conservative approach operative dentistry
TRANSCRIPT
Surgical Approach
1) Lack of understanding of the
caries process in particular the
potential for re-mineralization.
2) The poor physical properties of
available restorative materials.
Black’s principles of extension for prevention
Sacrifice sound enamel
and dentin to place cavity
margins into self
cleansing areas or caries
immune sites.
Dictate the extension of
preparation through
fissures to allow cavo-
surface margins to
terminate on non-fissured
enamel.
Implementing through :
Caries risk assessment
Prevention and re-
mineralization of non
cavitated lesion.
The resistance and
retention form required to
prevent amalgam failures.
Consequences of Black’s principle of extension for preventionI. Gross weakening of the
remaining tooth
structure.
II. Structural and marginal
failure of the restoration.
III. Increased potential to
pulpal irritation.(overextension
will maximize the chemical , electrical,
thermal, bacterial, osmotic and
evaporative stimuli)
IV. Increased gingival and
periodontal
irritation.(subgingival margins,
roughness and plaque accumulation)
V. Increased restorative
display.
VI. More time money and
effort consumption.
VII. Difficult maintenance of
the restorative system.
In the past decades , conservatism
was just targeting the minimization
of tooth structure cutting whereas
in the modern conservative theory
there’s an intention to use a
medical model and avoid cutting if
possible. this would require the
detection and discovery of the
lesion in its subclinical stage
before it initiates any defect that
would need repair.
Adoption of medical model would save money , effort and time by :1. Preventing the development of
defects or new cavities.
2. Preventing periodontal problems.
3. Stopping the progress of existing
lesions and decay spots.
4. Maintaining existing old
restorations.
It focuses on a minimal invasive
dentistry or preservative dentistry,
which allows a shift from the
traditional surgical approach to a
control of defects without cutting or
if cutting is to be done it has to be
restricted as much as possible.
Conservative approach encompasses the following principles Control of causative factor or
cariogenicity to eliminate further
demineralization.
Remineralization of early lesions.
Minimal surgical intervention for
cavitated lesions.
Repair rather than replace for
defective restorations.
Essentials to allow conservation
The operator.
The tools used.
The restorative materials.
The oral environment conditions.
The socioeconomic conditions of
the patient.
The operator
Major role is played by the clinician
performing the job.
Knowledge and understanding of
the defect ,demineralization / re-
mineralization cycle.
Treating the disease by allowing
re-mineralization to occur more
than demineralization. (saturation of
saliva with fluoride, calcium and phosphates to
drive them inside the tooth thus enhancing re-
mineralization)
The tools used
Magnification :
1. loupes.
2. Microscopes
Advanced diagnostic tools to
detect incipient lesions:
1. The intraoral camera.
2. Digital radiography.
3. Laser based device.
(DIAGNOdent)
4. Light fluorescence.
5. The high resolution
transilluminator (Digital imaging
fiber optic transillumination tool
DIFOTI)
6. Electrical caries monitor (ECM).
Ideal Cutting Instrument
Comfort.
Ease of use.
Discriminate and remove diseased
tissue only.
Painless.
Silent.
Required minimal pressure.
No heat generation or vibration.
Affordable.
ShouldFulfill:
Minimal or non-invasive cutting
tools:
1. Air abrasion technology.
2. Chemo-mechanical removal of
tooth tissues.
3. Ultrasonic cutting.
4. Laser cutting.
5. Enzymes.
6. Ozone treatment.
The restorative materials
Adhesion is thus different from
micromechanical bonding which
relies for retention and sealing on
an intermediary joint consisting of
a system of numerous resin
microtags and resin tooth hybrid
created in the top 2-5 лm layer of
tooth
So …..It seems essential to substitute the term
adhesion by Bododontics to be more
precise in description of this science.
Thus ….Bonding allow maximum preservation of
tooth structure and hence maximum
conservation.
The cavities to be cut should be
complying with the properties of
the different restorative materials.
These properties thus impose
certain depth , width , wall’s
inclination and finishing of
enamels.
Selection of materials that would
achieve conservatism becomes
imperative and therefore there’s a
marked trend to shift to direct tooth
colored restoratives rather than
metallic and indirect restoratives.
The oral environment conditions
Salivary flow and pH. Resting flow
rate range between 0.3-0.4ml/min
while stimulated flow rate has an
average rate between 1-2ml/min.
Buffering effect of saliva
Oral microbes , chemical
degradation potentials ,
masticatory forces and chewing
habits.
The socioeconomic conditions of the patient
Privileged , educated , employed
patients regular dental check
ups attendee low caries risk
individuals suitable candidate
for conservative approach.
The opposite individuals would
require much more radical
approach.
To Drill or not to Drill ? Or when to Prepare a Cavity ?
