The aim of the study was to perform a randomized controlled clinical study in order to compare the effects of a bovine derived xenograft (with 10% collagen) + a bioabsorbable membrane (control group, CG) vs a bovine derived xenograft (with 10% collagen) alone (test group, TG) on the surgical treatment of mandibular type II furcation defects.

The aim of the study was to perform a randomized controlled clinical study in order to compare the effects of a bovine derived xenograft (with 10% collagen) + a bioabsorbable membrane (control group, CG) vs a bovine derived xenograft (with 10% collagen) alone (test group, TG) on the surgical treatment of mandibular type II furcation defects. The patients all underwent the same surgical intervention with the only difference between the two groups being the use or not of a collagen membrane.

Inclusion Criteria:

• Patients diagnosed with chronic periodontitis
• Initial phase (oral hygiene instructions + full mouth scaling and root planing) performed at least eight weeks before inclusion
• Full-mouth plaque score ≦ 20% (at least eight weeks after initial phase and during the whole treatment)
• Clinical evidence of vestibular or lingual mandibular Class II furcation defects (≧ 3mm of horizontal probing depth)
• Presence of at least 2 mm of keratinized gingiva on the selected tooth surface facing the furcation
• Tooth vitality confirmed by clinical tests (cold testing)

Exclusion Criteria:

• Presence of any systemic disease
• Smokers
• Devitalized tooth or tooth presenting periapical or pulpar pathology (confirmed with a retro-alveolar radiograph)
• Allergies to any of the products used in the present study
• Pregnant or breastfeeding women
• History or current RX therapy

The patients didn't know whether they were the control or test group