Effect of UVA-activated Riboflavin on Dentin Bonding

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.

Role of Dentin MMPs in Caries Progression and Bond Stability

“…The potential of cross-linkers is related to the possibility of improving the mechanical strength of the collagen network (Bedran-Russo et al 2014), improving the resistance to enzymatic degradation, and inactivating exposed MMPs bound to matrix collagen (Liu et al 2011;Tjäderhane et al 2013b). Together, this leads to a stable dentin matrix network, which ultimately could determine the formation of a stable HL (Cova et al 2011;Mazzoni, Angeloni, et al 2013;Tjäderhane et al 2013b;Bedran-Russo et al 2014;Mazzoni et al 2014). …”

Nanoleakage evaluation at adhesive-dentin interfaces by different observation methods

“…Depending on various high-resolving power microscopes, nanoleakage can be observed. Light microscope (LM) [13][14][15] , fieldemission scanning electron microscope (FESEM) 8,16,17) , and transmission electron microscope (TEM) 13,18) are the most commonly used qualitative or quantitative nanoleakage observation methods. However, under different approaches, whether the bonding interfaces from the same tooth could produce similar images and statistical results is still unknown.…”

Effects of matrix metalloproteinase enzyms on adhesive bonding

“…Çapraz Bağ Ajanları Çapraz bağ ajanlarının, MMP inhibisyon özellikleri olduğu gösterilmiştir 36,37 ve demineralize dentinde kollajen yıkımına karşı direnç geliştirmek için kullanılır. 20 Riboflavin; UVA ile aktive olan, biyouyumlu bir çapraz bağ ajanıdır ve son zamanlarda diş hekimliğinde kullanımı artmıştır.…”

“…20 Riboflavin; UVA ile aktive olan, biyouyumlu bir çapraz bağ ajanıdır ve son zamanlarda diş hekimliğinde kullanımı artmıştır. 36,37 Riboflavin, bağlanma dayanımını arttırır, adeziv ara yüzeyi stabilize eder ve dentin MMPlerini inhibe eder. 36,38 Proantosiyanidin; doğal olarak oluşan polifenolik bileşenidir, tannin olarak da adlandırılır.…”

“…36,37 Riboflavin, bağlanma dayanımını arttırır, adeziv ara yüzeyi stabilize eder ve dentin MMPlerini inhibe eder. 36,38 Proantosiyanidin; doğal olarak oluşan polifenolik bileşenidir, tannin olarak da adlandırılır. Antioksidan özelliği olan çapraz bağ ajanıdır ve toksisitesi düşüktür.…”