INDIAN DENTAL ACADEMY     Leader in Continuing Dental Education        www.indiandentalacademy.comwww.indiandentalacademy....
POST AND CORE                    CONTENTSIntroductionHistoryTreatment planning for post and coreClassification of postsFac...
INTRODUCTIONEndodontic treatment      good prognosisLoss of considerable amount of tooth structureCariesEndodontic treatme...
HISTORY   Methods of restoring pulp less teeth for more than 250yrs.1728-Pierre Fouchard -roots of maxillary anteriors tee...
1849-Sir John Tomes - Dental philosophy and surgery           principles of fabricating posts1878-C.M.Richmond-porcelain f...
1880-U.S. seasoned wood as pivots19th century-Davis crown -gold casting1960-carbon fiber post1968-Mare Reymond-      DT Li...
TREATMENT PLANNINGGood apical sealNo apical sensitivityNo sensitivity to pressureNo active inflammationNo exudateNo sinus ...
Changes accompanying root canal therapy    Loss of tooth structure    Altered physical characteristics    Altered esthetic...
Why post and core?         post strengthen the root??     Retain the core buildup material                       &     Rei...
POST AND COREPOST(DOWEL):  The dowel is a post or other relatively rigid restorative material placed in the root of a non ...
Preformed dowel system can be further categorized basedon their geometric shapeTapered postsParallel postsfurther classifi...
Based on materialNon metallic postsC-postAestheti Plus postCera postMetallic postsDentatus postRoot postPara post         ...
Ideal properties of a post.Maximum protection.Adequate retention with in the root.Maximum retention of the core and crown....
Factors which effect the post selectionpost lengthpost shapepost diameterSurface configurationpost material/compositionLut...
POST LENGTH  Equal to the cervico incisal or cervico occlusal length of crown  Longer than the crown  One and one third th...
Three quarters the length of root in long rooted teethIn average length teeth-retain apical 5.00mmShould extend at leas...
POST SHAPEParallel sided parallel sided posts - removal of more tooth structure less chance of root fracture Parallel desi...
POST DIAMETERLarge diameter post - higher retention                                           -Standlee, KvistIncrease in ...
Teeth with thicker diameter (1.8mm) post fractured moreeasily than with a thinner (1.3mm)                                 ...
To avoid root perforation by excessive preparation,safe instrument diameters are proposed                     Tilk et al  ...
SURFACE CONFIGURATIONSmooth surface - least retentiveSerrated surface - more retentiveThreaded surface - most retentive   ...
LUTING AGENTSResin cementsHigher retentionLower microleakageprotection by strengthening of rootSuperiority of one cement o...
POST MATERIALSfunctional stress, resist corrosion and biocompatible           stress– adequate stiffness- high yield stren...
PRINCIPLES OF TOOTH PREPARATIONMany of the principles relating to the tooth preparationapply equally to the endodotically ...
Conservation of tooth structureROOT CANALRemove only minimal tooth structure from the canalOver enlargement lead to weaken...
CrownThe amount of remaining tooth structure      is the single most important predictor of clinical successCaries, previo...
RETENTION FORMDislodgement of post retained anterior crownis due to inadequate retention form of the prepared postRetentio...
PREPARATION GEOMETRYAnterior teethSome canals have nearly circular cross section - prepared to giveparallel walls or a min...
Posterior teethRelatively long post with circular cross section should be  avoidedRelatively short posts in divergent cana...
RESISTANCE FORMAn excessive internal preparation of rootweakens the root and possibility of failure in restorationPost des...
2. Vertical remaining tooth structure-3. Anti rotational features-Oblong canal space provides resistance to rotational for...
Crown& crown preparationMinimum of 2mm dentin axial wall heightParallel axial wallsMetal should encircle the toothMargins ...
Greatest stress concentration in the tooth is found at theshoulder,inter proximally and at the apexdentin should be preser...
THE FERRULE EFFECT                 FERRULE is a metal ring or cap put around the endof a tool, cane to provide added stren...
Types of ferrule                                    &Core ferrule andCrown ferruleCrown ferrule > effective - core ferrule...
CORE AND CORE MATERIALSThe core is anchored to the tooth by a direct connection of the core into canal or through a postTo...
Desirable properties of core material include•Dimensional stability•Ease of manipulation•Natural tooth color•Rapid and har...
CAST COREA cast core forming a one piece post and coretraditional and proven method of restoring a toothAdvantagesCore doe...
