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good morning1MANAGEMENT OF DEEP CARIOUS LESIONSDr . Sindhura Reddy2CONTENTSTYPES AND LAYERS OF DENTINAL CARIOUS LESIONS

EFFECTS OF CARIES ON THE P-D ORGAN

EFFECT AND FATE OF MICROORGANISMS SEALED IN A CAVITY WITH AN INERT SEALER

INTRODUCTION AND HISTORY DECAYED ZONE SEPTIC ZONE DEMINERALIZED ZONETRANSPARENT ZONEOPAQUE ZONE3CONTENTSMACROSCOPIC DIRECT PULP EXPOSURES

MICROSCOPIC DIRECT PULP EXPOSURES

THE DISINFECTION OF DENTIN

DIAGNOSIS & PROGNOSIS

TREATMENT OF ACUTE DECAY

TREATMENT OF CHRONIC DECAY

IPC - INDIRECT PULP CAPPING

DPC - DIRECT PULP CAPPING

RECENT ADVANCES AND CONCLUSION

REFERENCES4INTRODUCTION

5INTRODUCTIONPRIMARY OBJECTIVE of pulp treatment is to maintain the integrity and health of the oral tissues.

It is desirable to attempt to maintain the vitality of the pulp of a tooth affected or infected by caries, traumatic injury, or other causes.

It is possible to stabilize pulp autolysis or eliminate the pulp entirely without significantly compromising the function of the tooth.

Appropriate pulp therapy is predicated upon the acquisition and analysis of appropriate diagnostic data.6PULP THERAPY - HISTORYThe earliest account of pulp therapy was in 1756, when PFAFFpacked a small piece of gold leaf over an exposed vital pulp to promote healing.

BLACK'S overall percentage of pulp capping success was so small that he told that pulp capping have no future.

By 1922, REBEL summarized his thoughts in the expression "The exposed pulp is a doomed organ". He concluded that recovery of the pulp once exposed was impossible and that one must consider it a lost organ.

During 1940s and 1950 it became apparent that the pulp, like any other organ of the body, could heal itself provided overwhelming adverse conditions were removed.77In 1920, HERMAN'S introduction of promising new material, was tested which consisted of spicules of dentin and pastes utilizing calcium hydroxide.

This started a new era in the treatment of dental pulp by demonstration of calcium hydroxide, called Calxyl, induced bridging of the exposed pulp surface with reparative dentin.88

TYPES AND LAYERS OF DENTINAL CARIOUS LESIONS TWO TYPES OF CARIOUS PR0CESSES ACUTE Dynamics of their creation CHRONIC The reaction of tissues to them the resultant end products of their activity

ANY DENTINAL CARIOUS LESION IN A VITAL P-D ORGAN WILL EXHIBIT 5 LAYERS / ZONES. DECAYED ZONESEPTIC ZONEDEMINERALIZED ZONETRANSPARENT ZONEOPAQUE ZONE9ZONES OF DECAY IN ACUTE DECAY

DECAYED ZONESEPTIC ZONEDEMINERALIZED ZONEOPAQUE ZONETRANSPARENT ZONE10

DECAYED ZONEZONES OF DECAY IN CHRONIC DECAYSEPTIC ZONEDEMINERALIZED ZONETRANSPARENT ZONEOPAQUE ZONE11DECAYED ZONEIN ACUTE DECAY

IN CHRONIC DECAYDentin -Devoid of minerals lessClinically similarMore odiferousDarker in colourGreater activity of chromogenic bacteria.

Dentin - Devoid of minerals -- more Clinically similarOrganic matrix completely decomposed to an unrecognizable state.

Collagen fibers completely loss cross striations and links.

High concentration of micro organisms , plaque

The only activity is MICROBIAL

Thickness vary opened , partly opened , closed lesion{maximum thickness}12SEPTIC ZONEIn acute Dentin decalcifed moreSmaller dimension than chronicCosistency - softerIn chronicDentin decalcifed lessGreater dimension compare to acuteLess softer consistency

Highest concentrartions of micro organisms

Although dentin is very well decalcified -- framework structure still recognized.

Collagen fibers fewer cross band striations, & inter molecular links are lost.

Remaining mineral crystals deformed , irregularly scattered , show no relation to collagen fibers

Dentinal tubules extremely widened and cavitated.

The only activity is MICROBIALColor resembles decayed zone light yellow to dark reddish brown.

13DEMINERALIZED ZONEIN CHRONIC Dimension - Smaller than acute Minimum width - 50m Remineralization activity moreMicroorganisms found through out the zoneColor yellow brown / dark brownConsistency and hardness of dentin - moreCrystal deposition activities will be evenly distributed through out the caries cone

IN ACUTE DECAYDimension greaterMaximum width -1750mRemineralization activities are much less pronouncedMicroorganisms confined to superficial 1/3-1/2 of this zoneColor - straw yellowConsistency and hardness of dentin 15 times lessRepair activities will be more noticeable at the sides of the dentinal caries cone, decreasing gradually to the tip

14DEMINERALIZED ZONEClinically most signifiant zone diagnostically & therapeutically.

