EUGENIA EFTIMIE TOTU, CORINA MARILENA CRISTACHE, ROXANA BUGA, FLORINA DUMITRU, TIBERIU TOTU A CARD DOUBLE FACE: COMPOUNDS FUNCTIONALITY AND SYNERGY OF A TOPICAL TREATMENT PROPOSED FOR ORAL HEALTH IMPROVEMENT IN PERIODONTAL DISEASE The application of an active mixture of melatonin, hyaluronic acid and tetracycline, as antibiotic adjuvant, for scaling and root planing in periodontal disease is exploited. The hyaluronic acid gel has been used as matrix for this topical mixture. The mixture of active ingredients has been structurally studied applying UV-Vis and FT-IR spectrophotometry and fluorescence microscopy. Our target was to put in evidence if melatonin, hyaluronic acid and tetracycline were preserving their specific characteristics when they would be mixed together. The recorded results are encouraging as each active compound maintains its characteristic functional groups imparting their biological action. The improved topical treatment based on melatonin, hyaluronic acid and tetracycline is presenting itself as a promising candidate for improving the oral health for patients with periodontitis.