Effect of phytic acid etchant on the structural stability of demineralized dentine and dentine bonding.
OBJECTIVE
This study examined the effect of phytic acid (IP6) in stabilizing the morphology of dentine collagen network and resin-dentine bonding.


METHODS
Dentine beams were fully demineralized with 10% phosphoric acid (PA) or 1% IP6 (pH 1.2). PA-demineralized beams were divided into three groups: (a) no further treatment (control), (b) treatment with 5% glutaraldehyde (GA) for 1 h and (c) treatment with 1% IP6 (pH 7) for 1 h. IP6-demineralized beams received no further treatment. The beams were then subjected to ultimate tensile strength (UTS) testing. Dentine micromorphology evaluation was performed using a field-emission scanning electron microscope (FE-SEM). Dentine disks were etched with 35% PA for 15 s or 1% IP6 for 30s. PA-etched dentine disks were divided into three groups as (a), (b) and (c) as for UTS testing, but the treatment with GA or IP6 was done in 1min. For microtensile bond strength (µTBS) testing, flat dentine surfaces etched with PA or IP6 were blot-dried (wet dentine) or air-dried for 10s (dry dentine) and bonded with an etch-and-rinse adhesive followed by composite build-up.


RESULTS
IP6-demineralized dentine showed significantly higher UTS, when compared to PA-demineralized dentine. GA and IP6 significantly improved UTS of PA-demineralized dentine. FE-SEM observation revealed that dentine collagen network was preserved by GA and IP6. No significant difference in µTBS was found between the wet and dry IP6-etched dentine groups.


CONCLUSIONS
IP6 etching showed a structural stabilizing effect on demineralized dentine matrix and produced good resin-dentine bonding, regardless of dentine moistness or dryness.
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: kongkalyan@yahoo.com.
Kalyan
K
Kong
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: soheltmd@gmail.com.
Md Sofiqul
MS
Islam
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: nassarnar@gmail.com.
Mohannad
M
Nassar
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Pokfulam, Hong Kong. Electronic address: hiraope@tmd.ac.jp.
Noriko
N
Hiraishi
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: otsuki.ope@tmd.ac.jp.
Masayuki
M
Otsuki
Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Pokfulam, Hong Kong. Electronic address: ckyyiu@hku.hk.
Cynthia K Y
CKY
Yiu
Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; Global Center of Excellence (GCOE) Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: tagami.ope@tmd.ac.jp.
Junji
J
Tagami
D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D010833:Phytic Acid / Q000494:pharmacology*; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength; D014070:Tooth / Q000187:drug effects* / Q000502:physiology
C093073:Demineralized Dentin Matrix; D019279:Resin Cements; D010833:Phytic Acid
Cross-linker; Glutaraldehyde; Microtensile bond strength; Phosphoric acid; Phytic acid; Ultimate tensile strength