Only dentin is demineralized , with dentinal matrix still intact.

Collagen fibers normal cross band structure striations & inter molecular cross links.Remaining mineral crystals - still attached to collagen fibers.

Dentinal tubules - normal dimensions

Although there are destructive activities - decalcification

Repair activities remineralization , precipitating a variety of phosphate crystals - different shape & composition eg: tricalcium phosphate(white lockite),caries crystals,large rhombohedric crystals , regular apatite crystals 15TRANSPARENT ZONEIN CHRONIC DECAYMore pronouncedContain few microorganismsDentin is harder

IN ACUTE DECAYSmaller dimension , occasionally interrupted.Discontinuity tip of the caries cone.

Appears transparent in ground sections, radiopaque in radiograph

Area of undisturbed mineralization repair

Zone of dentinal sclerosis and the calcific barrier impermeable & impenetrable types of dentin

Clinically slightly discoloured - due to remineralization of decalcified stained dentin

Dentin - extremely hard when compared to normal dentin (19 times greater on average)16OPAQUE ZONEFound pulpal to transparent zone.

Characterized by intra tubular fatty degeneration - lipid deposits peripheral odontoblastic processes sclerosis of dentinal tubules.

Appears radiolucent in radiograph.

More pronounced in acute lesions .

The maximum resistance to pulpal protection arrival of transparent zone , and demineralized zone

But if the septic zone penetrates the pulp chamber -- pd organ - not offer any resistance

17EFFECTS OF CARIES ON THE P-D ORGANThe carious process creates three distinct forms of irritants Biological irritants Chemical irritants ppt a reaction in the PD organ Physico- mechanical irritants

Some investigators , PD organ react to caries as early as the stage of enamel caries

Others say , no actual reaction starts caries is 2mm / less from pulp

It is essential to correctly diagnose the type , extent, nature of pulp dentin reactions to the decay process.18The following factors like:

Type of decayDuration of decay processDepth of involvementNumber and pathogenecity of microorganismsTooth resistanceIndividual reaction of the PD organ 19TYPE OF DECAYThe more acute the decay process less efective the defensive reparative mechanism - greater tendency towards a destructive reaction in the PD organ

Chronic decay accompained by substantial repair provided it has not involved the pulp20DURATION OF THE DECAY PROCESSIn acute decay longer the duration - more massive the destruction of tooth structure.

In chronic decay longer the duration greater the chances of repair , provided the pulp not involved directly.

Chronic decay possess potential to be irritating microbial population &virulence in the lesions

Can stimulate repair isolated from the underlying pulpal tissues by sound dentin.

In acute decay high diffusion of microbials irritants carious process very destructive. 21DEPTH OF INVOLVEMENTThe deeper the caries cavity process is , the nearer the sources of irritation .

Greater intensity of irritation greater possibility of pulpal destruction.

Peripheral involvement -- either no pulpal reaction at all or reparative reaction in both acute and chronic lesions.Outer 1/3rd or less of dentin

Moderate involvement outer 2/3rds or less of dentin, some resolved pulp destruction is observed.

22Profound depth involvement -- more than 2/3rds of dentin short of perforation can expect repair ,resolved pulpal destruction in chronic decay and definite destruction in acute.

Perforating lesions can expect pulpal destruction in both types of decay

23NUMBER AND PATHOGENECITY OF MICROORGANISMSGreater that the virulence and population of microorganisms

The greater is the likelihood of the pulpal reaction ultimately being destruction.24TOOTH RESISTANCEInvolves infinite number of fractors ranging from :

Thickness of dentin.Permeability of the involved dentin.Solubility of the involved dentin. Fluoride content of the involved dentin.Calcium content of the involved dentin.Susceptibility of the tooth & so forth.25INDIVIDUAL REACTION OF THE PD ORGANFactors which influence the individual reaction of the PD organ include :Tooth agePatients ageCellularity of the pulpal and root canal system tissuesVascularity

EFFECTIVE DEPTH : It is the area of minimum thickness of sound dentin separating the pulpal tissues from the carious lesions.This is usually found in deepest portion of caries activity.26Effective depth in the pd organ 2mm / more expect healthy reparative reaction.

Effective depth from 0.8 to 2mm expectunhealthy reparative reaction.

Effective depth less than 0.3 to 0.8 mm range expect pulpal destruction.27EFFECT & FATE OF MICROORGANISMS SEALED IN A CAVITY WITH AN INERT SEALERSevereal experiments were done, the results of these revealed that :

Sharp decrease in the number of microorganisms.

No traces of lactobacilli or spirochetes

Residual microorganisms had undergone morphological changes

No carious activity in the form of demineralization was observed

In certain cases there were some signs of remineralization.

