A zinc oxide-modified hydroxyapatite-based cement favored sealing ability in endodontically treated teeth

Area of Science:

• Biomaterials Science
• Endodontology
• Dental Materials

Background:

• Dentin permeability and viscoelastic properties are crucial for endodontic sealer effectiveness.
• Evaluating novel materials like hydroxyapatite-based cements is essential for improving root canal treatment outcomes.
• Understanding the interaction between sealers and root dentin is key to preventing secondary infections.

Purpose of the Study:

• To assess the efficacy of different endodontic canal sealers in reducing dentin permeability.
• To determine the viscoelastic performance of root dentin following sealer application.
• To compare experimental hydroxyapatite-based cements (calcypatite, oxipatite) with AH Plus and gutta-percha.

Main Methods:

• Root dentin surfaces (cervical, medial, apical) were treated with calcypatite, oxipatite, AH Plus, or gutta-percha.
• Fluid filtration assays evaluated dentin permeability.
• Advanced techniques including SEM, EDS, AFM, Young's modulus, and Nano-DMA analyzed dentin at inner and outer zones.

Main Results:

• Oxipatite exhibited the lowest microleakage, forming zinc-based salt formations and sealing tubules.
• Oxipatite showed the highest Young's modulus (Ei) in cervical dentin and promoted superior complex modulus and tan delta values in inner cervical and medial dentin.
• Calcypatite resulted in the lowest tan delta in apical dentin.

Conclusions:

• Oxipatite demonstrated superior sealing ability by reinforcing inner root dentin through tubule, void, and pore closure.
• Homogeneous viscoelastic properties with oxipatite facilitated energy dissipation, preventing stress concentration and micro-cracking.
• Oxipatite is proposed as a promising endodontic canal filling material and sealer due to its sealing and remineralization capabilities.