Minimal invasive dentistry

1. Minimal invasive dentistry
in caris management
Dr. Malaz Mohammed Elhassan

2. Introduction
• Minimal Intervention dentistry (MID) can be defined as a
philosophy of professional care concerned with the first
occurrence, early detection, and earliest possible cure of
disease on micro levels, followed by minimally invasive,
patient-friendly treatment to repair irreversible damage
caused by such disease.

3. The benefits for patients from Minimal
Intervention are:
1. Better oral health through disease healing and not merely on
symptom relief.
2. Assists in reducing widespread patient dental anxieties.
3. more conservative approach to caries treatment and
simultaneously offer patients less invasive, health-oriented
treatment options

4. • Minimal intervention approach starts with diagnosis and risk
assessment of the disease in order to allow for proper
treatment decision. Different techniques for management of
initial carious lesion include non-invasive management and
operative care. The main goal of minimal intervention is to
increase the life of the teeth, which was restored with less
intervention. Now the concept is “prevention of extension”
rather than “extension for prevention.”

5. Minimal intervention operative dentistry is
dependent on the following factors
• The demineralization - remineralization cycle
• Adhesion in restorative dentistry
• Biomimetic restorative materials

6. Dental Materials Used for Minimally
Invasive Treatment
• Introduction of adhesive materials has played a major
role in minimally intervention dentistry because they do
not require the incorporation of mechanical retention
features. Various adhesive restorations are glass ionomer
cements, resin-based composites, dentin bonding agents
and combination of composites and GICs.

7. Glass Ionomer Cement
• Glass ionomer cement has various advantages like chemical
adhesion to tooth structure, esthetics and anticariogenicity.
Added advantage of glass ionomer cement is that set cement
is “rechargeable”, This means it can take up fluoride from the
environment, which is provided by exposure to fluoride
treatments and toothpaste. Recently resin modified glass
ionomer cements have been introduced which are easier to
place, light cured and have improved esthetic qualities.

8. Composites Resins
• These materials show effective bonding to enamel and dentin. In
these, tooth preparations are designed to conserve maximum
tooth structure because these materials adhere to tooth via
micromechanical retention achieved by etching enamel and dentin
and formation of a hybrid layer. Newer flowable resin-based
composites have low viscosity and are commonly used for smaller,
preventive resin type preparations, along with class V
preparations

9. Minimally Invasive Treatment Options for
Cavitated Lesions
• Atraumatic Restorative Technique
• Atraumatic restorative technique (ART) was pioneered in mid-1980s in
Zimbabwe and Tanzania in the need for basic treatment of carious teeth in
communities with limited resources. In this excavation of caries is done using
hand instruments and then tooth is restored using glass ionomer cement, an
adhesive material. Evidence-based studies have shown ART restorations in
single-surface cavities in deciduous posterior teeth to survive as long as
comparable amalgam restorations.

10. Goals of ART are:
• Preserving the tooth structure
• Reducing infection
• Avoiding discomfort

11. The essential instrument used for ART are:
1. Mouth mirror
2. Explorer
3. Pair of tweezers
4. Dental hatchet
5. Small, medium sized spoon excavators
6. Glass slab
7. Spatula
8. Carver

12. The materials used are:
1. Gloves
2. Cotton rolls and pellets
3. Glass ionomer restorative material
4. Dentin conditioner
5. Petroleum jelly
6. Wedges
7. Plastic strips and water

15. fig 1. preoperative
fig 2. excavation of caries
fig 3. cavity after removal caries
fig 4. cavity conditioning

16. fig. 5- Dispensing of GIC
fig. 6- Mixing of GIC
fig. 7- Insertion of GIC
fig. 8- Restored cavity

17. Advantages of ART
• Easily available inexpensive hand instruments are used rather than the
expensive electrically driven dental equipment.
• As it is almost a painless procedure the need for local anesthesia is eliminated
or minimized.
• ART involves the removal of only decalcified tooth tissues, which results in
relatively small cavities and conserves sound tooth tissues as much as
possible.
• Sound tooth tissue need not be cut for retention of filling material.

18. • The leaching of fluoride from glass ionomer probably remineralizes sterile
demineralized dentin and prevents development of secondary caries.
• The combined preventing and curative treatment can be done in one
appointment.
• Repairing of defects in the restoration can be easily done
• It is less expensive and less time consuming.
• It enables to oral health workers to reach people who otherwise never would
have received any oral health service.