28INCIDENTS OF MACROSCOPIC DIRECT PULP EXPOSURESIt has been documented , whenever a carious lesion extends 3-4mm pulpally /axially to the DEJ visible perforation to the pulp chamber can be expected in the 75 % of the cases.

Increases-- younger the chronological /physiological age of the tooth.

Also occurs if the carious lesion is the first irritant.29INCIDENTS OF MICROSCOPIC DIRECT PULP EXPOSURESThe peripheral pupal tissue shows odontoblastic layer , sub odontoblastic layer, layer 0f weil- if involved direct pulp exposure & no hemorrhage.

Only evidence of perforation of pulp chamber oozing of color less dental pulp fluid can only be observed microscopically.

The unaided eye will not detect perforation.

30THE LACK OF RELIABLE CLINICAL DEVICES TO DIFFERENTIATE B/W REMINERALIZABLE AND NON REMINERALIZABLE AFFECTED DENTINDepend upon tactile sense using explorers , excavators ,or round burs to verify soundness of all dentinal walls - undesirable non remineralizable dentin.

These techniques unmeasurable, uncontrollable, tests of the hardness and abrassive resistance of the remaining dentin.

These diagnostic tools inherent human errors usually unreliable resultsFusiama & his coworkers hardness testing Knoop Hardn.ess Number KHN of the remaining dentin KHN using spoon excavator 22.8 +__ 9.95 KHN

Using round bur KHN 28.4 +_ 16.36

KHN Of sound dentin is 69

31THE DISINFECTION OF DENTINIn Chronic or acute decay noneed for disinfectants to ensure or aid the reparative capacity of the PD organ.

In acute decay reparable areas of dentin completely devoid of microorgnisms

In chronic decay impregnation of microbia in to sound / repaired dentin

Effective disinfectants interfere with physiological function of PD organ. 32TRATMENT OF ACUTE DECAYDeep lesions deeper than 2mm from the DEJ confirmed as acute decay.

Can be treated in the following sequence:

All possible information regarding the status of the pd organ should be collected using diagnostic tools.All undermined and unwanted enamel in preparation should be removed .It is safe to remove all soft dentin with out creating an exposureThe deepest layer should be left providedPD organ healthyThe remaining dentin -- reparableThe softened dentin -- located in the deepest part of the pulpal / axial wallThe surrounding walls -- hard sound dentin33TREATMENT OF CHRONIC DECAYAll possible information regarding the status of the pd organ should be collected using diagnostic tools.

All undermined and unwanted enamel in preparation should be removed .

It is safe to remove all soft dentin using spoon excavators ,large stainless steel burs in slow speed handpiece.

The soundness of the remaining dentinal matrix appropriate dyes

If leads to an exposure proceed with appropriate pulp capping procedure or with endodontic therapy.

34SCHEME OF DIAGNOSIS FOR PULP AND PERIRADICULAR DISEASES

3535DIAGNOSIS AND PROGNOSIS OF DEEP CARIOUS LESIONSPain

Radiographs Pulp testing

Direct pulp exposure

Percussion sensitivity

36Type of dentin

Removal of tooth structure without anesthesia

Selective infiltration / ligmental anesthesia

Use of dyes to differentiate reparable and irreparable dentin

3737

APPLIED MORPHOLOGY OF THE DENTAL PULP IN PRIMARY AND PERMANENT DENTITION

PRIMARY MOLAR PERMANENT MOLAR38 INDIRECT PULP CAPPING

Definition :Mc Donald; The procedure in which only gross caries is removed from the lesion & the cavity is sealed for a time with a biocompatible material.

Ingle; Procedure where in small amount of carious dentin is retained in deep areas of the cavity preparation to avoid exposure of pulp, followed by placement of a suitable medicament / restorative material that seals of the carious dentin & encourages pulp recovery.39Mathewson: Indirect pulp capping is defined as the application of a medicament over a thin layer of remaining carious dentin after deep excavation, with no exposure of the pulp.

Damle : Described the purpose of indirect pulp capping as the use of "reconstructed" dentin to prevent pulp exposure.40

AIM :

- Giving pulp the opportunity to recover from toxins of DC by judiciously removing infected dentin & isolating the remaining carious lesion from oral fluids with a restorative material.

41OBJECTIVE OF INDIRECT PULP TREATMENT

Maintain pulp vitality

Arresting the carious process.

Promoting dentin sclerosis (reducing permeability)

Stimulating the formation of tertiary dentin

Reminerlizing the carious dentin.

4242Historical ReviewPierre Fauchard ; (18th century) All caries should not be removed in deep & sensitive cavitiesJohn Tomes ; (19th century) It is better that a layer of discolored dentin should be allowed to remain for protection of the pulp rather than run the risk of sacrificing the tooth

43 Fusayama (1966);

a) outer layer / infected dentin irreversible denatured , incapable of remineralization, bacteria & should be removed

b) inner layer / affected dentin reversible denatured , capable of remineralization & should be preserved

44

Kopel (1976) ; a) Necrotic, soft, brown dentin, teeming with bacteria & not painful to remove b) Firm, but still softened, discolored dentin with few bacteria & painful to remove c) Sound dentin, a discolored area, bacterial invasion & painful to instrumentation.

