Fluoride Flashcards
Inhibits demin, promotes remin of subsurface lesions
MI paste
What are the 3 mechanisms of action of Fluoride? Which is the most important?
-
Topical (most important)
- inhibits demin, promotes remin -
Antimicrobial (somewhat important)
- disrupts bacterial metabolism – interferes with enolase to inhibit glycolysis, concentrates in plaque -
Systemic (least important)
- improves enamel crystallinity, reduces acid solubility, improves tooth morphology
What are 3 forms of topical fluoride?
NaF
SnF2
APF (acidulated phosphate fluoride)
also silver diamine
How do you convert %NaF to mg/L
(0.45)(%NaF) = % F ion
(%F ion)(10,000) = ppm F = mg/L F
mg/L = mg/1000mL
so mg/L÷1000 = mg/mL
Fluoride conversion
% NaF to % F ion
(0.45)(%NaF) = % F ion
Fluoride conversion
% SnF to % F ion
(0.25)(%SnF) = % F ion
Fluoride conversion
% F ion to ppm F
(104)(% F ion) = ppm F
1ppm = how many moles of F- ion?
52.6 µmol F- ion is 1ppm
What ppm F- is a typical OTC fluoride rinse containing 0.05% NaF? (like ACT?)
(0. 05% NaF)(0.45) = 0.0225 % F- ion
(104) (0.0225% F- ion) = 225 ppm
1000 ppm is a typical toothpaste, what % F- ion is this?
0.1 %
(1000 ppm/104)
How many mg of F- are there in a 4 oz tube of Prevident 5000?
Prevident is 5000 ppm F = 5000 mg F/L
= 5.0 mg F/mL
There are about 30 mL in 1 oz.
so there are about 150 mg F/oz in Prevident
A 4-oz tube of Prevident therefore has 600 mg F-
This is lethal for anybody weighing under 40 kg = 88 lbs
(using 15 mg/kg as lethal dose)
1.23% APF is what ppm F-
12,300
(1.23x10000)
2%NaF gel = ? ppm F- = ?mgF/cc
2% NaF gel = 9040 ppm F = 9 mg/cc
How much F- is there in a large (6.4 oz) tube of toothpaste? A small tube (4.6 oz)?
If toothpaste is ~1100 ppm (typical for NaF)
1100 ppm = 1.1 mg F/mL
30 mL in 1 oz
~33 mg F/ oz
- 4 oz = 211 mg F-
- 6 oz = 152 mg F-
How many mg does a smear of toothpaste have?
0.1 mg F-
How many mg in pea-sized amt of toothpaste?
0.25 mg F-
What is the optimal dose of F-?
0.05 mg/kg/day
What age range is “no more than” a smear (rice grain size) recommended?
<3 years of age
“Current best practice includes twice-daily brushing with fluoridated toothpaste for ALL children in optimally fluoridated and fluoride-deficient communities.”
What age range is “no more than” a pea-sized amt of toothpaste recommended and what is the mg of F- in a pea-sized amt?
3-6 y.o.
0.25 mg F-
To maximize the beneficial effect of Fluoride in the toothpaste, rinsing after brushing should be kept to a minimum or eliminated altogether.
Fluoride ppms to know
1.23% acidulated phosphate fluoride (APF) = 12,300 ppm
2% NaF gel = 9000 ppm
5% sodium fluoride varnish = 22,500 ppm
0.2% sodium fluoride mouthrinse = 900 ppm
Brush-on gel/pastes (e.g. Prevident) = 5000 ppm
0.05% sodium fluoride mouthwash (e.g. OTC mouthrinseslike ACT) = 225 ppm = 1 mg/5mL (1 t. = 1 mg F-)
OTC toothpaste = 1000 ppm
ppm = mg/L!!!
What is the probably toxic dose of F-?
5 mg F/kg
What is the certain lethal dose of F-?
16-32 mg F/kg
32-64 mg F/kg (Hodge and Smith)
OR 15 mg F/kg (whitford)
What is treatment for fluoride toxicity?
< 8 mg F/kg: milk, observe > 6hrs, refer if symptoms
≥ 8 mg F/kg: induce vomiting, milk, ER immediately
unknown dose & asymptomatic => tx as if <8 mg F/kg
unknown dose & symptomatic => milk + ER immediately
ER tx usually gastric lavage, IV Calcium gluconate.
What are the symptoms of F- toxicity?
- GI effects (nausea, vomiting, abdominal pain)
- CNS effects (tremors, weakness, convulsions)
shallow respirations
excessive salivation, abnormal taste
What are the symptoms of lethal overdose on F-?
- Muscle tetany
- Hypocalcemia and hyperkalemia lead to 3 Cs:
1. coma
2. convulsions
3. cardiac arrhythmias
If your 15 kg toddler ate one 4.6 oz tube of NaF toothpaste, what is the dose and what do you do?
152 mg F in the tube
÷ 15 kg weight of child
= 10.1 mg F/kg
> 8 mg F/ kg so induce vomiting, give milk, and take to the ER
How is fluoride absorbed and excreted?
Fluoride is absorbed through stomach and intestine.
Excreted through kidneys.
The rest is incorporated into bones.
When does blood plasma F- levels peak?
60 minutes after ingestion
How much of absorbed F- is deposited in bones?
50%
How is F- excreted?
Kidneys
What ions delay F- absorption?
Ca, Fe, Mg
What is the optimal level of F- in community water supply?
