Periodontics Flashcards
List four types of periodontal tissue
- Gingiva
- Root cementum
- Periodontal ligament
- Alveolar bone
List the classifications of periodontal diseases
- Gingival Disease
- Chronic periodontitis
- Aggressive periodontitis
- Periodontitis as a manifestation of Systemic Diseases
- Necrotizing Periodontal Disease
- Abscesses of the Periodontium
- Periodontitis associated with endodontic lesions
- Developmental or Acquired Deformities and Conditions
Risk factors for Periodontal Disease:
- Smoking
- Aging
- Plaque accumulation
List correlated systemic diseases to periodontal diseases:
- Coronary heart diseases
- Stroke
- Diabetes mellitus
- Preterm birth (low birth weight)
Specific periodontal pathogens:
- Red complex: porphyromonas gingivalis, treponema denticola, tannerella forsynthensis/forsythia
- Prevotella intermedia
- Fusobacterium nucleatum
- Aggregatibacter actinomycetemcomitans
List periodontium duties:
- Connect tooth to jaw bone
- Fixation of tooth within jaw bone
- Stabilization of dental arch
- Force absorption occlusal force
- Overload warning (sensory neurons in periodontium)
- Blood supply
- Sealing inner environment from oral cavity
T/F - Gingiva is only visible tissue in bad periodontium
False, it is visible only in healthy periodontium
List zones of periodontium
- gingival margin
- Free gingiva
- Free gingival groove
- Attached gingiva
- Mucogingival junction
- Alveolar mucosa
Col of free gingiva is?
Non-keratinized epithelium
Describe the free gingiva
- Coronal connective tissue
- buccal/labial and lingual/palatal sides
- Interdental papillae between teeth
- Col is non-keratinized epithelium
Describe free gingival groove
Delineates border between attached gingiva and free gingiva in 40% of people
Describe attached gingiva
- Firmly attached to underlying alveolar bone and cementum
- Immobile
- Stippling
Describe mucogingival junction
Delineates border between attached gingiva and alveolar mucosa: absent on palatal side
Describe alveolar mucosa
- Loosely bound to underlying bone
- Mobile
- No stippling
List the types of gingival epithelium
- Oral (outer) epithelium
- Sulcular epithelium
- Junctional epithelium
Oral (outer) epithelium is
Orthokeratinized
Sulcular epithelium is
Non-keratinized
Junctional epithelium is
Non-keratinized
Function of gingival epithelium
It’s keratinized:
- Protects deeper structures
- Allows selective interchange with oral cavity
- Ortho-, para- and non-keratinized
Cells in gingival epithelium include:
- Keratinocytes
- Langerhans cells
- Melanocytes
- Merkel cells
Function of keratinocytes
90% of cells in gingival epithelium; synthesizes keratin
Function of Langerhans cells
- Defence of oral mucosa - macrophage-like cells; react with antigen penetrating epithelium; initiate early immunological response
Melanocytes function
Synthesizes pigment
Merkel cells are
Light touch sensory cells
Describe junctional epithelium
- Firmly attached to tooth surface (barrier)
- Non-keratinized
- Allow gingival cervical fluid, inflammatory cells, and immune cells access to gingival margin
- Rapid turn-over of cells: rapid repair; host-parasite equilibrium/defence
Describe cementum of the root
Mineralized, but heterogenous connective tissue covering surface of roots
Root cementum is thicker apically
True
Root cementum is deposited over a lifetime
True
Root cementum does not protect root surface from resorption.
False, it does protect the root surface
Components of root cementum
- Organic: collagen type 1
- Inorganic: hydroxyapatite (65%)
Cells of the root cementum include
- Cementoblasts: form cementum on surface
- Cementocytes: inside cementum
- Fibroblasts (specialized): form cementum too
List the four types of cementum:
- Acellular afibrillar cementum (AAC)
- Acellular extrinsic fibre cementum (AEFC)
- Cellular intrinsic fibre cementum (CIFC)
- Cellular mixed fibre cementum (CMC)
Acellular afibrillar cementum (AAC) is located at?
Only located at CEJ
Acellular afibrillar cementum (AAC) has no cells and no collagen
True
Ameloblasts die and leave behind matrix of the acellular afibrillar cementum (AAC)
True
Acellular extrinsic fibre cementum is located at?
Coronal 2/3 of root, as it anchors cementum
Acellular extrinsic fibre cementum contains?
Sharpey’s fibres
Acellular extrinsic fibre cementum is only formed by?
Specialized fibroblasts of dental follicle
Acellular extrinsic fibre cementum is only formed during?
Tooth development
Cellular intrinsic fibre cementum (CIFC) is found where?
Found in apical 1/3 of root
Cellular intrinsic fibre cementum contains?
Contains cells and intrinsic fibres only
Cellular intrinsic fibre cementum is formed in?
Formed in late cementum development
Cellular mixed fibre cementum (CMC) is found where?
Found in apical areas and bifurcations
Cellular mixed fibre cementum contains?
Contains cells, intrinsic and extrinsic fibre
Describe AEFC (root cementum) formation in tooth development
- Mantle predentine forms
- Mineralization of predentine forms dentine
- Secretion and deposition of enamel matrix proteins occurs from the hertwigs epithelial root sheath (HERS)
- HERS separates which induces differentiation and formation of cementum forming cells (i.e. fibroblasts)
- Acellular extrinsic fibre cementum (AEFC) forms from specialized fibroblasts.
List cells in periodontal ligament
- Fibroblasts
- Osteoblasts and osteoclasts
- Cementoblasts
- Osteo-/Cemento-progenitor cells
- Epithelial cells
- Endothelial cells
- Blood cells
- Nerves/nerve cells
- Lymphatic system
How are alveolar crest fibres orientated?
Cementum to just below CEJ to rim of alveolus
How are horizontal fibres orientated?
Cementum to bone just below alveolar crest
How are apical fibres orientated?
Apex of root to bone of socket
How are interradicular fibres orientated?
Bifurcation of root to interradicular septum
How are oblique fibres orientated?
Only fibres that resists occlusal forces; all other fibres resist tensile force.
Which periodontal ligament fibres is the most abundant?
Oblique
Describe cortical bone
Hard dense external bony layer
Descibe cancellous bone
Bone trabeculae and bone marrow
Describe bone marrow contents
Cells, blood vessels and nerves
Describe alveolar bone/bundle bone and cribriform plate
Bone that makes tooth socket and connects with root cementum
Describe marginal alveolar bone
- Scalloped shape
- Distance from CEJ in healthy periodontium: buccal = 1 to 2.4 mm, lingual = 1.5 mm
Alveolar bone/bundle bone in radiographs is called?
Lamina dura
how thick is alveolar bone
0.1-0.4 mm thick
Function of alveolar bone/bundle bone
Anchors sharpey’s fibres,
Alveolar bone/bundle bone lines?
Lines inner surface of tooth socket
Alveolar bone is perforated by?
Numerous Volkmann’s canals
Functionally and structurally, alveolar bone is similar to?
Root cementum
Size and shape of alveolar bone adapts to?
Root
Buccal marginal alveolar bone is how wide?
1 to 2.4 mm
Lingual marginal alveolar bone is how wide?
1.5 mm
