Dental caries is an infectious, communicable disease, which
causes destruction of teeth by acid-forming bacteria found in
dental plaque. The most important concept to remember is
that caries is a dynamic disease process, and not a static
problem. Secondly, before a cavity is formed in the tooth, the
caries infection can actually be reversed!
Caries progression or reversal is determined by the balance
between protective and pathological factors in the mouth. The
development of dental caries is a dynamic process:
Demineralization of the hard dental tissue by the acidic products
of bacterial metabolism – alternating with periods of
The development of the carious lesion is episodic, with periods of
demineralization alternating with periods of remineralization The
lactic acid produced by the cariogenic bacterial dissolve the
calcium phosphate mineral of the tooth enamel in a process call
demineralization. Baby teeth have thinner enamel than
permanent teeth, making them very susceptible to caries.
Streptococcus mutans is the major cariogenic bacterium.
S. mutans forms glucan and levan polymers that are
adhesive. The bacteria, along with the polymers, work
together to form a biofilm – called dental plaque. The
bacteria use a substrate (sugar) to produce acids that
dissolve dental enamel. Repeated demineralization by
these acids leads to dental cavities.
S. mutans has been highly associated with dental caries.
The proportion of S. mutans in plaque associated with ECC
can be 30% to 50% of the total viable bacterial counts in
dental plaque. In contrast, S. mutans usually constitutes
less than 1% of the plaque flora in non-caries active
children. Lactobacilli are highly acidogenic
microorganisms, associated more with deep cavities in
dentin than with the initiation of the disease. Lactobacilli
counts alone are not considered reliable enough in
predicting dental caries activity, however.
The Process of Demineralization and Remineralization
A tooth enamel is covered by plaque, which
consists mainly of bacteria. Plaque is often found
close to the gum, in between teeth, in fissures
and at other "hidden" sites.
When sugar and other fermentable carbohydrates reaches the
bacteria, they form acids which start to dissolve the enamel - an
early caries lesion occurs due to loss of Calcium and Phosphates
When sugar consumption has ceased, saliva can wash away
sugars and buffer the acids. Calcium and Phosphates can again
enter the tooth. The process is strongly facilitated by fluorides
•Frequent intake of carbohydrate-rich or sugary
foods enables the cariogenic bacteria to maintain
a low pH on the surfaces of the teeth.
•Night- time bottle feeding, or prolonged use of a
sippy cup, can lead to early childhood caries. The
flow of saliva is decreased during sleep, so
clearance of the sugary liquid from the oral cavity
is slowed down.
•The earlier that a child’s mouth is infected with
Mutans streptococci, the greater the risk for
future caries development.
The causes of caries are multifactorial, and the individual
risk factors associated with ECC are therefore not
•Children who already have one or more dental
cavities are considered high risk for developing
•A low fluoride level on the surface of the teeth
reduces the remineralization process and
increases the risk for caries.
•When the saliva flow is below 0.7 ml/minute,
the saliva cannot wash carbohydrates off the
dental surface. In addition, low salivary buffering
capacity, low salivary IgA, low salivary calcium,
and low salivary phosphate reduce the potential
for neutralization of acids in the dental plaque.
•Finally, a low socioeconomic status can reduce
interest in oral hygiene and a healthy diet.
Factors to which the tooth surface is directly exposed, and
which contributes to the development of the lesion:-
1. Amount of plaque
2. Type of bacteria
3. Type of diet
4. Frequency of carbohydrates
5. Saliva secretion
6. Saliva buffer capacity
Saliva has a critical role in the prevention of dental caries.
Saliva provides calcium, phosphate, proteins, lipids,
antibacterial substances, and buffers. Saliva buffering can
reverse the low pH in plaque, and with a higher pH,
calcium and phosphate can be driven back into the tooth
enamel. One factor that lowers the risk of cavity
formation is normal salivary flow. Anything less than 0.7
ml/minute increases the risk for cavity development.
The general diagnostic principles of caries
detection have always been clinical
evaluation consisting of tactile probing
and visual identification of carious tooth
structure, radiographic evidence and
clinical symptoms of sensitivity.
CARIES DETECTION METHODS
1. CLINICAL OBSERVATIONS
The oldest and most used method for the
detection of caries is visual. The clinical look of
tooth structure along with a feel of the tooth
surface using probes combines to form the basic
clinical evaluation method. Today, more and more
clinicians are enhancing their vision with
2. RADIOGRAPHIC DIAGNOSIS
For the ages, dental radiographs have been the
one diagnostic tool which dentists have used as
their secret weapon. If we couldn't see it clinically
and the tooth hurt, then..." there must be
something on this x-ray I'm looking at".