45RATIONALE OF INDIRECT PULP CAPPING

Indirect pulp capping is a technique in which an effort is made to avoid pulpal exposure during the treatment of teeth with deep carious lesions, without any evidence of pulpal degeneration or periapical pathology.

The procedure reduces the risk of direct pulp exposure and preserves pulp vitality.

This technique is predicted on removing the outer layers of the carious dentin AFFECTED DENTIN, that contain the majority of the microorganisms, reducing the continued demineralization of the deeper dentin layers INFECTED DENTIN from bacterial toxins, and sealing the lesion to allow the pulp to generate reparative dentin4646 Dental caries slow & intermittent process

Two stages Acute lesion ; organisms found in the outer layer of decay, deeper decalcified layer, free from bacteria

Arrested lesion ; surface layer not contaminated, surface layer hard & leathery, deep sclerotic layer & free from organisms

47 INDICATION :

History - tolerable dull, mild discomfort from chemical / thermal stimuli - absence of spontaneous pain

Clinical examination - large carious lesion - normal appearance of gingiva - color of tooth - no lymphadenopathy

48 Radiographic examination - large carious lesion, close to pulp - normal lamina dura - normal PDL space - no interradicular / periapical radiolucency

49 CONTRAINDICATION :

History ; - sharp, penetrating pain that persists after withdrawal of stimuli - prolonged night pain / nocturnal pain

Clinical examination ; - mobility - parulis in gingiva approx to the roots - discoloration of tooth - no response to pulp testing50 Radiographic examination ; - large carious lesion with apparent pulp exposure - interrupted / broken lamina dura - widened PDL space - radiolucency about the apices / furcation area 51Teeth selected for Indirect pulp treatment should fulfill the following criteriaNo History of spontaneous, unprovoked toothache.

No Tenderness to percussion .

No abnormal mobility.

No radiographic evidence of radicular disease.

No radiographic evidence of abnormal internal or external root resorption.5252OVERVIEW

a deep lesion close to the pulp in an asymptomatic vital tooth.decay is removed, a calcium hydroxide base is placed.residual decay is arrested and the pulp has repaired by laying down secondary dentine5353PROCEDURE IPT can be performed as two-appointment or one-appointment procedure..

local anesthesia and isolate with a rubber dam.

cavity outline with a high-speed hand-piece.

soft, mushy infected dentin should be removed with a large round bur in a slow-speed hand piece without exposing pulp

5454Remove peripheral carious dentin with sharp spoon excavators.

Irrigate the cavity and dry with cotton.

Cover the affected dentin with a hard setting calcium hydroxide dressing.

Fill or base the remainder of the cavity with IRM

Do not disturb this sealed cavity for 6-8 weeks

55552 ND VISITTooth has to be

Asymptomaticsurrounding soft tissues are free from swellingtemporary filling is intact.

Bitewing radiographs of the treated tooth should be assessed for the presence of reparative dentin.

Again use local anesthesia and rubber dam isolation.

Carefully remove all temporary filling material, especially the calcium hydroxide dressing over the deep portions of the cavity floor.

5656The remaining affected carious dentin should appear dehydrated and "flaky" and should be easily removed. The area around the potential exposure should appear whitish and may be soft pre-dentin - should not be disturbed.

The cavity preparation should be irrigated and gently dried.

5757Cover the entire floor with a hard-setting calcium hydroxide dressing.

A base should be placed with reinforced zinc oxide eugenol or glass ionomer cement, and the tooth should receive a final restoration.

The reentry restorative procedure is still questionable. Research has shown that carious dentin will remineralize with the restoration.

Thus if the recall radiograph shows a layer of secondary dentin, reentry is not necessary.5858ONE-APPOINTMENT TECHNIQUEone-appointment Indirect pulp treatment must be based on clinical judgment..

Leung et al, and Fairbourn and colleagues have shown a significant decrease of bacteria in deep caries lesions after being covered with calcium hydroxide or modified zinc oxide eugenol for period ranging from 1-15 months.

These investigators suggests that re-entry to remove the residual minimal carious dentin may not be necessary.5959ONE-APPOINTMENT TECHNIQUE

6060THREE TECHNIQUES OF INDIRECT PULP TREATMENT MOST COMMONLY EMPLOYED ARE1ST METHOD

A thin layer of calcium hydroxide paste placed over the area of near exposure.

A thicker layer of zinc oxide-eugenol applied.

After 6 to 9 weeks the tooth reopened - remaining carious material removed.

Calcium hydroxide is placed as a dressing, and the tooth restored by routine procedures.61612nd METHODA thin layer of zinc oxide-eugenol paste placed over the area of near exposure.

