The Impact of Local vs. Systemic Adjuvant Antibiotics During Non-surgical Periodontitis Therapy on Clinical Parameters, Bacterial Count and Cytokine Levels - a Randomized Clinical Trial

Study protocol:

This randomized clinical study will include 40 patients diagnosed with periodontitis stage 3. The investigation will be conducted at the Department of Periodontology and Oral Medicine, at the School of Dental Medicine, University of Belgrade. The laboratory part of the research will be carried out at the Department of Human genetics, at the School of Dental Medicine, University of Belgrade. Patients will be divided into two groups. The test group will consist of 20 patients who will be prescribed a local antibiotic (LA group), while the control group will consist of 20 patients who will be prescribed systemic antibiotic therapy (SA group). The division of patients into groups will be done with randomization envelopes after the diagnostic procedure.

Upon clinical examination, clinical periodontal parameters such as periodontal probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI) will be recorded for each patient around every tooth. Previous to treatment, subgingival crevicular fluid will be sampled with paper points from periodontal pockets for laboratory analysis.

Sampling will be performed as follows: first, a relatively dry working field will be established using paper water rollers and air jets, and then 3 paper points (number 30 - marked in blue) will be applied for 30 seconds in the periodontal pocket area of the selected premolar/molar tooth with a depth of more than 5mm. The procedure will be repeated immediately in the same region, to obtain duplicate samples. After that, the paper points will be placed in Eppendorf tubes and immediately transported to the basic research laboratory, where they will be stored at a temperature of -80 degrees Celsius and where microbiological and molecular analyses will be carried out.

After sampling, all patients will undergo a non-surgical phase of periodontal therapy, following a Full-mouth disinfection protocol. Six months after the NSPT, at the follow-up, clinical examination, detection of clinical parameters, and sampling procedure will be repeated. In the LA group, antibiotics will be applied after the NSPT, while in the SA group therapy will be prescribed at the beginning of the treatment. Locally will be applied a combination of piperacillin and tazobactam in gel form (Gelcide ®, Italmed MedTechDental, Florence, Italy) designed for use in the subgingival region. The local antibiotic will be applied into the periodontal pockets, using a syringe and a flexible blunt needle, 24 hours after the NSPT. The administration will be done by quadrants, following the principles of a dry work field, and after application, the dry field should be maintained for 5 minutes. After this procedure, the patient should not rinse the oral cavity for 15 minutes. For systemic use in the SA group, patients will receive a combination of Amoxicillin (Amoxicillin ®, 500mg, 3 times a day, 7 days) and Metronidazole (Orvagyl ®, 400mg, 3 times a day, 7 days) for oral use.