Methods: Fifty-two patients with at least 1 infrabony defect > 3mm in depth with a probing pocket depth ≥ 6mm were randomly treated with EMD/BC or EMD alone. Clinical and radiographic parameters were evaluated at baseline, 6 and 12 months after surgery. To standardize the procedure an acrylic stent and a millimetre radiographic grid were used. The primary outcome was the change in clinical attachment level (CAL).