The new direction of caries detection
has taken a path towards three basic areas:-
light illumination and
Another useful, older diagnostic tool, risk
assessment, is making a comeback of sorts in the
1.Electrical resistance measurements such as a.c.
impedance spectroscopy, electrical conductance
measurements (ECMs), electrical resistance monitors;
2.light illumination such as laser fluorescence,
stereomicroscopy, fiberoptic transillumination;
3.strip mutans test for risk measurement, and
ultrasonic imaging have all shown promise if not
singly, surely in concert.
is based on the simple theory that
when an electrical current is passed
through a whole, sound, caries-free
tooth it will have a differing resistance
reading than a decayed, unsound or
KaVo DIAGNOdent®: Laser Cavity Detection
CARIES RISK ASSESSMENT
The ability to identify caries-susceptible
individuals has always been a goal of
research. Most studies have focused on
the direct cause of caries, bacteria, and
also some of the mitigating factors such
as salivary pH, protein makeup or home
Though most practitioners are well aware
of the technology, most feel that the
radiographs produced by the new digital
radiographic systems are inferior to
conventional radiographs. This is a
misrepresentation of both technologies.
Digital radiographic systems, has abilities
to modify and enhance the original image,
become far more accurate in the caries
This method of caries detection uses a light
source, preferably bright, to illuminate the tooth.
This then shows internal variations of color,
shading and morphology which goes undetected
when the tooth is exposed to only low, mainly
Caries or demineralized areas in dentin or enamel
show up as darkened areas with this technique.
You can do this simply with a fiber-optic hand
piece and illuminate the tooth from inside to
outside the mouth.
• Acid red
• Basic fuchsin
• Carbolan green
• Coomassie blue
• Lissamin blue
F A C T O R S I N F L U E N C I N G C A R I E S I N T E R P R E T A T I O N
1. Errors in technique may result in non-diagnostic films. For
example, a bite-wing film that is used to detect dental caries
must be free of overlapped contacts. Improper horizontal
angulation causes overlapped contact areas ( red arrows) and
makes it impossible to interpret the interproximal regions for
2. Errors in exposure may also result in non-diagnostic films. For
example, a dental radiograph used to detect dental caries must
exhibit proper contrast and density. Incorrect exposure factors
result in films that are too dark or too light and are useless in
the detection of caries.
Restorative materials, such as composites, silicates and acrylics,
may appear radiolucent and resemble dental caries on a
radiograph. The appearance of an anterior cavity preparation
restored with these materials differs from the appearance of
interproximal caries and can be identified by the well-defined,
Abrasion refers to the wearing away of tooth structure from the friction
of a foreign object. The surface of the tooth affected depends on the
causative factor. The most frequent type of abrasion is caused by tooth
brushing and is seen at the cervical margin of the teeth. Tooth brush
abrasion affects the root surface of a tooth and may be confused with
root surface caries.
Attrition, or the mechanical wearing down of teeth, may be mistaken for
dental caries on a radiograph. Attrition may be seen on the incisal or
occlusal surfaces of deciduous or permanent teeth. When the incisal or
occlusal enamel is worn away, the underlying dentin wears away rapidly,
and shallow concavities may form (red arrows). These concavities may
resemble occlusal or incisal caries on a dental radiograph. Clinical
examination enables the dental professional to distinguish attrition from
Cervical burnout, a radiolucent artifact seen on dental radiographs, may
also be confused with dental caries. Cervical burnout appears as a
collar or wedge-shaped radiolucency on the mesial and distal root
surfaces near the CEJ of a tooth (red arrows).
Sequella of Preventive Strategies for caries
• Identify the individuals caries risk and
activity by a complete assessment procedure
• Control oral bacterial levels
- Restorations as needed ("incision and drainage").
- Chemotherapeutics (refers to use of fluoride varnish,
Chlorhexidine rinse, Xylitol and MI Paste).
• Identify measures which will shift the patient at risk to a
low risk category.
• Identify how non-cavitated lesions should be treated for
remineralization and reversal.
• Cavitated lesions will be treated in the traditional manner.
