DOI: 10.4103/tdj.tdj_71_26 ISSN: 1687-8574

Fatigue resistance of endodontically treated teeth restored with different designs of indirect adhesive restorations (in-vitro study)

Dalia H. Aboelnasr, Waleed M. Elshahawy, Abeer A. Younis
Show PDF Cite

Background

Endocrowns and overlays with fiber-reinforced composite bases restore endodontically treated teeth. Their comparative performance remains unclear.

Aim

Assessing fatigue resistance and modes of failure of CAD/CAM resin composite endocrowns and overlays supported by differently oriented fiber-reinforced composite bases.

Patients and methods

Recently extracted, 60 mandibular molars received endodontic therapy, sectioned 2 mm overhead cementoenamel junction. Pulp chamber divergence was created. Following immediate sealing of dentin and resin coat application, specimens were randomly allocated into three groups ( n = 20): endocrown (EC, control), overlay with pulp chamber wallpapered with long polyethylene fibers and filled with short fiber-reinforced composite (OW), and overlay with pulp chamber filled with short fiber-reinforced composite and occlusally covered with long polyethylene fibers (OC). Restorations were adhesively luted, thermocycled, then step-stress fatigue tested. Fatigue resistance and cycles numbers were recorded and scrutinized using one-way analysis of variance with Bonferroni post-hoc comparisons. Failure modes were examined using stereomicroscope, classified by repairability, and compared using Fisher’s exact test. Survival was appraised using Kaplan–Meier curves and log-rank test ( P ≤ 0.05).

Results

Fatigue resistance and cycles numbers varied considerably between groups ( P < 0.05). Values were greatest in OC (2184 ± 496.6 N), (94 200 ± 24 830.5) followed by OW (1838.9 ± 472.7 N), (76 947 ± 23 637.2), then EC (1648.3 ± 522.9 N, 67 413 ± 26 145.6), with no significant difference between OW and EC. Kaplan–Meier analysis confirmed this (P = 0.005). Failure modes differed significantly ( P < 0.05). Repairable failures were highest in OC, then OW and EC.

Conclusion

Restoring endodontically treated teeth with overlays supported by fiber-reinforced composite bases improves mechanical performance.

More from our Archive