 Radiographic assessments Radiographs were taken with a parallel, standardized, technique at baseline Eickholz et al. 2004. Radiographs were digitized and analysed using NIH Image Analysis software. The anatomical landmarks for the study included cementum-enamel junction CEJ, alveolar crest AC and base of the defect BD Schei et al. 1959. Radiographic defect depth was measured along the root surface, parallel to the root axis, as the distance between CEJ and BD. 