Fracture Strength of Flared Root Canals Restored with Different Post Systems

Area of Science:

• Dental materials science
• Biomaterials engineering
• Restorative dentistry

Background:

• Intra-radicular posts are used to restore endodontically treated teeth with significant coronal destruction.
• Flared root canals present unique challenges for post placement and retention.
• Evaluating the fracture resistance of different post systems is crucial for long-term clinical success.

Purpose of the Study:

• To compare the fracture resistance of glass fibre posts (GFP), pre-fabricated metal posts (PMP), and cast metal cores (CMC) in flared root canals.
• To analyze the fracture patterns associated with each post system under mechanical loading.

Main Methods:

• Sixty human canine teeth with standardized root lengths were endodontically treated and restored.
• Teeth were divided into three groups: GFP, PMP, and CMC, each with resin composite cores.
• Samples underwent mechanical compression testing at 45 degrees, and fracture patterns were evaluated.

Main Results:

• No statistically significant difference in fracture resistance was found among the three groups (P=0.193).
• Glass fibre posts and pre-fabricated metal posts exhibited predominantly Type I fractures (55% and 45%, respectively), considered repairable.
• Cast metal cores showed 50% Type V fractures, which are irreparable.

Conclusions:

• Glass fibre posts and pre-fabricated metal posts demonstrate adequate fracture resistance for restoring flared root canals.
• The favorable fracture patterns of GFP and PMP facilitate easier clinical repair compared to cast metal cores.