STONE V PRINTED MODELS

Transcription

1 STONE V PRINTED MODELS

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5 COMPOSITE CROWNS eg Gradia

6 COMPOSITE CROWNS

7 5 Year old composite it deteriorates with time

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9 Composite also wears with the passage of time this overlay is 12 years old and is nearly worn through on the occlusal surfacee

10 TEMPORARY CROWNS Prevent sensitivity Protect the pulp Prevent tissue overgrowth Maintain the spacial position of the prepared tooth in the arch during crown fabrication Diagnostic Acrylic v composite Never use an ultrasonic or apply leverage for removal!

11 Make the temps before you take the impression Never use Vaseline as a separating medium

12 CROWN CEMENTATION

13 Check there is no residual cement on the prep Check the contact points If not seating ensure you did not leave any sharp edges on the prep If still not seating try using eg Fit Checker to see if there are any casting blebs on the fit surfaces and remove Probably the crown will never fit and it was a distorted or poor impression

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15 DIFFERENTIAL WEAR

16 DIFFERENTIAL WEAR HARDER MATERIALS ABRADE SOFTER ONES. ENAMEL,DENTINE, COMPOSITE, GOLD AND PORCELAIN ALL WEAR AT DIFFERENT RATES. THE RESULTANT UNEVENESS OF THE OCCLUSAL LINE RARELY INTRODUCES PREMATURITIES IN CENTRIC BUT OFTEN INTRODUCES INTERFERENCES IN ECCENTRIC MANDIBULAR MOVEMENTS IF THE OCCLUSION OF A CROWN OR BRIDGE IS ADJUSTED ALWAYS ENSURE THAT THE OCCLUSAL SURFACE IS RE-GLAZED OR REPOLISHED TO AVOID WEAR

17 Crown adjustment Glazed porcelain Surface texture following adjustment with diamond bur Porcelain surface after polishing with the Meisinger porcelain polishing kit

18 e.max and Zirconia in particular require specialist finishing kits 1 ZIRCONIA FINISHING & POLISHING - CRA SEPT 16

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22 TEMPORARY CROWNS Any missing bits of the tooth being treated can be replaced and moulded with red carding wax. If the whole tooth is missing preformed acrylic moulds are manufactured For your mould you can use alginate, putty or specific products such as Template I suggest using sectional trays they can be purchased or simply cutting lower acrylic trays If using putty you must use a tray there is too much risk of flexure For complex cases you can have laboratory fabricated and called blowdowns or suckdowns. They are either hard or soft The material of choice is either acrylic or composite There are lubricants available if you are unsure if the temp will come off easily. Although materials such as Vaseline or Slaycris can be used, beware as they are not water soluble and difficult to remove off the prep a problem if you are taking impressions after. Water soluble lubricants such as Wink (Pulpdent) or K- Y Jelly Trimming maintain contact points and do not over-trim to ensure there is no gingival overgrowth Temporary cements

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27 Temporary crowns

28 The wax up duplicated in the temporary crowns

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34 YOU MUST HAVE PARALELL PREPS FOR ONE PIECE TEMPS

35 LUTING CEMENTS

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38 ZINC OXIDE EUGENOL

39 UNTIL VERY RECENTLY, USING A TEMPORARY CEMENT WHICH HAD ZINC OXIDE EUGENOL AS A COMPONENT WAS NOT ADVISED IF A RESIN CEMENT WAS TO BE USED AS A LUTING AGENT AS THE EUGENOL COMPONENT WOULD INETREFERE WITH THE POLYMERISATION OF THE RESIN. RECENT STUDIES HAVE SHOWN THAT IF THE TEMPORARY CEMENT HAS BEEN IN PLACE FOR LONGER THAN 2 WEEKS, THE EUGENOL WILL HAVE DE-ACTIVATED. SIMILARLY IF MICROABRASION IS AVAILABLE, THE EUGENOL LAYER IS SUPERFICIAL AND REMOVED WITH THIS TECHNIQUE OF CLEANING THE PREPARATION PRIOR TO FINAL CEMENTATION

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42 ZINC PHOSPHATE

43 POLYCARBOXYLATE

44 GLASS IONOMER

45 RESIN MODIFIED GLASS IONOMER

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49 COMPOSITE RESIN LUTING CEMENTS Conventional Self adhesive Self etch Panavia

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51 Self adhesive

52 Self etch

53 Panavia

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56 CROWN REMOVERS

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60 FINISHING LINES

61 CHAMFER

62 SHOULDER

63 SHOULDER BEVEL

64 FEATHER

65 THE ROLE OF GROOVES TO IMPROVE RETENTION OF CROWNS

66 TO IMPROVE RETENTION IN ANTERIOR TEETH THE GROOVES SHOULD BE PLACED MESIALLY AND DISTALLY - ON POSTERIOR TEETH BUCCALLY AND LINGUALLY. TO INCREASE RETENTION FURTHER IN THE POSTERIOR SEGMENTS, ADDITIONAL GROOVES CAN BE PLACED MESIALLY AND DISTALLY

67 PREP DESIGN

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