COMPOSITE RESIN COREAdvantagesEase of manipulationLess time consuming andA additional retention and anti rotation features...
GLASS IONOMER/ METAL MODOFIED GIC COREIn teeth with significant amount of dentinremaining and additional retention is avai...
RMGIC CORE:Improved properties conventional GICBond strength close to that of bonded composite restorationMinimal microlea...
CORONAL RADICULAR COREUsed as an alternative - traditional cast post and coreThis consists of core that replaces the coron...
TECHNIQUES FOR POST AND CORE FABRICATIONTooth preparation for post and core can be accomplished in      3 steps-1.removal ...
REMOVAL OF ENDODONTIC FILLING MATERIAL  The amount of gutta percha removal is dictated byThe desired post length, type, bo...
ENLAREMENT OF THE ROOT CANAL SPACEThe Peeso reamers & Gates Glidden drillAvailable in sizes 0.7-1.7mm & 0.6-1.5mm dia in g...
PHILOSOPHIES OF POST SPACE PREPARATIONConservationist –               narrowest diameter for certain post length          ...
PROCEDUREBegin removal of gutta percha with heated condenserMeasure as large size Peeso reamer as will fit theobturated sp...
PREPARATION OF THE CORONAL TOOTH STRUCTUREPrepare the remaining tooth structure adequatelyfor the extra coronal restoratio...
www.indiandentalacademy.com
PREFABRICATED POSTSEnlarge the canal one to two sizes with a drill or reamer  smaller than the drill prescribed by the man...
Maximum recommended dowel size with outline of  root at mid root portion with root outlineand post diameters.Outline ofRoo...
CUSTOM CAST POST AND COREFABRICATION TECHNIQUEDirect or indirect techniqueA direct technique using inlay wax, auto polymer...
Deficiency or excess is corrected and coronal partis shapedThe finish line prepared should be on tooth andnot on the coreR...
Indirect techniqueimpression is made with a elastomeric impression material withadequate reinforcement to prevent distorti...
Direct indirect technique —pick up casting or core                      Miscellaneous                      Dowel inlays an...
PROVISIONAL RESTRORATIONS INPOST AND CORE FABRICATIONA provisional restoration plays an important rolein the successful re...
crown formers and posts can be used in various combinations-•Polycarbonate crowns relined with acrylic•Plastic posts relin...
RECENT ADVANCESPrefabricated posts- increasingly popularEase of placement andCrown preparationFIBER POSTSCARBON FIBER COMP...
DisadvantagesDark in colorRadiolucent in appearanceReduction of strength after placementCause stress concentration at the ...
carbonite postavailable in 3 reamer sizes as 2, 3, & 4 -- 1.20, 1.35 &1.50                               Mira post        ...
Bond between tooth, core and post - adhesive techniqueparapost,glassix, fiberkor, lucent anchor, Mirafit white - glass  fi...
FRC POSTECGlass fiber reinforced Composite postElasticity dentin and dentin like shadesize 1 and 3 with correspondingreame...
CERAMIC AND ZIRCONIUM POSTS ceramic and zirconium posts - translucentEsthetically superior to metal posts and for all cera...
Direct methodIndirect method - ReinforcementCosmo post, snow post                www.indiandentalacademy.com
METAL POSTSWorld postsupplied with primary reamer and secondary drillsecondary drill- tier-stabilizes & bottoming outLengt...
Flexi-post               Flexi-flange postSs, titanium alloySplit shank design             Access post                    ...
Para post xp- ss, TiPara post xh – TiPara post xt – TiPara post xp-casting kitPRO POSTY-2-0.94mmR-3-1.20mmB-4-1.45mmG-5-1....
Cytcok Ni Ti post          Dentatus post            www.indiandentalacademy.com
CUSTOM MADE VS PRE FABRICATED POSTThe canal is prepared to fit the prefabricated post,   but custom made post is made to f...
CONCLUSIONPrefabricated posts - popular + ease of placement and+ allow restoring the tooth for immediate crown preparation...
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Post & core /certified fixed orthodontic courses by Indian dental academy

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Welcome to Indian Dental Academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.


Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients

State of the art comprehensive training-Faculty of world wide repute &Very affordable.

