Polynucleotides and Hyaluronic Acid vs Enamel Matrix Proteins in the Treatment of Intrabony Defects

The goal of this clinical trial is to compare two periodontal regenerative treatments in adults with Stage III or IV periodontitis and infrabony periodontal defects ≥3 mm. The study aims to determine whether hyaluronic acid and polynucleotides (Regenfast®) combined with bovine bone graft material (Bio-Oss®) provides similar or improved periodontal regeneration compared with enamel matrix derivative proteins (Emdogain®) combined with Bio-Oss®. Researchers will evaluate: * Periodontal healing and bone regeneration * Changes in probing depth, clinical attachment level, gingival recession, and tooth mobility * Radiographic bone fill * Survival of treated teeth after 1, 3, and 5 years Participants will: * Receive initial periodontal treatment and oral hygiene instruction * Undergo clinical and radiographic evaluation * Receive minimally invasive periodontal regenerative surgery under local anesthesia * Be randomly assigned to receive either Regenfast® + Bio-Oss® or Emdogain® + Bio-Oss® * Attend follow-up visits with periodontal examinations and radiographs over 5 years