Comparative Evaluation of Microtissue-Engineered Root Dentin with Three Different Nanoparticles in Improving Fatigue Resistance of Endodontically Treated Teeth - An In Vitro Study.

Aim: This study aims to analyze the fatigue resistance, surface mechanical properties, and biomechanical responsiveness of microtissue-engineered root dentin using cellulose nanofibers, hydroxyapatite nanocrystals, and walnut shell nanopowders.

Methodology: The objectives are to evaluate the differences in fatigue resistance and biomechanics and surface mechanical characteristics by infiltrating these nanomaterials into the root canal of endodontically treated teeth. Forty human permanent single-rooted teeth were collected with the patient's consent. Fatigue resistance was measured using cyclic loading, and surface roughness was measured by scanning electron microscopy (SEM).

Results: The results showed a fatigue resistance of 36.81 ± 4.58 MPa, attributed to the availability of calcium ions at 9%, the highest compared to other groups. Non-microtissue-engineered root dentin exhibited a stress resistance of 12.3 ± 3.1 MPa and a strain resistance of 4.1 ± 1.1 MPa. Walnut shell nanopowder (WNP) exhibited higher fatigue resistance than other groups (P > 0.05).

Conclusion: Root dentin engineered with HaNPs showed a fatigue resistance of 36.81 ± 4.58 MPa and surface roughness of 4.2 ± 0.5 MPa, attributed to the availability of calcium ions at 9%, the highest compared to other groups. Non-microtissue-engineered root dentin exhibited a fatigue resistance of 12.3 ± 3.1 MPa, while microtissue-engineered root dentin showed 36.81 ± 4.58 MPa, which is three times higher.