- Radiographic measurements: The infrabony component was recorded in millimetres. The following measurements were made: 1) distance from the cemento-enamel junction to the bottom of the defect (CEJ-BD), 2) distance from the CEJ to the most coronal extension of the alveolar bone crest (CEJ-BC). The infrabony component (INFRA) of the defects was defined as (CEJ-BD) - (CEJ-BC), 3) angulation of the defect, assessed by measuring the angle between the intersection of a line across the long axis of the tooth and the delimitation of the wall of the defect (GeoGebra® 5.022.0-3D), and 4) number of the remaining walls of the defect, that were confirmed intrasurgically.