This document discusses the concepts and techniques of Minimal Intervention Dentistry (MID). MID aims to preserve healthy tooth structure and detect and treat dental caries at an early stage. Key concepts of MID include early diagnosis of caries, assessing individual caries risk, using radiographs to determine caries depth and progression, arresting and remineralizing lesions, and restoring cavities with minimal preparation. Techniques discussed include chemomechanical caries removal, air abrasion, laser preparation and repairing restorations instead of replacement. The goal of MID is to minimize removal of healthy tooth structure.

1. Minimal Intervention Dentistry
DR SAURABH SHARMA
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTICS

2. • Extension for prevention v/s prevention of
extension: the former approach require
removal of diseased portion of tooth along
with extension of cavities to the areas prone
to caries but the later approach involves the
minimal disturbance and involvement of the
healthy tooth structure.

3. • MID approach in managing dental caries
incorporates detecting, diagnosing,
intercepting and treating dental caries on the
microscopic level.

4. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

5. EARLY DIAGNOSIS OF CARIES
• It involves early detection of carious lesions
and also determination of caries activity.
Caries activity can be determined by
monitoring the lesion overtime.
• Radiographs, clinical information can be used
to detect caries.
• Electrical conductance method, quantitative
laser fluorescence, tuned aperture computed
tomography can also be used.

6. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

7. Assessment of individual caries risk
• Risk assessment is a diagnostic tool that helps
professionals supervise individual’s oral health.
• It is a process that attempts to identify those
children who are at greater risk for a high level of
caries and will need more oral health supervision.
• The risk factors are:
– Physical- variation in tooth enamel, deep pits and fissures,
anatomically suspected areas.
– Gastric reflux
– High streptococcus mutans
– Previous caries experience

8. Behavioural:
• Bottle used at night for sleep
• Frequent snacking
• Inadequate oral hygiene
• Eating disorder
• Socio environmental:
Inadequate fluoride
Poor family oral health
Poverty

9. • Disease or treatment related:
– Special carbohydrate diet
– Frequent saliva flow from medication
– Orthodontic appliances

10. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

11. Radiographic assessment of caries
depth and progress
• Radiographs such as bite wings are helpful in
detecting and analyzing the depth of caries.
• Follow up radiographs at random can also
describe the progress of caries.
• Digital radiographs are also helpful.

12. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

13. Decreasing the risk of further demineralization
and arresting existing lesion
• It involves use of various chemicals and other
agents that can reduce the rate of progression
of caries.
• Generally fluorides are being used for this
process.

14. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

15. Remineralization of the existing lesion
• It has established that it is possible to arrest and even
reverse the mineral loss associated with caries at an
early stage before cavitation takes place.
• The cyclic loss and gain of Ca and phosphate form the
basis of demineralization and remineralization. The ph
of the oral cavity matters in this regard.
• Taking advantage of the tooth’s ability to remineralize,
the balance can be tipped in favour of remineralization
by altering oral environment. The phenomenon of
alteration include:

16. • Decreasing the frequency of intake of refined
carbohydrates.
• Following plaque control measures
• Maintaining salivary flow
• Motivating and educating the patient.
• The chlorhexidine and fluorides also
encourages remineralization.

17. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective restorations.

18. Restoring cavitated lesions using
minimal tooth preparation
• The tooth can be restored by one of the
following methods:
– Preparation with hand instruments
– Preparation with high speed instruments
– Air abrasion
– Chemo-mechanical cavity preparation
– Laser cavity preparation
– Sonic oscillating system

19. Preparation with hand instruments ART-
atraumatic restorative treatment
• This technique involves the removal of the
affected tooth tissues with hand instruments,
followed by the restoration of the cavity with
specially designed glass ionomer cement.

