Surface coatings of the tooth Flashcards
What is nasmyths membrane?
Reduced enamel epithelium + underlying basement membrane (primary enamel cuticle)
What does junctional epithelium develop from?
The reduced enamel epithelium and oral epithelium
What is the reduced enamel epithelium?
Fully differentiated ameloblasts and stratum intermedium (may also include remnants of the stellate reticulum and outer enamel epithelium)
What is the primary enamel cuticle?
Separates reduced enamel epithelium from the enamel (basal lamina like structure)
What happens when a tooth starts to erupt?
The reduced enamel epithelium proliferates and fuses with the oral epithelium = becomes primary junctional epithelium
When does the primary junctional epithelium become the secondary junctional epithelium?
Following migration down the tooth and apoptosis, it is shorter and attaches the connective tissue to the tooth
Where is the sulcular epithelium?
Where gingivae is not attached to the tooth (lines inside of gingival sulcus)
What type of tissue is secondary junctional epithelium?
Stratified, non-keratinised epithelium
What is the funnel effect?
The secondary junctional epithelium is thinner at the base (near cementoenamel junction)
What additional protection does the secondary junctional epithelium have?
Just below the epithelium new cells are forming and funnel up to top of sulcus (become desquamates) and pushes toxins back out into sulcus before they can breach into the connective tissue; additionally there are wide intercellular spaces (in cats and dogs anyway) that contains neutrophils and nerve endings
How is the secondary junctional epithelium unique?
It has 2 basal lamina: external basal lamina (normal - faces the connective tissue) but also the internal basal lamina which faces the tooth enamel
What is the epithelial attachment layer?
Lines the internal basal lamina = integrins and bullous pemphigoid antigens etc.
What is bullous pemphigoid disease?
Autoimmune disease of bullous pemphigoid antigens = separation of underlying cells from basal lamina = fluid filled blisters covering body
What is the role of the junctional epithelium?
Prevention of infection (barrier, flow of gingival crevicular fluid, permeability) and acquired pellicle formation
What do the constituents of gingival crevicular fluid arise from?
Microbial plaque (endotoxins, enzymes, metabolic end products), host inflammatory cells (PMN’s, leukocytic enzymes, lactoferrin, lysozyme), host tissue (collagen, proteoglycans, matrix proteins), serum derived factors (IgG’s, complement, cytokines, eicosanoid - prostaglandins and leukotrienes)