0.7 mg/L
= 0.7 ppm
the department of HHS has recently proposed to not have a fluoride RANGE but rather to limit the recommendation to the lower limit of 0.7 ppm F.
What is the current reduction of caries through fluoridated water?
20%
(Historically, 50-60% reduction)
What is the recommendation for F- supplementation
for age range 0 to <6 mo?
ZERO at all levels of F- in water
What is the recommendation for F- supplementation
for age range 6 mo to < 3yr?
0.25 mg for water that is < 0.3 ppm
ZERO for water that is > 0.3 ppm
What is the recommendation for F- supplementation
for age range 3yr to <6 yr?
0.5 mg for < 0.3 ppm water
0.25 mg for 0.3 – 0.6 ppm water
ZERO for > 0.6 ppm water
What is the recommendation for F- supplementation
for age range 6 yr – 16 yr?
1.0 mg for < 0.3 ppm water
0.5 mg for 0.3 – 0.6 ppm
ZERO for above 0.6 ppm
Draw the table of F- supplementation in your head.
What is the Halo effect for F-?
Other sources of F- other than drinking water
Sources of dietary fluoride include:
drinking water from home, daycare, school
beverages such as soda, juice, infant formula
prepared food
toothpaste
Rx for F- supplement for
1 year old with <0.3 ppm F-
Want 0.25 mg/day
RX: NaF drops 0.125 mg F/drop
Disp 30 cc
Sig after bedtime brushing, dispense 2 drops on tongue or inside cheek, NPO after.
What is the maximum F- you can rx at a time?
120 mg F-
Define Fluorosis
Permanent intrinsic white/brown discoloration of enamel
Subsurface hypomineralization defect
Fluorosis is associated with cumulative fluoride intake during enamel development with severity dependent upon the dose, duration and timing of intake
What percent of 12-15 year oldshave mild fluorosis? Moderate?
8%, 5%
When does fluorosis occur?
During tooth formation/mineralization
What is the window of fluorosis for maxillary incisors?
Risk begins at 1 yo, highest risk around age 2 (22 months)
Name the four different indices for measuring fluorosis:
- Dean’s index (mild to severe)
- Tooth surface Index of Fluorosis (TSIF)
- Fluorosis Risk Index (FRI
- Thylstrup-Fejerskov Index (TF)
How does remineralization happen?
- F- is bound and accumulates in plaque
- When pH falls (acids by bacteria) F- is released
- F- interferes with further acid production and promotes remin
How much fluoride does ready-to-use infant formula in the US and Canada have?
0.1 – 0.3 mg/L
Fluoride is effective!
How does the literature support?
- Fluoride varnish in primary teeth twice/year – at least 4 RCTs
- Fluoride varnish in permanent teeth at 3 or 6 mo intervals – at least 4 RCTs
- Fluoride gels at 3-12 mo intervals efficacious in perm teeth according to meta-analyses of 14 placebo-controlled trials
- No clinical trials to show efficacy of topical fluoride gel and foams with shorter than four-minute application times
- Limited evidence that topical fluoride foams are efficacious
- 0.2% NaF mouthrinse (900 ppm) and brush-on gels/pastes (1.1% NaF, 5000 ppm F) shown to be effective in reducing dental caries in permanent teeth – evidence from RCTs
- Meta-analyses of >70 RCTs show fluoride toothpaste is efficacious in reducing dental caries in perm teeth (with effect increased in children with higher baseline of caries, higher [] F-, greater frequency of use, and supervision of brushing)
- Meta-analyses of 8 clinical trials shows tb with F- toothpaste reduces caries prevalence in primary dentition (preschool children)
- RCTs support that fluoride dietary supplements are effective in reducing dental caries and should be considered for children at risk who have <0.6 ppm water
Home use of fluoride products for children should focus on regimens that maximize topical contact, in (lower/higher)-dose, (lower/higher) frequency approaches.
Lower, higher
T/F Fluoride aids in prevention, inhibition, and reversal of caries.
True
How does swallowed fluoride contribute to topical effect?
Topical effect on erupted teeth (before swallowed, as well as topical effect due to increasing salivary and gingival crevicular fluoride levels)
Elevated plasma fluoride levels can treat the outer surface of fully mineralized, but unerupted, teeth topically.
Similarly, topical fluoride that is swallowed may have a systemic effect
How does fluoride already incorporated into enamel contribute to anti-caries effect?
When pH drops in response to acid production, this fluoride is released and becomes available to remineralize enamel or affect bacterial metabolism.
Fluoride has reduced caries by what % in the last half-century?
55-60%
from community water fluoridation
recent data shows reduction of approximately 25%
What % of the US is not fluoridated?
More than one-third
Fluoride content of ready-to-useinfant formulas range from?
.1 to .3mg/L
Caution with concentrated/powdered formulas reconstituted with (optimally) fluoridated water
Infant formulas, especially powdered that have been reconstituted with fluoridated water, have been associated with an increased risk of fluorosis.
*Soy based products have more fluoride than milk based
When can you use 0.5% F- toothpaste?
Age 3 and up, with caution.
Assume that kids ≥6 can spit
Sealants decrease restorative txby what % over the next 3 yrs
72%
What’s the success rate of sealants even after a decade?
80-90% - study by Feigal
What percentage of caries in school-age children occurs in pits and fissures?
As much as 90%
Also:
80-90% of permanent posterior teeth caries is pit/fissure
How long should primary enamel be etched?
15 seconds
