The behaviour of post-retained core materials supported by coronal tooth structure in vitro

Area of Science:

• Restorative Dentistry
• Dental Materials Science
• Biomaterials Engineering

Background:

• Post-retained restorations are crucial for restoring endodontically treated teeth.
• The influence of remaining coronal tooth structure on the mechanical performance of these restorations is not fully understood.
• Evaluating fracture resistance is key to assessing the longevity and success of dental restorative systems.

Purpose of the Study:

• To investigate the impact of preserving coronal tooth substance on the performance of post-retained core materials.
• To compare the fracture resistance of silver amalgam and silver-glass cermet core materials when coronal substance is retained.
• To compare the fracture resistance of these restored teeth against intact teeth of similar dimensions.

Main Methods:

• Three groups of ten teeth were prepared: unrestored (control), restored with post-retained silver amalgam, and restored with post-retained silver-glass cermet.
• All restored teeth featured a retained single wall of coronal tooth substance.
• Teeth were subjected to a shearing load to determine fracture resistance.

Main Results:

• No statistically significant difference in fracture resistance was observed between unrestored teeth and those restored with silver-glass cermet.
• Teeth restored with silver amalgam exhibited significantly higher fracture resistance (P > 0.01) compared to the other groups.
• However, silver amalgam restorations were associated with a greater tendency for root fracture.

Conclusions:

• Retaining coronal tooth substance positively influences the performance of post-retained core materials.
• Silver amalgam offers superior fracture resistance but carries an increased risk of root fracture.
• Silver-glass cermet demonstrates comparable fracture resistance to intact teeth, suggesting a potentially safer profile regarding root integrity.