Fracture Strength of Semi-direct Fiber-reinforced Composite Restorations on Endodontically Treated Teeth: An in-vitro Study

Abstract

Background:
Restoration of endodontically treated teeth (ETT) is critical for long-term function and aesthetics. The use of semi-direct fiber-reinforced composite (SDFRC) restorations has gained popularity due to their biomimetic approach and potential to preserve tooth structure.

Objective:
To evaluate and compare the fracture strength and failure modes of ETT restored with SDFRC restorations with and without cuspal coverage.

Methods:
Fifty-one sound human maxillary premolars were collected and divided into three groups:

• Group 1 (Control): Sound teeth with no treatment

• Group 2: ETT restored with SDFRC restorations with cuspal coverage

• Group 3: ETT restored with SDFRC restorations without cuspal coverage

All specimens underwent standardized endodontic and restorative procedures using biomimetic principles. They were subjected to artificial aging and static load testing using a universal testing machine. Statistical analysis was conducted using one-way ANOVA for fracture strength and the Chi-square test for failure modes.

Results:
The mean fracture strength of Group 3 (849.38N ± 147.40N) was significantly higher than Group 2 (647.44N ± 168.43N) (p < 0.05). There was no significant difference in failure modes among the groups (p = 0.052).

Conclusion:
Semi-direct fiber-reinforced composite restorations without cuspal coverage demonstrated higher fracture strength than those with cuspal coverage. Minimally invasive restorations that preserve coronal structure may provide favorable outcomes in ETT treatment.