File containing: Part A, Raw numerical data of RNA concentration at each concentration and duration of application of the mouthwashes; part B, raw phase contrast photomicrograph of fibroblast cell line after application of mouthwashes at different concentrations and durations.

Background: The maintenance of oral health can be achieved mainly by mechanical and chemical means. Among chemical agents, mouthwashes are widely used for personal oral hygiene because of their ability to inhibit dental plaque. The antibacterial effects of essential oils (EOs) and chlorhexidine (CHX) are well documented; however, the reaction of host tissue to these substances has a poor documentation. Until now studies have not examined the effect of EOs with sodium fluoride (EOF) on fibroblast cell lines. The aim of this study was to examine the effect of mouth rinse EOs, EOF and CHX on the apoptosis of fibroblast cell line. Methods: BHK-21 fibroblast cell line was cultured and incubated in Eagle's Minimum Essential Medium containing EOs, EOF and CHX mouthwashes with different doses (15% or 25%) and various exposure times. Cell apoptosis was assayed using RT-PCR. Results: EOs, EOF and CHX induce apoptotic effects on fibroblasts in a dose and time dependent manner. Conclusion: CHX is the most cytotoxic mouthwash to fibroblasts as compared to mouthwashes containing EOs and EOF.