Transcript WAX PATTERN FABRICATION

WAX PATTERN FABRICATION
FOR FPD
INTRODUCTION
USUALLY WAX PATTERN FABRICATION DENOTES
THE WAX PATTERN FABRICATED TO CAST METAL OR
CASTABLE GLASS CERAMICS (DICOR). WAX PATTERN
FABRICATION INVOLVES THREE MAJOR STEPS
NAMELY FABRICATION OF THE RETAINER,THE
PONTIC AND CONNECTOR
FABRICATION OF THE
RETAINER WAX PATTERN
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THE METHOD OF FABRICATION OF THE RETAINER
COMPONENT WILL VARY ACCORDING TO THE
MATERIAL USED AND THE DESIGN OF THE
RESTORATION
1.
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DIRECT TECHNIQUE
WAX PATTERN IS FABRICATED DIRECTLY OVER THE
PREPARED TOOTH IN THE ORAL CAVITY
DONE WITH TYPE-I WAX,HENCE NOT USED FOR
FIXED PARTIAL DENTURE PATTERN
2. INDIRECT TECHNIQUE
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PATTERN IS FABRICATED OVER THE PREPAIRED
TOOTH IN THE DIE OR CAST
MADE USING TYPE-II WAX
ADVANTAGES:
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DONE IN THE LAB THEREBY REDUCING THE
CHAIRSIDE TIME
DONE BY TECHNICIAN THEREBY REDUCING
WORK LOAD OF DENTIST
ALLOWS BETTER VISUALISATION OF THE
MARGINS OF THE RESTORATION ESPECIALLY
FROM THE GINGIVAL ASPECT
PROCEDURE
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FABRICATED BY PREPARING A WAX
COPING FOLLOWED BY ADDING
LAYERS OF WAX TO BUILD UP AXIAL
AND OCCLUSAL CONTOUR
COPING PREPARATION
PROCEDURE
 SURFACE CONTOURING AND MARGINAL FINISH
ARE NECESSARY FOR ALL METAL OR DICOR
CERAMIC RETAINER
 IN METAL CERAMIC RETAINER COPING IS
ALONE PREPARED AND CASTED USING METAL
CERAMIC ALLOY
 THE COTOURS AND MARGINS ARE DIERECTLY
PREPARED USING CERAMIC AND FIRED
COPING PREPARATION
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DONE USING WAX OR HEATED SHEET OF RESIN
WAX COATED ON THE TOOTH USING A WAX
SPATULA OR BY DIPPING THE DIE INTO THE HOT
WAX
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WHILE ADDING NEW LAYERS OF WAX THE
PREVIOUS LAYER SHOULD BE MELTED TO AVOID
FORMATION OF VOIDS
COPING SHOULD BE WAXED IN EXCESS MESIALLO
DISTALLY TO PRESERVE PROXIMAL CONTACT
PREPARING THE AXIAL
CONTOURS
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ESTABLISHING THE PROXIMAL CONTACT
USUALY THE PROXIMAL CONTACT OCCUR AT HE
OCCLUSAL THIRD WHEN VIEWED FROM SIDE
PROXIMAL CONTACT SHOULD BE FACIALLY
LOCATED WHEN VIEWED OCCLUSALLY
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CONTACT AREA SHOULD BE OPTIMUM
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AXIAL SURFACE BELOW THE CONTACT SHOULD
NEVER BE CONVEX
LINGUAL PROMINENCE IS GREATER FOR
MANDIBULAR POSTERIORS THAN MAXILLARY
POSTERIORS
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HEIGHT OF CONTOUR ON THE LINGUAL SURFACE
MAXILLARY POSTERIORS OCCUR IN CERVICAL
THIRD AND THE SAME IN MANDIBULAR
POSTERIORS OCCUR IN MIDDLE THIRD
PREPARING THE OCCLUSAL CONTOUR OR
DEVELOPING OCCLUSAL MORPHOLOGY
IT SHOULD BE IN HARMONY WITH ADJUSENT OR
OPPOSITE TEETH
 P.K. THOMAS CARVERS ARE USED TO CARVE THE
OCLUSAL SURFACE
PROCEDURE:
 TAIL END OF PKT CARVER SHOULD BE USED TO BUILT
CONES OF WAX OVER THE AREAS WHERE THE CUSPS
ARE TO BE FORMED
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MARGINAL RIDGES AND CUSP RIDGES ARE BUILT
USING SAME INSTRUMENT
PARTIALY WAXED OCCLUSAL SURFACE IS
OCCLUDED AGAINST THE OPPOSING CAST
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INTERNAL INCLINES OF THE CUSP ARE CONTORED
RIDGES SHOULD BE CONVEX
OCCLUSAL MORPHOLOGY SHOULD BE MODIFIED
ACCORDING TO SURROUNDING TEETH
FINISHING THE MARGINS OF
THE PATTERN
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MARGINS ARE FINISHED TO A FINE EDGE USING
BURNISHER
A COTTON PELLET SOAKED IN DIE LUBRICANT IS
USED TO FINISH THE OCCLUSAL GROOVES
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THE AXIAL SURFACE IS FINISHED WITH A COTTON
ROLL DIPPED IN A DIE LUBRICANT
REMOVE THE LUBRICANT AFTER FINISHING
PONTIC FABRICATION
FABRICATION OF WAX PATTERN FOR METAL CERAMIC AND
RESIN VENEERED PONTICS :
PROCEDURE :
 AXIAL SURFACES ARE CONTOURED AS DESCRIBED FOR A
RETAINER
 INLAY WAX IS SOFTENED AND FUSED TOOTH RETAINER IN
THE FORM OF A CYLINDER
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WAX CONE SHOULD BE PLACED ON THE FLAT
OCCLUSAL SURFACE INORDER TO CONTOUR THE
OCCLUSAL SURFACE
THE RETAINER PATTERNS ARE FINISHED AND THE
PROXIMAL AND THE GINGIVAL SURFACE OF THE
PONTIC ARE CONTOURED ACCORDING TO THE
NEIGHBOURING TEETH
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GINGIVAL SURFACE IS CONTOURED ACCORDING TO
DESIGN OF THE PONTIC