A thicker layer of zinc oxide-eugenol is then applied. The tooth is reopened after 6 to 8 weeks and the remaining carious material is removed.

Calcium hydroxide is placed as a dressing, and the tooth is restored by routine procedures.62623rd METHODA dressing of calcium hydroxide paste with or without zinc oxide-eugenol is placed over the residual caries.

Routine cavity preparation is completed prior to removal of the gross caries, and an amalgam restoration is placed over the dressing.

Complete removal of caries is delayed for 8 weeks to 6 months.

Do not reenter the tooth if it appears clinically and radiographically to be healthy.6363RESPONSE TO TREATMENTSayegh found three distinct types of new dentin in response to indirect pulp treatment.

Cellular fibrillar dentin at 2 months post- treatment.

Presence of globular dentin during the first 3 month.

Tubular dentin in a more uniformly mineralized pattern.

6464 CONCLUDED New dentin faster thin dentin pulp under treatment - new dentinPrimary teeth than permanent teethMales > females

65MEDICAMENTS USED FOR I.P.CCALCIUM HYDROXIDEZINC OXIDE EUGENOLTRICALCIUM PHOSPHATEDENTINE CHIPSHYDROXYAPATITEANTIBIOTICS/CORTICOSTEROIDSCOLLAGEN FIBRESMINERAL TRIOXIDE AGGREGATE (MTA) 66 MATERIALS USED :

CALCIUM HYDROXIDE ;

Hermann (1930) pharmaceutical - grade Ca(OH)2 - 95% calcium highly soluble in water

Law & Lewis clinically & radiographically sound

Types ; a) Pulpdent 52.5 % Ca(OH)2 suspended in an aqueous methyl cellulose solution

67

b) Dycal (1962) two paste compound Base titanium dioxide in a glycol salicylate with a pigment Catalyst - Ca(OH)2 & zinc oxide in ethyl-toluene sulfonamide

c) Hydrex two paste Non essential oil, Ca(OH)2 ,barium sulfate, titanium dioxide & a resin Berk & Stanley matrix bridge in 2 weeksSawusch sedative (Dycal)

68Advantages Ca(OH )2 DisadvantagesInitially bacteriocidal to bacteriostaticPromote healing & repairHigh PH stimulates fibroblastsNeutralizes low PH of acids Stops internal resorptionInexpensive & easy to useParticles may obturate open tubules.

Doesnt exclusive stimulate dentinogenesis, reparative dentin or dentinal bridge formationAssociated with primary tooth root resorptionMay dissolve within 1yr.Degrade the interphase during etching process, or during tooth flexure, or condensation of amalgamRecurrent caries upon lossDoesnt adhere to vital dentin, or bonding resin composite system69 Reactionary dentinogenesis

Murray et al.,investigated stimulation of reactionary dentinogenesis in the cultured tissues after cavity preparation under carefully controlled conditions.

Conditioning of the cavity with EDTA for 60 secs and the thickness of the residual dentine beneath the cavity were observed to be important factors in the intensity of the reactionary dentinogenic response. 70.It thus seems probable that the matrix solubilising effects of cavity conditioning agents on dentine matrix result in release of TGF-j31 from the tissue, which can then diffuse down the dentinal tubules and invoke a reactionary dentinogenic response in the underlying odontoblasts.

Calcium hydroxide is also able to solubilise TGFj3-1 from dentine matrix .

71 REPARATIVE DENTINOGENESIS

Bio-active molecules (TGF-13s), - induction of odontoblast-like cell differentiation and up-regulation of secretory activity of these cells help in formation of reparative as well as reactionary dentinogenesis.

The solubilising effect of calcium hydroxide on dentine matrix components, including TGFj3-1, maybe of particular importance for the latter cellular activities. 72 Extracellular matrix components solubilised in association with growth factors may be important in such situations with the application of EDTA

Application of growth factors alone at similar sites often involves intermediary fibrodentine matrix formation.

The frequently observed deposition of a fibrodentinal matrix in calcium hydroxide mediated wound healing may reflect the multifactorial nature of the healing process as well as possible sub-optimal solubilisation of bio-active matrix components.

73

74

75Exogenous signalling molecules Exogenous growth factors for stimulating reparative dentinogenesis Sloan and Smith ;recombinant TGF-j3 1 to stimulate a reactionary response when directly applied to the odontoblast layer.

But only TGF-j3 containing dentine matrix fractions have been shown to invoke such a response when applied in the base of an unexposed cavity

The ability of the TGF-j3s and BMPs to induce reparative dentinogenesis in pulp capping situations in vivo, provides the basis for development of a possible new generation of bio-materials.

The specificity of these growth factor to induce reparative processes is still not clear. 76The development of new treatment modalities based on application of exogenous signalling molecules like growth factors will require consideration of:1. The delivery vehicle used for the molecules many of these bio-active molecules show potent effects at the picogram level and appropriate carriers will be required to facilitate their handling in the clinical situation.