20. Clinical technique:
 Isolate the tooth or teeth to be treated with cotton wool
rolls and clean the tooth surface with a wet cotton pellet.
 Widen the entrance of the lesion with the help of a dental
hatchet
 Remove the soft caries with an excavator and wash cavity
with lukewarm water.
 Insert mixed glassionomer in to the cavity and overfill
slightly .with petroleum jelly coated gloved finger apply
slight pressure on the occlusal surface for a few sec
 Check the bite and adjust the occlusion with the help of an
articulating paper ,cover the filling with petrolleum jelly or
dental varnish.

22. • Advantages :
– No sophisticated dental equipment is needed
– Treatment is not dependent on elctricity
– Operator requires minimal training.
– Fluoride release from GIC will have a cariostatic
effect.
– Cost very less
– Time consumed is very less

23. Preparation with rotary instrument
• Tunnel preparation: It is performed by
accessing the carious dentin from the occlusal
surface while reserving the marginal ridge.
• Tunnel preparation proceeds from occlusal
surface to the proximal carious lesions, leaving
the marginal ridge intact.

24. • Tunnel restorations are divided into three types:
1. Internal- It is the cavity preparation touching the
lesion, there is no actual cavitation and objective
is remineralization.
2. Partial- In this, enamel is smoothened around
the periphery and the remaining lesion in touch
with the preparation can remineralize.
3. Total tunnel preparation- All demineralized
enamel is removed.

26. Technique
• Adjacent tooth is protected with matrix band
• Access is gained through nearest pit depending upon
the side
• Small round bur is used to make access, directing the
bur at 45 degree towards the proximal surface
• Once the lesion is approached, the access can be
slightly widened using tapering fissure bur.
• Carious lesion is excavated thoroughly by moving the
bur in occlusal and gingival direction.
• Then filling is done.

28. Advantage
• Preservation of tooth structure
• Maintenance of marginal ridge
• Negligible effect on gingival tissue
• Cost effective
• Aesthetic preparation
• Risk of overhang is minimal.

29. Disadvantages
• Limited accessbility
• Risk of incomplete removal of caries
• Risk of pulp involvement
• Marginal adaptibility of restoration is poor
• Difficulty in insertion and finishing of the
restorative material
• Marginal ridge being undermined, may break.

30. Minibox or slot preparation
• This involves the removal of the marginal
ridge, but do not include the occlusal pit and
fissures if caries removal is not necessary.
• These cavities have either box or saucer shape
and may be restored with resin based
composite or amlagam.

32. Air Abrasion
• It is non rotary method of cutting hard tissues.
The technique uses pseudo mechanical kinetic
energy from a stream of abrasive particle thrown
at tooth surface at a certain velocity.
• Commonly used abrasive particles are aluminium
oxides with size 25-30 micron meter.
• The abrasive particles strike the tooth with high
velocity and remove small amounts of tooth
structure.

34.  Efficiency of removal is relative to the hardness
of the tissue or material being removed and the
operating parameters of the air abrasion device.
 A number of parameters such as
 the amount of air pressure
 particle size
 quantity of particles passing through the nozzle
 nozzle diameter of the handpiece
 angulation of nozzle of the handpiece
 distance from object, and time of exposure to
the object vary the quantity of tooth removal
and depth of penetration.

35. • Air abrasion used to remove & restore pit & fissure caries using 27 micron-sized
powder particles. 1) Fissure caries seen on occlusal surface of mandibular 2nd
molar. 2)Tip of air abrasion device placed on molar. 3) Removal of caries with
minimal cavity preparation width. 4) Cavity restored with preventive resin
restoration.

36. Uses
• As an adjunct to acid etching
• As a repair modality- fractured porecelain and
composite restoration
• As a preventive measure: application of pit and
fissure sealants
• Detecting early carious lesion- air polishing using
sodium bicarbonate powder is utilized to remove
the surface stains. The tooth then can be dried
and examined for any opacity on the surface of
the enamel.

