The goal of this clinical trial is to assess the safety and effectiveness of adjunctive Emdogain® therapy in non-surgical periodontal treatment for patients with stage 3 and 4 periodontitis. The main questions it aims to answer are: * Will adjunctive treatment with Emdogain® result in a greater reduction in Bleeding on Probing and probing pocket depth compared to non-surgical periodontal treatment alone? • Will adjunctive treatment with Emdogain® lead to a greater mean Radiographic attachment level (rAL) gain per quadrant compared to non-surgical periodontal treatment alone? * Will adjunctive treatment with Emdogain® result in a lower proportion of treated teeth requiring surgery (PPD ≥6mm) at 12 months after treatment? Participants in the study will undergo the following tasks: * Screening and randomization * Receival of non-surgical periodontal treatment in all quadrants and in two quadrants adjunctive Emdogain® * 6-month follow-up assessment * 12-month follow-up assessment Clinical and radiological assesment will be performed in two quadrants treated with adjunctive Emdogain® therapy and two quadrants treated with non-surgical periodontal treatment alone. This comparison will help determine the effects of adjunctive therapy with Emdogain®. The study aims to provide insights into the safety and efficacy of adjunctive Emdogain® therapy in non-surgical periodontal treatment, specifically in patients with stage 3 and 4 periodontitis.