1. The document discusses dental caries, its progression, and how to best stop it. 2. It describes how caries forms through demineralization caused by acid from plaque and bacteria, and how the lesions progress through enamel and dentin over time. 3. The document advocates for a biological approach to cavity preparation that removes only completely demineralized tooth structure using hand instruments, in order to best preserve healthy tooth material and prevent further decay.

1. DENTINE CARIES
ITS PROGRESSION AND
HOW BEST TO STOP IT

2. Dental Caries
Sugar and plaque, the arch
criminals of dental caries

3. Dental Caries
Demineralization, remineralization
Sugar + Dental Plaque
ACID
S
Demineralization
Cavities

4. Dental Caries
Demineralization, remineralization
Subsurface
demineralization of
enamel

5. Dental Caries
Demineralization, remineralization
Occlusal lesions can
be arrested by
remineralization

6. Dental Caries
Demineralization, remineralization
recently cleaned front teeth
with signs of demineralization
and gingivitis
after some weeks
remineralization has taken
place and the gingivitis is
healed

7. Dental Caries
Demineralization, remineralization
No sugar before
sleeping

8. Dental Caries
The Caries Balance
Resistance
 Plaque
removal
 Sugar reduction
 Fluoride
 Sealants
 Chlorhexidine

9. Dental Caries
Structure of dentine





Living tissue
Peritubular dentine
Intertubular dentine
Apatite crystals
Intermolecular cross-linking

10. Dental Caries
Dentine Structure

11. Dental Caries
Progression of dentine caries
Bacterial Invasion
1
2
3
4
5
6
7
8

12. Dental Caries
Progression of dentine caries

Bacterial Invasion
1
2
3

Bacteria need to have a source of nutrients,
i.e. from the oral environment.

Bacteria are found mostly in the biomass
with few being found in the dentine tubules.
4
5
6
7
8

13. Dental Caries
Progression of dentine caries
Crystal Removal Process
1
2
3
4
5
6
7
8

14. Dental Caries
Progression of dentine caries
Crystal Removal Process
1

2
3
4
5
6
7
8


Acid from fermentation process penetrates
the dentine tubules ahead of bacterial
invasion.
This softens the dentine matrix.
The collagen fibres are reversibly damaged
in the dissolution process.
cont’d

15. Dental Caries
Progression of dentine caries
Crystal Removal Process (cont’d)
1

2
3
4
5
6
7
8

Continuation of acid production dissolves
crystals in the peritubular and intertubular
dentine.
Further continuation of acid production
breaks the intermolecular crosslinks of
collagen fibres irreversibly.

16. Dental Caries
Progression of dentine caries
Defense reaction in dentine
1
2
3
4
5
6
7
8

17. Dental Caries
Progression of dentine caries

1
2
3
4
5
6
7
8
Defense reaction in dentine
A
defence reaction takes place in the
dentine.
 Dissolution alters the hydroxyapatite crystals.
 Crystals with a lower hardness and a lower
calcium density (= whitelockite) remain.
 The dentine tubules are blocked by
precipitated intratubular whitelockite crystals.
cont’d

18. Dental Caries
Progression of dentine caries
Defense reaction in dentine
1
2
3
4
5
6
7
8
 These
(cont’d)
crystals originate from the
peritubular and intertubular dentine.
 This process is known as TUBULAR
SCLEROSIS.
 It is seen clinically as yellow-brownish
discoloration of the dentine.

19. Outer Carious Dentine
Knoop Hardness Number
70
- bacterial invasion
- unremineralizable
- dead
- without sensation
60
50
Dental Caries
Inner Carious Dentine
- minimal bacterial invasion
- remineralizable
- alive
- sensitive
40
30
transparant zone
20
10
zone of almost total
demineralization
E-D Junction
zone of partial demineralization
1000
2000
Sound Dentine
3000 µm
Crystals in Tubule Lumen
Peritubular dentine
Intertubular dentine
Bacteria
Odontoblast Process

20. Dental Caries
Two layers of carious dentine
Outer (‘infected’)
 Bacterial
Invasion
 Unreminerizable
 Dead
 Without sensation
Inner (‘affected’)
 Few
Bacterial
 Reminerizable
 Alive
 Sensitive

21. Dental Caries
Remineralization of inner carious
dentine
Prerequisites physiological
remineralization:
 Presence
collagen fibers
 Living odontoblastic process
External remineralization:
 Saliva
, calcium and phosphate
 Exposure bio-active agents

22. Dental Caries
Characteristics of occlusal caries
Fissure enamel caries
1
2
3
4

23. Dental Caries
Characteristics of occlusal caries
1
2
3
4
Fissure enamel and
dentine caries

24. Dental Caries
Characteristics of occlusal caries
Fissure cavity
1
2
3
4
3.6 mm

25. Dental Caries
Characteristics of occlusal caries
Lateral spread of fissure
cavity
1
2
3
4
3.6 mm

26. Dental Caries
Dentinal lesion formation and
progression: a summary
1

2


Enamel demineralization follows the
enamel rods.
Initial dentine demineralization does not
spread along the Enamel Dentine
Junction (EDJ) beyond the periphery of
the lesion in the enamel.
This leads to a cone shape lesion with
the base at the EDJ.

