Inclusion Criteria:  18 years of age or older: with at least 20 permanent natural teeth, excluding crowns; affiliated to a social security system; having received information about the protocol and having given their free, informed and written consent.  Exclusion Criteria:  with periodontitis in the month prior to inclusion; with significant carious lesions deeply modifying the oral microbiota in the month prior to inclusion; having undergone oral surgical treatment within 3 months prior to inclusion; wearing orthodontic appliances; having undergone periodontal procedures in the month prior to inclusion; suffering from severe chronic pathologies deemed incompatible with study entry; allergic to one of the swab components; allergic to any of the components of the BUCCOTHERM mouthwash or the placebo; on drugs that may cause gingival hypertrophy, such as Hydantoins (phenytoin), Dihydropyridines, Diltiazem or Ciclosporin; Medications that can cause gingival bleeding (anticoagulants, antiplatelet agents and aspirin); Antibiotic therapy or professional scaling in the month prior to inclusion; having used oral or topical antibiotics, antiseptics and/or antifungals (e.g., mouthwash, dental gels, etc.) in the month prior to inclusion. Subjects with poor written and spoken French language skills; previously included in the BUCCOTHERM study; simultaneously participating in another trial that may interfere with the conduct of the BUCCOTHERM study or in a period of exclusion after participation in another clinical study; protected persons (adults under legal protection (legal guardianship, curatorship, tutorship), persons deprived of liberty, pregnant or breastfeeding women, women of childbearing age without effective contraception (estrogen-progestin treatments, IUD, tubal ligation), minors.