37. Chemomechanical Preparation
• Chemomechanical caries removal system involves
the chemical softening of carious dentine
followed by its removal by gentle excavation
using specialized hand instruments.
• Routinely used chemical is CARISOLV.
• The material is available in 2 tubes.
• One tube contains amino acids leucine, lysine,
glutamic acid and carboxymethyl cellulose and
sodium hyrdoxide.
• The other tube contains sodium hypochlorite.

38. • Active gel is formed by mixing two equal parts
of these two components.
• Once the gel is mixed, the amino acids bind
chlorine form chloramine at high ph.
• Then this cholramine binds to different areas
of protein in carious dentin. The porous
nature of the degraded dentin allows the gel
to penetrate and to break down.

39. 1
• Enamel lesion can be removed using bur
• Agent is applied to carious dentin
2
• After 30 sec., the caries is excavated using excavator
• The lesion is kept soaked with the gel
3
• Excavation is continued till the gel no longer turns cloudy
• Remaining part is checked for any left out debris. After caries
removal, surface has frosted appearance.

40. painless
Conservative
cavity
preparation
Patient’s
acceptance
Time consuming
Rotary
instruments may
be required
Allergy to
chemical

41. Laser cavity preparation
• The Er: YAG and Nd: YAG laser haven been used
to cut dentinal tissues, whereas carbon dioxide
lasers facilitate sealing of fissure.
• Laser treatment reduces the number of carious
bacteria and also volatizes the water in the caries.
• Laser can allow the dentin to remove caries
selectively by maintaining healthy enamel and
dentin.
• Preparation are similar to those made with air
abrasion.

42. Advantages
• Safe and efficient treatment modality for
caries removal
• No need for anesthesia, thus avoiding any
numbness
• No vibration, little noise
• No smell
Disadvantages: cost factor, need to learn the
technique.

43. Restorative materials-
1. Glass Ionomer Cements: the advantages of GICs
include adhesion to tooth structure and release of
fluoride and other ions. They perform well in low
stress areas. Set GIC is rechargeable, meaning it can
take up fluoride from the environment, which is
provided by exposure to fluoride varnishes and
fluoride containing tooth pastes. Disadvantage
include technique sensitivity and their opaque nature.
The handling properties and bitterness of the material
can be overcome by adding resin to the material
resulting in resin modified GIC, which are easier to
place, are light cured and have improved esthetics.

44. 2. COMPOSITE RESIN: It is widely used in the
restorative process
3. Bonded silver amalgam: It was introduced with
an idea to improve the bonding of the amalgam
to the cavity wall.
The thickness of the silver amalgam required for
resistance form also makes the use of bonded
silver amalgam controversial in MID.
Adv.- can be used in short clinical crowns, marginal
leakage is checked, the sealed and bonded
restoration prevents further progress of caries.
Disadv.- increased cost and time, might not be
feasible in minimum cavity preparation.

45. • MID approach includes the following
concepts:
» Early diagnosis of caries
» Assessment of individual caries risk
» Radiographic assessment of caries depth and progress
» Decreasing the risk of further demineralization and
arresting existing lesion’
» Remineralization of existing lesion
» Restoring cavitated lesions using minimal tooth
preparation
» Repair rather than replacement of defective
restorations.

46. Repair rather than replacement of
defective restorations
• It is established that with every replacement, the loss of
tooth structure increases. This loss is much more in case of
composites and other tooth coloured restorations. The
repeated restoration replacement lead to need of more
complex and costly treatment, may be indirect restorations.
• The repair process is being accepted in the profession with
the evolution of composite and bonding agents.
• Cavity preparation should ensure independent retention
and resistance form for the repair.
• The decision to repair rather than replacement depends on
the patient risk of developing caries and individual clinical
judgement.

47. • The composite has shown promises in the re-
attachment of the fractures anterior teeth.
• Repair with GIC may be preferable in cervical
areas, because of the potential for fluoride
release and GIC’s excellent adhesion,