[1][m] minimally invasive restorative dentistry
TRANSCRIPT
Minimally Invasive Restorative Dentistry
Introduction• It is generally accepted by dental
practitioners that prevention is the most
conservative, least costly method of
maintaining their patients’ teeth over the long
term.
• Prevention has been the cornerstone of
modern dentistry
Factors Influencing Conservative Approach
• Operator• Tools:
DiagnosticOperating
• Restorative materials• Oral environment condition• Socioeconomic condition of the patient
Operator
Understanding the caries disease nature
Caries irreversible defects
Caries irreversible defects Demineralization followed
by organic degradation
Caries reversible disease Demineralization followed
by remineralization
Understanding the caries disease nature
Caries reversible defects
Elimination microorganism to suppress demineralization
Saturation the saliva with fluoride, calcium, and phosphate To increase remineralization
Understanding the caries disease nature
[I] Caries Prevention
[1] Fluoride ExposureFluoride in trace amounts increases the resistance of
tooth structure to demineralization and is therefore a
particularly important consideration for caries prevention.
When fluoride is available during cycles of tooth
demineralization, it is a major factor in reduced caries
activity
The availability of fluoride to reduce caries risk is
primarily achieved by fluoridated community
water systems, but also may occur from fluoride
in the:
Diet
Toothpastes
Mouthrinses
Professional topical applications.
The optimal fluoride level for public water supplies is about 1 part per million (ppm).
Public water fluoridation has been one of the most successful public health measures.
At 0.1 ppm and below, the preventive effect is lost and the caries rate is higher for such populations lacking sufficient fluoride exposure.
Excessive fluoride exposure (10 ppm or
more) results in fluorosis, a brownish
discoloration of enamel, termed mottled
enamel.
Mottled Enamel.
Fluorides exert their anticaries effect by three different mechanisms;
First:
The presence of fluoride ion greatly
enhances the precipitation into tooth
structure of fluorapatite from calcium
and phosphate ions present in saliva.
This insoluble precipitate replaces the
soluble salts containing manganese and
carbonate that were lost because of
bacterial-mediated demineralization.
This exchange process results in the
enamel becoming more acid-resistant.
Second
Incipient, noncavitated, carious lesions are
remineralized by the same process.
Third
Fluoride has antimicrobial activity.
In low concentrationsFluoride ion inhibits the enzymatic production
of glucosyltransferase.
In high concentrations (12,000 ppm)Used in topical fluoride treatments, fluoride
ion is directly toxic to some oral
microorganisms, including MS.
[2] Immunization IgA antibodies are capable of agglutination
(clumping) of oral bacteria.
This prevents adherence to the teeth and
other oral structures, and they are more
easily cleared from the mouth by swallowing.
For patients with high concentrations of
MS, agglutinating IgA may have an
important anticaries effect.
However, it is known that the procedure is
more effective against smooth surface
lesions than pit-and-fissure lesions.
[3] Salivary FunctioningSaliva is very important in the
prevention of caries.
While xerostomia may occur because
of aging, it is more commonly a result
of a medical condition or medication.
Lack of saliva greatly increases the
incidence of caries.
Saliva stimulants (gums, paraffin waxes,
or saliva substitutes) also may be
prescribed for patients with impaired
salivary functioning.
[4] Antimicrobial AgentsA variety of antimicrobial agents also are
available to help prevent caries.
In rare cases, antibiotics might be considered,
but the systemic effects must be considered.
As already presented, fluoride has antimicrobial
effects.
Chlorhexidine
Is showing excellent results. It was prescribed as a 0.12%
rinse for high-risk patients for short-term use.
It may used in as varnish and the most effective mode of
varnish use is as a professionally applied material .
Chlorhexidine varnish enhances remineralization and
decreases MS presence.
[5] DietDietary sucrose has two important detrimental
effects on plaque.
First, frequent ingestion of foods containing
sucrose provides a stronger potential for
colonization by MS, enhancing the caries
potential of the plaque.
Second, mature plaque exposed frequently
to sucrose rapidly metabolizes it into organic
acids, resulting in a profound and prolonged
drop in plaque pH.
