Concepts of minimal intervention dentistry from British Dental journal MID series

1. MINIMAL
INTERVENTION
DENTISTRY
1

2. CONTENTS
2
• EVOLUTION FROM SURGICAL APPROACH TO MID
• THE CONCEPT OF MID
• MINIMAL INTERVENTION Vs MINIMALLY INVASIVE
• BUILDING THE TREATMENT CARE PLAN
• CARIES RISK ASSESSMENT IN ADULTS
• CARIES RISK ASSESSMENT IN CHILDREN
• DETECTION AND DIAGNOSIS OF INITIAL CARIES LESION
• CARIES INHIBITION BY RESIN INFILTRATION
• ART (ATRAUMATIC RESTORATIVE TREATMENT)
• MINIMALLY INVASIVE OPERATIVE CARIES MANAGEMENT: RATIONALE AND TECHNIQUES

3. INTRODUCTION
3
G.V.BLACKS CLASSIFICATION OF DENTAL CARIES
Surgical approach – removal of diseased portions
EXTENSION FOR PREVENTION
Extension to areas presumed to be caries resistant.
A lack of understanding of the caries process, in particular the potential for remineralisation, and
the poor physical properties of available restorative materials.

4. 4
Traditional preparation- removal of smaller
amounts of caries as compared to healthy dentine

5.  Since the development of ultra-high speed rotary cutting instruments in the 1950s, there has been
a tendency to extend a cavity even further, and the resultant weakening of the tooth crown has led
to a marked increase in ‘replacement dentistry’, wherein there is further loss of tooth structure
upon each replacement of a restoration
REPLACEMENT DENTISTRY
5

6. Case study
6
A patient aged 33 at the time of the
photograph, who has, judging by the
number of endodontic treatments present,
been obliged to visit the dentist on
numerous occasions in the past. The
problem of oral hygiene has not been
resolved and, the caries process, which is
very aggressive, has not been halted.
Restorative and endodontic treatment do not in themselves solve problems of oral health

7. "a systematic respect for the original tissue."
The concept bridges the traditional gap between prevention and surgical
procedures.
It integrates concepts of prevention, control and treatment and is based on all
factors that affect the onset and progression of oral diseases.
So there is a shift from compulsive restorative dentistry to rational therapeutic
strategies with least invasive solutions.
THE CONCEPT
7
The profession should now be encouraged to adopt an entirely new attitude to the
repair and restoration of demineralised tooth structure

8. “ a philosophy of professional care concerned with the first
occurrence, earliest detection, and earliest possible cure of disease
on micro (molecular) levels, followed by minimally invasive and
patient-friendly treatment to repair irreversible damage caused by
such disease”
DEFINITION
8
Tyas MJ, Anusavice KJ, Frencken JE, Mount GJ. Minimal intervention dentistry—a review. FDI Commission Project
1-97. Int Dent J 2000;50:1–12.

9. Minimal intervention deals with causes of dental disease and not just the symptoms
and is based on biological solutions rather than purely restorative, that is prevention
and control of disease.
Minimal invasive dentistry or ultraconservative and micro dentistry embraces
operative restorative approaches. It is a component of the minimal intervention
dentistry.
INTERVENTION Vs INVASIVE
9

10. Is a concept of patient care that deals with causes of dental disease and not just the
symptoms.
Biological solutions rather than purely restorative treatment
Prevention and control of oral disease.
MINIMAL INTERVENTION DENTISTRY
10

11. Primary prevention (prevention of new
cases)
• Community level: Artificial fluoridation of
water/school oral health programmes
• Individual level: prevent early colonization of
children's teeth by cariogenic bacteria.
• Also management of cariogenic diet rich in
fermentable carbohydrates with poor oral
hygiene habits.
LEVELS OF PREVENTION
11
Secondary prevention (prevent disease
from becoming established and
progressing)
• Screening to detect carious lesions at the
earliest
Tertiary prevention: (prevent recurrence)
• Prevent failure of preventive and restorative
care initially implemented
When it involves MID involves carious lesion therapeutic strategies are required but in this case the least invasive solutions
are chosen ex: remineralisation, therapeutic sealant, restorative care aimed at conserving the maximum amount of tissue

