performed at a head speed of 1 cm/min to assess mechanical properties.

Main Results:

• One two-piece casting failed at the post head-to-core interface; all other specimens failed within the post.
• No statistically significant difference in tensile strength was observed between the one-piece and two-piece casting techniques.
• The casting alloys and technique did not yield significant variations in failure modes.

Conclusions:

• Both one-piece and two-piece post and core casting techniques demonstrate comparable mechanical performance.
• The choice between one-piece and two-piece castings may not significantly impact the structural integrity of the restoration.
• Further research could explore long-term clinical performance and different alloy systems.