• Home and office maintenance procedures
Assessment of dental caries risk and caries activity
must involve the following:-
1. Host risk factors:
• Medical history
• Dental caries status
• Fluoride use
• Salivary assessment
2. Diet assessment
3. Bacterial assessment
4. Tooth surface activity assessment
1. COLLECTING RELEVANT BACKGROUND DATA
• General diseases of importance
• Social situation
• Dietary habits
2. CLINICAL INVESTIGATION
• Estimation of caries prevalence (DMFT & DMFS) and incidence
• Checking for aggravating factors
• Factors immediately involved in the caries process
3. TEST METHODS: ORAL MICROBIOLOGY, SALIVA, PLAQUE
• Description of the Strip mutans test .
• Chair side test method: Dentocult.
• Saliva flow - measurement of saliva secretion rate
• Saliva buffer capacity
Socio-economic factors or circumstances which may indicate
increased caries risk, examples:
•Socially deprived, no work, bad economy
•Low knowledge, low education of parents
•No regular dental check-up
Epidemiological factors or circumstances which may indicate
increased caries risk, examples:
•Living in high DMF country
•Living in high DMF area
•Member of high DMF family
•High past caries experience
•Intra-oral distribution of earlier lesions/fillings
Clinical findings which may indicate increased caries risk,
Early signs of the disease (for example white spot lesions) Newly erupted
•Exposed root surfaces
•Deep fissures or other "natural" retentive sites
•Retentive sites caused by dental treatment
1) Environmental factors are noted:
Existing dental caries, estimated sugar intake,
estimated fluoride exposure, socioeconomic status,
oral hygiene practices, and dietary habits are
2) Infectious agents can be assessed using
microbial sampling, such as the Dentocult SM Strip
for assaying MS levels in the mouth.
3) Genetic factors can be evaluated, including:
Salivary flow, salivary buffering capacity, and tooth
THE FIRST DENTAL VISIT
The purpose of the first dental visit is to assess individual risk,
and to educate the parent or caregiver about reducing such risk. A
clinical examination is an essential part of a child’s first dental
visit, and as an important part of risk assessment. A correct and
efficient diagnostic investigation must include the identification
and evaluation of risk factors.
THE FIRST DENTAL VISIT
1. Shop smart!! Do not routinely stock your pantry with sugary or starch
snacks. But “fun foods” just for special times
2. Limit the number of snacks; choose nutritious snacks
3. Provide a balanced diet, and save foods with sugar or starch for mealtimes
4. Don’t put your young child to bed with a bottle of milk, formula, or juice
5. If your child chews gum or sips soda, choose those without sugar
The American Academy of Pediatric Dentistry, the American
Dental Association, and the Academy of General Dentistry
recommend that children visit a dentist within six months of
the eruption of the first tooth, and no later than 12 months of
•Infants should not be put to sleep with a bottle. Breast-
feeding at night should be avoided after 12 months of age.
•Infants should be weaned from the bottle at 12-14 months of
•Consumption of juice from a bottle or sippy cup should be
avoided. Juice should be offered to a child only in a cup.
Infants and toddlers should drink no more than 6 ounces of juice
•Cleansing of the baby teeth should be started by the time of
eruption of the first primary tooth. A small piece of clean gauze or
a small toothbrush can be used.
HOW CAN PARENTS PREVENT DENTAL CARIES?
1. Parents can modify oral hygiene techniques, depending on the child's age.
For small infants, the gums need to be cleaned once or twice a day with a
piece of clean gauze. This will help to establish a healthy oral environment
for the baby teeth. Infants should be introduced to the toothbrush around
the age of one.
2. Parents should not put children to sleep with a bottle containing any liquid
other than water. Parents should encourage their infants to begin drinking
from a cup around their first birthday.
3. Parents should help brush their children's teeth every day, after every meal.
4. Parents should not let their children drink fruit juice or sweetened drinks
from a bottle or "tippy" cup, since this prolongs the exposure of teeth to
5. Parents should provide healthy, balanced meals for children. They should
limit the amount of sugar-laden foods and snacks in their diet. Plenty of
healthy snacks should be available for children. Cheese products actually
fight dental caries.
6. Parents can help make children's teeth more decay-resistant
by using an ADA-approved children's toothpaste. Place only a
pea-sized drop of toothpaste on the toothbrush. Until a child is
3 years old, parents should only use baby tooth cleanser - to
avoid causing fluorosis discoloration of the adult teeth.
