Caries Basics: Enamel homeostasis and the development of caries Flashcards
What ways can tooth minerals be lost by acids
Caries
Gustatory acids
Dietary sources
Erosion
What ways can tooth mechanical wear cause the loss of tooth minerals
Attrition
Abfraction
Abrasion
What are caries
- Loss of tooth substance by metabolically produced acids
- Bacterial disease
- Many influences
- Saliva
What are primary caries
Lesions on unrestored surfaces
What are secondary caries
Recurrent - adjacent to fillings
What are residual caries
Demineralised tissue left behind before a filling is placed
What are active caries
Considered to be progressive
What are arrested caries
No longer progressing
What is a white spot lesion
The is the first visible sign by the naked eye, usually visible with strong white light
What is a brown spot lesion
Usually indicative of an inactive white spot lesion discoloured by the uptake of dye
What are rampant caries
Multiple active carious lesions in the same patient
What are hidden caries
These are usually in dentin and only detectable by radiography
What are the 4 zones of a white spot lesion
1 - Surface Layer
2 - Body of Lesion
3 - Dark Zone
4 - Translucent zone
What is kinda mad about the surface zone of white spot lesions
Most of the demineralisation begins to occur at a subsurface level, leaving the surface zone relatively unaffected
Write down the reaction that occurs between hydroxyapatite and acid
Hydroxyapatite + 8H+ =
10Ca2+ + 6HPO4,2- + 2H2O
What are some of the functions of saliva
- Neutralises organic acids
- Inhibits demineralisation/ enhances remineralisation
- Recycles ingested fluoride to the mouth
- Discourages bacterial growth
- Proteins sustain enamel surface
- Protects tissue
- Enhances taste
- Lubricates food
- Facilitates removal of carbohydrates
If oral pH moves to 4 does saliva levels increase or decrease
Increase significantly
How does salivary proteins affinity for Ca2+ change when the pH becomes more acidic
The affinity fo Ca2+ decreases significantly and more free calcium is released into the mouth
What are the benefits of saliva acting as a source of calcium and phohsphate
- Prevent enamel dissolution
- Enable remineralisation of initial carious lesions
- Disadvantage: possibility of unwanted
What is a normal Ca2+ conc
12.5 ppm
What can cause xerostemia
- Autoimmune
- Head and neck radiotherapy
- Salivary gland disease
- Medication
- Aplasia of salivary glands
Name some types of drugs that can cause xerostemina
- Tricyclic antidepressants
- Anti-psychotics
- Antihistaminics
- Diuretics
- Anti-inflammatory
- Anti-histamines
- Anti-epileptic
- Anti-hypertensive
How does xerostemia affect the stephan curve
The pH drops a little lower than the normal one and then takes significantly longer to recover back to a resting pH.
What kinds of proteins are directly related to tissue maintenance
Proline-rich proteins
Histidine-rich proteins
Cysteine containing proteins
Tyrosine rich proteins
