Riboflavin-ultraviolet-A-induced collagen cross-linking treatments in improving dentin bonding

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Adhesive Dentistry

Background:

• Dentin bonding is crucial for durable dental restorations.
• Collagen cross-linking enhances the stability of the hybrid layer.
• Evaluating novel cross-linking agents is essential for improving bond longevity.

Purpose of the Study:

• To compare the efficacy of riboflavin-ultraviolet-A (RF/UVA) and glutaraldehyde in cross-linking dentinal collagen.
• To assess the impact of these cross-linkers on dentin bond strength and durability.
• To investigate the ultrastructural changes in the hybrid layer following cross-linking treatments.

Main Methods:

• Collagen cross-linking ability was assessed using gel electrophoresis.
• Mechanical properties of treated dentin were evaluated using nanoindentation.
• Microtensile bond strength (μTBS) and nanoleakage were tested after 24 hours and 5000 thermocycles.

Main Results:

• Glutaraldehyde induced strong collagen gelation; RF/UVA showed milder cross-linking.
• RF/UVA (0.1%RF/2-min) and glutaraldehyde treatments increased dentin stiffness.
• 0.1%RF/2-minUVA maintained high μTBS after thermocycles and exhibited minimal nanoleakage.

Conclusions:

• The 0.1% RF/UVA treatment significantly enhances resin-dentin bond strength and durability.
• This enhancement is attributed to increased stiffness and preservation of the collagen matrix.
• RF/UVA presents a promising alternative for improving the longevity of dental adhesive bonds.