7. Children taking oral medications should have their teeth
cleansed after each dose of medication. Nearly 100% of
children's medications contain sucrose, which can increase the
risk of developing dental caries.
8. Children should have their first oral/dental health evaluation
by the age of 12 months, or within 6 months of the eruption of
the first tooth
9. Parents should consider providing children with xylitol-
containing chewing gum, which can help prevent dental caries.
1) Gaining control of the bacterial infection:
The control of S. mutans is accomplished in two phases: Caries
control, followed by chemotherapeutic medication. We will start
with caries control – treating the cavitated lesions with glass
Caries control: Minimally invasive caries control, also called
Atraumatic Restorative Treatment,
Chemotherapeutic medication: A combination of fluoride
varnish and Chlorhexidine application is used to lower the Mutans
- The varnishes contain 5% sodium fluoride (NaF) at 22,600 ppm of fluoride.
There is a mean caries reduction of 38% when fluoride varnish is used in
caries prevention. In an aggressive preventive program, varnish can be
applied 3 times within a 10 day period. This is followed by another varnish
application every 3 months for the first year.
- The 0.12% Chlorhexidine gluconate can be applied to toddlers’ teeth twice
a day for 14 days. It is applied at least 30 minutes after the use of
toothpaste because the sodium lauryl sulfate contained in most toothpastes
will neutralize chlohexidine gluconate
2) Reduction of risk levels:
Step two in the medical model is reduction of the risk levels for patients. First,
sugar intake must be reduced. A dietary assessment can identify when sugar
consumption needs to decreased . Increasing fluoride use at home will also
reduce the risk of dental caries.
3) Remineralization of teeth:
Step three in the medical model of caries management is the reversal of active
caries site by remineralization. There are four parts to this step:
a) Fluoride varnish is applied 3 times in a 10 day period.
b) Fluoride is applied at home. A fluoridated dentifrice is used twice daily.
Application of 1.1% NaF gel by toothbrush is recommended for very high risk
children with dentin caries.
c) Xylitol gum is recommended.
d) A source of calcium, such as cheese, is also recommended.
4) Long term follow-up:
The last step in the medical model is long term follow-up at home and in the
dental office. The office recall frequency should be every 3 months for high risk
patients and every six months for low risk cases. Caries activity and risk are re-
evaluated at the dental recall visits.
There are three principal ways to prevent dental
caries or ECC:
Professional dental measures
Home Fluoride rinses (0.05%)
Builds CaF2 layer at enamel/cuticle interface.
Home fluoride at night for 1 year.
Increases remineralization and decreases deminerealization.
Decreases acid production.
Inhibits mutans streptococci (ms) growth.
Inhibits plaque growth.
1. Systemic fluoride
• Community water fluoridation
• School water fluoridation
• Fluoride tables
2. Topical fluoride
3. Fluoride supplements
• Dental material with fluoride
- glass ionomer
- impression materials
• Fluoridated milk
• Fluoridated salts
• Fluoridated tooth pastes
decrease in caries: primary = 40%, permanent = 50-60%
Mechanism of action of fluorides:
- decreases enamel solubility.
- improves crystalinity.
- promotes remineralization.
- decreases free surface energy of bacteria so it cannot stick on
- bacteriocidal or bacteriostatic.
- causes developing crystal to get bigger, less soluble
Systemic Fluoride Supplements
• No evidence to support prenatal benefit
• Benefit to mother is primarily topical
Fluorine, from which fluoride is derived, is the 13th most abundant element
and is released into the environment naturally in both water and air.
Fluoride is naturally present in all water. Community water fluoridation is
the addition of fluoride to adjust the natural fluoride concentration of a
community's water supply to the level recommended for optimal dental
health, approximately 1.0 ppm . One ppm is the equivalent of 1 mg/L, or 1
inch in 16 miles.
Community water fluoridation is an effective, safe, and inexpensive way to
prevent tooth decay.
Children and adults who are at low risk of dental decay can stay cavity-free
through frequent exposure to small amounts of fluoride. This is best gained
by drinking fluoridated water and using a fluoride toothpaste twice daily.
Children and adults at high risk of dental decay may benefit from using
additional fluoride products, including dietary supplements (for children
who do not have adequate levels of fluoride in their drinking water), mouth
rinses, and professionally applied gels and varnishes.
Fluoride was first added to drinking water to prevent tooth decay in Grand
Rapids, Michigan. Fluoridation of drinking water has been used successfully
in the United States for more than 50 years.
