Effect of UVA-activated riboflavin on dentin bonding

J Dent Res. 2011 Dec;90(12):1439-45. doi: 10.1177/0022034511423397. Epub 2011 Sep 22.

Abstract

Recent studies have reported collagen cross-linking after exposure to riboflavin followed by ultraviolet-A (UVA) exposure. This study is the first to investigate the effect of a riboflavin-containing primer on adhesive interface stability and dentinal matrix metalloproteinase activity. Human dentin was etched with 35% phosphoric acid, treated with 0.1% riboflavin, exposed to UVA for 2 min, and bonded with a two-step etch-and-rinse adhesive. Adhesive was applied to control specimens without riboflavin/UVA. Specimens were subjected to microtensile bond strength tests and pulled to failure after storage for 24 hrs, 6 mos, or 1 yr. Interfacial nanoleakage was evaluated by light and transmission electron microscopy. To investigate dentinal matrix metalloproteinase activity, we performed correlative zymographic assays on protein extracts obtained from phosphoric-acid-etched dentin powder with or without riboflavin/UVA treatment and XP Bond. Ultraviolet-activated riboflavin treatment increased the immediate bond strength to dentin at all aging intervals (p < 0.05 vs. control) and decreased interfacial nanoleakage in aged specimens (1 yr; p < 0.05). Zymograms revealed that riboflavin/UVA pre-treatment inhibited dentinal matrix metalloproteinase activity (especially MMP-9). In conclusion, dentinal collagen cross-linking induced by riboflavin/UVA increased immediate bond strength, stabilized the adhesive interface, and inhibited dentin matrix metalloproteinases, thereby increasing the durability of resin-dentin bonds.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Collagen Type I / chemistry
  • Cross-Linking Reagents
  • Dental Bonding / methods*
  • Dental Leakage / prevention & control
  • Dental Stress Analysis
  • Dentin / enzymology*
  • Dentin-Bonding Agents / chemistry*
  • Electrophoresis, Polyacrylamide Gel / methods*
  • Humans
  • Matrix Metalloproteinase Inhibitors
  • Riboflavin / radiation effects*
  • Tensile Strength
  • Time Factors
  • Ultraviolet Rays*

Substances

  • Collagen Type I
  • Cross-Linking Reagents
  • Dentin-Bonding Agents
  • Matrix Metalloproteinase Inhibitors
  • XP-Bond
  • Riboflavin