Hard Tissues of Periodontium

The periodontium consists of the investing layer and supporting tissues of the tooth: gingiva periodontal ligament cementum and alveolar bone. It has been divided into 2 parts: Gingiva : protects the underlying tissuesAttachment apparatus : composed of periodontal ligament cementum and alveolar bone.Cementum is considered a part of the periodontium because with the bone it serves as the support for the fibres of the periodontal ligament. It is the hard bone like tissue covering the anatomic roots of the teeth.Alveolar process is that portion of the maxilla and mandible that forms or supports the tooth sockets (alveoli).It forms when the tooth erupts to provide the osseous attachment to the forming periodontal ligament; it disappears gradually after the tooth is lost.