The Periodontium is defined as a connective tissue organ, protected by epithelium, that attaches the teeth to the bone of the jaws and provides a continually adapting apparatus for their support during function. The four connective tissues of the periodontium are the lamina propria of the gingiva, the periodontal ligament, the cementum and the alveolar bone. Periodontal therapy involves two primary components; Removal of bacterial plaque and calculus, and of the anatomic defects produced. There are two primary approaches to eliminate these defects: Resective and Regenerative, both surgical. Regenerative Surgery seeks to eliminate periodontal defects by creating new bone and periodontal ligament and coronally displacing the gingival attachment and margin. The method for the prevention of epithelial migration along the cemental wall of the pocket that has gained wide attention is called Guided Tissue Regeneration.It consists of placing barrier membranes of different types to cover the bone and periodontal ligament. Это и многое другое вы найдете в книге Guided Tissue Regeneration- A Boon to Periodontology (Sakshi Garg and Kamalpreet Chhina)