In vitro cytocompatibility of N-acetylcysteine-supplemented dentin bonding agents.
BACKGROUND
Cytotoxic resin components of dentin bonding agents are known to cause oxidative damage and suppress odontogenic differentiation of dental pulp cells. Because antioxidants were found to protect cells from cytotoxicity of resin monomers in previous studies, we investigated the effect of N-acetylcysteine (NAC) on cytotoxicity and anti-differentiation activity of bonding agents.


METHODS
Human dental pulp cells were treated with the extracts of dentin bonding agents (Prime & Bond NT, Adper Single Bond, and Dentin Cement), and then cell viability, alkaline phosphatase (ALP) activity, and matrix mineralization were observed. To assess the effects of NAC, NAC was directly added into culture media or mixed with bonding agents before extraction. Release of NAC from bonding agents was also observed by high-performance liquid chromatography.


RESULTS
NAC enhanced ALP activity and mRNA expression of dentin sialophosphoprotein gene, whereas extracts of dentin bonding agents inhibited the induction of ALP activity. When the cells were treated with extracts of the bonding agents, the NAC in the culture media reduced the cytotoxicity of the bonding agents. When NAC was incorporated into bonding agents, a protective effect was only seen for Prime & Bond NT containing more than 1% NAC. The disruption of ALP activity and matrix mineralization in pulp cells was partially reversed by NAC only in Prime & Bond NT-treated cells. High-performance liquid chromatography analysis of NAC showed that the amount of NAC effluxed from Prime & Bond NT was not greater than that effluxed from Adper Single Bond.


CONCLUSIONS
NAC was useful for reversing cytotoxicity and anti-differentiation effects of Prime & Bond NT on human dental pulp cells.
Department of Dental Biomaterials Science and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
Na Ryoung
NR
Kim
Hee Chul
HC
Park
Insook
I
Kim
Bum-Soon
BS
Lim
Hyeong-Cheol
HC
Yang
D000111:Acetylcysteine / Q000737:chemistry / Q000494:pharmacology*; D000469:Alkaline Phosphatase / Q000187:drug effects; D000880:Anthraquinones; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000633:toxicity; D002113:Calcification, Physiologic / Q000187:drug effects; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents; D003470:Culture Media; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects*; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000633:toxicity*; D004058:Diffusion; D016326:Extracellular Matrix Proteins / Q000187:drug effects; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D005899:Glass Ionomer Cements / Q000633:toxicity; D006801:Humans; D008422:Materials Testing; D015675:Osteocalcin / Q000187:drug effects; D010750:Phosphoproteins / Q000187:drug effects; D011109:Polymethacrylic Acids / Q000633:toxicity; D012795:Sialoglycoproteins / Q000187:drug effects; D000099311:Dentin Sialophosphoprotein
D000111:Acetylcysteine; D000469:Alkaline Phosphatase; D000880:Anthraquinones; D000975:Antioxidants; D017438:Bisphenol A-Glycidyl Methacrylate; D004396:Coloring Agents; D003470:Culture Media; D017220:Dentin-Bonding Agents; D016326:Extracellular Matrix Proteins; D016166:Free Radical Scavengers; D005899:Glass Ionomer Cements; D015675:Osteocalcin; D010750:Phosphoproteins; D011109:Polymethacrylic Acids; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C425843:Prime and Bond NT; C115612:single bond; C004468:Alizarin Red S