Management of deep carious

#ENDODONTICS

1. MANAGEMENT OF DEEP CARIOUS LESIONS

2. WHAT ARE DEEP CARIOUS LESIONS? Deep carious lesion is a clinical diagnosis that is given when the caries process has penetrated deep into the dentin with possible pulpal exposure. Deep carious lesions cause pulpal inflammation( i.e. pulpitis); if not managed ,they may result in pulp necrosis and involvement of the periradicular tissues, with possible pain requiring endodontic treatment or extraction.

3. DENTINAL CARIES When enamel caries reaches the dentinoenamel junction it spreads rapidly laterally because it is least resistant to caries. Caries advancement in dentin proceeds through three changes: Weak organic acids demineralize the dentin The organic material of dentin ,particularly collagen , degenerates and dissolves The loss of structural integrity followed by invasion of bacteria

4. FIVE DIFFERENT ZONES IN CARIOUS DENTIN ZONE 1: NORMAL DENTIN Deepest area Have tubules with odontoblastic processes Intertubular dentin with normal cross banded collagen ZONE 2 : SUBTRANSPARENT DENTIN Zone of demineralization of intertubular dentin Damage to odontoblastic process evident Dentin capable of remineralization ZONE 3 : TRANSPARENT DENTIN Zone of carious dentin softer than normal dentin Collagen cross linking remains intact

5. Pulp remains vital ZONE 4 : TURBID DENTIN Zone of bacterial invasion widening and distortion of dentinal tubules Collagen irreversibly denatured Not self repair zone ZONE 5 : INFECTED DENTIN Outermost zone Consists of decomposed dentin No recognizable str u cture to dentin teeming with bacteria Great numbers of bacteria dispersed in granular material

6. Affected and infected dentin In operative procedures , it is convenient to term dentin as either infected or affected dentin AFFECTED DENTIN- softened, demineralized dentin that is not yet invaded by bacteria- inner carious dentin(does not require removal) INFECTED DENTIN- outer carious dentin and bacterial plaque – both softened and contaminated with bacteria ( requires bacteria)

7. PULPITIS Pulpitis is inflammation of dental pulp tissue.

8. CAUSES OF PULPAL INFLAMMATION Bacterial cause Can damage pulp through toxins secreted by bacteria from caries Accidental exposure Mechanical cause Traumatic accident Attrition Abrasion Luxation or avulsion of tooth

9. Thermal cause Uninsulated metallic restoration During cutting Bleaching Electrosurgical procedures Laser beam Periodontal curettage Periapical curettage Idiopathic cause Aging resorption: internal or external

10. GROSSMAN’S CLINICAL CLASSIFICATION PULPITIS: Pulpitis Reversible papulosis Irreversible pulpitis Symptomatic (acute) Asymptomatic (chronic) acute chronic Abnormally responsive to cold Abnormally responsive to heat Asymptomatic with pulp exposure Hyperplastic pulpitis Internal resorption

11. 2. PULP DEGENERATION: calcific ( radiographic diagnosis) Other ( histopathological diagnosis) 3. NECROSIS

12. REVERSIBLE PULPITIS Reversible pulpitis is a mild to moderate inflammatory condition of the pulp caused by noxious stimuli in which the pulp is capable of returning to the normal state following removal of stimuli. SYMPTOMS Characterized by sharp pain lasting for a moment , commonly caused by cold stimuli May result from incipient caries and is resolved on removal of caries Pain does not occur simultaneously

13. TREATMENT Best treatment is prevention No endodontic treatment is needed Periodic care to prevent caries , desensitization of hyperactive teeth and use of cavity varnish or base before insertion of restoration is recommended If pain persists despite of proper treatment then it should be considered as reversible

14. IRREVERSIBLE PULPITIS It is a persistent inflammatory condition of the pulp , symptomatic or asymptomatic , caused by a noxious stimulus. It has both acute and chronic stages in pulp CLINICAL FEATURES EARLY STAGE Paroxysm of pain caused by: sudden temperature changes like cold , sweet, acid foodstuffs Pain often continues when cause has been removed May come and go spontaneously Pain: sharp, piercing, shooting, generally severe

15. LATE STAGE Pain more severe and throbbing Increased by heat and sometimes relieved by cold , although continued application of cold may intensify pain DIAGNOSIS Visual examination and history : on inspection may see deep cavity involving pulp or secondary caries under restorations Radiographic findings : may show depth and extent of caries Percussion: tender on percussion(due to increased intrapulpal pressure)