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Post & core /certified fixed orthodontic courses by Indian dental academy

  1. 1. INDIAN DENTAL ACADEMY Leader in Continuing Dental Education www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. POST AND CORE CONTENTSIntroductionHistoryTreatment planning for post and coreClassification of postsFactors affecting selection of postPrinciples of tooth preparation for post and coreThe ferrule effectCore and core materialsTechniques of fabricationRecent advancesconclusion www.indiandentalacademy.com
  3. 3. INTRODUCTIONEndodontic treatment good prognosisLoss of considerable amount of tooth structureCariesEndodontic treatment &/or previous restorationRetention of subsequent restoration problematicIncreases # functionRestoring teeth complex procedures www.indiandentalacademy.com
  4. 4. HISTORY Methods of restoring pulp less teeth for more than 250yrs.1728-Pierre Fouchard -roots of maxillary anteriors teethPivot teeth –Mastic “Tenons” Replacement crowns1800-Dubois de chamante-porcelain teeth-pivot teeth1839-Chapin Harris - The Dental Art –pivoting of the artificial crowns to natural roots “The best that can be employed” www.indiandentalacademy.com
  5. 5. 1849-Sir John Tomes - Dental philosophy and surgery principles of fabricating posts1878-C.M.Richmond-porcelain faced dowel crowns Pivot/post with porcelain facing www.indiandentalacademy.com
  6. 6. 1880-U.S. seasoned wood as pivots19th century-Davis crown -gold casting1960-carbon fiber post1968-Mare Reymond- DT Light transmitting post1989- modification of carbon fiber post1996-Meyeberg - Zirconium posts www.indiandentalacademy.com
  7. 7. TREATMENT PLANNINGGood apical sealNo apical sensitivityNo sensitivity to pressureNo active inflammationNo exudateNo sinus www.indiandentalacademy.com
  8. 8. Changes accompanying root canal therapy Loss of tooth structure Altered physical characteristics Altered estheticsAmount of remaining tooth structureAnatomic position of the toothFunctional load on the toothEsthetic requirements for the tooth www.indiandentalacademy.com
  9. 9. Why post and core? post strengthen the root?? Retain the core buildup material & Reinforce coronal tooth structureReplace the missing portion and toprotect the remaining tooth structureBasically consists of•Post•Core and•Final restoration www.indiandentalacademy.com
  10. 10. POST AND COREPOST(DOWEL): The dowel is a post or other relatively rigid restorative material placed in the root of a non vital tooth”CORE:The core consists of restorative material placed in thecoronal area of a tooth It replaces the carious, fractured or otherwise missingcoronal structure and retains the final restoration/crown.CLASSIFICATION OF POST(DOWEL):Categorized by number of different waysBroadly categorized into: Custom cast posts and Preformed post systems www.indiandentalacademy.com
  11. 11. Preformed dowel system can be further categorized basedon their geometric shapeTapered postsParallel postsfurther classified by their surface configuration asSmooth postsSerrated postsThreaded postsBased on mode of retention of the post to the canal portionActive posts Passive postsv-lock post c-post snow postflexi-post cosmopost aestheti post para pos www.indiandentalacademy.com
  12. 12. Based on materialNon metallic postsC-postAestheti Plus postCera postMetallic postsDentatus postRoot postPara post www.indiandentalacademy.com
  13. 13. Ideal properties of a post.Maximum protection.Adequate retention with in the root.Maximum retention of the core and crown.Maximum protection of the crown margin/cementseal.Pleasing esthetics when indicated.High radiographic visibility.Retrievability.Biocompatibility www.indiandentalacademy.com
  14. 14. Factors which effect the post selectionpost lengthpost shapepost diameterSurface configurationpost material/compositionLuting agent www.indiandentalacademy.com
  15. 15. POST LENGTH Equal to the cervico incisal or cervico occlusal length of crown Longer than the crown One and one third the crown length Half the root length Two third the root length Four fifth the root length Half way between crestal bone and root apex As long as possible without disturbing the apical seal 4.00mm safety zone is required for apical seal• 2-3mm ---definite leakage 4 mm-- adequate—Nixon et al 5mm—Apical seal---Mattison et al www.indiandentalacademy.com
  16. 16. Three quarters the length of root in long rooted teethIn average length teeth-retain apical 5.00mmShould extend at least 4mm apical to bone crestMolar posts not be extended more than 7mm www.indiandentalacademy.com
