Influence of chlorine dioxide on cell death and cell cycle of human gingival fibroblasts

Nishikiori, Ryo; Nomura, Yuji; Sawajiri, Masahiko; Masuki, Kohei; Hirata, Isao; Okazaki, Masayuki

doi:10.1016/j.jdent.2008.08.006

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Volume 36, Issue 12 , Pages 993-998, December 2008

Influence of chlorine dioxide on cell death and cell cycle of human gingival fibroblasts

Ryo Nishikiori
- Department of Biomaterials Science, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8553, Japan
Yuji Nomura
- Department of Biomaterials Science, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8553, Japan
- Corresponding author. Tel.: +81 82 257 5647; fax: +81 82 257 5649.
Masahiko Sawajiri
- Hiroshima University Hospital, Hiroshima, Japan
Kohei Masuki
- Department of Biomaterials Science, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8553, Japan
Isao Hirata
- Department of Biomaterials Science, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8553, Japan
Masayuki Okazaki
- Department of Biomaterials Science, Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8553, Japan

Received 22 May 2008; received in revised form 7 August 2008; accepted 16 August 2008.

Abstract

Objectives

The effects of chlorine dioxide (ClO₂), sodium hypochlorite (NaOCl), and hydrogen peroxide (H₂O₂) on cell death and the cell cycle of human gingival fibroblast (HGF) cells were examined.

Methods

The inhibition of HGF cell growth was evaluated using a Cell Counting Kit-8. The cell cycle was assessed with propidium iodide-stained cells (distribution of cells in G₀/G₁, S, and G₂/M phases) using flow cytometry. The patterns of cell death (necrosis and apoptosis) were analyzed using flow cytometry with annexin V-FITC/PI staining.

Results

The lethal doses for 50% of the cells (LD₅₀) of ClO₂, NaOCl, and H₂O₂ were 0.16, 0.79, and 0.11mM, respectively. All three dental disinfectants induced G₀/G₁ cell cycle arrest. H₂O₂ induced apoptosis at concentrations of 0.05 and 0.1mM, while NaOCl and ClO₂ did not induce significant apoptosis at any concentration examined.