Aim of the study is the efficiency assessment of porous Metronidazole loaded matrix based on gelatin/hydroxyethylcellulose blend in treatment of deep periodontal pockets resulting from severe chronic periodontitis. The matrix was invented and produced in Department of Drug Form Technology, Wroclaw Medical University.

The porous metronidazole (MTZ) loaded matrix was fabricated by the freeze-drying technique. The morphology, mechanical properties, in vitro degradation, MTZ release from dried sponge were evaluated and also the clinical trials were performed.

Patients suffering from chronic periodontitis are examined. To evaluate oral hygiene API (Approximal Plaque Index) and the gum inflammation BOP (Bleeding on Probing) and PBI (Papilla Bleeding Index) indices are used. The clinical examination is performed 3 times. On the first visit the output indicators are defined. The subgingival scaling is performed and Metronidazol on porous matrix is applied to the selected periodontal pockets. 2 control tests of periodontal indices are carried out after one week and one month from the application.

In the control group after scaling/root planing procedure, there is no application of metronidazole.

Inclusion Criteria:

• non-smokers
• suffering from chronic periodontitis

Exclusion Criteria:

• any antibiotics taken systematically or locally in the preceding six months