12. Operative approaches that respect both the dental tissues and patients comfort.
Objective: preserve sound tooth tissue and also tissues which has potential to
remineralize.
Use of adhesive biomaterials are preferred ex resin composites and glass-ionomer
cements
MINIMALLY INVASIVE DENTISTRY, ULTRA-
CONSERVATIVE OR MICRO-DENTISTRY
12

13. How is it different from traditional dentistry?
13
 In TD preparation and restoration of cavities are the only systematic response to presence of carious lesions.
 In MID, Placement of restorations is an ancillary phase of the overall management of patient care where
restorations are indicated only when the lesion has advanced to frank cavitation and where
remineralisation techniques have reached their limits.
 Micro-dentistry is performed preferably using optical aids (magnification, microscopes, intra-oral cameras)
 sophisticated devices other than traditional rotary instruments mounted on a contra-angle handpiece or air-
turbine, such as chemo-mechanical, air-abrasion, sono-abrasion and laser systems.

14. ‘Rational’ clinical practice is based on four key elements:
1. Control of the disease by identifying and managing the risk factors
2. The detection and remineralisation of early lesions
3. Minimally invasive surgical intervention
4. Where possible the repair rather than replacement of defective restorations
MINIMAL INTERVENTION DENTISTRY:
BUILDING THE TREATMENT (CARE)
PLAN?
14

15. A cariology-based care plan comprises three main
phases
15

16. • Why the disease (caries) has occurred and is used to evaluate the severity of the damage
caused.
• The determination of the individual caries risk factors and detection of carious lesions
(presence and activity).
DIAGNOSTIC PHASE
16
RISK PREDICTORS
• Past exposure to caries
• Presence of cavitated caries lesions
• recent restorations placed due to caries
• demographic factors relating to age, level of
education and disabilities that potentially
expose the patient to risk habits .
Ex:
• A teenager with uncontrolled eating habits,
• Elderly where oral hygiene is more difficult to
maintain due to loss of motor skills

17. Aims to readjust the balance between pathological and protective factors.
Measures required to curb the phenomena of demineralisation and to initiate remineralisation are
implemented.
Recommendations relating to
Hygiene and dietary habits
Antibacterial therapy
Prescription of appropriate fluoride measures
Placement of preventive sealants.
In the case of patients with cavitated lesions involving the dentine, atraumatic restorative care
can complement the arsenal of prophylactic or partial excavation of caries.
PROPHYLACTIC PHASE
17

18. • It concerns the reinforcement of patient education, monitoring the effectiveness of all
preventive and control measures implemented for example, fluoride and preventive sealants,
and therapeutic measures for example, the integrity of therapeutic sealants and restorations.
• During follow-up visits, potential failures can be intercepted and the recall interval adjusted
based on new clinical findings and the behaviour of the patient
FOLLOW UP AND MAINTAINANCE
18

19. Fit between control and surveillance
Required when the caries process has resulted in significant loss of dental tissue, to eliminate the
retention of plaque within cavities and restore physiological masticatory function and aesthetics.
Follow a minimally invasive approach, where caries removal/ cavity preparation is delayed until there
are cavitated dentine lesions and through the use of adhesive materials, these cavities can
remain minimally invasive.
Defective restorations are not systematically removed and replaced. These radical solutions need to
be rethought and nuanced; polishing reduces the indications for the complete replacement of the
restoration, the margins of restorations can be sealed and restorations can be repaired.
RESTORATIVE PHASE
19

20. 20
CARIES
RISK
ASSESSMENT
IN ADULTS

21. Risk-based prevention and disease management have been recognised as the cornerstones of modern caries
management.
CONTROVERSIES SURROUNDING CARIES RISK ASSESSMENT
It is difficult to identify such patients accurately and that even if we could, the evidence for preventive measures on high-risk
individuals is still not very strong.
But when the wellbeing of the patient is considered, it is more important to carry out a risk assessment incorporating the best
available evidence than just doing nothing due to lack of strong evidence.
Similar preventive measures should be administered to the whole population, regardless of the risk
Dental caries is unequally distributed in most populations around the world, with a small percentage of individuals carrying the
heavier burden of caries disease.
For most dentists in private practice, it becomes imperative to be able to identify a patient’s risk status in order to be able to
develop the most cost-effective treatment strategy for that individual.
RISK ASSESSMENT IS IT NEEDED?
21

