PROCESSING ERRORS IN DENTURE MAKINGVarun menon pThird BDS

introductionERRORS MAY BE MADE AT ANY OF INDIVIDUAL TREATMENT PROCEDURE & ARE NOT APPARENT UNTIL DENTURE INSERTION THE IMPORTANCE OF EARLY RECOGNITON OF ERRORS CAN MEAN THE DIFFERENCE BTW SUCCESS & FAILURE FAILURE MAY RESULT IF ERRORS OF MAJOR MAGNITUDE ARE ALLOWED TO PASS UNNOTICED UNTIL DENTURE ARE INSERTED

Procedures involvedTRYINLUTING OR WAX CONTOURINGDISARTICULATIONFLASKINGDEWAXINGACRYLIZATIONPROCESSING

Trial dentureTRIAL DENTURE:- PREMILINARY ARRANGEMENT OF DENTURE TEETH THAT HAS BEEN PREAPARED FOR PLACEMENT INTO THE PATIENTS MOUTH TO EVALUATE ESTHETICS & MAXILLOMANDIBULAR RELATIONSHIPS {GPT}TRYIN:-PROCESS OF PLACING A TRIAL DENTURE IN PATIENTS MOUTH FOR EVALUATION {GPT}

Procedure in tryinCHECK THE OCCLUSAL VERTICAL DIMENSIONCHECK THE ANTEROPOSTERIOR JAW RELATIONSHIPCHECK THE APPEARANCECHECK THE OCCLUSAL PLANE

Tryin the lower denture by itselfPeripheral outlineExtensionStabilityTongue spaceHeight of occlusal plane

Tryin the upper denture by itselfPeripheral outlineStabilityRetention

Both dentures together

Position of occlusion- horizontal relation-Vertical heightEvenness of occlusal contact-Appearance-Centerline-Shape of teeth-Size-Profile & lip form-Approval by the patient

Luting & wax contouringCONTOUR WAX CAREFULLY TO PREVENT MOVT OF THE TEETHAVOID BULKY WAX-UP ADDITIONAL BULK OF ACRYLIC RESIN CONTRIBUTE TO POROSITY & DIMENSIONAL ERRORIT SHOULD BE SMOOTH & THERE SHOULD BE NO UNDERCUTS

FlaskingIT IS THE PROCESS OF INVESTING THE CAST & A WAX REPLICA OF THE DESIRED FORM IN A FLASK PREPARATORY TO MOLDING THE RESTORATIVE MATERIAL INTO THE DESIRED PRODUCT PARTS OF FLASK:-TRIANGULAR BASECOUNTER OR BODYLID

During flasking

INCOMPLETE FLASK CLOSURETOOTH MOVT WHEN FLASKING & PACKINGREMOVE ANY UNDERCUTS IN THE INVESTMENT IT PREVENTS SEPERATION OF THE FLASKS AFTER BOILING

DewaxingDEWAXING DONE TO REMOVE THE WAX PATTERN SO THAT A MOLD SPACE IS CREATED FOR ACRYLIC RESIN TO FILL INREMOVE ALL WAX RESIDUE ACRYLIC RESIN WILL NOT ADHERE TO SURFACE COATED WITH WAXWHILE APPLICATION OF THE SEPARATING MEDIUM COATING THE MEDIUM OVER THE TEETH PREVENTS BONDING OF TEETH WITH THE DENTURE BASE

AcrylizationPROCEDURE INVOLVED:-APPLICATION OF SEPERATING MEDIUMMIXING OF MONOMER & POLYMERPACKINGBENCH CURINGPOLYMERIZATION CYCLE

While applying separating mediumSHOULD NOT BE APPLIED ON ACRYLIC RESIN TEETHINTERFERS WITH CHEMICAL BONDING BTWEEN ACRYLIC RESIN & DENTURE BASE RESINSHOULD BE APPLIED UNIFORMLY

