Transcript Slide 1

DENT 5302 TOPICS IN DENTAL BIOCHEMISTRY
16 April 2007
Objectives:
• Rationale for clinical use of fluoride and calcium phosphate
• Risk factors for development of dental fluorosis
Outline
Delivery means of fluoride as caries preventive agents
Effectiveness of fluoride products
CPP-ACP
Rationale for clinical use
Risk factors for fluorosis
Sample questions
Delivery means of fluoride
Systemic fluoride
Water fluoridation
community approach
Salt, milk, sugar fluoridation
Individual-based
Fluoride supplements
Topical fluoride
Professional (Operator-applied) fluoride products
Over-the-counter fluoride products
Fluoride-containing restorative materials
Individual-based
Effectiveness of fluoride products
Water fluoridation
Effectiveness:
(high caries prevalence)
40-49% in primary teeth
50-59% in permanent teeth
Low caries prevalence & use of other F-products: ~ 20%
Fluoridated toothpastes
Caries preventive effect ~ 25 %
Cariostatic effect in life-long use in population may be much greater
Fluoride mouthrinses
Weekly rinse: 0.1-0.2% (~1000-2000 ppm F)
Inconclusive when other fluoride products are used
Daily rinse: 0.025-0.05% (~250-500 ppm F)
10-65% caries reduction in subjects with root caries risk
Modified from: Ripa LW. J Dent Res 1990;69(Spec Iss):786-796.
Effectiveness of fluoride products
Fluoride gels
4-37 % caries inhibition (overall = 22%), independent of
F toothpaste or fluoridated water
Fluoride varnishes
Highest F concentration (5%) among F-containing product
Meta-analysis: 38% caries reduction (patients used F-toothpaste)
Modified from: Ripa LW. J Dent Res 1990;69(Spec Iss):786-796.
F-containing restorative materials
Glass ionomers provide protection against recurrent caries in
high risk patients (e.g., xerostomia) who did not routinely used
topical fluoride (less compliance)
McComb D et al. Oper Dent 2002;27:430-437.
Haveman CW et al. J Am Dent Assoc 2003;134:177-184.
Milk protein derivative CPP-ACP
Casein protein contributes to anticariogenic properties of milk
Casein phosphopeptides (CPP) derived from casein protein
stabilize amorphous calcium phosphate (ACP) in solution
CPP binds well to dental plaque
CPP localizes calcium and phosphate ions
Inhibit demin and promote remin
Reynolds EC. J Spec Care Dent 1998;18:8-16.
CPP-ACP enhances remineralization process
Sugar-free gum + CPP-ACP
100%
enamel remin vs control
Reynolds EC et al.
J Clin Dent 1999;10:86-8.
CPP-ACP
Tradename:
Recaldent
Rationale for clinical use
What factors
to consider?
Which
method?
Cost-Benefit
ratio
caries risk, product efficacy, patient compliance, cost-effectiveness
ratio, background F exposure, access to dental care, safety issues
Frequent exposure to low level F is more effective
Patient’s compliance may be more effective than the product per se
Example
F toothpaste + good dental care
Low caries prevalence
Water fluoridation + F toothpaste
Is professional fluoride application necessary?
Caries incidence in low caries group = 0.25 DMFS / year
Fluoride gel (2X year) reduced caries 22 %
How much?
Safety issues
Chronic toxicity or long-term effect
Save 0.055
DMFS per year
Dental fluorosis
Percentage of fluorosis cases attributable to specific fluoride sources
Optimally fluoridated community
Fluoride Source
F supplement:
During year 1-2
Attributable
risk (%)
13
Nonfluoridated population
Fluoride Source
Attributable
F supplement: (pre-1994)
Year 1
Year 2-8
risk (%)
29
65
Tooth brushing:
Tooth brushing:
> pea-sized &
> once per day
46
Began during Y 1 & 2
> once per day
34
> pea-sized &
once per day
22
Began during Y 1 & 2
once per day
8
pea-sized &
> once per day
2
Began after Y 2
> once per day
6
Used > pea-sized
45
Formula (powder
concentrate)
9
Formula feeding
0
Risk factors for dental fluorosis
Tooth brushing behavior with F toothpaste
32% of children under age 2 brushed with F toothpaste
91% among 4-year-olds brushed with F toothpaste
Preschoolers swallowed 55-79% (max 90 %) of toothpaste
34% of fluorosis in non-fluoridated areas:
children < 2 years old brushed > 1 per day
45% from > pea-sized amount of F toothpaste
68% of fluorosis cases in areas with optimal
water fluoridation: > pea-sized amount of F toothpaste
Odds ratio for fluorosis with the use of F-toothpaste = 1.6-1.8
Toothpastes with flavor for children
Is that a good idea???
