The aim of the present study is to determine whether the association of Melatonin and Hyaluronic Acid to the antimicrobial TM paste (3% Tetracyclin and 3% Metronidazole) for periodontal maintenance therapy can improve the attachment level (AL) and alveolar bone support for moderate chronic periodontitis.

Local drug delivery agents in periodontology has gained acceptance and popularity compared to systemic drugs due to decreased risk in development of resistant flora, opportunist infection, and side effects.

In order to improve the topical treatment for chronic periodontitis, Melatonin and Hyaluronic Acid have been added to antimicrobial topic paste commercially available.

• A complex matrix composed of Tetracycline, Metronidazole, Melatonin and Hyaluronic Acid have been developed for local treatment of chronic periodontitis.
• Microbiological, physical, chemical characterization of the newly obtained matrix and biocompatibility tests have been performed.
• A randomized clinical trial will be perform on 50 patients with moderate chronic periodontitis recruited based on eligibility criteria and informed consent signed.
• Mechanical debridement of the pockets by scaling and root planning will be performed prior to the adjunctive therapy.
• Extensive clinical examination including charting the remaining teeth, clinical attachment level (CAL), presence of dental plaque (PI), gingival index (GI), calculus (CI), bleeding on probing (BOP), radiographic assessment and identification of periodontal pathogens with micro-IDent® test will be performed at the beginning of the study and 6 month after its completion.
• Each patient will be randomized using sealed envelopes (according to a computer-generated randomization list) to one of the following topical administration (in the periodontal pocket of affected teeth), for 30 consecutive days: Tetracycline and Metronidazole paste (TM), n=25 patients and Tetracycline, Metronidazole, Melatonin, Hyaluronic Acid paste (TM-MHa), n=25 patients.
• A statistical evaluation of data recorded during the entire follow-up period will be performed.

Inclusion Criteria:

• moderate chronic periodontitis, that is, > 2 interproximal sites with AL > 4 mm (not on the same tooth), or > 2 interproximal sites with pocket depth (PD) > 5 mm (not on the same tooth) (1),
• at least 20 teeth present in the mouth,
• no periodontal therapy during the last 6 months,
• no antibiotic during the last 6 months,
• good general health (no systemic condition affecting the course of periodontal disease, including malignancy), pregnancy,
• no allergy to the product components,
• good mental health.

Exclusion Criteria:

• Patients not willing to sign consent form.
• Patients not agreeing with the treatment protocol.