Caries activity is most strongly stimulated by
the frequency, rather than the quantity, of
sucrose ingested.
[6] Oral HygienePlaque free tooth surfaces do not decay!
Daily removal of plaque by dental flossing,
tooth brushing, and rinsing is the single
best measure for preventing both caries and
periodontal disease
[7] Xylitol GumsXylitol is a natural five-carbon sugar
obtained from birch trees.
It keeps the sucrose molecule from
binding with MS.
Furthermore, MS cannot ferment (metabolize) xylitol.
Thus xylitol reduces MS by:
1) Altering their metabolic pathways
2) Enhances remineralization
3) Arrest dentinal caries.
It is usually recommended that a patient chew a
piece of xylitol gum after eating or snacking for
5 to 30 minutes.
Chewing any sugar-free gum after meals
reduces the acidogenicity of plaque because
chewing →→→ stimulates salivary flow,
which improves the buffering of the pH drop
that occurs after eating.
[8] Pit-And-Fissure SealantsAlthough fluoride treatments are most effective in
preventing smooth surface caries, they are less
effective in preventing pit-and-fissure caries.
In Sealants have three important preventive
effects;
First, sealants mechanically fill pits and fissures with
an acid-resistant resin.
Second, because the pits and fissures are
filled, sealants deny MS and other cariogenic
organisms their preferred habitat.
Third, sealants render the pits and fissures
easier to clean by tooth brushing and
mastication.
Diagnostic Tools
Loops and Microscope• Highly magnificatation, and
precise diagnostic tools (Loops, and microscope)
• Micro dentistry replaces macrodentisrty
– Microscopic removal of
diseased tissues
– Preservation of healthy
tissues and structural
integrity of the tooth
Digital Radiograph• Lower exposure of radiation
• It diagnose proximal caries
adequately
• Poor diagnosis for the oclusal
surface caries
• Image enhancement,
magnification, density
assessment and color coding if
required
Digital Radiograph
Classification for proximal caries– 0 = radiographiclly sound surface– 1 = lesion in the outer half of enamel
– 2 = lesion in the inner half of enamel– 3 = lesion in the outer half of dentin– 4 = lesion in the inner half of dentin
Diagnosis sophisticated, and treatment is by remineralization
Diagnosis easy, and treatment is by caries removal
Digital Radiograph
[II] New Methods in Caries Detection
[1] DIAGNOdent Laser Caries Detection Aid
DIAGNOdent uses a pulsed red light (655nm
wavelength) to illuminate the tooth and analyses the
emitted fluorescence from bacterial products, which
changes with tooth demineralization.
The demineralization is given a numerical value that
relates to the fluorescence intensity.
This technique can be used for the accurate
diagnosis of:
Primary occlusal caries
Caries on flat, accessible surfaces
But it does not detect:
Interproximal
Subgingival Caries
(a) The DIAGNOdent probe emits a red light, which is shine onto the tooth.(b) DIAGNOdent: The emitted fluorescence from the tooth surface changes with tooth demineralization
DIAGNOdent Laser Caries Detection Aid
The DIAGNOdent pen is a hand-held laser caries detection aid. DIAGNOdent aids in the detections of caries. Even very small lesions are detected at the earliest stage, enabling you to protect and preserve the tooth substance.
DIAGNOdent is an extremely accurate and reliable adjunct for the detection of subsurface caries.
It removes the guesswork that accompanies many treatment decisions regarding questionable areas, such as stained or discolored grooves.
Advantages1) Accurate - Over 90% accurate in detecting lesions not
detectable with an explorer or bitewing X-rays.
2) Safe - Uses light energy - no X-ray exposure.
3) Poses no danger to staff and patients.
4) Painless, non-invasive examination for patients.
5) Dental caries can be located and quantified at the earliest
possible stages of decay. This greatly reduces both the
amount of tooth structure that needs to be removed and the
possibility of incorrectly diagnosing decay when it actually
does not exist.
The Diagnodent is a pen-like probe that sends a safe,
painless laser beam into the tooth and checks its
health.
