The treatment of intrabony defects in patients with aggressive periodontitis remains a challenging procedure and novel therapeutic strategies are sought. The purpose of this study is to compare the clinical and radiographic outcomes of using guided tissue regeneration (GTR) with radiation-sterilized allogenic bone grafts (material prepared in the Central Tissue Bank in Warsaw, Poland) versus guided tissue regeneration with xenogenic grafts (Bio-Oss®, Geistlich Biomaterials, Princeton, New Jersey, United States) in the treatment of localized intrabony defects in patients with aggressive periodontitis.

Inclusion Criteria:

• Diagnosis of aggressive periodontitis in line with American Academy of Periodontology classification (Lang et al. 1999)
• Familial aggregation (history of periodontitis in parents or siblings)
• Presence of at least two teeth with probing pocket depth (PPD) ≥ 6mm and clinical attachment level (CAL) ≥ 5 mm associated with an intrabony defect of at least 3 mm as detected in diagnostic periapical radiographs
• No furcation involvement of the teeth presenting the intraosseous defects
• The width of keratinized tissue on the facial aspect of the selected teeth ≥ 2 mm

Exclusion Criteria:

• Full-mouth plaque index ≥ 20% (Ainamo & Bay 1975)
• Full-mouth sulcus bleeding index ≥ 15% (Mühlemann & Son 1971)
• Smoking more than 10 cigarettes/day
• Systemic diseases with compromised healing potential of infectious diseases
• Drugs affecting periodontal health / healing
• Pregnant and lactating females
• Previous periodontal surgery in the area