Periodontics

• Periodontium


  Functional system of tissues that surrounds teeth and attaches them to the jawbone
• Supporting tissues of teeth


  Attachment apparatus
• Tissues comprising periodontium


  • Gingiva
  • Periodontal ligament
  • Root cementum
  • Alveolar bone
• Healthy periodontium


  • Protects underlying tooth-supporting structures from oral environment through defense mechanisms like saliva and immune system
• Gingiva


  Part of mucosa that surrounds cervical portions of teeth and covers alveolar process
• Junctional epithelium


  Specialized epithelial tissue that attaches gingiva
• Free gingiva


  Unattached portion that surrounds a tooth in the region of CEJ
• Attached gingiva


  Part of gingiva that is tightly bound to the underlying cementum
• Interdental gingiva


  Portion of gingiva that fills the interdental space between 2 adjacent teeth
• Gingival sulcus


  1. shaped shallow space between free gingiva and tooth surface
• Gingival crevicular fluid (GCF)


  Fluid that seeps from underlying connective tissue into the sulcular space
• Periodontal ligament (PDL)


  Layer of connective tissue that covers the root of the tooth and attaches it to the bone of the tooth socket
• Functions of periodontal ligament


  • Supportive, sensory, nutritive, formative, remodeling
• Root cementum


  Thin layer of hard, mineralized connective tissue that covers the surface of the root
• Functions of root cementum


  • Primary function is for periodontal ligament attachment, seals off open dentinal tubules, compensates for occlusal attrition to maintain tooth length
• Hypercementosis


  Excess deposit of cementum in apical third of root which may obstruct apical foramen
• Alveolar bone


  Mineralized connective tissue that forms bones of the upper and lower jaw to support roots of teeth
• Alveolar bone


  • Forms bony sockets that provide support to roots of teeth, existence is dependent on presence of teeth
• Layers of alveolar bone


  • Alveolar bone proper (cribriform plate)
  • Cortical bone (compact bone)
  • Cancellous bone (spongy bone)
• Periosteum


  Layer of connective tissue that covers the outer surface of bone
• If teeth are extracted, alveolar bone will resorb with time
• If teeth do not erupt, alveolar bone does not develop