Question | Answer |
What species of bacteria must be present for development of smooth surface caries? | streptococcus mutans |
What species of bacteria must be present for development of root caries? | Acetomyces viscous |
What species of bacteria must be present for development of pit and fissure caries | Lactobacilli |
What are the differences between steptococcus mutans, lactobacilli, and acetomyces visous? | MS: Smooth Surface Caries; predominant organism in caries process
Lb: Pit and fissure caries
Av: Root surface caries |
What do dextrans do? How do they contribute to caries? | Dextrans make plaque adhere to teeth> absorb more sugar> produce acid attack |
Frequency of sugar intake aids in lower pH, thicker plaque, and more colonization of plaque. | w/in seconds bacteria produce acid for 20 min up to 2 hrs the more frequent increase drop in PH. If teeth are left unclean for 3 days the PH drops to about 4.5 or 5 remains at this PH until teeth are cleaned. |
What are the differences between dextrans and levans? Why is this important in caries formation? Which one enables colonization? What are insoluble polysaccharides? | Dextrans- insoluble, produced from glucostransferase polysaccharides.
Levans- polyfructans produced from fructose, increase plaque acidification not colonized.
Dextrans enable colonization and levans enable acid production. |
Know the types of sugars, what they are and the microkals for each bond. | Sucrose- glucose & fructose- 6600
Maltose- glucose & glucose- 3600
Lactose- galactose & glucose- 3600 |
Discuss critical pH | when saliva ceases to be saturated w/ Ca and PO4 below this is when the tooth starts to dissolve: enamel= 5.5, cementum and dentil= 6.4, and Fl2 enamel= 4.7. |
Discuss demineralization | dissolution of enamel crystals by acid occurs in body of lesion and translucent zone. |
Discuss remineralization | much stronger rebuilds crystals and enamel rods occurs in dark zone and surface zone. # of free Ca in saliva and biofilm so Ca leaves the tooth a compound wraps around to fill in spaces. |
Discuss chelation | erosion- increase acid in environment pulls Ca out of tooth to wrap around acid> erosion |
Discuss KSP | law of constant solubility never changes like gravity PO4 has to stay constant so it takes it from the tooth to balance thus causing dissolving. |
Know the sucrose, fructose truck transport system | Biofilm+sucrose>glucostransferase>breaks down sucrose into fructose &glucose>glucose remains outside cell wall in form of dextrans, fructose travels into the tooth some stored as glycogen rest forms lactic acid which can spit back out in form of levans |
How do infants become caries susceptible? | 75% infected between 19-30 months, 3-7 yrs later form cavities. Primary care givers are the source, sm and other bacteria passed from parents. |
What should parents do to prevent caries in their infants? | practice good OH, use Fl2, have caries filled, avoid direct transfer, decrease intake of refined CHO, use xyilotol 5-10 mg/day. Reduce feeding at night, feed only when holding, clean mouth after. |
What are the differences for our teeth between acid added to foods and acid produced by S. mutans? | Acid produced by SM can cause decay, acid added to food cause chelation or erosion. |
What are the sugar rules and why are they the rules? | Eat only w/ a meal
Eat sweets all at once
Avoid snacking in between meals
Avoid sticky
Rinse mouth after if unable to brush
All decrease acid attacks on tooth |
thoroughly discuss the philosophy of caries treatment. “Treating the High Risk Caries Patient.” Be able to list the tx steps. | Limit substrate (CHO) frequency!
Modify microflora chlorihexidine
Practice good OH
Increase recall
Increase Fl2
Stimulate saliva (sugar free gum)
Restore tooth surfaces (fill cavities, sealant) |
Why is xylitol so good for caries reduction? (JADA - maintaining the integrity of the enamel) | Can inhibit acid produced by SM resulting in minimal depression of plaque PH results in less cariogenic bacterial flora. 5-10 mg/day |
What is the critical pH at which enamel demineralizes? What is it if the tooth has had lots of Fluoride? | when the tooth starts to dissolve: enamel= 5.5, cementum and dentin= 6.4, and Fl2 enamel= 4.7. |
What would be the best thing for soon-to-be parents to do if they were caries active? Note: Very little Fluoride passes the placenta to the fetus. | Get parents teeth healthy first, help them become caries innactive
Practice good OH(parents)
reduce CHO intake by child
parent use xylitol lozenge/gum
Parent Use Fl2
Avoid direct transfer
Fl2 when teeth erupt
clean infants mouth after feeding |
Can you use caries susceptibility tests for diagnosis? | NO!!
