Transcript Chapter 7 Body Systems

Dental Caries
2
Introduction
 Dental
caries (tooth decay) is an
infectious bacterial disease that has
plagued human beings since the
beginning of recorded history
 Today, because of scientific advances
and new technologies, dentistry is
developing new strategies for managing
dental caries

These strategies emphasize prevention and
early intervention
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Bacterial Infection
 Two
specific groups of bacteria found in
the mouth are responsible for dental
caries:


Mutans streptococci (MS) (Streptococcus
mutans) (strong disease causing)
Lactobacilli (LB)
 They
are found in relatively large numbers
in dental plaque
 The presence of lactobacilli in the mouth
indicates a high sugar intake
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Transmission of Caries-Causing
Bacteria

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Mutans streptococci are transmitted through
saliva, most frequently the mother’s, to the infant
When a mother has a high count of mutans
streptococci in her mouth, the baby has a high
count of the same bacteria in his or her mouth
Women should be certain that their own mouths
are healthy
When the number of caries-causing bacteria in
the mouth increases, the risk of dental caries also
increases
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Dental Plaque

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Dental plaque is a
colorless, soft, sticky
coating that adheres
to the teeth
Plaque remains
attached to the tooth
despite movement of
the tongue, water
rinsing, water spray,
and less-thanthorough brushing
Formation of plaque
on a tooth
concentrates millions
of microorganisms on
that tooth
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Dental Plaque
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Enamel Structure

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Enamel is the most highly mineralized tissue in
the body
It is stronger than bone
Enamel consists of microscopic crystals of
hydroxyapatite arranged in structural layers or
rods, also known as prism
The enamel crystals are surrounded by water
The water and protein components in the
tooth are important because that is how the
acids travel into the tooth, the minerals travel
out, and the tooth structure dissolves
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The Caries Process
 For
caries to develop, three factors must be
present at the same time:
 A susceptible tooth
 A diet rich in fermentable carbohydrates
 Specific bacteria (regardless of other factors,
caries cannot occur without bacteria)
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Areas for Development of Caries
 Pit-and-fissure
caries occurs primarily on the
occlusal surfaces and the buccal and lingual
grooves of posterior teeth, as well as in the
lingual pits of the maxillary incisors
 Smooth surface caries occurs on intact enamel
other than pits and fissures
 Root surface caries occurs on any surface of the
root
 Secondary, or recurrent, caries occurs on the
tooth surrounding a restoration
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Stages of Caries Development
 It
usually takes some time, months to years, for a
carious lesion to develop
 Caries is an ongoing process characterized by
alternating periods of demineralization and
remineralization


 It
Demineralization is the dissolution of the calcium
and phosphate from the hydroxyapatite crystals
Remineralization is the redeposition of calcium
and phosphate in previously demineralized areas
is possible for the processes of
demineralization and remineralization to occur
without any loss of tooth structure
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Demineralization and Remineralization
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Stages of Caries Development
 An
incipient lesion (a watch) develops
when caries begins to demineralize the
enamel
 An overt, or frank, lesion is characterized
by cavitation (the development of a
cavity or hole in the tooth)
 Rampant caries describes the time
between the onset of the incipient lesion
and the development of the cavity; it is
rapid and there are multiple lesions
throughout the mouth
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Early Carious Lesion, or White Spot
of Demineralization
Courtesy Dr. John D.B. Featherstone, School of Dentistry, University of California San Francisco.
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Overt Carious Lesion
Courtesy Dr. Frank Hodges, Santa Rosa, CA.
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Rampant Caries
Courtesy Dr. Frank Hodges, Santa Rosa, CA.
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Severely Decayed Molar on a
Child
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Decay on the Lingual Surface
of a Maxillary Lateral Incisor
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Secondary (Recurrent) Caries
 Form
in the spaces between the teeth
and margins of a restoration
 Not easily seen, thus diagnosis is difficult
 New restorative materials may prevent
recurrent decay
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Root Caries
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Occurs on the root of teeth that have gingival
recession that exposes root surfaces
Becoming more prevalent and is a concern for
members of the elderly population, who often have
gingival recession, exposing the root surfaces
Older people often take medications known to
reduce saliva flow, which contributes to caries
Carious lesions form more quickly on root surfaces
than coronal caries does because the cementum on
the root surface is softer than enamel and dentin
Like coronal caries, root caries has periods of
demineralization and remineralization
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Recurrent Decay
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Root Surface Caries
Courtesy Dr. John D.B. Featherstone, School of Dentistry, University of California San Francisco.
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Early Childhood Caries (ECC)