•Fluoridation of community water has been credited with reducing tooth decay
by 50 - 60 in the United States since World War II.
•Fluoride's main effect occurs after the tooth has erupted above the gum. This
topical effect happens when small amounts of fluoride are maintained in the
mouth in saliva and dental plaque.
•Fluoride works by stopping or even reversing the tooth decay process. It
keeps the tooth enamel strong and solid by preventing the loss of (and
enhancing the reattachment of) important minerals from the tooth enamel.
•Water fluoridation costs, on average, 72 cents per person per year in U.S.
communities (1999 dollars).
•Consumption of fluids--water, soft drinks, and juice--accounts for
approximately 75 percent of fluoride intake in the United States.
•Children under age six years may develop enamel fluorosis if they ingest more
fluoride than needed. Enamel fluorosis is a chalk-like discoloration (white spots)
of tooth enamel. A common source of extra fluoride is unsupervised use of
toothpaste in very young children.
Fluoride is needed regularly throughout life to
protect teeth against caries. Fluoride in
solution, from topical sources, enhances
remineralization by speeding up the growth of
a new surface in the partially demineralized
subsurface crystals in the carious dental lesion.
Recommendations for fluoride supplementation can
be made based on
1. the fluoride content of the water,
2. the child’s age, and
3. the child’s caries risk.
The risk of dental fluorosis is highest during the
period of enamel maturation, from 1 to 3 years of
Cariostatic Action of Topical Fluoride
Fluoride in the liquid phase around the apatite
crystal is today believed to be more important in
decreasing dissolution of crystal than fluoride
incorporation into the crystal lattice.
Very low liquid fluoride concentrations under low
pH conditions can block crystal dissolution and
reduce the rate of demineralization
High fluoride concentrations on the tooth surface results in
Ca(F)2 like deposits. This is deposited on the surface and
into porous enamel at decalcified sites. As pH drops the
globular Ca(F)2 dissociates into Ca++ and F-, it provides
both ions for remineralization. Some ions will also diffuse
into the plaque. It is important to maintain these ions in
Cariostatic Action of Topical Fluoride
Saliva is not as good in remineralization as is a
calcifying solutions (with Ca & HPO4 ions). There
are fewer free ions in saliva due to such factors as
•Using Ca(F)2 and Na2HPO4 rinses in sprays enhance
•Also using Ca++ salt + buffer + Na2SiF6 is good. This
provides Ca(F)2 for the production of amorphous CaHPO4
which in turn induces rapid enamel remineralizatiton.
•Researchers are using CO2 lasers to enhance
•Remineralization does not usually replace the old
carbonated hydroxy-apatite. Fluorapatite formed as a
veneer over old crystals and is more most insoluble.
Topical Fluoride Therapy:
1. Efficacy depends on potency, frequency, duration
a. Low doses at high frequency is currently believed to be the best method
2. Routine office applications: high potency & low frequency
a. 2% Na F: 4 applications over 2 weeks at 2-3 yr intervals (10 g F/ml)
b. 8% SnF2 for 4 min Gel or Powder (20 mg F/ml)
c. 1.23% APF for 4 min (thixotropic gels) (12.3 mg F/ml)
d. Foam vs Gel (0.6-0.8 mg/tray vs 3-4 mg/tray)
3. Home or school programs: high frequency & low potency
a. 0.2% Na F weekly 1 min rinse (1 mgF/ml)-most rinses are with 10 ml
b. 0.05% Na F daily 1 min rinse (0.25 mg F/ml) high alcohol concentration
(+20%) 0.2 mgF/ml bid offers better protection
c. 0.4% SnF2 gel, daily in trays or brush (1.0 mg F/ml =1000 ppm)
d. Toothpaste (1000ppm is 0.1% F): one 9oz tube has 270 mg F
Low strength fluoride mouthwashes
For children with very active caries, a fluoride mouthwash for home use
may be useful provided that the patient is motivated to use it. There
are two options:-
1. The Principal Dental Officer can provide a prescription for a three-
month supply of a 0.05% sodium fluoride mouthwash.
2. Colgate and Macleans market low strength (0.05 percent) fluoride
mouthwashes (Fluorigard and Coolmint with fluoride, respectively).
3. Pre-school children who cannot spit well may have fluoride solution
applied by parents using a cotton bud.
Most toothpastes at 1,000 ppm or 0.1% F.
