A patient complains of periodical gingival hemorrhages during tooth brushing and increased teeth sensitivity to thermal and chemical stimuli, which persist for the last 6 years. On examination the gums are swollen and hyperemic. Periodontal pockets are 5mm deep with serous purulent content, tooth cervices are bared, I degree tooth mobility is observed. On X-ray: irregular resorption of of alveolar septa up to their 1/2. What diagnosis corresponds with the given clinical presentation?