The Influence of Local Antibiotic Therapy on the Microbiological, Clinical, and Radiological Outcomes Following Minimally Invasive Periodontal Surgery in the Treatment of Intrabony Defects—A Randomized Clinical Trial

<b>Objectives</b>: Comparison of clinical, radiological, and microbiological outcomes following periodontal regeneration procedures with or without local antibiotic therapy. <b>Methods</b>: Forty patients, each presenting with a single vertical defect, were randomly assigned to either the test (SRP+ANB+MIST/M-MIST) or the control group (SRP+MIST/M-MIST). The periodontal regenerative procedures were carried out according to the general minimally invasive surgical technique principles, and the vertical bone defect was filled with an enamel matrix derivative (EMD-Emdogain^®). Periodontal condition assessments were performed two weeks before the procedure, on the day of the surgical procedure, and at follow-up visit after 6 months. Radiographs were taken two weeks before, and 6 months after the surgery. To determine the microbiological profile of the surgical sites, subgingival plaque samples were collected for PCR analysis. <b>Results</b>: In both groups, a statistically significant pocket depth (PD) reduction and clinical attachment level (CAL) gain were observed over the 6-month follow-up period. The difference between the groups for PD and CAL parameters at 6 months was not statistically significant. Both groups showed a statistically significant reduction in the radiological depth and width of intrabony defects. Microbiological analysis revealed a statistically significant difference between the groups two weeks after subgingival antibiotic application for <i>Fusobacterium nucleatum</i>, <i>Tannerella forsythia</i>, and <i>Prevotella intermedia</i>. <b>Conclusions</b>: Periodontal tissue regeneration procedures according to minimally invasive principles (MIST/M-MIST) with the use of EMD lead to improvements in clinical and radiological parameters. Local antibiotic application results in a reduction in bacterial counts in short-term observations. Its use prior to regeneration procedures does not lead to additional improvements in clinical and radiological parameters.