Effect of UVA-activated riboflavin on dentin bonding

A. Cova, L. Breschi, F. Nato, A. Ruggeri, M. Carrilho, L. Tjäderhane, C. Prati, R. Di Lenarda, Franklin Chi Meng Tay, David Henry Pashley, A. Mazzoni

Research output: Contribution to journalArticlepeer-review

126 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)1439-1445
Number of pages7
JournalJournal of Dental Research
Issue number12
StatePublished - Dec 2011


  • collagen cross-linking
  • dentin bonding agent
  • dentin matrix
  • matrix metalloproteinases
  • nanoleakage
  • riboflavin

ASJC Scopus subject areas

  • General Dentistry


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