1. Pulpal Irritants and Dentin-Pulp Reactions Presented by: Dr. Reza Hatam

2. Dental pulp as a connective tissue: How respond to irritants? What makes it prone to degeneration?

3. Unique environment of dental pulp Unyielding walls of dentin Resistant and resilient fiber-reinforced ground substance Does not have a consistent effective collateral circulation

4. Pulpal Reactions Caries Local Anesthetics Restorative Procedures Dental Materials Vital Bleaching Periodontal Procedures Orthodontic Movement

6. Permeability of Dentin

8. The role of odontoblasts

9. Hydrodynamic Theory

11. Pulpal Reaction to Caries Decrease in dentin permeability Tertiary dentin formation Inflammatory and immune reactions

12. Formation of Sclerotic Dentin

14. Bioactive Molecules Sequestered During Dentinogenesis Heparin-binding growth factor Transforming growth factor (TGF)-β1, β3 Insulin-like growth factor Platelet-derived growth factor Bone morphogenetic protein (BMP) The TGF-β super family in particular seems to be important

15. Formation of Tertiary Dentin

16. Pulpal Immune Response The early inflammatory response is accumulation of chronic inflammatory cells

17. Dental caries stimulates the accumulation of pulpal dendritic cells in and around odontoblastic layer

19. Calcium hydroxide produces an inflammatory response that stimulates dentinal bridge formation

20. The high PH can liberate bioactive molecules

23. Vital Pulp Therapy

24. Definition “Treatment initiated to preserve and maintain pulpal tissue in a healthy state, tissue that has been compromised by caries, trauma or restorative procedures’’

25. Goals of pulp therapy Primary objective is to maintain the integrity and health of the oral tissues Stimulate the formation of reparative dentin to retain the tooth as a functional unit Apexogenesis of the immature permanent tooth

26. Correct diagnosis - important in planning for treatment Reversible pulp pathosis Irreversible pulp pathosis Aim – preservation of pulp vitality

27. Potentially ReversibleProbably Irreversible Pain Momentary-dissipates readily after stimulus is removed (e.g. cold)(A-  fiber stimulation Continous-persists for minutes to hours after stimulus is removed;presence of internal(secondary) irritant (C fibers stimulation) Throbbing-may be present;due to arterial pulsation in area of increased pulpal pressure(C fibers stimulation) Stimulus Requires external stimulus Spontaneous does not require external stimulus; dead or injured pulp tissue present in chamber or canal Intermittent-spontaneous pain of short duration History Patient may have undergone recent dental procedures Patient may have had extensive restoration, pulp capping, deep caries or trauma

28. Potentially ReversibleProbably Irreversible Electric pulp test May be premature response May be premature, delayed or mixed response Percussion Negative response May respond in advanced stages of pulpitis when concomitant acute apical periodontitis is present Lying down Negative because of minimally affected pulp tissue Common finding because increase in cephalic blood pressure increases already excessive intrapulpal pressure Color Negative May be present as a result of tissue lysis and intra pulpal hemorrhage Radiograph Probable cause (e.g. restoration or caries) Peri-apex negative Probable cause (e.g. restoration or caries) Peri-apex- may be slight widening of apical periodontal space

29. Treatment Modalities Indirect pulp capping therapy Direct pulp capping therapy Pulpotomy Pulpectomy Apexogenesis Apexification

30. Definition Indirect pulp capping therapy The procedure involving a tooth with a deep carious lesion where carious dentin removal is left incomplete, and the decay process is treated with a biocompatible material for sometime in order to avoid pulp tissue exposure

31. Indirect Pulp Capping Therapy Rationale

32. Outer layer Irreversibly denatured Non remineralizable Infected Should be removed Inner layer Reversibly denatured Remineralizable Not infected Should be preserved

33. Necrotic, soft brown, teeming with bacteria and not painful to remove Firm but still softened discolored dentin with fewer bacteria, painful to remove Sound dentin, discolored area, minimal amount of bacteria, painful to instrumentation Three dentinal layers encountered in active caries

34. Indirect Pulp Capping Therapy Objectives Arrest the carious process Remineralization of carious or pre-carious dentin Reduction in anaerobic bacteria Formation of reparative dentin Vital pulp maintenance Continued normal root closure

35. Indirect Pulp Capping Therapy Indications Pain history – No extremes – May be associated with eating specially carbohydrates – Sometimes dull Clinical examination – Large carious lesion – Normal mobility – No gingival pathologic condition – Normal color of tooth Radiographic examination – Probable carious exposure – Normal peri-apical tissues

36. Indirect Pulp Capping Therapy Contraindications Pain history – Sharp, penetrating pulpalgia indicating acute pulp inflammation and/or necrosis – Prolonged night pain Clinical examination – Mobility of tooth – Discoloration of tooth – Negative reaction to electric pulp testing Radiographic examination – large carious lesion producing definite pulp exposure – Interrupted lamina dura – Widened periodontal ligament space radiolucency