22. Caries risk assessment should be useful in the clinical management of dental caries by helping to
• Determine lesion activity
• Estimate the degree of risk so the intensity of the treatment (for example, fluoride concentration and delivery method) and
frequency of appointments can be customised
• Identify the main aetiological agents contributing to the current disease that might be targeted in the management of the
disease (for example, diet control)
• Establish the need for additional diagnostic procedures (for example, salivary flow rate/buffering measurements)
• Formulate the best restorative treatment (care) plan for this patient (for example, dental material selection)
• Enhance the overall prognosis of the patient
• Appraise the efficacy of the caries management plan established at recall visits.
CARIES RISK ASSESSMENT IN PRACTICE
22

23. Clinical observations that tell about the past caries history and activity and includes
variables related to disease experience.
RISK INDICATORS
23
CARIES EXPERIENCE
- Past caries experience and current lesion activity
-Epidemiological studies have shown a positive strong
correlation between past caries experience and future caries
development, which is why all available risk tools include this
indicator very prominently
In adults, there is also a clear association between coronal
caries and the risk of developing root caries.
Socio-demographic
indicators
• Is a stronger predictor of caries risk in children than in
adults, it is still important in adults.
• Because dental caries generally is more prevalent in
lower than higher socioeconomic classes the dentist
should consider the social environment of the patient
(for example, education, income, occupation etc)
elicited through history.

24. A risk factor plays an essential role in the aetiology of the disease, while a risk indicator is indirectly associated with the
disease.
Risk factors are the biologic reasons, or factors, that have caused or contributed to the disease, or will contribute to its
future manifestation on the tooth.
RISK FACTORS
24
Genetics
Only factor that cannot be measured currently in clinical practice
The amount of evidence relating to genes and caries experience has
increased significantly in the last decade
Genes have been identified linking tooth
development, salivary function and diet/taste to
caries risk or protection.
:as the understanding of genetics associated with caries
risk increase, so does the future possibility of using
salivary diagnostics based on genetic scans to develop
either better risk assessment tools or to better target
specific interventions”

25. SALIVA
Most common salivary paramteres for risk assessment include salivary
flow rate, buffering capacity and ph.
Hypo- salivation – strongest salivary indicators for an increased
risk of dental caries.
Unfortunately, subjective complaint of xerostomia often does not
correlate with objective findings of reduced salivary flow rate.
Recommended that dental care professionals ask their patients the
following questions:
Does your mouth feel dry when eating a meal? Do you sip liquids to
aid swallowing dry foods? Do you have difficulty swallowing any
foods? Does the amount of saliva in your mouth seem to be too
little, too much or do you not notice it?
Rather than ‘is your mouth dry?’
25
BACTERIA
People with high numbers of cariogenic bacteria are at higher
risk for developing future lesions.
Plaque indices - ineffective predictors of future caries
DC- fissures and interproximal areas
PI - based on smooth surface scores
Salivary bacterial tests - controversy in the literature regarding
the accuracy of salivary tests for mutans streptococci and
lactobacilli in predicting future caries in adults.
No proper tests for caries risk assessment but these tests can
be useful for patient motivation.

26. Diet
Sugar exposure is an important aetiological factor in caries
development.
Self-reported sugar intake seems to have little value at identifying,
by itself, patients at risk.
Other dietary considerations include the retentiveness of the food,
frequency of consumption (this being the most important),
consumption between meals, the presence of protective factors
in foods (for example, calcium, fluoride) and the type of
carbohydrate.
Excessive frequent consumption of soft drinks remains a major
risk factor that may be partly responsible for the high rate of caries in
26
Others
Mental and/or physical disabilities that affect
regular oral hygiene.
Enamel defects, such as hypoplasia, have
also been related to increase caries risk,
especially in children

27. Although the clinician should analyse all protective factors the patient is exposed
to, of great importance is the exposure to fluorides.
The dental care professional should consider all fluoride sources to which the
patient is exposed, for example, fluoridated drinking water, foods/ drinks, home
topical fluoride products and periodic professional fluoride exposures.
As the risk is increased, so should be the level of fluoride exposure, both at home
and in office.
PROTECTIVE FACTORS
27

