CLINICAL SIGNIFICANCE OF DENTIN.pptx

clinical significance of dentin

1. CLINICAL SIGNIFICANCE OF DENTIN

2. DENTIN Calcified tissue Physically and chemically dentin closely resembles the bone Orbans Oral Histology and Embryology 13 th edition

3. CLINICAL SIGNIFICANCE OF DENTIN

4. DENTINAL CARIES

5. INFECTED AND AFFECTED DENTIN Infected dentin Affected dentin Outer carious dentin soft and leathery in consistency Inner carious dentin hard in consistency dark brown in colour. light brown in colour high concentration of bacteria does not contain bacteria collagen is irreversibly denatured Collagen is reversibly denatured not remineralized and must be removed Can be remineralized and therefore should preserved

6. Caries-affected dentin produces lower bond strength and poor quality of the hybrid layer than normal dentin. Nakajima M, Kunawarote S, Prasansuttiporn T, Tagami J. Bonding to caries-affected dentin. Japanese Dental Science Review. 2011 Aug 1;47(2):102-14.

7. DENTIN HYPERSENSITIVITY .

8. HYDRODYNAMIC THEORY

9. CLINICAL FEATURE AND MANAGEMENT Sharp pain Management-seal the dentinal tubules Desensitizing toothpastes,flourides,dental adhesives,lasers etc

10. PERMEABILITY OF DENTIN

11. Permeability of dentin is directly related to its protective function

12. REMAINING DENTIN THICKNESS Type of restoration Shallow RDT >2mm Moderately deep RDT(>0.5- 2mm) Deep RDT <0.5mm Silver amalgam varnish Base –e.g. zinc phosphate , zinc polycarboxylate Calcium hydroxide (sub base) with base Glass ionomer cement Not required Not required Calcium hydroxide as liner Composite resin Dentin bonding Dentin bonding agent Dentin bonding agent Calcium hydroxide as liner followed by GIC as base Cast restoration Base Calcium hydroxide as liner with base over it “pulp protection”

13. DENTIN ADHESION The concept of dentistry with the introduction of adhesives has changed from - Extension for Prevention to PREVENTION OF EXTENSION !!!

14. MOIST V/S DRY DENTIN

15. Most new adhesives utilize the ‘wet bonding technique’. The ‘wet bonding’ has repeatedly shown enhanced bond strengths as water preserves the porosity of collagen network available for monomer interdiffusion

16. SMEAR LAYER

17. Smear layer is an amorphous, relatively smoothlayer of microcrystalline debris with a featureless surface that cannot be seen with naked eye [ Pashley DH 1984]

18. SMEAR LAYER IN RESTORATIVE DENTISTRY Composite resin restorations Early bonding agents were hydrophobic and were bonded directly to dentin smear layer- Bond strength unsatisfactory. Newer bonding system leads to:- a) Complete removal of smear layer prior to the bonding procedure by using etch and rinse adhesive b) Incorporation of smear layer into bonding layer by using self etch adhesives

19. Amalgam restorations Dentin smear layer are left in place for unbonded amlagam restorations It produces some degree of dentinal tubule sealing , although it is 25 % to 30% porous

20. ROLE OF SMEAR LAYER IN ENDODONTICS ADVANTAGES :- Apical dentin chip plug – biological seal Reduction of dentin permability to bacteria,toxins and oral fluids ( Pashley 1985) Violich DR, Chandler NP. The smear layer in endodontics –a review. International endodontic journal. 2010 Jan;43(1):2-15 .

21. Obliteration of pulp chamber and root canal Smear layer itself is infected blocks antimicrobial effect of intracanal medications DISADVANTAGES Violich DR, Chandler NP. The smear layer in endodontics –a review. International endodontic journal. 2010 Jan;43(1):2-15 .

22. Presence of smear layer would necessitate use of higher concentration and/ or amount of anti bacterial agents. Smear layer removal improved the fluid-tight seal of the root canal system , whereas other factors such as filling technique or the type of sealer did not produce significant effects Shahravan et al. (2007)

23. IMMEDIATE DENTINAL SEALING

24. PERIPHERAL SEAL ZONE CONCEPT

25. The objectives of biomimetic dentistry are enumerated as follows: Eliminating infections and cracks in dentin Immediately sealing dentin Bonding the tooth side-to-side, front-to-back, and top-to bottom to prevent re-infection and new crack initiation Lowering stress/strain in the tooth/restoration 5. Resisting loss of tooth structure from attrition, abrasion, erosion and abfaction 6. Marching the tooth’s natural anatomy

26. EFFECT OF RESTORATIVE MATERIALS

27. CALCIUM HYDROXIDE “Reparative dentin bridge formation”

28. . BIODENTINE

29. COMPOSITE

30. Effect of operative procedures on dentin Dessication during cavity preparation has long been known to cause aspiration of odontoblastic nuclei into dentinal tubules. Heat produced during deep cavity preparation causes loss of odontoblasts or their aspiration into the dentinal tubules.

31. AVOID Excessive cutting Heat generation Continuous drying-dislodgement –aspiration into tubules USE Air water coolent Sharp instruments

32. ROLE OF DENTIN IN PULPAL REPAIR AND REGENERATION Dentine matrix contains a diverse pool of bioactive molecules, which are released during injury and therapeutic procedures to facilitate reparative processes. Release of these molecules can be stimulated during REPs by irrigation, medicament, and materials placement. EDTA is conducive to DMC release, whereas NaOCl has a negative effect on stem cell recruitment processes. Endogenous GFs are essential and can be harnessed for the healing response in REPs. Endodontic advances and Evidence based clinical guidelines, by Hany M.A Ahamed

33. CONCLUSION Dentin forms an integral part of tooth structure It has a regenerative potential and is a vital tissue that provides support to the overlying enamel and protection to the underlying pulp Thus we as clinicians should consider its importance in each and every aspect of treatment without doing any harm intentionally or unintentionally

34. Orban’s oral histology and embryology- 13th edition. Sturdevent’s art & science of operative dentistry- Second South Asia Edition Cohen pathology of the pulp 12th edition Violich DR, Chandler NP. The smear layer in endodontics –a review. International endodontic journal. 2010 Jan;43(1):2-15. REFERENCES Endodontic advances and Evidence based clinical guidelines, by Hany M.A Ahamed Nakajima M, Kunawarote S, Prasansuttiporn T, Tagami J. Bonding to caries-affected dentin. Japanese Dental Science Review. 2011 Aug 1;47(2):102-14.

35. Samartzi TK, Papalexopoulos D, Sarafianou A, Kourtis S. Immediate dentin sealing: A literature review. Clinical, cosmetic and investigational dentistry. 2021 Jun 21:233-56. Perdigão J, Reis A, Loguercio AD. Dentin adhesion and MMPs: a comprehensive review. Journal of esthetic and restorative dentistry. 2013 Aug;25(4):219-41. Nakajima M, Kunawarote S, Prasansuttiporn T, Tagami J. Bonding to caries-affected dentin. Japanese Dental Science Review. 2011 Aug 1;47(2):102-14.