  17. 17. POST SHAPEParallel sided parallel sided posts - removal of more tooth structure less chance of root fracture Parallel design improves post retention and force distribution. distribution More retentive than tapered formsTapered formProduce wedging effect - significant lateral forces vertical root fracture Requires less removal of tooth structureLimited to use in tapered root systems www.indiandentalacademy.com
  18. 18. POST DIAMETERLarge diameter post - higher retention -Standlee, KvistIncrease in diameter - no significant increase in retention -Kurer,HarisonLength is most important factor in post retention and diameter is only a secondary factor - Krupp et alIncrease in post diameter causes higher stress in the tooth — MattisonPotential for root fracture increases by SIX times/mm ofdiameter www.indiandentalacademy.com
  19. 19. Teeth with thicker diameter (1.8mm) post fractured moreeasily than with a thinner (1.3mm) --Trabert et alPhotoelastic studies - internal stresses are less with thinner postsFEM studies have failed to demonstrate increase in stresswith increase in diameter of the postsRecent FEM analysis and fractographic analysis —Dent. Trauma—2004Tensile loading—strains/deformations in inner dentin andstress at the outer dentin surface www.indiandentalacademy.com
  20. 20. To avoid root perforation by excessive preparation,safe instrument diameters are proposed Tilk et al Shillingburg et alSmall teeth 0.6-0.7mm 0.7mmLarger diameter 1.00mm 1.7mmRemaining 0.8-0.9mm 1.3mmsmall diameter root—0.6-0.7mmlarge diameter root---1-1.2mmin molars-should not exceed more than 7mm in length even in thicker roots. www.indiandentalacademy.com
  21. 21. SURFACE CONFIGURATIONSmooth surface - least retentiveSerrated surface - more retentiveThreaded surface - most retentive intended to engage canal walls significant stress in the toothModifications of surface www.indiandentalacademy.com
  22. 22. LUTING AGENTSResin cementsHigher retentionLower microleakageprotection by strengthening of rootSuperiority of one cement over another is not clearBonded resin cements - strengthening effects in roots for some period of timeTechnique sensitiveContamination Delivery of the etchent/ bonding agentWhen using resin cements use dual cure resin cement www.indiandentalacademy.com
  23. 23. POST MATERIALSfunctional stress, resist corrosion and biocompatible stress– adequate stiffness- high yield strength- favorable fatigue properties to function adequatelyAllergy and sensitivity with Ni-Cr alloyTitanium preformed post-carbon fiber postCeramic postsPoly ethylene woven posts www.indiandentalacademy.com
  24. 24. PRINCIPLES OF TOOTH PREPARATIONMany of the principles relating to the tooth preparationapply equally to the endodotically treated teethAdditional concepts to avoid failureConservation of tooth structureRetention formResistance form www.indiandentalacademy.com
  25. 25. Conservation of tooth structureROOT CANALRemove only minimal tooth structure from the canalOver enlargement lead to weakening or perforation chances of splitting while cementation or functioningCanal be enlarged to enable the post to fit snugly for strength & retention www.indiandentalacademy.com
  26. 26. CrownThe amount of remaining tooth structure is the single most important predictor of clinical successCaries, previous restoration andendodontic cavity preparation considerable loss of tooth structureFurther reduction to accommodate the crown andto remove undercuts little coronal dentinAs much coronal tooth structure should be conserved to reduce the stress concentration at the gingival margin Extension of the axial wall of the crown apical to the missing tooth structure provides as a ferrule - hold theremaining tooth structure preventing root fracture during function www.indiandentalacademy.com
  27. 27. RETENTION FORMDislodgement of post retained anterior crownis due to inadequate retention form of the prepared postRetention of the post is mainly affected by –The preparation geometryPost lengthPost diameterSurface textureThe luting agent www.indiandentalacademy.com
  28. 28. PREPARATION GEOMETRYAnterior teethSome canals have nearly circular cross section - prepared to giveparallel walls or a minimum taper allowing the use of preformed post of respective configurationRetention is proportional to the surface area www.indiandentalacademy.com
  29. 29. Posterior teethRelatively long post with circular cross section should be avoidedRelatively short posts in divergent canals better retention3mm or more amount of tooth structure is present -- preparation of the root canal is not necessaryWidest canals are selected for post placement in posterior teeth www.indiandentalacademy.com