It's multifactorial, you would explore the tooth surface and take radiographs |
What are some caries susceptibility tests? And what do they test for? | Modified snyder medium-tests cariogenic probability of bacteria in mouth (drool test)
Salivary caries conductivity-(PH paper) tests acidity of saliva
Visual indicator- demonstrates acid production of bacteria in plaque |
Is acid formed within seconds to two minutes after sucrose ingestion? | Yes |
What is the length of an acid attack? How long does it take to clear entirely? | 20min to 2 hours |
What are the specific roles of saliva in the remineralization/demineralization process? | Lubrication/protection
Flushing/rinsing/diluting
Antimicrobial/immune system
Maintenance of supersaturation of Ca & PO4...demineralization/remineralization or "Liquid Enamel" and other chemicals
Initiating digestion, maintaining pH in upper dig. tract |
what does the saliva have in it that helps in the oral fight against caries? | Bicarbonate
Statherin & Histadine
Lysozome
Lactoferrin
Peroxidase
Sialin
Minerals
Secretory immunoglobulin A
Agglutinens |
What is bicarbonates function as it relates to oral health? | primary buffering system
raises pH when flow is stimulated
lasts about 15 mins then breaks down |
What is the function of Statherin and Histadine as it relates to oral health? | This protein helps control Ca and PO4 in the saliva, which prevents loss and prevents rapid drop of pH |
What is the function of lysozymes as it relates to oral health? | (a protein) that suppresses plaque formation on the tooth surface
Interferes with cell walls |
What is the function of lactoferrin as it relates to oral health? | Deprives sM of essential nutrients, inhibits growth of sM
Binds iron |
What is the function of Peroxidase as it relates to oral health? | inhibits sM use of glucose
protects from peroxides |
What is the function of Sialin as it relates to oral health? | Makes NH3 (buffer)
Raises pH |
Why do minerals help to protect against caries? | Consist of Ca and PO4 |
What is the function of Secretory Immunoglobulin A as it relates to oral health? | It migrates from sulcus into saliva
Ties up or binds sites for sM
Caries free people have more of them than do caries active people |
What is the function of agglutinins as it relates to oral health? | they clump bacteria |
How many microns into the enamel does demineralization/remineraliztion occur? | 200 microns |
What is zone 1 of an advancing lesion? | translucent zone-slight demineralization, deepest portion, advancing front |
What is zone 2 of an advancing lesion? | dark zone-remineraliztion |
What is zone 3 of an advancing lesion? | body of lesion-largest portion, bacteria present |
What is zone 4 of an advancing lesion? | intact enamel (surface zone)-may be hypomineralized, white spot, remineralization can occur |
What is cavitation? | (pathologic) when demineralization outstrips the remineralization |
What are the four things that must be present for caries to occur? | Microbes, host & teeth, substrate (food/drink), time |
What are the characteristics of s. Mutans | ability to:
adhere to tooth surface
produce insoluble dextrans
quickly reproduce lactic acid
reproduce and colonize
be tolerant of acit
produce intracellular polysaccharide stores for later energy use (ATP bonds); allows them to survive b/w feedings |
What is the best substrate? | Sucrose |
Pit and fissure caries are the same as smooth surface caries because both require plaque to be present (T/F) | False |
What is characteristic of the process we call caries?
A. it is pathological
B. it is infections
C. it is occuring in everyone all the time
D. it dissolves the calcium and phosphate minerals out of the tooth
E. All of the above | E. all of the above |
Pit and fissure caries are:
A. easily prevented with good home care
B. prevented with the use of topical fluorides
C. a result of too many exposures to fermentable carbohydrates
D. a result of too many colonies of s. Mutans | C. a result of too many exposures to fermentable carbs |
S. Mutans has the ability to:
A. produce dextrans
B. break apart sucrose and make use of the high energy bond
C. reproduce and form branched colonies
D. quickly and efficiently produce lactic acid
E. all of the above | E. all of the above |
The dark zone of carious enamel is where
A. the largest amount of bacteria is present
B. the surface of the tooth is intact
C. advancing front of the lesion
D. the remineralization is occurring | D. where remineralization is occurring |
A white spot lesion, also called an incipient lesion, may have lost up to ______________% of its mineral content
A. 20%
B. 50%
C. 40%
D. 30%
E. 60% | B. 50% |
Which of the items listed below is least apt to be a risk for caries?
A. Not flossing
B. No Fl source
C. High frequency of fermentable carbs
D. s. Mutans > 100,000 CFU/ml saliva
E. Mother w/ high rate of smooth surface caries | E. Mother w/ high rate of smooth surface caries |
Cell wall of single s. Mutans has enzymes that carry fructose into cell.
A. Fructose comes from dextrans
B. Fructose is used to make glycogen
C. Means that fructose more damaging than glucose
D. This fructose is used to make energy & lactic acid
E. B | E. Both B & D |
pH drop is influenced by what? | Amount of plaque/biofilm
Predominant flora
Rate of salivary flow
Type of substrate (lactic acid has more available H+ ions than other acids) |
The Vipeholm study: | increase in caries if sucrose eaten between meals.
Increase caries if sugars were sticky
No increase if sugar eaten with a meal |
Hopewood study | Even though poor HC, if diet was sugar free and carbs were whole grains, then no caries |
Turku study | sucrose most cariogenic, fructose less and xylitol showed remarkable reduction in caries |
This salivary flow indicates xerostomia | less than .7mL |
How long do the buffers from the parotid salivary gland hang around after eating? | 15 minutes |
Where are the primary buffers from? | Parotid salivary gland |
what are the sugar rules | eat sugar with a meal
eat sweets all at once
avoid b/w meal snacks
avoid sticky retentive carbs
rinse mouth after eating if you can't clean thoroughly |