Periodontal Tissues in Health Flashcards
What is the periodontium?
The supporting apparatus of the tooth
What are the 4 tissues which make up the periodontium?
- Gingiva
- Periodontal ligament
- Alveolar bone
- Cementum
What is the function of the interdental papilla?
Prevent food impaction
What are the 2 types of gingiva?
- Alveolar mucosa
2. Attached gingiva
Describe the attached gingiva
Keratinised gingival tissue attached tightly to underlying alveolar bone
Describe the 4 main clinical appearances of healthy gingiva
- Pink
- Stippled
- Knife edged margin
- Scalloped profile
Describe 2 overall functions of the gingiva
- Provide attachment between oral mucous membrane and dental hard tissues
- Protects underlying periodontal tissues from invasion by bacteria present in oral cavity
What are the 3 distinct types of the gingival epithelium?
- Junctional epithelium
- Sulcular epithelium
- Oral gingival epithelium
Which part of the gingival epithelium is free?
Oral gingival epithelium
What cells make up the junctional eptithelium?
Stratified non keratinised cells approximately 1mm in length
Describe 2 functions of junction epithelium
- Forms the attachment of the gingiva to the tooth surface
2. Defence role against bacterial invasion
Describe the cells which make up the sulcular epithelium
Stratified squamous non-keratinised epithelium
What is the approximate depth of sulcular epithelium?
0.5-2mm in depth
Describe the cells of the oral gingival epithelium
Stratified squamous keratinised epithelium
Name 5 components of the gingival connective tissue
- Fibroblasts
- Many blood vessels
- Nerve cells
- Collagen fibres bedded in extra cellular matrix
- GAGs, proteoglycans and glycoproteins
Describe the relationship between fibroblasts and periodontal connective tissues
Major cell types in periodontal connective tissue which secretes all components of extracellular matrix
What are 5 types of collagen fibres in periodontal connective tissues?
- Circular fibres
- Dentogingival fibres
- Alveolar crestal fibres
- Dentoperiosteal fibres
- Transceptal fibres
What is the periodontal ligament?
Fibrous attachment which inserts into the tooth and alveolar bone
What types of joint is the periodontal ligament?
Gomphosis as it allows some movement but is not from bone to bone
What are Sharpey’s fibres?
End of ligament fibres embedded into bone which are mineralised
What is the primary function of the periodontal ligament?
Supportive role of tooth, protecting against resorption and remodelling role
Describe 3 features of the alveolar bone proper
- Thin lamella of bone surround root of tooth
- Attachment to principle fibres of PDL
- Perforated due to ingress of nerves and vessels
What are 3 components of alveolar bone?
- Alveolar bone proper
- Cancellous bone
- Cortical plates
What is the function of cancellous bone of alveolar bone?
Surrounds the alveolar bone proper and gives support to the socket
Describe the cancellous bone of the alveolar bone
Spongy bone consisting of widely spaced concentric or transverse lamella enclosing marrow spaces
Describe cortical plates of the alveolar bone
Facial and lingual plates of compact bone forming the outer and inner plates of alveolar bone
What cells are responsible for resorption of alveolar bone?
Multi-nucleated osteoclasts residing in Howships lacunae
What 2 cells are responsible for deposition of alveolar bone?
- Osteoblasts
2. Osteoprogenitor cells
Give an overview of cementum
- Calcified mesenchymal tissue covering entire root surface
- Avascular and not innervated
- Formed slowly throughout life
- Thicker at apices
- Resistant to resorption
Name 2 types of cementum
- Acellular
2. Cellular
Describe acellular cementum
- Forms a thin layer often confined to cervical portions of the root
- Doesn’t contain cementocytes but cementoblasts can be found on surface
Describe cellular cementum
- Contains cementocytes in lacunae
- Communicate with each other through network of canaliculi
What is hypercementosis?
Increased deposition of cementum generally around the apical regions of the tooth