Special toothpaste with
500 ppm F for young children
Children < 6 years old, unless fully developed
swallowing reflex:
Pea-size amount of F toothpaste
Toddler:
No F toothpaste until 2 years of age
ADA, Nov 2006
Risk factors for dental fluorosis
Fluoride supplements
Inappropriate use causes fluorosis
Prescribed by dentists/physicians
Not in areas with water fluoridation
Test F in the water supplies.
Other sources of fluoride: juice or bottled water
Animal studies: threshold plasma F level for dental fluorosis
One ‘spike’ of 0.2 ppm/day for 1 week
dental fluorosis
One or two ‘spikes’ of 0.1 ppm/day for 1 week
no dental fluorosis
If a child (5 kg,10 lb, ? < 1 year old) is given 0.5 mg F = 0.1 mg/kg
Ingesting 0.1 mg/kg can raise plasma F level to exceed 0.2 ppm
Recommended Dietary Fluoride Supplement Schedule
Fluoride concentration in community drinking water
Age
< 0.3 ppm
0.3-0.6 ppm
> 0.6 ppm
None
None
None
6 months – 3 years
0.25 mg/day
None
None
3 – 6 years
0.50 mg/day
0.25 mg/day
None
6 – 12 years
1.0 mg/day
0.50 mg/day
None
0 – 6 months
How much fluoride is in my water?
http//apps.nccd.cdc/gov/MWF/Index.asp
My Water’s Fluoride, Oral Health Resources
National Center for Chronic Disease Prevention and Health Promotion, CDC
Where to send water to test fluoride content?
Fluoride Testing Service, School of Dentistry, University of Minnesota
Order water kit box from Doug Magne 612-624-9123
Dr. Robert Ophaug 612-625-5198
Multiple sources of drinking water
Example • 5 year old child
• Home water is 0.25 ppm F
• School water is 1 ppm F
• Ingest 50 % from each source
0.25 ppm x 0.5 = 0.125 ppm F
1 ppm x 0.5 = 0.5 ppm F
Effective concentration = 0.625 ppm F
Therefore, if you base the recommendation according to home water
fluoride level, the child will get 0.5 mg F supplement.
However, according to the effective concentration, the child does not
need any F supplement.
Risk factors for dental fluorosis
Fluoridated water
Drinking optimally F water by itself is not a risk factor
Most bottled waters < 0.3 ppmF
Home filtration (distillation/reverse osmosis) removes > 90% F
Carbon/charcoal filters do not remove F
Juices: 0.02 – 2.8 ppmF; 42% > 0.6 ppmF (halo)
Soft drinks: 0.02 – 1.28 ppmF ; 77% > 0.6 ppmF (halo)
USDA National Fluoride Database of Selected Beverages and Foods
http://www.nal.usda.gov/fnic/foodcomp/Data/Fluoride/fluoride.pdf
Aquafina
Dannon
Perrier
0.05 ppm
0.11 ppm
0.31 ppm
Crystal
0.24 ppm
Dasani
0.07 ppm
Dannon Fluoride To Go
0.78 ppm
Risk factors for dental fluorosis
Infant formula reconstituted with fluoridated water
Significant source of F (1 ppm for powder concentrates, 0.5 ppm
for liquid concentrates), especially when > 1 L is ingested.
Responsible for 9% of dental fluorosis
Recommendation for infants (birth to 12 months): Liquid
concentrate or powdered infant formula should be mixed with
water that is fluoride free or contains low levels of fluoride.
Labeled: purified, demineralized, deionized, distilled or reverse
osmosis filtered water
Breast milk and cow milk: very low in fluoride (0.01-0.04 ppm)
1979: US manufacturers voluntarily reduced F to 0.15-0.30 ppm
Note: Infant chicken product can have 8 ppm F; 20 times higher than infant fruit
Recommended references
1. Brambilla E. Fluoride - Is it capable of fighting old and new dental
diseases? Caries Res 2001;35(suppl 1):6-9.