37. Procedure First appointment 1.Isolation with rubber dam 2.Cavity outline with high speed water spray hand piece 3.Remove superficial debris and soft necrotic dentin with slow speed hand piece and large round burs, but do not expose the pulp 4.Potentially exposed site is covered with a commercial hard set calcium hydroxide or other capping material. 5.Seal the cavity for 1-3 months

38. Procedure Second appointment Between appointment history should be negative and restoration intact 1.Take bitewing radiograph-sclerotic dentin 2.Isolation 3.Carefully remove temporary dressing 4.Remaining carious dentin “flaky” and easily removed 5.Calcium hydroxide dressing 6.Reinforced zinc oxide eugenol or glass ionomer cement

39. Evaluation of therapy Minimally 1-3 months – to produce adequate remineralization of the cavity floor Good long lasting seal of restoration Tooth asymptomatic 1.Carious decalcified dentin 2.Rhythmic layers of irregular reparative dentin 3.Regular tubular dentin 4.Normal pulp with slight increase in fibrous elements

40. One step approach 1. local anesthetic 2. Isolation 3. Removal of caries at enamel-dentine junction. 4. Judicious removal of soft, deep carious dentin 5. placement of lining material 6. final restoration

41. The major difficulties Determine at what point excavation halt Voids under restorative material Restoration failure and reactivation of lesion

42. Definition Direct pulp capping therapy “treatment of an exposed vital pulp by sealing the pulpal wound with a dental material placed directly on a mechanical or traumatized exposure to facilitate formation of reparative dentin and maintenance of vital pulp.” During cavity preparation Traumatic injury Due to caries

43. Direct Pulp Capping Therapy Contraindications Severe toothaches at night Spontaneous pain Tooth mobility Thickening of periodontal ligament Radiographic evidence of pulp or peri-radicular degeneration Excess of hemorrhage at the time of exposure Purulent or serous exudate from the exposure

44. Clinical success Maintenance of pulp vitality Absence of sensitivity or pain Minimal pulp inflammatory responses Absence of radiographic signs of dystrophic changes

45. Direct Pulp Capping Therapy Treatment considerations Debridement Hemorrhage and clotting Exposure enlargement Bacterial decontamination Medications and materials

48. Direct Pulp Capping Therapy Medicaments Zinc oxide eugenol cement (Glass & Zander 1949) Corticosteroids and antibiotics Polycarboxylate cements Inert materials – Isobutyl cyanoacrylate (Berkman 1971) – Tricalcium phosphate ceramic (Heller 1975) Collagen fibers Formocresol Adhesive dentin bonding agents

49. Direct Pulp Capping Therapy – calcium hydroxide Herman 1930, seltzer & Bender 1958

50. An ideal pulp capping material Stimulate reparative dentin formation Maintain pulpal vitality Release fluoride to prevent secondary caries Bactericidal or bacteriostatic Adhere to dentin Adhere to restorative material Resist forces during restoration placement Sterile Radiopaque Provide bacterial seal

51. MTA Sustain alkaline PH after curing Small particle size Slow release of calcium ions Induce pulpal cell proliferation and hard tissue formation A gap free interface precludes microleakage Resist compression when final restoration

54. Partial pulpotomy “Surgical removal of small portion of the coronal pulp as a means of preserving the remaining coronal and radicular pulp”

55. Prognosis is extremely good (94-96%)

56. Definitions Pulpotomy “The complete removal of the coronal portion of the dental pulp, followed by placement of a suitable dressing or a medicament that will promote healing and preserve vitality of the tooth” this technique is advocated for deciduous teeth.

57. Caries Removal Dental dam isolation and Under magnification and using dye are critical. Propylene glycol solution of Acid Red52. The retained caries affected of dentin allows for remineralization by calcium phosphate from pulp.

58. Hemostasis The one significant measurable variable to predict the outcome. If hemostasis is not within 5-10 min, diagnosis of irriversible pulpitis. Ferric sulfate, epinephrine, H2O2, NaOCL NaOCL clearance of dentin chips, biofilm removal, chemical removal of blood cloth, disinfection of the cavity

59. Another emerging potential hemostatic agent is MTAD An irrigant and antimicrobial agent for removal of smear layer Doxycycline, acid citric and Tween 80

60. Postoperative Follow-up When MTA is used as pulp cap next visit can be at 5-10 days. If treatment appears successful next follow-up 6 weeks, then 6 and 12 months. In immature permanent teeth (apexogenesis) the tooth compared with contralateral tooth.

61. Regenerative Endodontics The interplay among stem cells growth factors scaffolds (biologic materials)

66. Future researches…