title: N-Acetyl cysteine restores viability and function of rat odontoblast-like cells impaired by polymethylmethacrylate dental resin extract.
abstract: There is concern that dental-resin materials directly loaded on a prepared tooth adversely affect dental pulp tissue by releasing the resin chemicals through dentinal tubes. This study determined whether self-curing polymethyl methacrylate (PMMA)-based dental resin extract adversely affected the viability and function of odontoblast-like cells and whether the cytotoxicity of this resin, if any, could be eliminated by N-acetyl cysteine, an antioxidant amino acid derivative. Odontoblast-like cells isolated from rat maxillary incisor dental pulp tissue were exposed to a PMMA resin extract with or without N-acetyl cysteine for 1 h and then cultured in osteoblastic media. The percentage of viable cells 24 h after seeding was 20% in cells exposed to the resin extract without N-acetyl cysteine, whereas 45% of cells were viable after exposure to the N-acetyl cysteine-supplemented extract. The cells that had been exposed to the extract showed a strong tendency for apoptosis associated with the increased reactive oxygen species production and decreased intracellular glutathione level, which was improved by the addition of N-acetyl cysteine. N-Acetyl cysteine supplementation almost completely restored the significantly reduced alkaline phosphatase activity and matrix mineralization by the resin extract. These results conclusively demonstrated that exposure of odontoblast-like cells to the resin extract impaired the cell viability and function and, more intriguingly, N-acetyl cysteine supplementation to the extract significantly prevented these toxic effects.
authors.affiliation: The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, California 90095-1668, USA. masa0316@ucla.edu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamada
authors.forename: Norinaga
authors.initials: N
authors.lastname: Kojima
authors.forename: Wael
authors.initials: W
authors.lastname: Att
authors.forename: Norio
authors.initials: N
authors.lastname: Hori
authors.forename: Takeo
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009804:Odontoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019904:Polymethyl Methacrylate / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012117:Resins, Synthetic / Q000633:toxicity*
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D012117:Resins, Synthetic; D019904:Polymethyl Methacrylate; D053148:Caspase 3; D053179:Caspase 7; D005978:Glutathione; D000111:Acetylcysteine