  30. 30. RESISTANCE FORMAn excessive internal preparation of rootweakens the root and possibility of failure in restorationPost design should distribute stresses as evenly as possibleFACTORS AFFECTING RESISTANCE1. Crown bevel- Part of the crown extends past post & core margin - extends on natural tooth structureEffective tooth 360 degrees and at least 1.5mm on to tooth structure below margin www.indiandentalacademy.com
  31. 31. 2. Vertical remaining tooth structure-3. Anti rotational features-Oblong canal space provides resistance to rotational forcesWhen coronal dentin is lost, anti rotation element can be placed in the bulkiest aspect of teeth www.indiandentalacademy.com
  32. 32. Crown& crown preparationMinimum of 2mm dentin axial wall heightParallel axial wallsMetal should encircle the toothMargins on solid tooth structureNot invade attachment apparatus www.indiandentalacademy.com
  33. 33. Greatest stress concentration in the tooth is found at theshoulder,inter proximally and at the apexdentin should be preserved in these areas if possibleStresses are reduced as the post length increasesParallel sided posts distribute stresses more evenlySharp angles should be avoided high stress during loadingHigh stress will be generated when cementing parallel sided postswhich don’t have escape vent www.indiandentalacademy.com
  34. 34. THE FERRULE EFFECT FERRULE is a metal ring or cap put around the endof a tool, cane to provide added strength OR Is a vertical band of tooth structure at the gingival aspect ofa crown preparationPrimarily -- resistance form and enhances longevityCircumferential contra bevel reinforces the coronal aspectPositive occlusal seat - acts as a anti rotational deviceIn teeth with little or no clinical crown remaining large contra bevel on root surface with finish of crown preparationacts as ferrule Ferrule must be on tooth structure and not invade theattachment apparatus www.indiandentalacademy.com
  35. 35. Types of ferrule &Core ferrule andCrown ferruleCrown ferrule > effective - core ferruleFerrule length is more important than the post length in increasing # of tooth. --- Int J P 19992mm of dentin ferrule of crown more effectivelyenhances # resistance of custom cast post and core. -----JPD2003Even presence of 1mm of ferrule provides twice the amountof resistance to fracture www.indiandentalacademy.com
  36. 36. CORE AND CORE MATERIALSThe core is anchored to the tooth by a direct connection of the core into canal or through a postTooth + post & core mechanical, chemical/adhesiveThe remaining tooth structure can be altered to enhance retention of the core or to provide resistanceto core rotation under functionThe irregular nature -residual coronal tooth structure,morphology of the pulp chamber & canal orifices additional alterations www.indiandentalacademy.com
  37. 37. Desirable properties of core material include•Dimensional stability•Ease of manipulation•Natural tooth color•Rapid and hard setting > immediate crown preparation•High compressive and tensile strength•High modulus of elasticity and fracture toughness•Low plastic deformation•Bio compatibility•Cariostatic and low cost www.indiandentalacademy.com
  38. 38. CAST COREA cast core forming a one piece post and coretraditional and proven method of restoring a toothAdvantagesCore does not depend on mechanical means Can be retrieved for endodontic retreatmentNon corrosive when cast with noble metalDisadvantagesThe number of appointments required are moreLaboratory expenses and time required for fabricationTechnique sensitive in the laboratory phase www.indiandentalacademy.com
  39. 39. COMPOSITE RESIN COREAdvantagesEase of manipulationLess time consuming andA additional retention and anti rotation features easily achievedDisadvantagesPolymerization shrinkage & contraction- marginal discrepancy & micro cracksDifference in co-efficient of thermal expansion micro leakageAt least 2mm coronal tooth structure - for build upTechnique sensitivityRetention of core with zirconium posts www.indiandentalacademy.com
  40. 40. GLASS IONOMER/ METAL MODOFIED GIC COREIn teeth with significant amount of dentinremaining and additional retention is availableMain advantage is the anticariogenic potentialHigh solubility and moisture sensitivityLimited for building up of small areaLow retention to preformed dowelsLow strength and fracture toughnessTechnique sensitivityUsually not recommended - low strength --JPD-1982 www.indiandentalacademy.com