- During brushing F may go to the following forms:
• Calcium F.
• Free F.
- Between brushing saliva F levels from 0.02-0.08 ppm. This
helps to transfer Ca++ and HPO4= into enamel.
- Three types of F toothpastes FDA approved:
• Sodium Fluoride:-
provides free F. Does not use Ca++ abrasives.
• Sodium Monofluorophosphate:-
This F complex releases free F when in contact with salivary
phosphotases. Can use Ca++ abrasives.
• Stannous Fluoride:-
Aids in controlling gingivitis. Not as popular as other two.
Brushing with the new toothpaste (Enamelon)
provides fluoride, which will facilitates uptake of
the ions, as well as adequate concentrations of
calcium and phosphate to remineralize and
strengthen the tooth enamel. This presumably will
aid in the reversal and healing of this
lesion. Studies are currently underway to
determine the ability of this new toothpaste to do
Clinical application of fluoride
The selective use of professionally applied topical fluorides is encouraged in
the school dental service. The decision to use topical fluorides should be
based on the assessment of the caries risk of the child.
There are two types of professionally applied topical fluoride preparation in
common use in school dental.
These are: a gel of either neutral or acidulated fluoride and a fluoride
1. Topical fluoride gel
Professionally applied topical fluoride gel is an effective way of preventing
dental decay in patients with moderate to high caries activity. It is
particularly useful in controlling smooth surface proximal caries, and has
its maximum effect on newly erupted teeth.
1. Check that the tray fits in the child’s mouth and
covers all teeth.
2. Limit the amount of gel placed in each tray to no
more than 2 mls (5 cm), or a smear over the inner
surface of the tray.
3. Seat the patient in an upright position during
4. Leave the fluoride gel in place for the time
specified by the manufacturer.
5. Use suction to remove excess saliva/gel mixture
during and after the procedure.
6. Instruct the patient to spit out as much of the
material as possible following the removal of trays
and not to rinse, eat or drink for 30 minutes after
Topical fluoride gel technique
PreviDent®-Self applied topical neutral fluoride
containing 1.1% sodium fluoride for use as a dental
caries preventive in adults and children. This prescription
product is not a dentifrice and is used in cases where caries
activity is high. It increases tooth resistance to acid
dissolution and enhance penetration of the fluoride ion into
tooth enamel. . Apply a thin ribbon of gel to the teeth with
a toothbrush or mouthtrays for at least one minute,
preferably at bedtime. After use, adults expectorate gel.
For best results, do not eat, drink orrinse for 30 minutes.
Children expectorate gel after use and rinse mouth
Fluoride foams for topical fluoride application
are also available and have some
advantages over fluoride gels. Fluoride
foams provide better control and are less
likely to overflow the applicator tray, thus
reducing gagging and ingestion. The
consistency of the foam is also claimed to
provide better interproximal coverage.
3. Fluoride varnish
The fluoride varnish currently in use in the school dental services is
Each ml of Duraphat contains 50 mg of sodium fluoride (22.6 mg of
available fluoride) in a suspension of natural resins. Each tube of
Duraphat contains 10 ml of varnish or 226 mg of available fluoride.
Duraphat fluoride varnish reduces decay into dentine by 20–50 percent
depending on the surfaces it is applied to and their state of
demineralisation. Applications to smooth surfaces showed the
Fluoride varnish is used in
• the school dental services principally for spot applications of fluoride
on enamel caries diagnosed visually or by radiograph, rather than for
whole mouth applications.
• the occlusal surfaces of partly erupted permanent molars and
hypoplastic areas of teeth. For maximal effect the varnish should be
applied to demineralised surfaces more than once during a year
(several applications over several weeks were more effective than
annual or bi-annual applications). Such repeat applications can often
be carried out when the child comes to the clinic for restorative
Fluoride varnish contains 2.26% fluoride ion.
The actual amount of fluoride used per treatment is
5-11 mg. The volume of fluoride varnish per
treatment (0.2 – 0.5 ml) is significantly less than
the probable toxic value for a 10 kg child (2.0 ml).
The plasma fluoride concentration after varnish
application is barely measurable.
Therefore, fluoride varnish is very safe for use on
The varnish is applied with a small soft brush, and
reapplication is recommended every 3 to 6 months. Data
show an overall reduction of caries incidence after fluoride
varnish applications, ranging from 18% to 70%, compared
with untreated control subjects.
