Regeneration of supporting tissue to tooth surfaces affected by periodontitis has long been an ideal goal of periodontal therapy. Periodontitis affected root surfaces are hyper mineralized and contaminated with cytotoxic and other biologically active substances. Such surfaces are not biocompatible with adjacent periodontal cells, the proliferation of which is pivotal for periodontal wound healing. Traditional surgical and non-surgical periodontal therapies aim at arresting periodontal disease by removal of plaque-"invested" tissues from disease-affected roots. However complete removal appears...