Ions-modified nanoparticles affect functional remineralization and energy dissipation through the resin-dentin...

Area of Science:

• Dental Materials Science
• Nanotechnology in Dentistry
• Biomaterials Engineering

Background:

• Improving the durability and longevity of resin-dentin bonds is crucial in restorative dentistry.
• Nanoparticle infiltration offers a novel approach to enhance the mechanical and chemical properties of the adhesive interface.
• Understanding the behavior of zinc (Zn-NPs) and calcium (Ca-NPs) nanoparticles at the resin-dentin interface is essential for optimizing dental adhesives.

Purpose of the Study:

• To evaluate the impact of pre-infiltration with polymeric nanoparticles (NPs) on the mechanical properties, chemical behavior, and bonding ability of dentin interfaces.
• To assess the changes in complex modulus, storage modulus, and tan delta (δ) after nanoparticle infiltration and aging.
• To investigate the chemical and structural modifications at the resin-dentin interface using AFM and Raman spectroscopy.

Main Methods:

• Dentin surfaces were acid-etched and infiltrated with an ethanol suspension of NPs, Zn-NPs, or Ca-NPs before adhesive application (Single Bond).
• Microtensile bond strength tests were performed after 24h of storage.
• Dynamic Mechanical Analysis (Nano-DMA), Atomic Force Microscopy (AFM), and Raman spectroscopy were used to evaluate interface properties after 24h and 21 days of storage.

Main Results:

• Nanoparticle infiltration did not significantly alter the initial bond strength.
• After 21 days, Zn-NPs decreased tan delta (energy dissipation), while Ca-NPs and non-doped NPs increased it.
• Zn-NPs improved collagen crosslinking and secondary structure; Ca-NPs promoted remineralization and favorable energy dissipation, minimizing stress concentration.

Conclusions:

• Polymeric nanoparticle infiltration is a promising strategy for enhancing resin-dentin interface properties without compromising initial bond strength.
• Zn-NPs contribute to improved collagen integrity, while Ca-NPs facilitate remineralization and stress dissipation, leading to a more durable interface.
• The specific ion doping (Zn or Ca) influences the viscoelastic properties and structural integrity of the resin-dentin interface differently.