Certain data have to be collected prior to decision making about the necessity of operative procedure.
Diet assessment Clinical examination
Radiographic examination
Caries risk evaluation
Diet assessment
Estimation of food cariogenicity.
Frequency of intake of meals and
snacks.
Patient motivation for adopting
healthy habits.
Failures are faced due to the
difficulty of convincing the patient
to change their dietary habits.
Diet counselor.
Caries risk assessment
It is based on the fact that for
caries to develop , there are
several factors that should be
present to contribute to its
occurance. By modifying the factor
that play the major , this could
successfully prevent the
development of the disease.
Caries risk assessment
Amount of plaque.
Type of bacteria.
Type of diet.
Salivary secretion.
Salivary buffering capacity.
Amounts of fluoride ingested.
Socioeconomic conditions.
Patient’s general health.
This done to predictIf an individual wouldDevelop caries at A certain time in A specified periodOf time
According to this caries risk
assessment the patient could be
either :
No Care Advised
Preventive Care Advised
Operative Care Advised
Clinical assessment
Allow identification of the defect
and correlation of previously gather
data with the clinical picture. Upon
diagnosis , the defect should be
classified as carious or non-carious
and dealt with accordingly.
Biological or medical model of treatment This model deals with caries as a
disease that should be treated
prior to any restorative proceduresDiet and habits modification.Salivary flow and buffering capacity adjustment.Mechanical preventive measures ( calculus and Biofilm control)to fit into a dental office preventive Program.Use of antimicrobials to fit into a home care preventiveProgram.Remineralization of initial lesions.Fissure sealing for susceptible sites.Close follow up to monitor the healing procedure.Perform minimal intervention and prevention for diseased tissuesthat can’t be remineralized and restore them conservatively.
Surgical Model of Treatment The diseased tissues are beyond
healing and couldn’t be
remineralized.
Drilling and cutting away the
diseased tissue without giving
attention to the MO as a causative
factors.
Cavity is prepared minimally with
maximum preservation of tooth
strength and anatomy followed by
its restoration for maximum
longevity.
Features of a conservative cavity Include all defective enamel and
dentin.
No extension beyond defective
areas.
Convenient instrumentation and
material placement.
Freeing of all margins with
adjacent surfaces.
Necessary resistance and
retention forms.
Black’s versus Mount and Hume’s
Black’s classification doesn’t
specify the size of the lesion.
Mount and Hume classified the
lesion based on site and size
(Si/Sta)
Site/Stage 0 1 2 3 4
1 1.0 1.1 1.2 1.3 1.4
2 2.0 2.1 2.2 2.3 2.4
3 3.0 3.1 3.2 3.3 3.4
Extension for prevention concept
Obtaining the resistance form
Removal of remaining carious dentin
Conservative cavity design
According to Black According to conservatism
Occlusal: Caries and convenience dictate the
outline.
Removal of all pits and fissures. Only carious fissures.
Mesially and distally extended midway
between the marginal ridge and depth of
the triangular fossa.
Shallow fissures can be treated by
enameloplasty or slanting bur technique.
Proximal : Pit and fissure sealant when there is a
catch.
Extended midway between axial line
angle and facial or lingual margin of
contact area.
Proximal
The gingival margin extends below the
crest of the healthy gum margin.
Facial and lingual margins extend just
beyond the contact area to free it. With a
clearance of 0.5mm.
The gingival margin extends just to
include defects.
Facial and lingual surfaces all margins
are dictated by the outline of the defect.
Obtaining the resistance and retention form
Black’s
Cavity width is governed
by margin placement
midway between the cusp
tip and depth of the
fissure
Depth almost 0.5mm
pulpual to DEJ.
Retention mainly through
macromechanical
Conservatism
Cavity width to be
extended to provide
convenience
Cavity could be in dentin
or in enamel.
Retention through
micromechanical
bonding.
Removal of Remaining Carious Dentin
Black’s
All caries must be
removed , if pulp exposed
then do Endo.
There could be
irreparable damage by
bacterial invasion so
every trace of carious
dentin should be
removed.
Conservatism
Differentiation between
affected and infected
dentin (Caries detector
dye)
Chemo-mechanical
caries removal (Carisolv)
Smartprep burs , Polymer
burs.
Conservative Cavity Design
Based on the shape and extent of
the lesion. No flat floors nor
squaring of the cavity. But with
refinements to satisfy certain
requirements.
Ginival crevice are not immune
from caries.(Subgingival Margins)
NoSelfCleansableAreas
Irritaion initiatesAn acidic-medium
Examples of Conservative Cavity Design Preventive resin restoration.
Simple box preparation.
Slot preparation
Tunnel preparation.(APA , Cermet
GI)
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