An infectious disease that can happen in any
family
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Many children live with the constant pain of
decayed teeth and swollen gums
In some states ECC affects one third of
preschool children
Tooth decay is the single most prevalent
disease of childhood

Early childhood caries can be prevented with
appropriate education of the parents and oral
health care for the child
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Risk Factors for ECC
 ECC
is common among families of lower
socioeconomic status

The rate of untreated dental disease among lowincome children aged 2 to 5 years is almost five
times higher than that seen in higher-income
families
 ECC
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
is more common among:
Particular ethnic groups
In those families who have limited access to dental
care
In areas where water fluoridation is lacking
 ECC
is also more common among children with
special needs
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How Children Get Early
Childhood Caries
 ECC

 It
is a transmissible disease
Bacteria in the parent’s or caregiver’s
mouth are passed to the child
is important for parents to keep their
own teeth healthy to keep their children’s
teeth healthy
 Baby bottle tooth decay is another term
for ECC
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The Importance of Saliva

Physical protection involves a cleansing effect
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Chemical protection contains calcium,
phosphate, and fluoride
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Thick, or viscous, saliva is less effective than a
more watery saliva in clearing carbohydrates
Keeps calcium at the ready, to be used during
remineralization
Chemical protection includes buffers,
bicarbonate, phosphate, and small proteins
that neutralize the acids after we ingest
fermentable carbohydrates
Antibacterial substances in saliva work
against the bacteria
If salivary function is reduced for any reason,
the teeth are at increased risk for decay
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Caries Diagnosis
The
following methods are used to
detect dental caries, and each has
specific limitations:
Dental explorer
Radiographs
Visual appearance
Indicator dyes
Laser caries detector
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Caries Detection Devices
 Several
types of devices have been
developed that can provide a higher
level of discrimination in the diagnosis of
dental caries
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Some detect bacterial by-products and
quantify sound signals to aid in caries
detection
Some detect differences in tooth structure
and display information on a screen
Others have software that analyzes density
changes on digital radiographs and
outlines potential lesions
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Laser Caries Detector
Used
to diagnose caries and reveal
bacterial activity under the enamel
surface
Carious tooth structure is less
dense and gives off a higher
reading than noncarious tooth
structure
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The DIAGNOdent
Courtesy KaVo Dental, Charlotte, NC.
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Visual and Radiographic
Appearance of Molar
Courtesy KaVo Dental, Charlotte, NC.
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Cross Section of Molar Showing
Decay
Courtesy KaVo Dental, Charlotte, NC.
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CAMBRA
 Caries

management by risk assessment
An evidence-based strategy for preventive
and reparative care for early dental caries
that can be used in any dental office
A
dental health professional assesses an
individual’s risk factors, and protective
factors, then determines the level of risk
for caries

An individualized preventive plan is
developed based on the determined level
of risk
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Methods of Caries Intervention
 Fluoride:
A variety of types are available
to strengthen the tooth against solubility
to acid
 Antibacterial rinses: Products such as
chlorhexidine rinses are effective
 Decreased fermentable carbohydrates:
Reduce the amount and frequency of
ingestion
 Increased salivary flow: Chewing sugarless
gum—for example, one with a nonsugar
sweetener such as xylitol
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Preventive Measures Against
Caries
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Caries Risk Assessment Tests
 Used
to identify the factors that contribute to an
increased risk for dental caries
 If the patient’s risk for dental caries can be
determined, it is possible to prevent the caries
from developing by beginning appropriate
preventive treatment
 Risk-assessment tests for caries are based on the
amount of mutans streptococci and lactobacilli
present in the saliva
 High bacterial counts indicate a high caries
risk, and low counts indicate a low risk for
caries
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Patients in Whom a Caries-Risk
Test Is Indicated
 New
patients with signs of caries activity
 Pregnant patients
 Patients experiencing a sudden increase in the
incidence of caries
 Individuals taking medications that may affect
the flow of saliva
 Xerostomic patients
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Patients in Whom a Caries-Risk
Test Is Indicated
Patients
about to undergo
chemotherapy
Patients who frequently
consume fermentable
carbohydrates
Patients suffering from diseases
of the autoimmune system