2. The dose response effects of the molecules and control of the extent of the repair process it will be important to identify the appropriate dose levels of these molecules for the level of response to achieve a required effect and to avoid uncontrolled obliteration of the pulp chamber by reactionary or reparative dentine deposition. 773. The half-life of the molecules and local tissue factors which may modulate their activity.

4. The possible immunological problems due to repeated implantation of active molecules78Clinical exploitation of the bio-active molecules in dentine matrix in a short period of time.. Endogenous signalling molecules the endogenous tissue pools of TGF-j3s and other growth factors in the dentine matrix may provide a natural delivery system.

The release of these growth factors by cavity conditioning agents and materials such as calcium hydroxide.

79Possible advantages and limitations of new strategies One of the major advantages of stimulating a reactionary or reparative dentinogenic response beneath injury in the tooth is to promote deposition of a protective hard-tissue barrier, between the pulpal cells and the injury.

Stimulation of a specific cellular response in the dentinepulp complex at the site of injury would allow a biologically directed approach to tissue repair rather than a simple mechanical approach. 80new strategies based on these approaches will have to address the problems of delivery and control of the bio-active molecules and also, pattern of dentinogenesis leading to matrix deposition in a pulpal direction

the latter point may be of lesser importance in situations of pulpal exposure, it will be significant where residual dentine remains.

Tissue engineering approaches may offer one possible solution ,but in the shorter term at least any new treatment modalities are likely to represent a combination of traditional and new approaches.

81 Zinc oxide eugenol

Eugenol ; 4-allyl-2-methoxyphenol (clove oil)

Zinc oxide ;Insoluble in water, mild astringent, & antiseptic Zinc oxide eugenol cement ;

Powder zinc oxide-42% ,Staybelite resin-27% ,bismuth subcarbonate-15% ,barium sulphate-15% & sodium borate-1%82 Liquid purified eugenol / clove oil

Reaction chelate matrix of zinc eugenolatePH neutral Highly soluble in water IRM Powder 10-40% finely divided natural / synthetic resin (polymethyl methacrylate, polystyrene or polycarbonate)Liquid remains the sameLow solubility & good sealing 83 EBA category Powder addition of quartz, alumina, / rosin Liquid EBA (ortho benzoic acid) added solubility, shrinkage

Cavit Zinc oxide, calcium sulfate, zinc sulfate, glycol acetate, polyvinyl acetate, polyvinyl chloride acetate, triethanolamine, & red pigment but no eugenolGood sealing

84 Successful IPC-

Formation of RD

Massler - regular tubular dentin - pulp showing inflammatory responseBoth Ca(OH)2 & zinc oxide eugenol - success rateAmalgam is the material of choiceTeeth free from painful pulpitis 8585 Notes ;IPC in primary teeth is less common than in permanent 1) pulp exposure from aggressive dentin removal 2) thinner dentin 3) behavior management

The future - Stark & Soelberg ; capping agent is immaterial seals the carious dentin - Gracia - Godoy ; direct treatment with agents to neutralize toxins, stifle microbes, & mollify pulp inflammation868687DIRECT PULP CAPPING

DIRECT PULP CAPPING : Definition (Kopel 1992); The placement of a medicament / non-medicated material on a pulp, that has been exposed in the course of excavating the last portions of deep dentinal caries / due to trauma. Involves the placement of a biocompatible agent on healthy pulp tissue that has been inadvertently exposed from caries excavation or traumatic injury.

Rationale:

To encourage young healthy pulp to initiate a dentin bridge thus walling off the exposure site.

88OBJECTIVESTo seal the pulp against bacterial leakage.

Encourage the pulp to wall off the exposure site by initiating a dentin bridge.

To maintain the vitality of underlying pulp tissue region.

89 HISTORY ;Hunter (1883) ; -mixture of sorghum molasses & the droppings of the english sparrow 98% success.Nyborg (1955) ; -Ca(OH)2 as most successful agent

90INDICATION FOR DPCTooth selection for direct pulp capping involves the same vital pulp therapy considered as for indirect pulp capping.

"pin point" mechanical exposures that are surrounded with sound dentin.

Exposed pulp tissue should be bright red in color and have a slight hemorrhage that is easily controlled with dry cotton pellets applied with minimal pressure.

Absence of pain.

No bleeding at the exposure site.91CONTRAINDICATION FOR DPCSpontaneous and nocturnal toothaches.

Excessive tooth mobility.

Thickening of periodontal ligament.

Radiographic evidence of periradicular degeneration.

Uncontrollable hemorrhage at the time of exposure.