  41. 41. RMGIC CORE:Improved properties conventional GICBond strength close to that of bonded composite restorationMinimal microleakageDisadvantageDimensional instability in the presence of moisture > expansionCan fracture/ failure of the ceramic crowns -IJP-1998 www.indiandentalacademy.com
  42. 42. CORONAL RADICULAR COREUsed as an alternative - traditional cast post and coreThis consists of core that replaces the coronal tooth structureextends 2-4mm into coronal portion of root canalUtilizes conventional restorative materials-amalgam,composite resins or modified GICProvides adequate strength and retention as a coreIn combination with bonding - gingival discoloration, providesprotection against coronal leakage www.indiandentalacademy.com
  43. 43. TECHNIQUES FOR POST AND CORE FABRICATIONTooth preparation for post and core can be accomplished in 3 steps-1.removal of root canal filling material2.enlargement of the canal3.preparation of the coronal tooth structure post and core fabrication is best doneafter the coronal preparation of the tooth structureAmount of tooth preparation to be donedepends on the final restoration it in turnaffects the extent of core fabrication www.indiandentalacademy.com
  44. 44. REMOVAL OF ENDODONTIC FILLING MATERIAL The amount of gutta percha removal is dictated byThe desired post length, type, bone height andthe root morphologyWarmed endodontic pluggerrotary instrumentRotary instrumentation > straying from the canal and cutting theexcess radicular dentin - weakening / result in lateral perforation www.indiandentalacademy.com
  45. 45. ENLAREMENT OF THE ROOT CANAL SPACEThe Peeso reamers & Gates Glidden drillAvailable in sizes 0.7-1.7mm & 0.6-1.5mm dia in graduated sizes from 1-6, non cutting tipscanal preparation - keyway or a groove with bur no. 170 in the bulkiest portion of Canal to a depth of diameter of the bur and length of bur www.indiandentalacademy.com
  46. 46. PHILOSOPHIES OF POST SPACE PREPARATIONConservationist – narrowest diameter for certain post length Pilo & TamseProportionists - diameter should not be > 1/3 root diameter Stern & HarshfieldPreservationists – at least 1mm of sound dentin around entire post www.indiandentalacademy.com
  47. 47. PROCEDUREBegin removal of gutta percha with heated condenserMeasure as large size Peeso reamer as will fit theobturated space against a radiograph leaving apical 5mm of filling with reference to a stable land markOnce gutta percha is removed check the accuracyEnlarge the canal to a desired size - preserve a minimum of 1mmaround the post at mid root and beyond and should not be onethird the diameter of the root at the CEJ www.indiandentalacademy.com
  48. 48. PREPARATION OF THE CORONAL TOOTH STRUCTUREPrepare the remaining tooth structure adequatelyfor the extra coronal restorationAll internal and external under cuts are removedAny unsupported tooth structure if present should be removedThe remaining portion is prepared perpendicular to the post which will create a positive stop while cementing thepost www.indiandentalacademy.com
  49. 49. www.indiandentalacademy.com
  50. 50. PREFABRICATED POSTSEnlarge the canal one to two sizes with a drill or reamer smaller than the drill prescribed by the manufacturerA wide range of prefabricated posts shapes and sizesparallel sided prefabricated are recommended for conservatively prepared root canals with roots of circular cross section.Excessively prepared canals managed with custom post. however situation should be evaluated on individual basis www.indiandentalacademy.com
  51. 51. Maximum recommended dowel size with outline of root at mid root portion with root outlineand post diameters.Outline ofRoot at midroot area and post diameters www.indiandentalacademy.com
  52. 52. CUSTOM CAST POST AND COREFABRICATION TECHNIQUEDirect or indirect techniqueA direct technique using inlay wax, auto polymerizing or lightpolymerizing resin usually for single teeth restoration Indirect technique – multiple teeth or tooth with multiple canalsThe post/pin should extend the full length of prepared canalsoft wax is added or a brush bead technique is used to add resin www.indiandentalacademy.com
  53. 53. Deficiency or excess is corrected and coronal partis shapedThe finish line prepared should be on tooth andnot on the coreRemove the pattern and proceed with thelaboratory steps www.indiandentalacademy.com
  54. 54. Indirect techniqueimpression is made with a elastomeric impression material withadequate reinforcement to prevent distortionthe impression material can either be placed in the canal with alentulo spiral or can be injected into the post Spaceimpression is removed , evaluated and working cast preparedpost pattern prepared and other procedures carried out www.indiandentalacademy.com
