Objective:The cytocompatibility of a new ozonized olive oil toward immortalized human gingival fibroblasts (HGFs) was evaluated and compared with two common antimicrobial agents based on chlorhexidine digluconate (CHX).Materials and Methods:The cytocompatibility of the samples was tested on immortalized HGF-1 cells by 3-(4, 5-dimethyl thiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were incubated for 2 or 24 h with increasing dilution of ozonized olive oil or CHX agents. The percentage of viable cells was calculated relative to control cells set to 100%.Results:The ozonized olive oil is cytocompatible, and the viability values of the cells treated for 2 or 24 h with increasing concentrations of ozonized olive oil were significantly higher (P < 0.01) compared with the values obtained using CHX.Conclusions:The present data demonstrate that due to its cytocompatibility, the new ozonized olive oil could be considered an alternative antibacterial agent.