Cardiovascular disease is the world's leading cause of death. Atherothrombosis is a common cause of ischemic stroke.

A strong epidemiological link has been established between periodontitis and the risk of stroke. It shares common risk factors with atherothrombosis, and its severe form is associated with low-grade systemic inflammation and daily low-intensity bacteremia. Atherothrombosis is a frequent cause of ischemic stroke.

Periodontal bacteria have been found within atheromatous plaques, correlated with a greater risk of rupture.

Thus, periodontitis could be a modifiable risk factor for atherothrombosis and future vascular events: its early diagnosis and treatment could have a major impact on cardiovascular prevention.

Hypothesis: In patients with periodontitis who have had an ischemic stroke, periodontal treatment may reduce atherosclerotic plaque activity.

Inclusion Criteria:

• Age ≥ 18 years
• Minor ischemic stroke of the anterior circulation (NIHSS ≤ 5) of atherothrombotic origin according to the TOAST scale <30 days
• Atheroma plaque of the ipsilateral carotid bulb >30% not eligible for intervention (endarterectomy or angioplasty-stenting)
• Severe periodontitis (stage 3 or 4)
• Signed informed consent
• Affiliation to a social security scheme

Exclusion Criteria:

• < 6 teeth
• Without independent oral hygiene
• Contraindications to PET scan
• Known allergy to fluoro-deoxyglucose and its excipient
• Immunosuppressive treatment
• Uncontrolled diabetes
• High risk of infective endocarditis
• Organ transplant pending
• Progressive infectious diseases
• Active smoking not stopped
• Patient deprived of liberty by judicial or administrative decision
• Patient under legal protection (guardianship, curatorship)
• Participation in another interventional research involving humans or being in the exclusion period following previous research involving humans
• Pregnant or breastfeeding woman Patient under AME (state medical aid)