Thirteen patients who will receive treatment with teeth brushing, dental floss and tongue scraper.

Thirteen patients who will receive treatment with teeth brushing, dental floss and antimicrobial photodynamic therapy applied to the back and middle third of the tongue.

Thirteen patients who will receive treatment with teeth brushing, dental floss and probiotics.

Thirteen patients who will receive treatment with teeth brushing, dental floss, antimicrobial photodynamic therapy applied to the back and middle third of the tongue and probiotics..

All participants will be instructed to brush with dentifrice containing amine fluoride in their composition (Elmex®) and floss with dental flossing, 3 times a day after meals for 30 days.

Oral air collection will follow the manufacturer's guidelines (Oral ChromaTM Manual Instruction) where the participant will be instructed to rinse with cysteine (10 mM) for 1 minute, then remain with his/her mouth closed for 1 minute. A syringe from the same manufacturer for collection of mouth air will be introduced into the patient's mouth. During 1 minute the patient will remain closed mouth, breathing through the nose, without touching the syringe with the tongue. The plunger will be pulled out, we will re-empty the syringe air into the patient's mouth and again pull the plunger to fill the syringe with the breath sample. We will wipe the tip of the syringe with gauze to remove moisture from the saliva, place the gas injection needle in the syringe, and adjust the plunger to 0.5 ml. The gases collected at the entrance door of the appliance are injected in a single movement.

Samples of the tongue coating will be collected using a sterile swab that will be passed on the surface of the back of the tongue with a back and forth movement (10 times). Samples will be deposited in sterile tubes that will be identified and stored at -80°C until analyzed. After thawing, the samples will be vortexed for one minute. For extraction of bacterial DNA, samples will be boiled for 10 minutes and then centrifuged at 10,000 rpm for 10 minutes. The supernatant will be placed in a new microtube containing 100μL of phenol/chloroform/isoamyl alcohol (25: 24: 1), followed by ethanol precipitation. The purified DNA will be resuspended in TE buffer. The levels of P. gingivalis, T. forsythia and T. denticola, will be analyzed by quantitative PCR. The quantitative analysis will be performed using real-time PCR using Step One Plus Thermal-Time PCR System and fluorescence-detected products using the Quantimix Easy SYG Kit, following the protocol recommended by the manufacturer.