19. Disadvantages of ART:
• ART restorations are not long lasting. The average life is two years depending
upon the rate of caries activity of the individual oral cavity.
• Because of the low wear resistance and low strength of the existing glass
ionomer materials their use is limited.
• A relatively unstandardized mix of glass ionomer may be produced due to
hand mixing.
• The continuous use of hand instruments over long period of time may result
in hand fatigue.
• As fundamental principles of cavity preparation are not followed all oral
health workers may not accept it.

20. Hall technique
• Another minimally invasive restoration therapy that may
be helpful in reducing the treatment burden of cavitated
dentine carious lesions is the Hall technique. A
prefabricated metal crown is cemented over the cavitated
tooth, using a low viscosity glass-ionomer after removing
debris but without removal of decomposed carious
dentine. However, few studies have been carried out

21. • A 5-year practice-based study, in which cavitated teeth
treated with the Hall technique were compared with
those restored using common practice in Scotland
showed significantly better performance for the Hall-
treated teeth than those treated by general dentists using
standard restorations. More studies are required before
the Hall technique can be recommended for general use.

23. Chemo mechanical Caries Removal
• Chemo mechanical caries removal (CMCR) involves the selective removal of
carious dentin. Reagents commonly available in market are Caridex and
Carisolv. Caridex consists of two solutions, viz. Solution I containing
sodium hypochlorite, and Solution II containing glycine, aminobutyric acid,
sodium chloride and sodium hydroxide. The two solutions are mixed
immediately before use. The solution is applied to the carious lesion by
means of applicator. Application is done until the sound dentin appears.

24. • Carisolv is available in two syringes, one containing the sodium hypochlorite
and other a pink viscous gel consisting of lysine, leucine and glutamic acid
amino acids, together with carboxymethylcellulose to make it viscous and
erythrosine to make it readily visible in use. The contents of the two syringes
are mixed together immediately before use. The gel is applied to the carious
lesion with hand instruments and after 30 seconds, carious dentin can be
gently removed.

25. Advantages
• No need for local anesthesia
• Suited for treatment of anxious and pediatric patients
• Indicated in medically compromised patients
• Conservation of sound tooth structure
• Reduced risk of pulp exposure

26. Disadvantages
• Instruments may still be needed for the removal of caries or
material.
• It leaves a surface with many overhangs and undercuts.
• Large volumes of solution are needed.
• Procedure is slow.
• It is ineffective in the removal of hard eburnated parts of the
lesion.
• Unpleasant taste

29. Comparison of two systems for
chemicomechanical removal of caries

31. Pit and Fissure Sealants and Preventive
Resin Restorations
• . A fissure sealant is a material which is placed in pits and fissures
of teeth so as to prevent or arrest the development of caries
• . Materials used for pit and fissure sealants are composite resins,
glass ionomer cement, compomers and fluorides releasing
sealants. Preventive resin restorations are placed in teeth with the
rationale that placement of a resin sealant isolates the carious
lesion from the surface biofilm.

32. Tunnel, Box and Slot Preparation
• For proximal lesions, modified preparation designs
include tunnel, box or slot preparations. Tunnel and slot
preparations are conservative preparations in which slot
preparation is indicated for lesions which are less than 2.5
mm from the marginal ridge whereas if the lesion is more
than 2.5 mm from the marginal ridge, a tunnel
preparation is indicated

33. tunnel preparation
• . In the tunnel preparation, access to carious lesion is
made from the occlusal surface, while preserving the
marginal ridge. Entry point for these preparations should
not be under occlusal load. For tooth preparation, small
tapered bur with long shank is directed at the lesion and
the preparation is completed using small round burs and
hand instruments.

34. Fig. 1. Initial approach – Enter the
lesion from the occlusal fossa
aiming towards the lesion.
Fig. 2. Gain access – Turn the bur
vertical and lean it buccally and
lingually to ‘funnel’ the cavity for
visibility.
Fig. 3. Completed cavity – axial wall
left untouched. Fig. 4. GIC Restoration done

35. Slot preparation
Fig. 1. Small carious lesion on
the proximal surface of the
first bicuspid
Fig. 2. Slot cavity preparation
Fig. 3. Finished slot cavity
Fig . 4 Resin modified GIC
Restoration done

36. Box preparation
Fig. 1. Proximal approach. A
small proximal lesion
becomes accessible through a
traditional cavity prepared in
the adjacent tooth
Fig. 2. Restoration. The
cavity has been restored
with GIC before placing
the other restoration

37. • For tunnel preparation, we preserve the marginal ridge
and the proximal surface enamel. Whereas in box or slot
preparations, there is removal of the marginal ridge, but
the preparation does not include the occlusal pits and
fissures if caries removal in these areas is not required.

