1. Demineralization Remineralization
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Demineralization Remineralization
단국대학교 대학원 치의학과
소아치과학 전공 석사 2학기 강지은

2. Contents Introduction
Enamel changes during early caries lesion development
Demineralization
Arrest of the caries lesion
Remineralization
Reference

3. 1. Introduction

4. 1. Introduction
Enamel - Composed mostly of mineral in the form of Hydroxyapatite (HAp) Ca10(PO4)2(OH)2
- Organic components
- HAp ions generally substituted
affecting the stability and acid solubility of the crystals

5. The importance of the mineral phase in enamel
5/10

6. 1. Introduction
Arrangement of microcrystal - Pararrel to major axis - Soluble than tale part
Arrangement of microcrystal - Inclined to major axis - Resistant than body part

7. 1. Introduction
The space between the crystals - Occupied by water, organic material
The color, hardness and other properties of enamel - Very high mineral content and minimal acellular matrix - Similar to those of hydroxyapatite

8. 1. Introduction
More than 40 trace elements have been identified in enamel
various ways to be incorporated into enamel - Ion exchange in the hydration shell layer of water adjacent to the crystal - Direct absorption on the surface of the crystal - Substitution with components of the crystal of similar size and charge

9. 1. Introduction
Substitution of PO43– ions by carbonate - Carbonate is present in relatively high levels when teeth erupt - Less stable enamel - More susceptible to demineralization

10. 1. Introduction
Acid solubility of a tooth and its caries resistance - Final mineral composition - Crystal size and shape - Proximity of the crystals

11. 2. Enamel changes during early caries lesion development

12. 2. Enamel changes during early caries lesion development
What occurs in the mouth at any site if a ‘protected area’ is created at a part of the tooth surface, so that dental plaque is allowed to accumulate undisturbed by mechanical forces for days and weeks?

13. 2. Enamel changes during early caries lesion development그림
before
After 1 week

14. 2. Enamel changes during early caries lesion development
After 4 weeks

15. 2. Enamel changes during early caries lesion development
1 week > 4weeks

16. 2. Enamel changes during early caries lesion development
Why does mineral loss occur predominantly underneath the enamel surface?
Not fully understood
Explanatory models
Salivary proline-rich proteins Other salivary inhibitors such as statherin - Dual function

17. 2. Enamel changes during early caries lesion development
Why does mineral loss occur predominantly underneath the enamel surface?
Prevent spontaneous and selective precipitation of calcium phosphate or crystal growth of these salts directly onto the enamel surface
Tend to inhibit demineralization

18. 2. Enamel changes during early caries lesion development
Why does mineral loss occur predominantly underneath the enamel surface?
The inhibitors are macromolecules  Cannot penetrate into the deeper parts of the enamel, their stabilizing role appears to be limited to the
surface

19. 2. Enamel changes during early caries lesion development
Initial stages of the caries lesion - Partial dissolution of the tissue - Leaving a µm-thick, rather well-mineralized surface layer - Subsurface body of the lesion with a mineral loss of up to 30-50% extending deep into the enamel and dentin

20. How does such early lesions change when dental plaque is removed?
2. Enamel changes during early caries lesion development
How does such early lesions change when dental plaque is removed?

21. 2. Enamel changes during early caries lesion development
Immediately after removal of 4 weeks of local protection
1 week after

22. 2. Enamel changes during early caries lesion development
Immediately after removal of 4 weeks of local protection
2 weeks after

23. 2. Enamel changes during early caries lesion development
Immediately after removal of 4 weeks of local protection
1 week after

24. 2. Enamel changes during early caries lesion development
2 weeks later
3 weeks after

25. 3. Demineralization

26. 3. Demineralization Why is apatite solubility increased by acid?
The solubility of hydroxylapatite and other calcium phosphates is greatly affected by pH Ca5(PO4)3OH ↔ 5Ca2+ + 3PO43- + OH-
↓ H + ↓ H +
HPO42- H2O
↓ H +
H2PO42-

27. 3. Demineralization

28. 3. Demineralization
Dissolution of a hydroxyapatite crystal - not isotropic - proceed more rapidly along the C-axis  Central cavity in partialy dissolved crystals

29. 3. Demineralization
Solubility of FAp
Solubility of HAp

30. 3. Demineralization
Supersaturation with respect to fluorapatite - Responsible for the maintenance and integrity of the surface layer
More supersaturated the solution with respect to fluorapatite - Thicker and less demineralized the surface layer

31. 3. Demineralization
Pore volume distribution

32. 3. Demineralization White-spot
Characteristic chalky surface - Increase in the internal enamel porosity  loss of translucency  opaque enamel

33. 4. Arrest of the caries lesion

34. 4. Arrest of the caries lesion
Remineralization = Arrest of caries lesion progression ?

35. 4. Arrest of the caries lesion
1. Removal of the acid-producing origin of the disease (The cariogenic plaque) 2. Wear and polishing of partly dissolved external microsurface of the active lesion
3. (Subtle rearrangement of crystals that is likely to occur after exposure to saliva or the redeposition of dissolved minerals in the subsurface lesion parts)

36. 4. Arrest of the caries lesion
Remineralization is not the cause of the arrest of further progress of the lesion, although reprecipitation of mineral from oral fluids may be consequence of lesion arrest

37. Caries development 4. Arrest of the caries lesion Cavitation
- Discoloration of tooth surface due to exogenic tinted material  proof of previous caries
- Hardening of residual exposure surface - Discoloration

38. 5. Remineralization

39. 5. Remineralization Remineralization of dental lesions requires…
- The presence of partially demineralized apatite crystals that can grow to their original size as a result of exposure to solutions supersaturated with respect to apatite

40. 5. Remineralization
Salivary components in the remineralization process
Saliva - Series of substances which are involved in the remineralization process - Inorganic compounds, mainly calcium, phosphate, and fluoride and organic elements - Maintain calcium and phosphate supersaturation

41. 5. Remineralization
Salivary components in the Remineralization process
Other salivary factors involved in remineralization - Salivary flow - Buffer capacity - Saturation level of mineral elements in the tooth especially calcium, phosphate, and fluoride

42. 5. Remineralization
Slow diffusion - Difficult to maintain the necessary supersaturation in the lesion fluid  remineralization of the lesion body is not obtained
Surface layer of the lesion Protect the underlying lesion body not only from demineralization but also from remineralization

43. 6. Reference
Dental caries – The Disease and its Clinical Management 2nd edi.
Fejerskov and Edwina Kidd
소아청소년 치과학
치과보존학
Defining, classifying, and placing incipient caries lesions in perspective
Dent Clin N Am 49 (2005) 701–723
Mount GJ
Austrailia

44. 6. Reference
Principles of demineralization: modern strategies for the isolation of organic frameworks. Part I. Common definitions and history
Micron Dec;39(8):
Ehrlich H, Koutsoukos PG, Demadis KD
Germany
The caries environment: saliva, pellicle, diet, and hard tissue ultrastructure
Dent Clin North Am Jul;54(3):455-67
Hara AT, Zero DT
USA

45. Thank you for your attention