Use of Photoreactive Riboflavin and Blue Light Irradiation in Improving Dentin Bonding-Multifaceted Evaluation

Area of Science:

• Biomaterials Science
• Dental Materials
• Biochemistry

Background:

• Photoactivated riboflavin (RF) treatments enhance resin-dentin bonding via collagen crosslinking.
• Ultraviolet A (UVA) light is currently used for RF activation in dental applications.

Purpose of the Study:

• To compare the efficacy of blue light (BL) activated RF with UVA activated RF.
• To evaluate the impact of BL-activated RF on collagen matrix strengthening, enzymatic degradation resistance, and adhesion.
• To determine the optimal RF concentration and irradiation time for BL activation.

Main Methods:

• Six experimental groups were established, including control, RF/UVA, and various RF/BL concentrations and durations.
• Gel electrophoresis validated collagen crosslinking.
• Nanoindentation assessed elastic modulus and nanohardness.
• Zymography evaluated matrix metalloproteinase-2 inhibition.
• Microtensile bond strength (µTBS) tests were performed pre- and post-enzymatic degradation.

Main Results:

• Both RF/UVA and RF/BL treatments increased the elastic modulus and nanohardness of demineralized dentin.
• All RF treatments inhibited matrix metalloproteinase-2.
• RF/UVA and RF/BL groups (0.1% RF) maintained high µTBS after 7-day enzymatic degradation.
• The RF0.1BL1 group exhibited a significantly thicker hybrid layer compared to other groups.
• 0.1% RF concentration was superior to 1% RF for enhancing dentin bonding.

Conclusions:

• Blue light (BL) activated riboflavin (RF) is as effective as UVA activated RF in crosslinking dentinal collagen and resisting enzymatic degradation.
• 0.1% RF with BL activation shows significant potential for improving resin-dentin bonding, with optimal parameters requiring further investigation.
• BL activation offers a promising alternative for RF treatments in dentistry, potentially enhancing bond durability and clinical outcomes.