  55. 55. Direct indirect technique —pick up casting or core Miscellaneous Dowel inlays and retrofit posts www.indiandentalacademy.com
  56. 56. PROVISIONAL RESTRORATIONS INPOST AND CORE FABRICATIONA provisional restoration plays an important rolein the successful restoration of a toothFUNCTIONS•Esthetics•Protection of the tooth from further damage•Prevents migration of adjacent teeth•provides occlusal function www.indiandentalacademy.com
  57. 57. crown formers and posts can be used in various combinations-•Polycarbonate crowns relined with acrylic•Plastic posts relined with acrylic resin•Silicone post reinforced with a paper clip or orthodontic wire•Braided SS wire with acrylic resin crown•SS crowns with reinforcement•Reamers or files reinforced with acrylic www.indiandentalacademy.com
  58. 58. RECENT ADVANCESPrefabricated posts- increasingly popularEase of placement andCrown preparationFIBER POSTSCARBON FIBER COMPOSITE POSTS-More flexible than metal posts andhave same modulus of elasticity of dentin approximatelyEven distribution of forces when bonded with resinsBiocompatible and non cytotoxicLess root fractureHave the highest strength among the fiber posts www.indiandentalacademy.com
  59. 59. DisadvantagesDark in colorRadiolucent in appearanceReduction of strength after placementCause stress concentration at the margins of the restorations --JDR-1999Fibers were unidirectionalMultidirectional arrangement has improved their longevityDark color is over come- coating the post with zirconium - aestheti plus postRecent versions are white and are relatively easier to remove byboring the middle of the post with ultrasonic or rotary instrument www.indiandentalacademy.com
  60. 60. carbonite postavailable in 3 reamer sizes as 2, 3, & 4 -- 1.20, 1.35 &1.50 Mira post www.indiandentalacademy.com
  61. 61. Bond between tooth, core and post - adhesive techniqueparapost,glassix, fiberkor, lucent anchor, Mirafit white - glass fiber postsluminex, light post—light transmitting postsAestheti plus, DT light post –quartz fiber postPara post white fiber Aestheti plus – A 2 www.indiandentalacademy.com
  62. 62. FRC POSTECGlass fiber reinforced Composite postElasticity dentin and dentin like shadesize 1 and 3 with correspondingreamer as white and Red colorPolymer matrix of urethane dimethacrylate & glycol dimethacrylate yitterbium trifluoride & dispersed si. DioxideImpression post of Cr-Ni Size 1-15mm, 0.8mm size 2 -18mm, 1mSize 1- 0.7mmSize 3- 0.9mm Direct or indirect tech. www.indiandentalacademy.com
  63. 63. CERAMIC AND ZIRCONIUM POSTS ceramic and zirconium posts - translucentEsthetically superior to metal posts and for all ceramic crowns ---JPD2000Its impossible to grind away the postsZirconium posts are not etchable ---Int sym-1998Retention of the coreceramic and zirconium posts #retrievable andthey should be avoided –AAE-2004Weaker than the metal postsThicker posts - Require additional removal of root dentin www.indiandentalacademy.com
  64. 64. Direct methodIndirect method - ReinforcementCosmo post, snow post www.indiandentalacademy.com
  65. 65. METAL POSTSWorld postsupplied with primary reamer and secondary drillsecondary drill- tier-stabilizes & bottoming outLength & head position Peeso Gates Primary reamer 1 2 0 3 4 1 4 5 2 5 6 3 www.indiandentalacademy.com
  66. 66. Flexi-post Flexi-flange postSs, titanium alloySplit shank design Access post Root post -Ti post www.indiandentalacademy.com
  67. 67. Para post xp- ss, TiPara post xh – TiPara post xt – TiPara post xp-casting kitPRO POSTY-2-0.94mmR-3-1.20mmB-4-1.45mmG-5-1.70mmSurface of post- acid etched www.indiandentalacademy.com
  68. 68. Cytcok Ni Ti post Dentatus post www.indiandentalacademy.com
  69. 69. CUSTOM MADE VS PRE FABRICATED POSTThe canal is prepared to fit the prefabricated post, but custom made post is made to fit the toothCustom made cast post better adaptation to canal configurationDo not require auxiliary means of retention routinelyGives the best results when change in the pathof insertion or crown angulation is required www.indiandentalacademy.com
  70. 70. CONCLUSIONPrefabricated posts - popular + ease of placement and+ allow restoring the tooth for immediate crown preparationIt is possible to achieve high level of clinical successwith most of the current available materials Further understanding and modification currently available material with their physical and mechanical properties will improve their performance. www.indiandentalacademy.com

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