Purulent or serous exudates from the exposure92MATERIALS USED FOR DPCAlternative to Calcium hydroxide suggested for direct pulp capping in primary and permanent teeth are

Zinc oxide eugenol cement

Polycarboxylate cements

Formocresol

Mineral trioxide aggregate

Corticosteroids and antibiotics

Collagen fibers

Hybridizing bonding agents

Calcium phosphate cement93 The past :Ca(OH)2 can elicit dentin bridge formationIn primary teeth promotes internal resorption Reasons two conditions favoring internal resorption in pulpotomies not in pulp caps ; geometry & inflammation 1) ratio of surface area of tissue in contact with Ca(OH)2 relative to the remaining tissue volume is considerably higher than in capping 2) pulpotomies are performed on carious teeth with inflammed pulpsSawusch ; -inorganic Ca(OH)2 & Dycal reported 13% & 7% failure rate.94 Kennedy & Kapala; -high cellular content -undifferentiated mesenchymal cells odontoclastic cells in response to either caries / capping material internal resorp

Cotton; -minimal pulp inflammation bridge adjacent the capping material -severe inflammation bridge form away from exposure95Controversies about success of DPC in primary teethPromote internal resorption

Gracia-Godoy

no evidence that demonstrates that appication of Ca(OH)2 to coronal pulp will elicit such a response

96 Suggestions for attempting Calcium hydroxide Direct pulp capping in primary teeth

The future ;Ca(OH)2 - Stanley inorganic Ca(OH)2(very basic pH) creates zone of obliteration & coagulation necrosis superficial to the deeper zones where reparative dentin begins. - Turner et al pulp capped with hard setting Ca(OH)2,less injurious (lower pH) & bridge were thinner - found no internal resorption , Ca(OH)2 acceptable over non-inflammed pulp.97 Gracia-Godoy on primary teeth protocol; - more extensive debridement & absolute hemostasis debridement 1) Cox, by NaOCL for total etch & bond pulp treatment 2) Cvek, by frank tissue excision for atraumatic exposure hemostasis - Stanley, astringent98 Agents used ;

Zinc oxide eugenol -Watts (1988), ZnOE in direct contact with pulp chronic inflammation-lack of calcific barrier necrosis

Corticosteroids & Antibiotics -Brosch (1966), neomycin & hydrocortisone -Bhaskar et al (1969),cortisone -Ledermix CH + prednisolone 99 Collagen fibers -less irritant than CH-minimal dentin bridging in 8 weeks -Fuks et al, found dentin bridge after 2 mnths in 73% of teeth

Formocresol -Garcia-Godoy, 96% clinical & radiographic success rate when capped with paste of 1/3rd dilution formocresol mixed with ZnOE paste & covered with reinforced ZnOE cement.

4-Meta Adhesive -soak into pulp, polymerize & form a hybrid layer -Cox, showed reparative dentin deposition without pulp pathosis100 Direct bonding;

- key component multi purpose dentin bonding adhesive when infiltrates into acid etch dentin forms an impermiable hybrid layer - Kopel, polymeric film can be layered over the exposed site without displacing pulp tissue & unto surrounding dentin where it permeates the tubules these adhesives are hydrophilic, light cured, & layer of composite is spread over the pulp & surrounding dentin101 Biologic properties;Primer & dentin adhesive work in a wet environmentHydrophilic adhesion flow well forming continuous seal onto the dentinDisplacement of composite is prevented.

Inokoshi et al, found chronic ulcerative pulpitis Katoh , found pulp irritation to be minimal, with 95% bridge formationCox, (primates); hemostasis is crucial- NaOCL & prevention of bacterial contamination.Priera (1997); sound premolars capped- mild inflammation & repair after several months.102 Controversial?????

Isobutyl Cyanoacrylate (Berkman,1971) - excellent hemostatic agent & reparative dentin stimulator - inflammation - no zone of necrosis

Disadvantage ; - cytotoxic when freshly polymerized but not after being exposed to air for 24hrs before polymerization - does not form continuous barrier of reparative dentin103 Denatured albumin - calcium binding properties - form matrix for calcification, thereby changes of biologic obliteration

- Molven, no hard tissue barrier / bridge / fibrous capsule was observed. inflammation was also not observed.104 MTA (Mineral Trioxide Aggregate) Pitts et al (1996) & Sluyk et al (1998) - it allows some micro leakage but superior sealing ability to amalgam, ZnOE / IRM - superior to CH in animal models (Torabinejab M et al, 1999 &Junn D.J et al, 1998)

Bone morphogenic protein (BMP) - Urist (1965), observed demineralized bone matrix could stimulate new bone formation when implanted to ectopic sites (muscles) - demineralized dentin from both bone & dentin - Soren J et al (1997), dentin formation by recombinant human osteogenic protien-1.105TECHNIQUEDEBRIDEMENT

it is prudent to remove peripheral masses of carious dentin before beginning the excavation where an exposure may occur as infected dentin chips are invariably pushed into the exposed pulp during the last stages of caries removal.

This debris can impede healing in the area by causing further pulpal inflammation and encapsulation of the dentin chips.

