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Ortho pt: has never had a restoration
What would you do? sealants, do nothing, etc. (agu put: do nothing)
Fluoride helps prevent caries in all ways except
lower pH of the oral cavity
Which material cannot be used to get cast impression
o Reversible hydrocolloid o Irreversible hydrocolloid o Polysulfide o PVS
The usual metabolic path of ingested fluoride primarily involves urinary excretion with remaining portion in
skeletal tissue
Polyether, disadvantage compared to other elastomeric
sticks to teeth/hard to remove from teeth, longer working time, less accuracy
Polysulfide gives out
water
Where does fluoride work the best
A. interproximal B. Pit and fissure (I saw this somewhere and it said smooth surfaces, pit and fissure is prr/sealant) ***WORKS BEST ON SMOOTH SURFACES***
What fluoride toothpaste should not be used in a patient with multiple porcelain crowns
Acidulated
Which type of fluoride is not in toothpaste
Acidulated fluoride
Which impression material is least distorted by water
Additional silicone (Condensation silicone better ans if available)
Why elastomer is not a good interocclusal record
Rebound when mounting FLUROIDE Fluoride BREAKSDOWN collagen, is bacteriocidal, fluoroapetite is more resistant to acid, decreases solubility of enamel, excreted by kidneys, & helps remineralizes. Hydroxyapatite + Fluoride à Flourapetite + Hydroxy Fluoride ions replace the hydroxyl radicals of the hydroxyapatite crystals in the enamel, producing fluorapatite, which is less soluble in catabolic acids produced by oral bacteria. - Fluorapetite has a lower critical pH of 4.5 (pH of dental enamel as 5.5) = harder to dissolve Fluoridation: know the primary/secondary/tertiary prevention differences. - Primary: aims to prevent the disease before it occurs. Health education, community fluoridated water, sealants. - Secondary: Eliminates or reduces disease after they occur. Composite filling - Tertiary: Rehabilitates an individual in later stages to restore tissues after the failure of secondary prevention. Examples include dentures and crown and bridge. Fluoride Facts ■ Food and Nutrition Board recommends public water supplies be fluoridated when levels are significantly below 0.7 mg/L. ■ Fluorine intake of 20-40 mg/day can inhibit the important enzyme phosphatase. ■ Phosphatase is needed for calcium utilization/metabolism in tissues including the bones and teeth. ■ Fluorine intake of 40-70 mg/day can cause heartburn and pains in the extremities. ■ Just as fluoride will displace calcium in the body, calcium therapies are used to treat fluoride toxicity. ■ Topical fluoride does not cause fluorosis (occur in permanent and primary teeth). ■ School water fluoridation ≈ 4.5 times that of city water (≈1 ppm). ■ Fluoride deposit in calcified tissues over time. ■ Greatest concentration of fluoride at outermost layer of enamel. ■ Proximal and smooth surfaces benefit the most from fluoride. ■ Fluoride is excreted by the kidney (in form of urine and sweat, up to 3 mg/day). —> should wait an hour before pouring casts ■ U.S. Public Health set optimal fluoride = 0.7-1.2 ppm for public water. ■ Cariostatic effect of fluoride is at calcification stage of tooth development. ■ Fluoride converts hydroxyapatite to fluorapatite. ■ Fluoride ↓ solubility of enamel. ■ Toothpaste contain 1100 ppm of fluoride. Fluoride Toxicity ■ Adult lethal dose = 4-5 g ■ Child lethal dose = 15 mg/kg ■ Odontogenic manifestation = fluorosis
Syneresis & imbibition applies to which impression material
Reversible hydrocolloid. Irreversible is not an option
A child with no decay but deep pits and fissures, what is the Tx plan
Sealants
Patient has deep grooves but no decay on permanent molars, what do you suggest
Sealants
Where is the biggest storage of fluoride in tissues
Skeletal tissues
What mouthwash is good for children with caries to rinse with
Sodium Fluoride (NaF)
Patient has 1 ppm fluoride in water. What is that equal to in mg/L
1mg/L
ADA recommends to apply in-office fluoride foam for how long
4 minutes
How many minutes do you place neutral sodium fluoride tray on teeth
4 minutes
What age does fluoride get incorporate into primary dentition
4 months in utero
At what age does fluorosis of anterior permanent teeth occur
4-6mo (others options: 0-4mo, 1year, 2years and 6 years)
Maximum allowed fluoride in the water by EPA (Environmental protection agency)
4.0 mg/liter (4 ppm)
The drinking water supply of a community has a natural F level of 0.6 ppm. The F level is raised by 0.4ppm. Tooth decay is expected to decrease by what % after 7 years
40%
7-year-old patient has no fluoride in drinking water. What do you give them systemically...
5 mg, 1 mg, 0.25 mg
At what age should supplemental fluoride be started
6 months
Minimum fluoride age
6 months
Which of the following systems is thought to malfunction in the hereditary form of angioneurotic edema
A. C-1 esterase B. C-1q inhibitor C. CH50 consumption D. Serine phosphatase E. Complement synthetase HYDROCOLLOID: Alginate (irreversible hydrocolloid) Setting time: - Increased water: powder ratio increases setting time & decreases expansion - mixing faster & increase water temperature decreases setting time ■ Imbibition, which is the process of absorbing water leads to alginate expansion. ■ Syneresis, which is the exudation of the liquid component of a gel leads to alginate shrinkage.