16. Vitality tests: Thermal test: hyperalgesic pulp responds more readily to cold stimulation than for normal tooth , pain may persist even after removal of irritant. Electric test: less current is required to initial stages . As tissue becomes more necrotile more current is required to generate the response

17. The results of diagnosis No exposure Pulp exposure Conventional cavity preparation and restoration Indirect pulp capping Vital (traumatic) exposure Non-vital (carious) exposure Direct pulp capping RCT

18. DENTIN THICKNESS We must remember that no material can provide better protection for the pulp than dentin The remaining dentin thickness , from the depth of cavity preparation to the pulp, is the most important factor in protecting the pulp

19. REMAINING DENTIN THICKNESS Shallow cavity depth- preparation 0.5 mm into dentin (ideal depth) Moderate cavity depth- remaining dentin over pulp of at least 1-2mm Deep cavity depth- depth of preparation with less than 1.0mm of remaining dentin over pulp

20. REACTIONARY DENTIN DEPOSITION Reactionary dentin deposition observed beneath cavities with RDT above 0.5mm as well as beneath cavities with a RDT below 0.25mm Maximal reactionary dentin appeared to be beneath cavities with an RDT between 0.5 to 0.25mm Area of reactionary repair influenced by the choice of restoration material (from greatest least calcium hydroxide ,composite ,resin modified glassionomer [RMGI] cement, and zinc oxide- eugenol) Odontoblast numbers maintained beneath cavities with a RDT above 0.25mm

21. INDIRECT PULP CAPPING It is a procedure performed in a tooth with deep carious lesions adjacent to pulp. In this procedure , all infected carious dentin is removed leaving behind the softened carious dentin adjacent to pulp. Caries near the pulp left in place to avoid pulp exposure and preparation is covered with a biocompatible material

22. DECISION MAKING IN USE OF SEALERS , LINERS AND/ OR BASES remaining dentin thickness in tooth preparation Thermal conductivity of restorative material Presence or absence of pulpal symptoms –pain to stimuli Thermal Osmotic changes Duration of symptom Spontaneous pain

23. INDICATIONS Deep carious lesions near the pulp tissue but not involving it No mobility of tooth no history of spontaneous toothache No tenderness on percussion No radiographic evidence in pulp pathology No root resorption or radicular disease CONTRAINDICATIONS Presence of pulp exposure Radiographic evidence of pulp pathology History of spontaneous toothache Tooth sensitive to percussion

24. CLINICAL TECHNIQUE Band the tooth if tooth is grossly decayed Remove soft caries either with spoon excavator or round bur A thin layer of dentin and some amount of caries is left to avoid pulp exposure Place calcium hydroxide paste on the exposed dentin Cover the calcium hydroxide with zinc oxide eugenol cement Teeth should be evaluated after 6 to 8 weeks After 2 to 3 months , remove the cement and evaluate the tooth preparation

25. During this waiting period : The carious process is arrested Soft caries hardened A protective layer of reparative dentin is laid down Success of indirect pulp capping depends upon Age of patient Size of exposure Restorative procedure Evidence of pulp vitality

26. DIRECT PULP CAPPING Procedure that involves the placement of biocompatible material over the site of pulp exposure to maintain vitality and promote healing

27. INDICATIONS Small mechanical exposure of pulp during : tooth preparation traumatic injury No or minimal bleeding at exposure site CONTRAINDICATIONS Wide pulp exposure Radiographic evidence of pulp pathology History of spontaneous pain Presence of bleeding at exposure site

28. CLINICAL PROCEDURE Administer local anesthesia Isolate the tooth with rubber dam When vital and healthy pulp exposed , check the fresh bleeding at exposure site Clean the area with distilled water or saline solution and thin dry it Apply calcium hydroxide over the exposed area

29. Give interim restoration such as zinc oxide eugenol for 6 to 8 weeks After 2 to 3 months , remove the cement very gently to exposure site . If secondary dentin formation takes place over the exposed site , restore the tooth permanently with protective cement base and restorative material. If favorable prognosis not there, pulpotomy or pulpectomy is done