A number scale and an alarm will signal when there
are signs of hidden decay.
This allows us to determine if decay is hidden
beneath the apparently healthy tooth surface.
This technology allows us to catch tooth decay at an
earlier stage, before the tooth is destroyed from the
inside out.
[2] Digital Imaging Fiber-Optic Transillumination
Digital imaging fiber-optic transillumination [DIFOTI] uses
visible light, not ionizing radiation, and is approved for the
detection of caries on:
1) Approximal, smooth surfaces
2) Occlusal surfaces
3) Recurrent caries.
DIFOTI uses the scattering of light by
carious tissue as a method of distinguishing
it from healthy enamel
Light is passed through the tooth, collected
using a camera, and the image displayed on a
computer screen.
The system has a choice of mouth pieces.
1) The interproximal mouthpiece
(Detecting interproximal caries) shines light from either
the buccal or lingual surface, which is imaged on the
opposite side by a CCD camera in the handpiece.
2) The occlusal mouthpiece
(Detecting occlusal caries) gathers light originating
from the buccal and lingual tooth surface.
In both cases, a standard personal computer with an
image capture card allows the image to be viewed on
a monitor.
The carious part of the tooth appears dark against a
light background of the healthy tooth
The DIFOTI system was not able to determine the depth
of lesions in contrast to radiographs.
FOTI equipment
Example of FOTI on a tooth. (a) Normal clinical vision, (b) with FOTI.
Advantages:
1) Has superior sensitivity over traditional radiography and can
detect early lesion.
2) Images is produced very fast as there is no need for
processing.
3) No Radiation is needed. Disadvantages:
4) Difficult to distinguish carious lesion from enamel hypo‐
mineralization and deeply stained fissures.
5) Doesn’t show the depth of the lesion thus difficult to
monitor the progress of any preventive regime.
Early Decay
Late Decay
Leaking Filling
The quantitative light-induced fluorescence (QLF)
system uses a blue light (∼488nm wavelength) to
illuminate the tooth, which normally fluoresces a green
color.
Teeth should be dried for 15s to produce more
consistent readings.
Carious lesions appear as dark areas.
[3] Quantitative Light-Induced Fluorescence
QLF Equipment. (a) The QLF unit light box,demonstrating the handpiece and liquid light guide
(b) A close-up of the intra-oral camera featuring a disposable mirror tip that also acts as an ambient light shield.
Tooth image without QLF Tooth image with QLF
The reflected light is passed through a yellow
filter, and after processing is displayed in real
time on a computer monitor.
A decrease in fluorescence is associated
with tooth demineralization and lesion
severity.
Images can be captured and analyzed to provide
measurements of:
1) Lesion area
2) Lesion depth
3) Lesion volume
This information is very useful for monitoring
enamel lesions on a longitudinal basis to see how
they respond to a preventive regime.
Disadvantage
1) QLF will only detect enamel demineralization
and cannot distinguish between caries limited
to the enamel and that which extends into
dentin
2) QLF cannot distinguish between decay and
hypoplasia.
Advantage 1) Patient education, and preventive clinical practice.
2) QLF can be used successfully to detect early secondary
caries around amalgam and tooth-colored filling
materials.
3) Demineralization of enamel adjacent to orthodontic
brackets
4) QLF can be used to detect enamel demineralization and
the success of a subsequent fluoride remineralization
regime.
[4] Electrical Conductance
This method uses the increase in electrical
conductivity of a tooth when it is demineralized.
Conductivity is measured from the enamel surface
to a ground electrode, and any increase in
conductivity is due to microscopic demineralized
spaces within the enamel.
The ECM device (Version 4) and its clinical application. (a) The ECM machine, (b) the ECM handpiece, (c) site specificmeasurement technique, (d) surface specific measurement technique.
[5] Ultrasound Techniques
The principle behind the technique is that sound
waves can pass through gases, liquids and solids
and the boundaries between them.
Images of tissues can be acquired by collecting the
reflected sound waves.
Disadvantages :Only for superficial enamel lesions
Ultrasonic Caries Detector