27. Dental Caries
Dentinal lesion formation and
progression: a summary
1

In any pit and fissure system there can
be multiple lesions in different stages of
progression. (Stages A, B and C.)

Only when there is frank cavitation and a
cariogenic environment, will dentine
demineralization spread in a lateral
direction. (Stage D)
2

28. Dental Caries
Characteristics of approximal
caries
1. Subsurface demineralization of enamel.
1
2
3
4

29. Dental Caries
Characteristics of approximal
caries
1
2
3
4
2. Partial demineralization of dentine directly
underneath enamel lesion

30. Dental Caries
Characteristics of approximal
caries
1
2
3
4
3. The dentine demineralization follows the
dentine tubules

31. Dental Caries
Characteristics of approximal
caries
1
2
3
4
4. Lateral spread of dentine caries occurs
mainly in cavitated lesions

32. Dental Caries
Characteristics of approximal
caries : a summary

Progression of approximal caries follows the
same principles as for occlusal caries.

It follows the enamel rods, but because of the
curved shape of the approximal tooth surface,
the lesion does not lead to a cone shape at the
EDJ as present in an occlusal fossa.

33. Dental Caries
Traditional concepts of cavity
design
1

2
3
4

GV Black’s cavity preparations followed
designs that were largely dictated by the
physical properties of the filling materials
(e.g., amalgam and silicate cement).
These materials needed mechanical
retention

34. Dental Caries
Traditional concepts of cavity
design
1
2
3
4
Mechanical retention
 Flat
floors
 Vertical walls
 Triangular retention
niches
 Undercut areas

35. Dental Caries
Traditional concepts of cavity
design
1

Shape of the prepared cavity was not limited to
the tooth destruction caused by caries.

The preparation did not follow the way a dentine
lesion progresses.

Black's principles could be considered as: 'the
application of a mechanical design on a biological
process'
2
3
4

36. Dental Caries
Traditional concepts of cavity
design
1
2
3
4
‘The application of a mechanical design on a
biological process'

37. Dental Caries
Longevity of amalgam
restorations

Research findings
 survival
time single surface: 10 – 8 years
 survival time multiple surface: 8 - 6 years

Reasons for failures
 secondary
caries
 marginal breakdown

38. Dental Caries
Repeat restoration cycle
1
2
3
Repeat restoration cycle
 Occlusal
lesion and occlusal restoration
 2-Surface restoration
 Extended restoration
 Crown or Extraction

39. Dental Caries
Repeat restoration cycle

1
2
3

‘Diagnoses’ are uncertain, with
considerable variation occurring
between dentists.
Extensive cavity preparations (Black) in
the name of outline form and extension
for prevention result in restorations with
weak margins, leading to marginal
breakdown and ‘ditching’.

40. Dental Caries
Repeat restoration cycle

1

2
3



Dentists have an urge to replace restorations
Perceived (but erroneous) requirement to
‘freshen up’ the cavity walls and margins.
The teeth inevitably become weaker, thereby
reducing their prognosis.
The complexity of the restorations increases or
Tooth needs to be extracted.

41. Dental Caries
Traditional approach:
a Summary
1

2


Much sound tooth tissue needs to be
removed.
Traditionally placed restorations, on
average, do not last long.
The replacement restorations, in many
cases, last for less time.

42. Dental Caries
Traditional approach:
a Summary

The end result is a tooth that became
weaker and weaker each time a
replacement was made.

The weaker the tooth becomes, the
more likely the restoration will fail,
resulting in a vicious cycle and termed
the ‘repeat restoration cycle’.
1
2

43. Dental Caries
Biological principals of cavity
preparation
1

2
Cavity cleaning





Obtaining access
Removal of dead dentine and enamel
Anatomy determines the shape
No preconceived cavity design
Black's principles are redundant

44. Dental Caries
Biological principals of cavity
preparation
1
2

45. Dental Caries
Appropriate instrumentation

Mechanical retention is no longer
needed with adhesive materials.

