The use of methylene blue as mouthwash in periodontology

Headnote

Abstract. The aim of this study is to investigate the cytotoxicity effects of methylene blue on the human gingival fibroblasts cell-lines in vitro.

3T3 human gingival fibroblast cell-lines were used to evaluate the cytotoxicity of mouthwashes containing methylene blue and chlorhexidine gluconate. The cultured fibroblasts were divided into two groups which subjected into chlorhexidine gluconate or methylene blue in vitro. The cells viability was determined at 30 seconds, 1 minute and 3 minutes of exposure to mouthwashes using by XTT colorimetric assay. Spectrophotometric absorbance was measured at 550 nm using ELISA analyzer. The IC₅₀ values were calculated for each time points for methylene blue and chlorhexidine gluconate mouthwashes.

The effect of the methylene blue and chlorhexidine gluconate on the human gingival fibroblast viability was expressed as a percentage of the control groups. Comparison between two groups in different time and concentration values showed that, chlorhexidine gluconate were found to be more cytotoxic on gingival fibroblast than methylene blue. Cell viability exposured to methylene blue in 1% concentration during 3 minutes was 99% and in 100% concentration the cell viability was 88%. The chlorhexidine gluconate at the same conditions was 92% and 18% respectively.

Our study demonstrates that 100% chlorhexidine gluconate (0.2% chlorhexidine gluconate concentration in commercially available products) has much more cytotoxic effect than methylene blue to human gingival fibroblast at clinical use time and different concentrations in vitro.

Key words: Methylene blue, chlorhexidine gluconate, cytotoxicity, mouthwash

1.Introduction

Gingivitis and periodontitis are the most common forms of inflammatory diseases in periodontology. Gingivitis is the inflammation of gingiva caused by plaque accumulation (1). Periodontitis can occur if an imbalance between host defense system and the bacterial niche becomes (2). Their primary etiology is bacterial plaque, which can initiate destruction of the gingival tissues and periodontal attachment apparatus (1, 3). The commonly used periodontal therapy is mechanic remove of the plaque or calculus and the use of topically applied antimicrobial agents which can inhibit periodonto-pathogenic bacteria (4). The scaling and root planning procedures using hand, sonic, or ultrasonic instruments is commonly used by dentists to remove calculus. The aim of scaling and root planning is to remove plaque and calculus and to reduce the subgingival bacteria to acceptable levels for preventing clinical inflammation (5). The...