Periodontal Tissues in Health & Disease I Flashcards
What 4 components make up the periodontium?
Collective term describing tooth supporting tissues including the;
- Root cementum
- Periodontal ligament
- Alveolar bone
- Gingiva
What are the 3 components of the tooth germ?
What do these become?
- Enamel organ: Enamel and primary epithelial attachment
- Dental papilla: Pulp and dentin
- Dental follicle: Cementum, periodontal ligament, alveolar bone
What is the gingiva?
The part of the oral mucosa covering the tooth-bearing part of the alveolar bone and the cervical neck of the tooth
What is the gingiva a major peripheral defence against? (2)
- Microbial infections
- Mechanical trauma
What is the gingival zenith?
The most apical point of the marginal gingival scallop
How do you work out biological width
Junctional Epithelial width + CT attachment width
What is interdental gingiva?
Occupies the gingival embrasure, which is the inter proximal space beneath the area of tooth contact
What shapes can interdental gingiva be? (2)
- Pyramidal shaped
- Col shaped
What does the periodontal phenotype describe? (2)
The combination of gingival phenotype (gingival thickness and keratinised tissue width) and the thickness of the buccal bone plate (bone morphotype)
With what instrument is periodontal phenotype assessed?
What do these results show;
Probe visibile?
Probe not visible?
- Periodontal probe
- Probe visible: THIN (≤1mm)
- Probe not visible: THICK (>1mm)
Name 3 periodontal phenotypes
- Thin scalloped
- Thick scalloped
- Flat thick
What is a common pigment found in the paeriodontium
Melanin
Describe the location of the oral gingival epithelium
Extends from the mucogingival junction to the tip of the gingival crest and is subdivided into the free marginal gingiva and the attached gingiva
What is the thickness of the oral gingival epithelium?
0.2-0.3 mm in thickness
What cell types can be found in the oral gingival epithelium? (5)
- Keratinocytes
- Langherans cells
- Melanocytes
- Merkel’s cells
- Inflammatory cells
Describe the location of the oral sulcular epithelium
Lines the gingival sulcus and extends from the tip of the gingival crest to the most coronal portion of the junctional epithelium
What are the histological and clinical depths of the gingival sulcus?
- Histological depth: 0-0.5mm
- Clinical depth: 0.5-3 mm
What is the junctional epithelium?
Forms the attachment of the gingiva to the tooth structure
What reinforces the junctional epithelium to the tooth?
Gingival fibers
What are the 4 components of the microscopic gingiva anatomy?
- Oral gingival epithelium
- Oral sulcular epithelium
- Junctional epithelium
- Connective tissue
What cells can be found in gingiva CT? (2)
- Fibroblasts
- Immune cells
What can fibroblasts in the gingiva synthesise? (4)
What can they regulate?
- Synthesise collagen and elastic fibres, as well as glycoproteins and GAGs
- Regulate collagen degradation
What are the 4 types of fibres in the gingiva CT?
Remember CORE Fibres
- COLLAGEN (mainly type I)
- RETICULIN
- OXYTALAN
- ELASTIC
Where are dento-gingival fibres located?
What do they do?
- Cementum to free gingival tissue
- Provide gingival support
Where are alveolo-gingival fibres located?
What do they attach?
- Start from periosteum covering the alveolar crest
and project coronally into the attached gingiva - They attach gingiva to bone
Where are dento-periosteal fibres located?
What do they do?
- CEMENTUM to ATTACHED GINIGVA
- Embedded in the same portion of the cementum as the dentogingival fibers but run their course apically over the vestibular and lingual bone crest and terminate in the attached gingiva
- Anchor tooth to bone and protect PDL
Where are circular fibres located?
What do they do?
- Run in the marginal and interdental gingiva
- Encircle each tooth in a cuff- or ring- like fashion
- Maintain contour and position of free marginal gingiva
Where are trans-septal fibres located?
What do they do?
- Extend between the supra-alveolar cementum of adjacent teeth
- Support interdental gingiva, secure positions of adjacent teeth and protect inter proximal bone
What is Gingival crevicular fluid (GCF)?
Inflammatory exudate that can be found in the crevice
Where do the molecules of GCF originate from? (3)
- Blood
- Host tissues
- Sub gingival plaque
What are the 3 main functions of the cementum?
- Anchorage (medium for attachment to the collagen fibres of PDL)
- Repair/resorption (continuous deposition thus it repairs the damages)
- Protection (seal for open dentinal tubules)
What is cementum?
Avascular mineralised tissue covering the root surface
What are cementoblasts;
Type of cell?
What do they synthesise? (2)
Mesenchymal cells that synthesise collagen and protein polysaccharides, which make up the organic matrix of cementum
What are cementocytes?
Cementoblasts become entrapped within their own matrix and become cementocytes
What are cementoclasts?
Multinucleated giant cells which have resorption and repair function
What is the anorganic matrix component of cementum made up of? (3)
- Hydroxapatite
- High fluoride
- Trace elements (Cu,K,Na)
What is the organic matrix component of cementum made up of? (2)
- Type I and III collagen
- Non-collagenous proteins
What produces extrinsic cementum fibres?
The PDL
What produces intrinsic cementum fibres?
Produced by cementoblasts and that are orientated more or less parallel to the cementum surface
What are the 4 main types of dental cementum?
AAC
(AEFC)
(CIFC)
(CMSC)
- Acellular Afibrillar Cementum (AAC)
- Acellular Extrinsic Fiber Cementum (AEFC)
- Cellular Intrinsic Fiber Cementum (CIFC)
- Cellular Mixed Stratified Cementum (CMSC)
Where is Cellular Mixed Stratified Cementum (CMSC) found?
Apical third of the root and furcation area
Where is Acellular Extrinsic Fiber Cementum (AEFC) found?
Coronal 2/3 of the root
Where is Cellular Intrinsic Fiber Cementum (CIFC) found?
Usually present as a component of cellular mixed stratified cementum (CMSC)
Where is Acellular Afibrillar Cementum (AAC) found?
May be found as coronal cementum over enamel at CEJ
What is the affect of ageing on cementum?
With ageing the surface of cementum becomes more irregular. This is caused by calcification of some fiber bundles where they were attached to cementum
