Structural resistance in immature teeth using root reinforcements in vitro.

Area of Science:

• Dental Materials Science
• Endodontics
• Biomaterials Engineering

Background:

• Immature non-vital teeth present unique endodontic challenges due to their thin dentin walls.
• Root reinforcement is crucial for restoring structural integrity and preventing catastrophic fracture in compromised teeth.

Purpose of the Study:

• To compare the in vitro efficacy of light-cured composite resin versus zirconium fiber posts for reinforcing simulated immature non-vital teeth.
• To evaluate the impact of these reinforcements on the fracture resistance of weakened root structures.

Main Methods:

• Fifty-six bovine incisors were prepared to simulate immature non-vital teeth and divided into four groups.
• Groups received either composite resin reinforcement, zirconium fiber post reinforcement, or served as positive/negative controls.
• Fracture resistance was assessed using a universal testing machine at a 45-degree angle.

Main Results:

• Both composite resin (122.38 kgf) and zirconium fiber post (122.08 kgf) groups showed significantly increased fracture resistance compared to controls (P < 0.05).
• No significant difference in fracture resistance was observed between the composite resin and zirconium fiber post groups (P > 0.05).

Conclusions:

• Root reinforcement with either composite resin or zirconium fiber posts significantly improves the structural resistance of weakened immature non-vital teeth.
• These findings suggest that both materials effectively reduce the risk of root fracture in compromised teeth.