Melatonin-doped polymeric nanoparticles induce high crystalline apatite formation in root dentin

Area of Science:

• Biomaterials Science
• Dental Materials
• Nanotechnology

Background:

• Endodontic treatment can compromise dentin's structural integrity and mechanical properties.
• Hydroxyapatite (HA) remineralization is crucial for restoring dentin's integrity.
• Nanoparticles (NPs) offer potential for enhanced remineralization and material properties.

Purpose of the Study:

• To evaluate the impact of novel melatonin-doped polymeric nanoparticles (ML-NPs) on dentin's nano-hardness, crystallinity, and ultrastructure post-endodontic treatment.
• To compare the effects of ML-NPs with undoped NPs and a control group over time.

Main Methods:

• Polymeric NPs, both undoped and ML-doped, were applied to radicular dentin.
• Nano-hardness, X-ray diffraction, and transmission electron microscopy were used to analyze dentin surfaces at 24 hours and 6 months.
• Statistical analysis included ANOVA and Student-Newman-Keuls tests.

Main Results:

• ML-NPs significantly enhanced nano-hardness and crystallinity in apical dentin, maintaining properties over 6 months.
• Dentin treated with ML-NPs exhibited thicker, more organized hydroxyapatite crystals, forming polycrystalline lattices.
• Undoped NPs resulted in poor crystallinity and increased microstrain, while the control group showed decreased mechanical properties over time.

Conclusions:

• ML-NPs promote the formation of stable, highly crystalline hydroxyapatite, potentially enhancing structural dentin stability and mechanical performance.
• The observed remineralization and structural improvements with ML-NPs suggest significant potential for root repair.
• Undoped NPs and the absence of NPs led to demineralization and degradation, highlighting the benefits of ML-NP treatment.