The area should be appropriately irrigated with nonirritating solutions such as normal saline to keep the pulp moist.

106HEMORRHAGE AND CLOTTING

Hemorrhage at the exposure site can be controlled with cotton pellet pressure.

A blood clot must not be allowed to form after the cessation of hemorrhage from the exposure site as it will impede pulpal healing.

The capping material must directly contact pulp tissue to exert a reparative dentin bridge response.107CONTROL OF BLEEDINGA capping agent should never be placed against a bleeding pulp.

It is also important to control any excessive oozing of serum or plasma that will occupy / fill, or create a space between the capping agent and the pulp tissue.

Bleeding usually can be stopped just by washing the area with sterile saline solution and drying with paper points laid across the exposure site.

In larger exposure sites cotton pellets are used.

If bleeding is not arrested with sterile saline solution alone, then hydrogen peroxide may be applied.

108EXPOSURE ENLARGEMENT There have been recommendations that the exposure site be enlarged by a modification of the direct capping technique known as pulp curettage or partial pulpotomy prior to the placement of capping material.

Enlarging this opening into the pulp itself serves three purposes:

It removes inflamed and/or infected tissue in the exposed area.It facilitates removal of carious and noncarious debris particularly dentin chips.It ensures intimate contact of the capping medicament with healthy pulp tissue below the exposure site.

109BACTERIAL CONTAMINATION

The success of pulp-capping procedures is dependent on prevention of micro leakage by an adequate seal.

Cox et al. have shown that pulp healing is more dependent on the capacity of the capping material to prevent bacterial micro leakage rather than the specific properties of the material itself.110THE SALIENT FEATURES OF A SUCCESSFUL PULP CAPPING Dentin bridging.

Maintenance of pulp vitality.

Lack of undue sensitivity or pain.

Minimum pulpal inflammatory response.

The ability of the pulp to maintain itself without progressive degeneration.

Lack of internal resorption and/or inter radicular pathosis.111

112113RECENT ADVANCES114

Chemo-mechanical caries removalCarisolv is a chemo-mechanical method for minimally invasive caries removal . The system comprises :

a gel that selectively attacks denatured collagen in the carious dentine, thus making the carious dentine softer. a set of specially designed instruments used for removal of the softened material.

115Carisolv gel consists of two carboxymethylcellulose based gels: a red gel containing : amino acids (glutamic acid, leucine and lysine), NaCl NaOH Erythrosine (added in order to make the gel visible during use ). and a second containing sodium hypochlorite

116The two gels are thoroughly mixed in equal parts at room temperature before use . The solution has a pH 11.The positively and negatively charged groups on the amino acids become chlorinated and further disrupt the collagen crosslinkage in the matrix of the carious dentine.

The gel is then applied onto the exposed carious dentine and left for 30 to 60 seconds then the softened dentine is gently but firmly abraded away leaving a hard, caries-free cavity . 117

A soft caries lesionGel application. Let gel slide onto the lesion. Wait 30 seconds.The lesion is gently scraped with a star instrumentRe-applied gel stays clear. Cavity is hard with a probe.118

The gel is removed with a dry pelletComplete caries removal is checked with an explorerThe cavity is cleaned with wet pelletsFinished cavity119Advantages of carisolvThe patients perceive the method as much more comfortable than drilling and anaesthetics are seldom needed.

Saves time

Avoids removal of unnecessary healthy dental tissues

Action of excavator. Healthy dentine is also removed.

Selective removal of softened dentine caries with the Carisolv instrument. Healthy dentine is not affected.

120Smartprep instrumentThe SMARTPREPTM Instrument is a POLYMER BUR or SMART BUR that safely and effectively remove decayed dentin, leaving healthy dentin intact. It is a self-limiting instrument and is not hard enough to penetrate healthy dentin. As it gently removes decay and contacts the healthy dentin, the instrument's edges become rounded and unable to cut healthy tooth structure. A high-speed carbide bur is first used to gain access to the decay. After access has been created, the SMARTPREPTM Instrument is used in a slow speed handpiece (500-800 rpm) to complete caries removal. They are single-patient-use rotary instruments. 121

122

Advantages :Conserve healthy tooth structure, Virtually no risk of inadvertent pulp exposure, Reduce the need for anesthesia and allow for same-visit cavity preparations on multiple quadrants, Designed to reduce post-operative sensitivity.

123 The restorative treatment doesn't cure the caries process, so identifying & eliminating the causative factors for caries must be the primary focus, in addition to the restorative repair of damage caused by caries.

124conclusionREFERENCESEndodontics Ingle Pathways of pulp Cohen and BurnOperative Dentistry M.A .MarzoukDentistry for the child and adolescent MC DonaldShoba Tandon Text book of Endodontics GrossmanJADA vol 139 ,716- 722 JADA 1980DCNA 1976 , DCNA 2000IEJ -- 2004GOOGLE.COM

125Thank you126