Shape of the cavity is determined by the
anatomy of the lesion.
1
2
3
4
5
6
7
8

46. Dental Caries
Appropriate instrumentation

Question:
1
2
3
4
5
6
7
8
Is a rotary instrument the best tool
when the cavity is determined by
the anatomy of the lesion ?

47. Dental Caries
Appropriate instrumentation

1
2
NO !!!!
A rotary instrument is not
the best instrument for:
3
4

removing only soft, completely
demineralized tooth tissue and

preserving as much as possible
remineralizable enamel and dentine.
5
6
7
8

48. Dental Caries
Appropriate instrumentation

1
2
Hand instrument:
 Dental
hatchet
3
4
5
6
7
8
(e.g., 10 – 6 - 12)

49. Dental Caries
Appropriate instrumentation

1
2
Hand instrument:
 Excavator
3
4
5
6
7
8
(e.g., 153 – 154)

50. Dental Caries
Appropriate instrumentation

Rotary instruments (only certain circumstances)
1
2
3
4
5
6
7
8
 Slow
speed drill
 with
straight bur for further opening of dentinal lesions
that have a very small entrance
 with round bur for gentle removal of dead tissue.

51. Dental Caries
Appropriate instrumentation

Rotary instruments (only certain circumstances)
1
2
3
4
5
6
7
8
 High
speed drill
 only
for opening cavities that are inaccessible
 removal of failed restorations.

52. Dental Caries
Appropriate instrumentation

1
2
3
4
5
6
7
8
Why hand instruments?
 creates
the most ideal (conservative) cavity
shape
 gives the operator improved tactile sense
 does not damage surfaces adjacent to the
lesion, in the case of approximal lesions and
 therefore, does not promote caries
development.

53. Dental Caries
Cavity restoration:





WHY
To stop the caries process
To facilitate plaque removal
To encourage remineralization of inner
carious dentine
To restore function
To restore aesthetics.

54. Dental Caries
Cavity restoration:

HOW
Application of a material that:
 produces
a seal against bacterial invasion
 encourages remineralization
 is sufficiently durable
 maintains function.

55. Dental Caries
Cavity restoration:
WHICH MATERIAL

Adhesive restorative materials
 composite
resins and polyacid-modified
composite resins (‘compomers’)
 glass-ionomers and resin-modified glassionomers.

Non-adhesive restorative materials
 amalgam

56. Dental Caries
Tooth preservation versus
cavity preparation
1
2
3
4
Preservation =
restoration + prevention

57. Dental Caries
Tooth preservation versus
cavity preparation
1
2
3
4
Sealant
restorations

58. Dental Caries
Tooth preservation versus
cavity preparation
1
2
3
4

For carious lesions in occlusal,
buccal and lingual surfaces of
posterior teeth:



Preventive resin restoration
Preventive glass-ionomer restoration
Atraumatic Restorative Treatment (ART )

59. Dental Caries
Tooth preservation versus
cavity preparation
1
2
3
4

For carious lesions in approximal
surfaces of posterior teeth:



Box-type restorations (outcome: good).
Tunnel preparation (outcome: dubious).
ART (outcome: unknown yet).

60. Dental Caries
Effect of sealed versus nonsealed restorations

Clinical trial in the USA.
 more
sound tooth structure was conserved
 restoration margins were better protected
 recurrent caries was less frequent
 clinical survival of restorations was
prolonged.

61. Dental Caries
Summary
1
2
3
4

The biological principle to the management of a
dentine lesion is to only remove soft, completely
demineralized tooth tissue. This is best achieved
through using hand instruments and/or a slowly
rotating drill rather than a high-speed drill. In doing
so, less sound tooth tissues are removed and
damage to surfaces of other teeth is minimized.

62. Dental Caries
Summary

1
2
3
4
Since only soft, completely
demineralized tissue is removed, there
can be no preconceived cavity design;
the anatomy of the carious lesion
dictates the size and shape of the cavity
preparation.

63. Dental Caries
Summary

1
2
3
4
The treatment is completed by placing an
adhesive filling material into the cleaned cavity
preparation, over its margin, and over the
adjacent pits and fissures. This sealant
restoration will arrest caries activity that is
present in dentine and enamel, provided that
the bonding of the material to these tooth
tissues is adequately established.

64. Dental Caries
Summary

1
2
3
4
This treatment modality has the potential
to:




control dentine caries
increase survival of the restoration
save tooth tissues and thus
increase tooth life expectancy.

65. Dental Caries

Remember:
 TO APPLY PREVENTIVE MEASURES
 TO ENCOURAGE ORAL
HYGIENE AND
 TO PROMOTE THE USE OF
TOOTHPASTE.
FLUORIDE