28. CARIES RISK ASSESSMENT TOOLS
28

29. 29

30. 30
An infant oral health visit consists of a six-step protocol:
1. Caries risk assessment
2. Proper positioning of the child (knee-to-knee exam)
3. Age appropriate tooth brushing prophylaxis
4. Clinical examination of the child’s oral cavity and
dentition
5. Fluoride varnish treatment
6. Assignment of risk, anticipatory guidance and
counselling.
Paediatric dental care –prevention and management protocols using caries risk assessment for infants and
young children

31. 31

32. 32

33. 33

34. 34
DETECTION AND
DIAGNOSIS OF INITIAL
CARIES LESIONS

35. The initial caries lesion can be defined as a primary
lesion which has not reached the stage of an
established lesion with cavitation .
High evidence-level studies are in agreement that the
ideal tool for detection of the initial lesion, the ‘gold
standard,’ has not yet been identified.
The conventional and validated tools for detecting
early carious lesions include visual and tactile
examination and radiography (bitewings).
TOOLS FOR DETECTING EARLY LESIONS
35

36. 36

37. 37

38. None of the new caries detection techniques developed in recent years is 100% reliable when used
alone
They are classified on the basis of the physical principles that underpin them.
The most prominent include
Transillumination Fluorescence systems
(Diagno.cam, Kavo®) (DIAGNOdent, Kavo®; CS 1600 Kodak;
staCam iX, DürrDental®; SoproLife, Acteon®).
NEW DIAGNOSTIC AIDS
38
1. Laser fluorescence
2. Fiber-optic transillumination
3.Digital imaging fiber-optic transillumination
4. Ultraviolet illumination
5. Electronic caries detector
6. Dye penetration method
7.Quantitative light-induced fluorescence (QLF)
8. Ultrasound imaging
9. Endoscope / Videoscope

39. 39
CARIES
INHIBITION BY
RESIN
INFILTRATION

40. Resin infiltration of carious lesions represents an approach to the treatment of non-
cavitated lesions on proximal and smooth surfaces of primary and permanent teeth.
The principal feature of this technique is that it is non-invasive, preserves tooth
structure and can be completed in a single visit.
The concept was first developed in Germany, at the Charité University Hospital in
Berlin, from in vitro studies on the penetration of resin into caries and marketed
under the brand name of Icon® (DMG America Company, Englewood, NJ).
40
RESIN INFILTRATION

41. THE PRINCIPLE
41
The principle of resin infiltration is to perfuse porous enamel with
resin by capillary action, thereby stopping the process of
demineralisation and stabilising the carious lesion. The principle can
be compared with the saturation of a sugar cube or sponge with a
liquid.

42. 42
The infiltration takes place within the enamel, in contrast to pit
and fissure sealants, which forms a superficial mechanical
barrier on the outer surface of the initial lesion, depriving the
bacteria that colonise the surface of the lesion of nutrients
from the biofilm)
Bacteria that have penetrated the demineralised enamel are
trapped in the infiltrating resin once it has been cured.

43. INDICATION
43

44. ARMEMENTARIUM TECHNIQUE
44

45. EVIDENCE
45
A systematic review of the literature comparing techniques for sealing and infiltration in the treatment of initial caries
lesion, concludes, with a good level of evidence, that the sealants act by forming a superficial barrier against the
penetration of bacteria and their by-products, while infiltration techniques create an internal barrier in the lesion
by replacing lost minerals with low viscosity light-cured resin.

46. Minimally invasive operative caries
management: rationale and
techniques
46
Minimally Invasive Dentistry describes contemporary
ultraconservative operative management of cavitated lesions requiring
surgical intervention.

47. Minimally Invasive Operative Caries Management
Strategy (MI OCMS)
47
The
histology
of the
dental
substrate
being
treated
The
chemistry/han
dling of the
adhesive
materials used
to restore the
cavity
Consideration of
the practical
operative
techniques
available to
excavate caries
minimally.
‘Golden triangle’ of MID
MINIMAL
INTERVENTION
DENTISTRY

48. ENAMEL CARIES
Carious enamel with its unsupported prismatic structure is
weak under stress from compressive/ shear occlusal
loads or from tensile shrinkage forces from photo-cured
resin-based adhesive materials..
If carious enamel is retained at the margin of the cavity
and subsequently restored. Then,
1) Cohesive microleakage
2) Secondary’ caries development along margins
LESION HISTOLOGY
48
DENTINAL CARIES
Two histopathological zones
1) The peripheral caries-infected zone
Irreversibly damaged, necrotic and softened by long
standing bacterial contamination and proteolytic
denaturation of collagen and acid demineralization of the
inorganic component
2) deeper caries-affected zone
Reversibly damaged by virtue of carious process, which
has the potential to repair under the correct conditions as
the collagen is not denatured.

