Dental Caries Flashcards
Define plaque
heterogeneous, gelatinous, and complex mass of bacteria adhering to the tooth surface
Carious lesions only occur…
under a mass of bacteria capable of producing a SUFFICIENTLY ACIDIC ENVIRONMENT TO DEMINERALIZE TOOTH STRUCTURE. This occurs over time
Dental plaque begins with __________ in saliva adhering to enamel surface forming the ____ ____
Begins with GLYCOPROTEINS in saliva adhering to enamel surface forming the ACQUIRED ENAMEL PELLICLE (AEP)
What does the acquired enamel pellicle allow for?
bacteria to ADHERE and begin colonization
microorganisms in dental plaque ferment ___ ___ for energy and produce ___ by-products
microorganisms in dental plaque ferment REFINED CARBOHYDRATES for energy and produce ACIDIC by-products
saliva contains ___ and ___ ions that serve in remineralization
calcium and phosphate ions.
two main bacteria associated with dental caries
Streptococcus Mutans and Lactobacilli
Aciduric vs acidogenic
Aciduric = tolerant of acidiv environments Acedogenic = produce great amounts of acids
Is S. mutan aciduric or acidogenic?
S. mutans is acidogenic, therefore it is associated with the PRODUCTION of caries/favourable for bacterial colonization
Is Lactobacillus aciduric or acidogenic?
Aciduric. Therefore it is associated with the PROGRESSION of caries
S. mutans and lactobacilli are stimuated by presence of ___
sucrose
Dominant member of plaque flora?
S. Mutans
why is low pH in the mouth bad?
Lower pH leads to hydroxyapatite breakdown (enamel crystal dissolution), which leaves behind more pores to which bacteria can adhere
Critical pH for enamel vs dentin where demineralization can occur?
Critical pH for:
-Enamel: 5.5
-Dentin: 6.2
Therefore, dentin is more prone to acid attack than enamel
What is remineralization?
- pH recovers
- Ca and PO4 re-precipitate on enamel mineral crystals as HA
Which is a slower process, remineralization or demineralization?
remineralization is slower
Components of keyes required for caries formation
- fermentable carbohydrates
- cariogenic biofilm
- host
- time
also primary modifying factors (ex. oral hygiene, diet, use of fluoride etc) and secondary modifying factors (ex. socioeconomic status, education, age, etc.) contribute to caries
Cariogenicity of plaque is dependent upon
- acidic pH for longer than 30 mins
- Frequency of acidic environment
- stichiness of plaque
- exposure to F-
- HIGH FREQUENCY SUCROSE EXPOSURE is the most important factor in producing cariogenic plaque
T/F: plaque growth without sucrose still leads to caries
False. Plaque growth without sucrose does NOT lead to caries
Name the autoimmune disorder which affects the salivary glands and reduces salivary flow
Sjogrens disease
Low salivary flow rate leads to
Reduced buffering capacity of saliva, which can lead to rampant caries. Presence of adequate saliva is important to neutralize and clear acids and carbs from dental plaque
T/F: F- is naturally present in saliva
True. In small amounts
How does F- inhibit demineralization?
-By the re-precipitation of dissolved calcium and phosphate, preventing these minerals from being leached out of enamel into the dental plaque and saliva.
HA replaced with FA (less soluble)
-Narrowing of pores in enamel, preventing diffusion pathways of acids to penetrate enamel
Fluorhydroxyapatite is more/less soluble than hydroxyapatite
FA is LESS soluble than HA
sites of carious lesions
pits and fissures, smooth surfaces, root surfaces
Why does plaque adhere and colonize more easily on root surfaces as opposed to enamel
because root surface is rougher than enamel
appearance of incipient caries when dessiccated
enamel appears chalky and opaque white when tooth is desiccated
Should you treat incipient caries?
naw, has the possibility of remineralizing
what is the deveopmental abnormality called in which areas of less mineralization spots exist in the teeth that make them more susceptible to caries, but not carious themselves
hypocalcified white spots
hypocalcified white spots appearance
opaque even when tooth is wet
Dentin is formed by ____ (cells)
odontoblasts
Dentin resoinds to caries the following ways:
- sclerosis (dentinal tubules fill with peritubular dentin)
- reparative dentin
- pulpal death (necrosis)
Pain from caries is a result of what?
pulpal stimulation caused by FLUID MOVEMENT through the dentinal tubules that have been exposed due to cavitation to the oral environment