38. Tooth Preparations Using Air Abrasion
• In this technique, kinetic energy is used to remove carious
lesion. Here powerful fen stream of moving aluminum
oxide particles is directed against the surface to be
removed. The abrasive particles hit the tooth with high
velocity and a small amount of tooth structure is
removed. Commonly used particle sizes are either 27 or
50 micrometers in diameter

39. • the speed of the abrasive particles when they hit the
target depends upon air pressure, size of particles,
powder flow, nozzle diameter, the angle of the tip and the
distance of tip from the tooth. Usually the distance from
the tooth ranges from 0.5 to 2 millimeters. As the
distance increases, the cutting efficiency decreases

42. Advantages of air abrasion:
• It is painless
• Local anesthesia is rarely needed
• It works quickly and the tooth with a small lesion is ready to restore in seconds
• It works quietly without the whine of the all too familiar dental handpiece
• There is no vibration or pressure to cause microfractures that weaken tooth.
• There is no production of heat to damage the dental pulp and lesser sound tooth
structure is removed.

43. Precautions
• Need to protect patient with glasses, rubber dam if possible.
• Dental team needs masks and glasses.
• Stop frequently to check the progress
• Start with low pressure and low power then increase as needed.
• Hold tip 1-2 mm away from tooth at a 45-degree angle then activate
• Always keep tip moving
• Requires external suction and air evacuation for the room.
• Use disposable mirrors.
• .
•

45. Ozone Treatment of Dental Caries
• Entry to the carious tooth is carried out by using aerator.
Disposable sterile cup on the ozone is used to form a seal around
the prepared tooth. Once the seal is obvious, ozone is delivered,
and refreshed 300 times per second, for 40 seconds.
Demineralizing solution which contains xylitol, fluoride, calcium,
phosphate and zinc, is applied to the demineralized tooth surface.
Tooth is restored with glass ionomer cement

47. • Ozone ultimately decomposes to a hydroxyl radical which is a
powerful oxidant. It oxidizes biomolecules like cysteine,
methionine, and histidine resulting in cell death. Just 20 to 40
second exposure of ozone kills all oral microbes and their
protective biofilm environment. Because of this change in
microenvironment, the remineralization of enamel and dentin can
be accomplished

48. Tooth Preparation Using Lasers
• Commonly used lasers for tooth preparation are erbium: yttrium-
aluminum-garnet lasers and erbium, chromium: yttrium-
scandium-gallium-garnet lasers. These lasers can remove soft
caries as well as hard tissue. Lasers have shown to remove caries
selectively while leaving the sound enamel and dentin. They can
be used without application of local anesthetics. Other advantages
include no vibration, little noise, no smell and tooth preparation
almost similar to that prepared by using air abrasion technique.

50. Repair instead of placement of the
restoration
• Old restorations are replaced instead of being repaired when there is
presence of secondary caries, fracture of restoration or failure of existing
restoration. But it has been seen that repairing defective restorations rather
than replacing them is a more conservative option for treatment if indicated
• the decision to repair rather than replace a restoration should be based on
the patient’s risk of developing caries, the professional’s judgment of
advantages vs risks and conservative principles of tooth preparation.

51. Factors to be Considered while Treating an
old Restoration
• Recontour and/or polish
• Seal margins
• Repair local defect

52. Replace restoration
Indications
• Secondary caries which cannot be removed during repair
procedure
• Need for esthetics
• Presence of pulpal pathology
• Fractured restoration

53. Individualized Treatment According to
ICDAS Classification

56. • . Minimal-stage caries that present in pits and fissures can be
addressed by the application of sealants, which act to prevent
bacterial contact with oral fluids. This seal essentially kills the
pathogens and prevents caries progression

57. • . Evidence has shown success using resin infiltrate in treating
radiographically visible caries for stage 1, 2 and 3 lesions

58. • For caries lesions that are considered moderate or extensive
(ICDAS stage 4 and stage 5), less conservative treatment may
be required.

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