Oral Micro Final Flashcards
Caries is a disease caused by microorganisms feeding on what?
Fermentable carbohydrates
T/F
Remineralization can occur in the early stages of Caries.
True
What are the 4 factors contributing to caries?
Microorganisms
Metabolic Substrates
Teeth and their environment
Time
*quality/quantity with each
What is the Main and 2 Minor ingredients to the Organic Matrix of teeth?
Protein (like collagen)
mucopolysaccharides, chondroitin sulfate
Ca10(PO4)6(OH)2
Hydroxyapatite
Name 5 positive ions and 2 negative Secondary ions that can make up teeth.
Lead, zinc, strontium, silver, nickel, iron
carbonate, fluoride
Enamel is ___% mineral and dentine is ____% mineral.
95%
70%
Describe hydroxyapatite crystal.
OH center
Phosphate and Calcium star of david
6 Calcium
In Hydroxyapatite, what can substitute OH?
What substitutes Phosphate?
What 5 substitutes for Calcium?
Fluoride for OH
Carbonate for Phosphate
Lead, strontium, radium, Iron, Magnesium for Calcium
What is the critical pH for net loss and demineralization of the tooth?
- 5
* above net gain, below net loss
What is more resistant to acid than optimally fluoridated human teeth?
Beaver enamel - lots of Iron instead of Calcium
T/F
Hydroxyapatite is covalently linked
False
With enamel maturation, the regularity of the hydroxyapatite crystals tend to increase ______
Spontaneously
Why can free ions diffuse into the mineral lattice of enamel?
Porous
T/F
Hydroxyapatite is essentially insoluble at neutral pH
True
What 2 ions are essentially in a saturated state (ready to precipitate) in the body?
Calcium
Phosphate
- rxn goes to right, dissolution, left, remineralization
- *pH dependent
Limited access for saliva, plaque retention, pits/fissures are all caries-suceptible.
True
The occlusal surfaces of Molars and Premolars most are susceptible to caries where?
Pits and fissures
______ of molars and _______ of maxillary incisors are susceptible to caries.
Buccal Pits
Palatal Pits
What approximal surface site is susceptible to caries?
Cervical to contact
T/F
The cervical margin just coronal to the gingival margin is susceptible to caries
True
In patients with gingival recession ________ surfaces area susceptible to caries.
Exposed root surfaces
T/F
Margins of deficient restorations, and tooth surfaces adjacent to dentures and bridges are susceptible to caries
True
Limited saliva access favors what?
Plaque retention
What is the sequence of plaque development?
Salivary proteins > Pellicle > Plaque bioflim > calculus
What is the acellular, homogenous, organic film that forms on enamel by selectively adsorbing glycoproteins and salivary proteins?
Pellicle
Are bacteria necessary for the formation of Pellicle?
no
*forms spontaneously
If the Pellicle is removed by meticulous cleaning, it takes how long to re-form?
Minutes to hours
T/F
The pellicle serves to protect the tooth
False
*maybe, but not proven
T/F
The plaque biofilm is soft and non-mineralized
True
What are the 3 layers making up the Plaque Biofilm?
Pellicle (plaque-tooth interface)
Microbial layers/colonies
Insoluble Intercellular matrix
What 2 things make up the Insoluble intercellular matrix of the plaque biofilm?
Carbohydrates (glucans, fructans, other polysaccharides)
Protein
*CHO produced by the bacteria
The metabolic fermenting process of bacteria on teeth of CHO produces what? (2 things)
H+
Extracellular Polymers
*some plaque bacteria produce these 2
Once inorganic deposits are present in plaque biofilm, what has formed?
What does this greatly increase risk for?
Calculus
Periodontitis
T/F
Germ free animals do not develop caries even when fed a cariogenic diet
True
What is the term for known oral flora used in testing?
What are the experiments called?
Gnotobiotic
Add-back
Testing using gnotobiotic animals in add-back experiments have implicated what 3 species of bacteria in caries?
S. mutans
Lactobacillus spp.
Actinomyces spp.
T/F
Caries is an infectious disease
True
Would bubble boy have dental caries?
I think so.
Still has a microbiome, just prone to infectious disease.
Name 3 byproducts of bacterial CHO metabolism
sachrolytic bacteria
EtOH
Acid
Lactic Acid