Dose and safety for fluoride varnish
The maximum usage of Duraphat on pre-school children
should be no more than 0.25 ml (5.65 mg of available
For the mixed dentition (5–11 years) the maximum usage
should be no more than 0.40 ml (9.04 mg of available
For the permanent dentition maximum usage should be
no more than 0.75 ml (16.95 mg of available fluoride).
• Deeper enamel penetration.
• Better localization, less systemic uptake.
• Good over incipient lesion especially if there
is a question about patient compliance.
• No prophy required. Have a patient brush
and apply after drying area.
• Currently, the dose and frequency needed to
arrest lesions and initiate remineralization
Advantage of fluoride varnish
1. Dispense the appropriate quantity of varnish on to a pad.
2. Remove any gross plaque from the surface(s) to be treated.
3. Isolate the tooth or teeth if possible, using cotton rolls.
4. Dry the enamel surface(s) to be treated using compressed air.
5. Apply fluoride varnish in a thin film to the specific surfaces to be
treated, using a suitable instrument. To ensure approximal surfaces are
treated, fluoride varnish can be placed above the contact and flossed
into the contact area.
6. Dry the varnish for 30 seconds if possible, using a gentle flow of
7. Ask the child not to eat or drink for 30 minutes after the application
and not to brush their teeth until the next day.
FUTURE TRENDS IN CARIES PREVENTION:
1. Chemotheraputic methods of fighting the caries-
causing bacteria will be used. These methods include
the application of fluoride varnish and chlorhexidine
gel on teeth.
2. Vaccines against dental caries. The vaccines would
function by giving a child an improved IgA or IgG
immune response to cariogenic bacteria.
3. Molecular probes to measure the level of cariogenic
bacteria in a child's mouth.
4. Earlier caries detection, including fluorescence and
5. Laser treatment of teeth. This technique would inhibit
the progression of dental caries by making the enamel
surface highly resistant to acid attack.
As the amount of fluoride is absorbed in the plasma and then
distributed to the various organs of the body the concentration of
fluoride in muscle, liver, heart and all soft tissues begins to rise.
After the fluoride has been absorbed from the stomach and the
intestines and is absorbed into the other soft tissues and other
organ systems the plasma level will decrease, primarily because
of the decrease by excretion of the kidneys and that of bone
uptake. Usually the plasma level will reach the pre-ingestion level
in three to six hours.
The excretion pattern of fluoride is interesting because it is
influenced by several factors -- the primary one being age. The age of an
individual will determine how much fluoride can be eliminated from the
body. The excreted percentage of fluoride varies as a direct function of
age. Obviously, the younger an individual, the less fluoride is excreted and
the older, the more rapidly a given does is excreted. This is primarily due to
the age of the skeleton and the surface area of bone mineral available for
fluoride uptake. Therefore, it is quite obvious that in a growing individual -
early childhood to adolescent years - those factors will favor the enhanced
fluoride uptake so that relatively less is excreted in the urine.
a. Dean's Classification: 0-4 scale
0- (None)59% of population at optimal fluoride level will exhibit no
1- (Very mild) 7.4% of population at optimal dose
2- (Mild) Greater than 25%, less than 50% of surface with opaque
defects greater than 1.2 ppm
3- (Moderate) Brown stains present ( greater than 2 ppm)
4- (Severe) Pitting and attrition problems ( reater than 2-3 ppm )
b. Fluorosis occurs during maturation process. For incisors, age 2-3
years is the critical period.
Improper use of dietary fluoride supplements and ingestion of
fluoride dentifrices by small children, particularly in fluoridated
communities, may result in dental fluorosis. Dental fluorosis is
defined as hypoplasia or hypomaturation of tooth enamel produced
by chronic ingestion of excessive amounts of fluoride as the teeth
are developing, and are manifested as whitish opacities on the
teeth. In severe cases, mottled enamel may occur.
a. CLD ( certain lethal dose ): 32-64 mg/kg in one source, 71-140
mg/kg in another source. A death has been reported at 17 mg/kg.
b. PTD ( Probable toxic dose ) 5mg/kg i.e. 50 mg for the average 10
kg 2 year old.
c. STD ( Safely tolerated dose ) 8-16 mg/kg
d. Toxicity at low doses is due to gastric irritation. Hypocalcemia and
hyperkalemia at high doses leads to cardiovascular collapse and
e. Treatment for overdose:
- less than 5mg/kg: oral calcium ( milk) and observe
- More than 5 but less than 15 mg/kg: induce vomiting, oral
calcium (milk, calcium gluconate, or calcium lactate), admit to
- More than 15 mg/kg: admit to hospital immediately, induce
vomiting, monitor cardiac function, 10% calcium gluconate
solution IV, monitor electrolytes.
