The in vitro activity of selected mouthrinses on the reference strains of Trichomonas tenax and Entamoeba gingivalis.

Protozoa, such as Trichomonas tenax, Entamoeba gingivalis and Leishmania braziliensis, may be present in the mouth but their role in the pathophysiology of oral diseases is not clear yet. The use of various types of mouthrinses plays an important role in maintaining proper oral hygiene and in removing some of the microbial components from the oral cavity. The purpose of this study was to investigate the effects of selected mouthrinses on the reference strains of Trichomonas tenax and Entamoeba gingivalis which can be a part of the oral cavity microbiota. Two standard strains Trichomonas tenax (ATCC 30207) and Entamoeba gingivalis (ATCC 30927) were used and metronidazole as a drug used in the treatment of infections caused by protozoa as well as fourteen agents used as mouthwashes were tested, with two pure compounds acting as mouthrinse ingredients, i.e. 20% benzocaine and 0.2% chlorhexidine, as well as 12 commercially-available formulas: Azulan, Colgate Plax Complete Care Sensitive, Corsodyl 0.2%, Curasept ADS 205, Dentosept, Dentosept A, Eludril Classic, Listerine Total Care, Octenidol, Oral-B Pro-Expert Clinic Line, Sylveco and Tinctura salviae. The protozoonicidal activity of the preparations was evaluated on the basis of the ratio of dead to living ratios after incubation in an incubator (37°C) for 1, 10 and 30 min. Protozoa were counted in the Bürker chamber in each case up to 100 cells in an optical microscope (over 400×). The criterion for the death of protozoa was the lack of movement and changes in the shape and characteristics of cell disintegration. The curves of activity were obtained after experiments conducted for 5–7 different solutions of each preparation. On the basis of the curves, the solution killing 50% of the population (CL50) was calculated. All mouthrinses tested in this work in their undiluted form acted lethally on both protozoa. Benzocaine, used as a local anesthetic, has etiotropic properties which can be useful for supporting antiprotozoal treatment. Chlorhexidine confirmed its high efficiency in the eradication of potentially pathogenic protozoa. The use of mouthrinses is an important complement for other procedures intended to maintain correct oral hygiene.