2. Conservative
Approach
•By Dr-Nashwan Mohammed
M.Sc , BDS.
Dr_nashwan@yahoo.com

3. Surgical Approach
1)
2)
Lack of understanding of the
caries process in particular the
potential for re-mineralization.
The poor physical properties of
available restorative materials.

4. 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 cavosurface margins to
terminate on non-fissured
enamel.

The resistance and
retention form required to
prevent amalgam failures.
Implementing through :
Caries risk assessment
Prevention and remineralization of non
cavitated lesion.

5. Consequences of Black’s
principle of extension for
prevention
I.
II.
III.
Gross weakening of the
remaining tooth
structure.
Structural and marginal
failure of the restoration.
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.
VI.
VII.
Increased restorative
display.
More time money and
effort consumption.
Difficult maintenance of
the restorative system.

6. 
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.

7. Adoption of medical
model would save
money , effort and time
by :
1.
2.
3.
4.
Preventing the development of
defects or new cavities.
Preventing periodontal problems.
Stopping the progress of existing
lesions and decay spots.
Maintaining existing old
restorations.

8. 
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.

9. 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.

10. Essentials to allow
conservation
 The operator.
 The tools used.
 The restorative materials.
 The oral environment conditions.
 The socioeconomic conditions of
the patient.

11. The operator



Major role is played by the clinician
performing the job.
Knowledge and understanding of
the defect ,demineralization / remineralization 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 remineralization)

12. The tools used

1.
2.
Magnification :
loupes.
Microscopes

13. 
1.
2.
3.
4.
5.
6.
Advanced diagnostic tools to
detect incipient lesions:
The intraoral camera.
Digital radiography.
Laser based device.
(DIAGNOdent)
Light fluorescence.
The high resolution
transilluminator (Digital imaging
fiber optic transillumination tool
DIFOTI)
Electrical caries monitor (ECM).

14. 

16. Ideal Cutting Instrument
Should
Fulfill:








Comfort.
Ease of use.
Discriminate and remove diseased
tissue only.
Painless.
Silent.
Required minimal pressure.
No heat generation or vibration.
Affordable.

17. 
1.
2.
3.
4.
5.
6.
Minimal or non-invasive cutting
tools:
Air abrasion technology.
Chemo-mechanical removal of
tooth tissues.
Ultrasonic cutting.
Laser cutting.
Enzymes.
Ozone treatment.

18. The restorative
materials

19. 
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

20. 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.

21. 


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.

22. 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.

23. 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.

24. Certain data have
to be collected
prior to decision
making about the
necessity of
operative
procedure.
Diet assessment
To Drill or not to Drill ?
Or when to Prepare a
Cavity ?
Caries risk evaluation
Clinical examination
Radiographic examination

25. 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.

26. 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.

27. Caries risk assessment

This done to
predict
If an individual
would
Develop caries
at
A certain time
in
A specified
period
Of time







Amount of plaque.
Type of bacteria.
Type of diet.
Salivary secretion.
Salivary buffering capacity.
Amounts of fluoride ingested.
Socioeconomic conditions.
Patient’s general health.

28. 
No Care
Advised
According to this caries risk
assessment the patient could be
either :
Preventive
Care Advised
Operative
Care Advised

29. 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.

30. Biological or medical
model of treatment

This model deals with caries as a
disease that should be treated
prior to any restorative procedures
Diet 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 preventive
Program.
Remineralization of initial lesions.
Fissure sealing for susceptible sites.
Close follow up to monitor the healing procedure.
Perform minimal intervention and prevention for diseased tissues
that can’t be remineralized and restore them conservatively.

31. 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.

32. 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.

33. 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

34. Extension for prevention concept
Obtaining the resistance form
Removal of remaining carious dentin
Conservative cavity design

35. According to Black
Occlusal:
According to conservatism
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 :
Extended midway between axial line
angle and facial or lingual margin of
contact area.
The gingival margin extends below the
crest of the healthy gum margin.
Pit and fissure sealant when there is a
catch.
Proximal
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.

36. 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.

37. 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.

38. Conservative Cavity
Design
Irritaion initiates
 Based on the shape and extent of
An acidic-medium
No
Self
Cleansable
Areas

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)

39. Examples of
Conservative Cavity
Design




Preventive resin restoration.
Simple box preparation.
Slot preparation
Tunnel preparation.(APA , Cermet
GI)

42. 
Thank you