This is a three arm randomized trial. The aim is to evaluate the antimicrobial activity of
chlorhexidine and polyhexamethylene biguanide oral antiseptics on the microorganisms of the
oral cavity. A total of 30 healthy volunteers will be enrolled and randomly allocated to
control group (CG, n=10), which will be instructed to rinse the mouth with 10ml of a sterile
saline solution for one minute, to chlorhexidine group (ClG, n=10), which will be instructed
to rinse the mouth with 10ml of an 0.12% chlorhexidine solution, for one minute, or to
polyhexamethylene biguanide group (PG, n=10), which will be instructed to rinse the mouth
with 10ml of an 0.07% polyhexamethylene biguanide solution, for one minute. Samples of saliva
will be collected before the mouth wash and after 30, 60 and 180 minutes. Samples will be
plated on manitol agar, mitis salivarius agar, EMB agar and Sabouraud agar. Samples will be
processed by a blinded microbiologist.