title: Effect of phytic acid used as etchant on bond strength, smear layer, and pulpal cells.
abstract: This study aimed to evaluate the effect of phytic acid (IP6), used as etchant, on resin-dentin bond strength, smear layer removal, and the viability of pulpal cells. Flat dentin surfaces with smear layer were etched with 1% IP6 for 60, 30, or 15 s; in the control group 37% phosphoric acid (PA) was used. Dentin surfaces were rinsed, blot-dried, and bonded with an etch-and-rinse adhesive, followed by composite build-ups. The specimens were subjected to tensile testing after 24 h of water storage at 37°C, and failure modes were determined using scanning electron microscopy. The effectiveness of IP6 to remove the smear layer was observed using scanning electron microscopy. To evaluate the effect on pulpal cells, solutions of 0.1 and 0.01% IP6 and of 3.7 and 0.37% PA were prepared and rat pulpal cells were treated with these solutions for 6 and 24 h. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results demonstrated that all application times of IP6 produced bond-strength values that were significantly higher than that of the control. Phytic acid effectively removed the smear layer and plugs, thus exposing the collagen network. Phytic acid had a minimal effect on pulpal cells, whereas PA resulted in a marked decrease in their viability.
authors.forename: Mohannad
authors.initials: M
authors.lastname: Nassar
authors.forename: Noriko
authors.initials: N
authors.lastname: Hiraishi
authors.forename: Md Sofiqul
authors.initials: MS
authors.lastname: Islam
authors.forename: Mamoru
authors.initials: M
authors.lastname: Aizawa
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Tamura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Otsuki
authors.forename: Shohei
authors.initials: S
authors.lastname: Kasugai
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ohya
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000818:Animals; D002470:Cell Survival; D001840:Dental Bonding / Q000379:methods*; D003782:Dental Pulp / Q000166:cytology*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010756:Phosphoric Acids / Q000737:chemistry*; D010833:Phytic Acid / Q000737:chemistry*; D051381:Rats; D019279:Resin Cements / Q000737:chemistry*; D016369:Smear Layer; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; D010833:Phytic Acid