30. Direct pulp capping techniques Calcium hydroxide technique Total etch technique hemostasis Disinfect cavity CaOH Resin modified glass ionomer IRM restoration hemostasis Disinfect cavity primers adhesives Resin modified glass ionomer restoration

31. FACTORS AFFECTING SUCCESS OF DIRECT PULP CAPPING Age of the patient Type of exposure Size of exposure History of pain

32. MATERIALS USED FOR PULP PROTECTION These materials help to: Insulate the pulp Protect the pulp in case of deep carious lesion Act as barriers to micro leakage Prevent the bacteria and toxins from affecting the pulp

33. PULP PROTECTING AGENTS CAVITY SEALERS: protective coating on the cavity walls creating a barrier to leakage, to seal dentinal tubules ADVANTAGES: Used to reduce micro leakage Reduces postoperative sensitivity Prevents discoloration of tooth by checking migration of ions into dentin In case of amalgam restoration , it improves the sealing ability of amalgam

34. RESIN BONDING AGENTS: an adhesive sealer is commonly used under compound restorations for application, cotton tip application is used to apply sealer on all areas of exposed dentin INDICATIONS: To seal dentinal tubules To treat dentin hypersensitivity LINERS: cement or resin coating of minimal thickness (less than 0.5mm) placed as a barrier to bacteria or to provide a therapeutic effect (pulpal sedative or antimicrobial effect).applied to cavity walls adjacent to pulp (calcium hydroxide, zinc oxide eugenol ) it also stimulate formation of reparative dentin

35. CAVITY BASES: placed to replace missing dentin , placed in thicknesses of 0.5-1mm Provide thermal insulation Encourage recovery of injured pulp from thermal, mechanical or chemical trauma, galvanic shock and micro leakage MATERIALS USED AS BASES: Zinc oxide eugenol Zinc phosphate cement Zinc polycarboxylate cement Glass ionomer cement

36. CALCIUM HYDROXIDE CEMENT calcium hydroxide has been used as a lining material since the 1920s Because of the basic pH of about 11, calcium hydroxide is both antibacterial and can neutralize the acidic bacterial byproducts. The high pH creates an environment conducive to the formation of reparative dentin In addition , calcium hydroxide has the capacity to mobilize growth factors from the dentin matrix , causing the formation of new dentin Biocompatible in nature

37. MERITS OF CALCIUM HYDROXIDE CEMENT OVER ADHESIVE CEMENTS Adhesive resins can be acidic and cause pulpal irritation Many dentin bonding agents and resin reinforced glass ionomers are actually detrimental to the pulpal tissues In contrast, calcium hydroxide has been shown to provide a significantly improved potential for pulpal repair compared to adhesive resins

38. DEMERITS OF CALCIUM HYDROXIDE Unfortunately , the self-setting calcium hydroxide liners are highly soluble and subject too dissolution over time Traditional calcium hydroxide liners are easily lost during acid etching Dentin bonding agents that contain water, acetone, or alcohol can also detrimentally affect the properties of calcium hydroxide Therefore, when a restoration of composite resin is planned, glass ionomer cement should line the cavity preparation, sealing over the calcium hydroxide material, if used

39. MINERAL TRIOXIDE AGGREGATE(MTA) In recent years, mineral trioxide aggregate (MTA) preparations have been introduced These silicate cements are antibacterial, biocompatible, have a high pH, and are cable to aid in the release of bioactive dentin matrix proteins MTA is a powder consisting of fine hydrophilic particles of tricalcium silicate, tricalcium aluminate, tricalcium oxide, and silicate oxide It also contains small amounts of other mineral oxides, which modify its chemical and physical properties

40. Hydration of the powder results in formation of colloidal gel with a pH value equal to 12.5 (similar to calcium hydroxide) that solidifies to form a strong impermeable hard solid barrier in approximately 3 to 4 hours It is hypothesized that tricalcium oxide reacts with tissue fluids to form calcium hydroxide

41. MERITS AND DEMERITS OF MTA The material has a low solubility and a radiopacity slightly greater than that of dentin Because of its low compressive strength , it should not b placed in functional areas Another significant disadvantage for the restoration is that the setting time may take several hours. As a result , 2 step procedures are frequently necessary , requiring interim restorations MTA is an excellent material for direct vital pulp exposures and numerous endodontic applications The material has good long term sealing capabilities , and some studies show greater success than conventional calcium hydroxide

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