title: Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.
abstract: Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration.
authors.affiliation: The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, UCLA School of Dentistry, Los Angeles, CA 90095-1668, USA.
authors.forename: Hajime
authors.initials: H
authors.lastname: Minamikawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamada
authors.forename: Fuminori
authors.initials: F
authors.lastname: Iwasa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ueno
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Deyama
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yawaka
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D002113:Calcification, Physiologic; D002470:Cell Survival; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D003782:Dental Pulp / Q000166:cytology* / Q000502:physiology*; D003785:Dental Pulp Capping / Q000295:instrumentation* / Q000379:methods; D005899:Glass Ionomer Cements / Q000737:chemistry / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012038:Regeneration / Q000502:physiology
chemical_list: D001672:Biocompatible Materials; D016207:Cytokines; D005899:Glass Ionomer Cements; D017382:Reactive Oxygen Species; D005978:Glutathione; D000111:Acetylcysteine