Common signs and symptoms of acute fluoride toxicity:
low dosages high dosages
hypersalivation cardiac arrhythmia
abdominal pain comatose
- pt becomes hypocalcaemia due to Ca binding with F
- Adult = 1.25 gms F or 2.5 gms of NaF is lethal. (8-16
mg/kg of body weight). Best to consider 8 mg of F/kg
body weight as lethal adult dose.
e.g. 80Kg adult x 8mg/Kg =640 mg of F.
- For a child 5 mg of F/kg body weight considered toxic.
e.g. 20 Kg child X 5 mg/Kg body weight= 100 mg of F
Small F tray may hold 2 ml each. APF = 12.3 mg F/ml,
2 trays = 4 ml x 12.3 mg= about 50 mg.
This is half the toxic dose
It is possible to prevent the adhesion of the micro-organisms to the tooth
surface by mechanical means which quite simply expressed means to
complete tooth brushing and dental flossing to break up the plaque
matrix. The use of plaque dissolving agents such as Chlorhexidine or
Dextranase to break up the plaque matrix. Or alter the production of
dextran as a byproduct of certain micro organisms which allow the micro-
organisms to attach and adhere to the tooth surface. Dextran is an extra
polysaccharide produced by specific organisms metabolizing specific
types of metabolites.
• Best for ms control.
• Can be used with fluoride.
• Will not penetrate enamel.
• Will not suppress lactobacillus.
• Suppression will last 3-5 months.
The Role of Xylitol in Caries Prevention
• Xylitol is a sugar alcohol produced from xylose (Wood Sugar) , obtained
mainly from the white birch tree. Corn cobs are another source of xylose
and recently it has been produced by fermentation.
• Sorbitol is also a sugar alcohol and is produced primarily from corn
starch in the U.S., but can be made from other sources of starch, such as
• Due to the increase of sugar consumption, sugar substitutes are
essential in caries prevention programs.
• Xylitol has good sweetening qualities and caries protective properties.
Use 2 sticks, 5x/day for 5 minutes.
• Its consumption does not promote low pH in dental plaque probably by
enhancing salivary flow and buffer capacity.
•It inhibits adhesion, growth and metabolism of oral
microorganisms. Suppresses ms even with sucrose intake.
•It allows remineralization of initial enamel lesions. Enhances
reversals (Turku study).
•When it is incorporated to chewing-gum, its action is increased
due to the stimulation of salivary secretion.
•In association with fluoride, a synergic action is observed.
The Role of Xylitol in Caries Prevention
A sealant is a plastic material that is bonded onto the
chewing surfaces of the back teeth. The sealant acts as
a barrier protecting this part of the tooth from decay-
causing bacterial plaque.
When are sealants necessary?
Depressions and grooves form in the enamel of the back teeth as they
develop. When these fissures are deep they are difficult to clean and
keep free of plaque. A sealant is a very effective plaque barrier.
Unfortunately this material is not effective on the smooth surfaces of
the teeth, which encompass the rest of the visible tooth structure.
These surfaces can be kept free of plaque by good brushing and
Factors In Using Sealants: -
• Caries risk is the major consideration, not age.
• Caries in pit and fissure extends beyond adolescence.
• Moderate to high risk patient having pit and fissure
morphology which would increase caries.
• Sealants can be used as a preventive measure.
• Incipient pit and fissure lesions limited to enamel are good
candidates for therapeutic sealants. If x-rays show caries
penetration into dentin is less than 1/3 and there is no cavitation,
fluoride release pit and fissure sealant is the choice. The
literature has shown that sealing frank caries terminates its
• Teeth with well-coalesced pit and fissures and with wide,
easily cleaned groves do not require sealants.
The greatest benefits of sealants are their application in
children soon after the erruption of a tooth that is a
candidate for sealant application.
Who should have sealants
The teeth are cleaned with an abrasive to remove all the
plaque, then they are dried and isolated to keep them free of
moisture. A material is placed on the teeth to allow the
sealant to bond and adhere to the tooth. The sealant is then
placed on the tooth and bonded to place with a high intensity
How are sealants applied?