49. Propylene glycol-based indicator dyes were developed to act as a marker for that
carious dentine requiring excavation, but many conflicting studies exist regarding their
efficacy in this regard.
The removal of grossly softened caries-infected dentine is recommended in most situations
(except perhaps in a deep lesion overlying the pulp where its vitality assessment leans
towards an acute inflammatory response and an adequate clinical seal can be achieved at
the periphery of the cavity).
Peripheral caries removal should extend to sound dentine where inadequate quantity and
How much dentine caries should be
excavated?
49

50. There are several clinical technologies available for cutting teeth and removing caries.
MINIMALLY INVASIVE OPERATIVE TECHNIQUES
50

51. Retention rate of PFS
• Meta-analyses have shown that auto-polymerizing sealants were found to have a
five-year retention rate of 64.7%.
• Resin-based light-polymerizing sealants and fluoride-releasing products
showed five-year retention rates of 83.8% and 69.9% respectively.
• However, poor retention rates of <19.3% were documented for UV-light-
polymerizing materials, compomers and GIC based sealants.
PIT and FISSURE SEALANTS
51

52. PRR is indicated in teeth with minimal teeth and fissures decay.
After etching, rinsing and drying the cavity is condensed with a normal composite or GIC.
PREVENTIVE RESIN RESTORATION
52
SURVIVAL RATE OF PRR

53. The manual selective excavation of tissues destroyed by the caries process,
involving excavation of the infected dentine while conserving the affected dentin.
A sealant restoration is then placed, which comprises a conventional adhesive
restoration combined with the sealing of adjacent pits and fissures.
Initially, this approach was proposed for the management of patients in developing
countries because it can be performed using only manual instruments.
The excellent results from clinical studies suggest that it also has its applications in
industrialised countries especially for patients with multiple caries lesions during the
stabilisation and motivation phase.
ATRAUMATIC RESTORATIVE TREATMENT
53

54. SURVIVAL RATE OF ART
54

55. AIR ABRASION
• The instrument was first developed in the
1940’s by Dr. Robert Black.
• It is a method of tooth structure removal that is
considered to be an effective alternative to the
standard dental drill.
• It removes tooth structure using a stream of aluminium
oxide particles generated from compressed air or
bottled carbon dioxide or nitrogen gas.
• The abrasive particles strike the tooth with high velocity
and remove a small amount of tooth structure.
AIR ABRASION AND LASERS
55
LASERS
(light amplification by stimulated emission of
radiation)
• In 1997, the Food and Drug Administration
approved the use of Erbium: Yttrium Aluminium
Garnet laser for caries removal in the USA.
• It operates at a wavelength of 2.94 μm and is
used for the caries removal, cavity preparation in
both enamel and dentine and for the preparation
of root canals.
• Laser treatment is appreciated by patients as
they are more comfortable than drilling.

56. • Many manufacturers are now producing smaller burs for cavity preparation using MI techniques. The burs are
spherical, tapered or elliptical. Examples include fissurotomy burs (SS White, USA) and narrow diamond burs
(Brassler, USA).
• The instruments are manufactured using a special high-tensile steel to produce a thin neck
MICRO-PREPARATION AND FISSUROTOMY BURS
56
SMART BURS (POLYMER BURS)
• Hardness is lesser than healthy dentin but greater than
infected dentin.
• These burs can easily remove the soft carious dentin, but
when they come in contact with hard dentin, they blunt out,
so that unnecessary cutting does not occur

