Pathogenesis
Bacterial
infections of teeth and gums (gingiva) begin early in
life and continue to progress throughout life with the possibility of
tooth loss.
Caulfield et al showed that mutan streptococci
(MS) are transmitted by the
mother to the child between 19 and 28
months of age. (If during this
“window of infectivity” the
child does not acquire MS the child was
caries free.) It is important to
note that mutan streptococci can be
present without cavities being noted. Less than 10,000 CFU’s
of MS in saliva coincided with caries free
children. It is only when the
infection overwhelms the host that
demineralization of enamel begins.
The bacteria involved are many, but
most frequently the species mutans
streptococci is associated with the
caries infection. The most often
mentioned bacteria in gingival infections
are gram negative anaerobes. The
bacteria form a complex community on the
teeth. This biofilm, called plaque,
adheres to tooth surfaces and increases
in amount unless disrupted daily.
The film is made up of bacteria that can
ferment sugars and other carbohydrates
producing lactic acids. Continued
production of acid can lead to
demineralization of the enamel. If
preventive interventions are not in place
or initiated early and daily, cavitation
(a cavity) will result. Therefore
many preventive recommendations attempt
to disrupt the process of
demineralization, neutralize the acid
attack and remineralize the early lesions.
In pediatric patients cavitation can begin as soon as
teeth erupt (5-6 months of age) and increases in
intensity especially in at-risk and vulnerable children.
If allowed to continue, severe destruction of teeth can
occur. Early childhood caries (ECC) is the
presence of one or more decayed, missing or filled tooth
surface in any primary tooth in a child 71 months of age
or younger. ECC is associated with feeding
practices that include prolonged use of
the bottle during the day and night with
carbohydrate containing liquids.
Not all children with habitual and
prolonged use of the bottle are
susceptible to this type of caries
infection. Other risk factors have
been identified and include tooth enamel
abnormalities, altered saliva production
and composition, defects in immune defense
mechanisms, insufficient or inappropriate
exposure to fluoride, absence of daily
oral hygiene, lack of professional dental
intervention, frequent liquid
medications, and finally a number of
social, educational, and cultural
factors.
Epidemiology
Since the 1970s national surveys
have reported on the oral health status
of US citizens. For this study
guide we will only report on findings of
pediatric patients of both preschool and
school age.
As background information, to measure
oral health a number of indices are
used. The most common for dental
decay is to count the number of decayed,
filled, or missing teeth or
surfaces. With the primary
dentition it is reported as dfmt or
dfs. In the permanent dentition it
is reported as DFS or DMFT.
Because most studies use
representative samples from schools,
reports of children below age six are
less available. Studies from Head
Start and WIC children reported that 6.4%
of infants one year old had cavities; 20%
of two year olds; 25% of three year olds,
and 49% of four year olds. In
another study of Medicaid eligible
children in a school clinic, 56% of
children between 24 – 36 months had
cavities.
Federally funded studies most often
reported are the National Institute of
Dental Research (NIDR) surveys. The
National Health and Nutrition Examination
Surveys (NHANES I, II, and III), and the
National Center for Health Statistics
(NCHS) surveys. All give us a good idea
of the prevalence of oral disease in
given populations conducted by seasoned
examiners at different time
periods. This allows us to track
progress being made in community wide and
professionally recommended preventive
interventions. The report stated
that 97.3% of five year olds were free of
decay in their permanent teeth while only
15.6% of seventeen year olds were free of
decay, clearly demonstrating the progress
of decay through the school years.
Over 40% of five year olds had decay
in their primary teeth and by age nine
the percent with decay was almost 60%,
again demonstrating the progress of decay
over time.
The good news is that since the
1960s reduction in decay in
pediatric patients has been reduced
dramatically probably due to the use of
fluorides. Nevertheless dental
decay continues to be one of the most
common diseases in children – more
common than asthma.
Furthermore, we also know that some
populations are at greater risk than
others. These include children of
families living in poverty, young Mexican-American children, some immigrant
children, Native American infants and
toddlers and non-Hispanic black children.
Early childhood caries (ECC) is
reported in six of ten children by age
five. A type of ECC, nursing caries
or baby bottle tooth decay in up to 10%
of children and 50% of native American
and Eskimo children.
Other Infections
Decay that is not treated will
progress through the enamel and into the
dentin, the layer of tooth with sensory
innervations. Complaints of
sensitivity and discomfort will
follow. Without intervention the
disease process will progress through the
dentin and into the pulp of the
tooth. Discomfort and pain will
increase. Pulpitis is a bacterial
infection in the pulp, and in early stages,
can be treated and the tooth
restored. If allowed to continue,
the infection can progress out of the
tooth into the surrounding bone. It
can further progress with the development of
an intra or extra-oral fistula that
allows for drainage of pus into the oral
cavity.
If the infection spreads to the
surrounding facial tissues, a cellulitis can
result with swelling and
inflammation. The sites can be on the neck or on the face.
Cellulitis requires immediate
intervention to prevent serious
progression. Treatment involves
removal of teeth (if the cellulitis is
tooth related), antibiotics and may
require incision and drainage.
While water fluoridation, the use of
fluoride products, dietary modification
including sugar restriction, improved
oral hygiene, and regular professional
care have led to dramatic reductions in
dental caries over the past 30 years, the
disease remains a major public health
problem.
Early phases of tooth decay are
currently difficult to detect.
While radiographs, or x-rays, can
disclose established cavities,
particularly those that occur between the
teeth, they are not effective in
detecting early decay, or caries in the
roots of teeth. The ongoing development
of more sensitive diagnostic techniques
to detect dental caries in its earliest
phases will pave the way for the use of
noninvasive treatment options to stop or
reverse the caries process. Current
data support the following treatment
options: fluorides, dental sealants,
combinations of chlorhexidine, fluoride,
and sealants; xylitol and health
education.
Water fluoridation and the use of
fluoridated toothpaste are highly
successful in preventing dental
caries. There is also evidence to
support the use of fluoride varnishes in
permanent teeth, as well as fluoride
gels, chlorhexidine gels, sealants, and
chewing gum containing xylitol, a sugar
substitute. Combined interventions
may be more effective in preventing
caries in children.
Early identification of children at
high risk for extensive caries is
important so that they may receive early
and intense preventive
intervention. Children at low risk
also need to be identified to reduce
unnecessary care and expenditures.
The most consistent predictor of caries
risk in children is past caries
experience. Children who experience
early childhood caries are more likely to
develop caries on their permanent
molars. Low socioeconomic status
(SES) is also associated with higher
caries rates.
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