When pouring gypsum material into an impression, which material will cause the least amount of bubbles
Polysulfide, polyether, silicone, irreversible hydrocolloid
Pt has a white discoloration with no sensitivity near cervical region of #29, what do you do
fill, 5% fluoride, do nothing TYPE OF FLUORIDE:
What type of fluoride is in water
fluorosilicic acid (hydrofluorosilicate) - most commonly used, sodium fluorosilicate, and sodium fluoride
Fluoride does all the following, except
Direct action on plaque
4 yrs old patient lives in community w/ 0.25 ppm fluoride intake, what do you give
Give her systemic fluoride (0.5 mg/day) Apply fluoride Change diet to more fluoride intake Prescription fluoride rinse
Addition silicones (PVS) releases
H2 (as secondary reaction)
What ion gets replaced in hydroxyapatite by fluoride
Hydroxyl
What happens when you increase water/powder ratio of an investment: increase thermal expansion, decrease thermal expansion, increase setting expansion...
IMPRESSION MATERIAL: à Polysulfide (rubber base) is an elastomeric impression material that has an - exothermic setting reaction with water as a by-product (see Table 3-4) - ✍✍✍✍✍✍✍Advantages: - ? long working time - ? flexible and tear resistant - ✍✍✍✍✍✍ Disadvantages: - ? long setting time - ? very unpleasant odor and taste - ? highest permanent deformation àCondensation silicone is an elastomeric impression material that sets in a - cross-linking polymerization reaction and gives off the by-product ethanol - (see Table 3-7). - ? Disadvantages: - ? Must be poured immediately - ? Poor dimensional stability due to evaporation of ethanol - ? Hydrophobic - ? Low tear strength àAddition silicone or PVS has become one of the most popular crown and bridge impression material (see Table 3-8.). There are no by-products compared to condensation silicones. ? Advantages: ? Excellent dimensional stability (up to 2 weeks) ? Excellent surface detail ? Low permanent deformation ? Disadvantages: ? Hydrophobic ? Temperature sensitive
Alginate impression in 100% humidity, why will shrinkage occur
Imbibemnt, syneresis, historgysm - syneresis = extraction or expulsion of a liquid from a gel àshrinkage
Fluorosis does what
Inhibits remineralization
Most inaccurate
Irreversible hydrocolloid
What happens when a kid with primary teeth ingests fluoride
It affects their permanent teeth.
Early Childhood Caries (ECC) are cause by all at night except
- bottle feeding with formula with fluoridated water - breast feeding - sippy cup with OJ - bottle feeding with processed water with no fluoride
4.5 y/o child with 0.75ppm fluoride in their water requires how much fluoride to be supplement
0 mg
3 y/o patient lives in area with 0.4 ppm fluoride. How much do you supplement
0 ppm
Fluoride is given to children in schools usually by rinse with what concentration
0.05 daily, 0.2 daily, 0.05 weekly, 0.2 weekly
How do they administer Fluoride in schools
0.2% Fluoride rinse 1x week
4 y/o pt with 0.4 ppm fluoride Supplement
0.25mg/day
Supplementation for 10-year-old with no other fluoride source
1 mg/day or 1 mg/week? SEALANTS RECOMMEND AGE: Do sealant age 6-12
7-year-old child lives in area with 0.2 ppm fluoridated water, what do you supplement
1.0 mg/day
Pt has fillings and full porc. Crowns, but has decalcification on class V
1.1 % NaF
What fluoride tx would you used in a pt with amalgams, PFM's, composite restorations, implants
1.1% NaF
What's the concentration of acidulated phosphate fluoride is used in the dental office
1.23% (takes the glaze off)
What happens when you take an impression & lip immediately swells
Angioedema (allergy reaction)
Impressions, what's wrong with polyether
It's hard & engages undercuts.
What happens if you increase water in gypsum stone
Less expansion and strength (b/c particles are farther apart)
How do you determine the severity of fluorosis
Look at the two worst teeth? - Higher the fluoride level, greater degree of enamel change
Property of interocclusal recording material
Low resistance to jaw closure
What rinse is used at home for developmental disabled child to reduce of plaque
NaF, stannous fluoride, chlorohexidine
High caries risk patient, when is he indicated for sealants
Obvious clinical cavitation on the occlusal, deep fissures without caries
Where does fluoride localize/accumulates
Outer enamel
Which is hardest one to remove from the oral cavity (STIFFEST)
Polyether
Which one most likely to get stuck in mouth
Polyether
What is least likely to cause baby bottle caries
Typical tube of toothpaste has about 285mg fluoride Fluoride likes calcified things i.e. bones a. Breast milk at night b. Formula made with fluoridated water c. Water with no fluoride d. juice
Which one is not useful in managing caries in elderly
Use of 1.1% fluoride as a standard of care FLUORIDE SUPPLEMENTS:
ECC (early childhood caries) is usually in what location
a. Max incisors and molars b. Man incisor and molars c. Max canine d. Man canine and molar - Primary max incisors (B&L), then primary molars, mandibular unaffected bc tongue blocks
The most stable elastic impression in moisture environment
a. polyether b. additional silicone c. condensation silicone d. polysulfide
A 2 y/o child has injested 20mg fluoride pill. What will likely happen
coma, nausea, renal failure, cardiac arrest QUE STION: How much fluoridation supplement would you give to a 5 y/o drinking 0.75ppm F in their water? 0 ppm
Which is not recommended for final FPD cast impression
• irreversible hydrocolloid • reversible hydrocolloid • PVS • Polyether
