Quiz 3. Carious Lesions Flashcards
Dental Caries Intro
One of the most common diseases in humans
#1 in children
Causes pain/disability
Lead to infection, tooth loss
G.V Black, founder of modern dentristy
Added microbic plaque was the source of acids which is still believed today
Multifactorial Disease Process
There must be Time, Susceptible Tooth, Plaque Microorganisms, Substrate (Food, Carbs) present in order for a Caries to form
Caries are:
Tooth covered by a film of bacteria that’s exposed to a carb substrate and bacterial metabolizes it.
Weak acid byproducts are produced
If enough acid changes pH, enamel demineralized
Description of Carious Lesions
Categorized where located. 4 General areas
Pit and fissure caries (occlusal surface grooves)
Smooth surface caries (anterior)
Root surface caries
Secondary/recurrent caries (on tooth surface adj to an existing restoration)
Incipient lesion
Initial stage of tooth decay, hasn’t penetrated enamel
Looks like white spot on enamel
How caries move
Start in enamel (hard to get through), get to junction, then dentin (spreads quickly)
Caries stages
Incipient
Progess of Demineralization
Over or frank lesions
All Caries start as incipient lesion
but not all turn out overt, can stop
Overt or frank lesions
characterized by actual cavitation (loss of enamel integrity)
Rampant decay occurs if:
development of overt lesions is rapid/extensive (on more than one tooth)
After excessive and frequent intake of sucrose (carbs) and presence of xerostomia
Direct Connection of Bacterial Biofilm to the body of a lesion
Demineralization
Remineralization
Enamel Rods (interlocking structure)
Ragged profile created from demineralization
Progression depends on pH in saliva, flow, rate
Caries almost always
start in the shape of a triangle
Dental Caries Bacteria
Mutans Steptococcus (main)
Lactobacillus: rod shaped
300 species of bacteria in plaque
Mutans Streptococci and caries (MAIN)
Major pathogenic species involved in caries.
Found in large numbers in plaque that forms instantly over developing smooth surface lesions
MS and caries are able
to produce extracellular glucans and acids (byproducts)
It causes damange through lactic acid (mostly) and other acid
What pH does enamel loss occur
5.5 or lower is demineralization
Lactobacilli and Caries
They aren’t required for caries development but can contribute to it.
Common after irradiation therapy for head and neck cancer, saliva is stickier
Sources of Acids
Sources of acid in oral biolfilm ecology: Dietary Bacterial Environmental Intrinsic (bulimina) May all work in combination
Diet
Solid/sticky sugars 40min to neutralize
Liquid sugars 20 min to neutralize
Times don’t start until fully out of teeth
Amount of sugars and frequency and time all affects caries rate
Tooth Susceptibility (Most)
1st and 2nd molars
Mand premolars
Tooth Susceptibility (Least)
Anterior teeth (Tongue, self cleaning)
Major Salivary Glands
Parotid
Submand
Sublingual
Saliva helps to prevent caries
Saliva
Repairs damage by neutralizing acids and replacing lost materials (remineralized)
Parotid Gland
Secrete sodium bicarbonate (neutralize acid)
Initiate carb digestion
Function of Saliva
Lubrication Clearance of food Buffer for pH 6.4-6.7 Antibacterial Ca, P, and Flouride saturation (used to remineralize)
Conditions in which caries happen
Coronal dentin caries (crown of tooth)
Occur at pH 6
Secondary/recurrent caries
Coronal Dentin Caries
Enamel protects underlying dentin Dentin protects pulp Pits and Fissures (susceptible) Smooth surface Interproximal (more susceptible, harder to remove bacterial from flossing)
Root caries
Must have root exposed
Risk factors are age, gender, flouride exposure, illness, oral hygiene
Secondary/Recurrent Caries
Occur from imperfections in/around restoration
Chance of happening again 50%
Prevention is key
Applying flouride-releasing materials to bone the tissue
The Stephan Curve
Drop and recovery curve w/ sucrose
Demineralization and Remineralization Principles
Demineralization is caused my plaque acid. Remineralization needs same ions w/ flouride as catalyst
Flouride chemically stronger than Ca
Fluorohydroxyapatite vs Hydroxyapatite
Flouri. is more resistant to acid damage
Depth of Remineralization
Topical procedures are successful in stimulating surface remineralization