57. A non invasive technique for eliminating infected dentin via a chemical agent.
This is a method of caries removal based on dissolution.
The chemicals used can be in the form of liquid (caridex) or gel (carisolv).
CHEMO MECHANICAL CARIES REMOVAL
57
Caridex
• Nmono chloroglycine and amino butyric acid and was
called as GK 101 E.
• The solution was claimed to cause disruption of
collagen in the carious dentine, thus facilitating its
removal.
It constitutes amino acids and 0.5% sodium
hypochlorite and is applied to the dentin.
The new system is marketed in two syringes:
Red Gel: Glutamic acid, leucine, lysine,
sodium chloride, erthrosine , water and sodium
hydroxide.
Transparent Gel: 0.5% Sodium hypochlorite
CARISOLV

58. TUNNEL PREPARATION
It could be used when the lesion is more than 2.5 mm below the crest of the marginal ridge and the
contact area may remain sound and the marginal ridge may be quite strong.
Access to the lesion through the occlusal surfaces should be limited to the extent required to achieve
visibility and should be undertaken from an area that is not under direct occlusal load.
Access may be gained through the occlusal surface with No. 2 bur about 2.0 mm from the marginal
ridge.
Resin-modified glass ionomer cement is the current material of choice for this restoration. They are
radiopaque and have been shown to prevent microleakage.
CAVITY DESIGNS FOR MINIMAL INTERVENTION
58

59. 59

60. It could be used when the lesion is less than 2.5 mm below the crest of the marginal ridge.
The basic principles of cavity design remain the same, with the objective of removing only that tooth
structure that has broken beyond the possibility of remineralization.
SLOT PREPARATION
60

61. In this preparation, the excavation of the dentin
lesion is same as for the previous preparations.
The design differs only in the handling of the
enamel.
Initially, the integrity of enamel wall needs to be
preserved by extending the margins where it can
be considered stable and durable.
A full box need not to be developed.
MINI BOX FULL BOX
61
It is a very common procedure, where the enamel is in
hopelessly poor condition and needs refining after
eradicating the dentin lesion.
The final refinement will depend on the type of
restoration to be placed.
For example, the preparation design for an amalgam or
composite restoration differs from the design for a
porcelain or gold inlay

62. CONCLUSION
In the twenty-first century, greater Emphasis must be placed on assessing
Caries risk, shifting patients to a Low caries risk status, remineralising
Noncavitated lesions, abandoning the Surgical approach to caries
management, And repairing rather than Replacing defective restorations.
62

63. WAY FORWARD
63
FUTURE RESEARCH
- Improve the sensitivity of diagnostic methods to
develop site-specific indicators of future caries risk
- Clear guidelines on management of caries
- Analyse the cost-benefit ratio of minimal intervention
techniques

64. REFERENCES
64
1. Tyas, M.J., et al., Minimal intervention dentistry--a review. FDI
2. Featherstone JD, Doméjean S. Minimal intervention dentistry: part 1.
From'compulsive'restorative dentistry to rational therapeutic strategies. British dental
journal. 2012 Nov;213(9):441.
3. Fontana M, Gonzalez-Cabezas C. Minimal intervention dentistry: part 2. Caries risk
assessment in adults. British dental journal. 2012 Nov;213(9):447.
4. Holmgren C, Gaucher C, Decerle N, Doméjean S. Minimal intervention dentistry II:
part 3. Management of non-cavitated (initial) occlusal caries lesions–non-invasive
approaches through remineralisation and therapeutic sealants. British dental journal.
2014 Mar;216(5):237.

65. 65
5) Guerrieri A, Gaucher C, Bonte E, Lasfargues JJ. Minimal intervention dentistry: part 4. Detection and
diagnosis of initial caries lesions. British dental journal. 2012 Dec;213(11):551.
6) Holmgren CJ, Roux D, Doméjean S. Minimal intervention dentistry: part 5. Atraumatic restorative
treatment (ART)–a minimum intervention and minimally invasive approach for the management of dental
caries. British dental journal. 2013 Jan;214(1):11.
7) Holmgren CJ, Roux D, Doméjean S. Minimal intervention dentistry: part 5. Atraumatic restorative
treatment (ART)–a minimum intervention and minimally invasive approach for the management of dental
caries. British dental journal. 2013 Jan;214(1):11.
8) Banerjee A. Minimal intervention dentistry: part 7. Minimally invasive operative caries management:
rationale and techniques. British dental journal. 2013 Feb;214(3):107.

66. THANK YOU
66