2. Ripa LW. An evaluation of the use of professional (operator-applied)
topical fluoride. J Dent Res 1990;69(Spec Iss):786-796.
3. Zimmer S. Caries-preventive effects of fluoride products when used in
conjunction with fluoride dentifrice. Caries Res 2001;35(suppl 1):18-21.
4. Warren JJ, Levy SM. Systemic Fluoride. Sources, amounts, and effects
of ingestion. Dent Clin N Am 1999;43:695-711.
5. Bowen WH. Fluorosis. Is it really a problem? J Am Dent Assoc
2002;133: 1405-1407.
6. Pendrys DG. Risk of enamel fluorosis in nonfluoridated and optimally
fluoridated populations: considerations for the dental professional. JADA
2000;131:746-755.
Sample questions: Fill in blank / short answer
Give one example of strategy to prevent dental caries if you believe
in the ecologic plaque hypothesis. (2 points)
______________________________________________________
Base on your knowledge on enamel composition and the
de/remineralization process, why do newly erupted teeth have
relatively greater caries susceptibility and become less caries
susceptible over time? (4 points)
1. __________________________________________________
__________________________________________________
2. ________________________________________________________
_______________________________________________________
This picture is a ground section of early enamel carious lesion.
Name the following zones and choose a description from the
given list that is the best matching with each zone.
1
2
3
4
Zone 1 ____________________
Description ______
Zone 2 ____________________
Description ______
Zone 3 ____________________
Description ______
List of description
A. This zone has very small porosities and the largest crystal
size as a result of remineralization process.
B. This zone is invaded by cariogenic bacteria.
C. Bacteria will not invade if this zone is still intact.
D. This zone has the same percentage of pore volume as
sound enamel.
E. This zone has the highest activity of demineralization.
F. This zone has the smallest crystal size and the most stable
because fluoride ions substitute hydroxyl ions.
Multiple choice
Which of the following F-containing product has the
highest absorption rate?
a. Toothpaste with sodium monofluorophosphate
b. NaF mouthrinse
c. Acidulated phosphate fluoride gel
d. Duraphat fluoride varnish
e. Fluoridated salt
Based on your knowledge of the effects of fluoride on the de/remineralization of
enamel, what would you expect to happen to the incidence (rate of
development) of dental caries in adults if optimal fluoridation of a low-fluoride
community water supply was discontinued?
a. The incidence of dental caries would increase due to the rapid loss of fluoride
from the enamel surface.
b. The incidence of dental caries would not change since the fluoride in surface
enamel is retained over long period of time.
c. The incidence of dental caries would increase because of the decrease in
fluoride concentration in dental plaque and plaque fluid.
d. The incidence of gingivitis would increase because plaque formation increases
dramatically if the concentration of fluoride in water is less than 0.2 ppm.
e. The incidence of dental caries would not change since the fluoride in surface
enamel can be released under acidic condition and add more fluoride ions to
the plaque fluid.
A 5-year old child resides in a home supplied with well water containing
0.45 ppmF, and goes to kindergarten with 1.0 ppmF in drinking water. It
is estimated that 40% of the child's drinking water is consumed at school
and 60% at home. According to the ADA’s fluoride supplementation
schedule above, this child should have _____________.
a. no fluoride supplement.
b. a daily supplement of 0.25 mg of Fc. a daily supplement of 0.25 mg of NaF
d. a daily supplement of 0.50 mg of Fe. a daily supplement of 1.0 mg of NaF
The mother of a 5 year-old child (25 kg body weight) calls your office and
informs you that the child became ill and vomited because the child had
eaten a sample dentifrice (4 oz tube, 1000 ppm fluoride).
The maximum amount of fluoride that could have been ingested by the
child is _______________. (1 oz is approximately 30 g)
a.
30 mg
b.
120 mg
c.
120 mg
d.
4,000 ppm
e.
4,000 mg
The correct response to the mother in the previous question is _________.
a. to tell her that nausea and vomiting are normal reactions to the
ingestion of fluoride at this level, and that emergency treatment and
hospitalization are not necessary.
b. to tell her that this situation has the potential to be life-threatening and
the child should be transported to a hospital immediately.
c. to tell her that the amount of ingested fluoride may have exceeded the
Probable Toxic Dose (PTD). Since the child has vomited, however, no
emergency treatment is needed.
d. Since the Minimum Lethal Dose of fluoride has not been exceeded no
emergency treatment or hospitalization is necessary.