While mixing monomer & polymerPOLYMER TO MONOMER RATIO 3:1 BY VOL 2:1 BY WTTOO MUCH MONOMER:-GREATER CURING OR POLYMERIZATION SHRINKAGEMORE TIME REQ TO REACH PACKING CONSISTENCYPOROSITY CAN OCCUR IN THE DENTURE

contdTOO LITTLE MONOMER:-NOT ALL THE POLYMER BEADS WILL BE WETTED BY MONOMER & CURED ACRYLIC RESIN WILL BE GRANULARDOUGH WILLL BE DIFFICULT TO MANAGEIDEAL:-RATIO OF 3:1 VOL PROVIDES SUFFICIENT MONOMER TO WET THE POLYMER PARTICLE & DOES NOT CONTRIBUTE TO EXCESS MONOMER THUS REDUCING POLYMERIZATION SHRINKAGE

While packingPLACEMENT & ADAPTATION OF DENTURE BASE RESIN WITHIN MOLD CAVITYOVER PACKING:- DENTURE BASE OF EXCESSIVE THICKNESS RESULTING IN MALPOSITIONING OF TEETHUNDERPACKING:-POROSITYPACKING PROCESS PERFORMED WHEN DENTURE BASE RESIN IS DOUGH LIKE STATE

Packing contdEARLY PACKING:- IN SANDY OR SRINGY STAGELOW VISCOSITY MATERIAL WILL FLOW OUT OF FLASK EASILY RESULT IN POROSITYLATE PACKING:- IN RUBBERY OR STIFF STAGE MATERIAL TOO VISCOUS RESULT IN MOVT OR FRACTURE OF TEETH LOSS OF DETAIL & INCREASE VERTICAL HEIGHT OF THE DENTURE

While bench curingPURPOSE OF BENCH CURING:-EQUALAIZATION OF PRESSURE THROUGH OUT THE MOLDALLOWS TIME FOR MORE UNIFORM DISPERSION OF MONOMER THROUGH THE MASS OF DOUGHLONGER EXPOSURE OF RESIN TEETH TO THE MONOMER IN THE DOUGH - BETTER BONDING

While polymerization cycleONE TECH INVOLVES PROCESSING OF DENTURE BASE RESIN IN A CONST TEMP WATERBATH AT 74 DEG CELSIUSFOR 8 Hr OR LONGER WITH NO TERMINAL BOILING TREATMEANTSEC TECH CONSIST OF PROCESSING IN A 74 DEG CELSIUS WATERBATH FOR 8 Hr & THEN INCREASING THE TEMP TO 100 DEG CELSIUS FOR 1 HrTHIRD TECH PROCESSING OF RESIN AT 74 DEG CELSIUS FOR 2 Hr & INCREASING THE OF WATER BATH TO 100 DEG CLESUIS & PROCESSING FOR 1 Hr

PorosityINTERNAL POROSITY:- POLYMERIZATION PROCEDURE IS EXOTHERMIC IF TEMP OF RESIN EXCEEDS THE BOILING POINT OF UNREACTED MONOMER OR LOW MOL WT POLYMERS THESE COMPONENTS BOIL RESULTING IN POROSITY THICKER PORTIONS OF DENTURE MORE PRONE TO POROSITY RESULTS FROM VAPORIZATION OF UNREACTED MONOMER& LOW MOL WT POLYMERSPOROSITY DUE TO INADEQUATE MIXING OF POWDER & LIQUID LOCALIZED SHRINKAGE VOIDS

Porosity contdTHIRD TYPE OF POROSITY CAUSED BY INADEQUATE PRESSURE OR INSUFFICIENT MATERIAL IN MOLD DURING POLYMERIZATION VOIDS IRREGULAR SHAPE RESIN LIGHTER & MORE OPAQUEFINAL TYPE OF POROSITY CAUSED BY AIR INCLUSION INCORPORATED DURING MIXING & PROCESSING PROCEDURE

DeflaskingTHE CURED ACRYLIC DENTURE IS RETRIEVED FROM THE FLASKFLASK SHOULD BE COOLED SLOWLY TO ROOM TEMPERATURERAPID COOLING RESULTS IN WARPING OF DENTURE BECAUSE OF DIFFERENCE IN THERMAL CONTRACTION OF RESIN & INVESTING STONESSHOULD BE DONE WITH GREAT CARE TO AVOID FLEXING& BREAKING OF THE ACRYLIC

Processed dentureWARPAGECRAZINGWATER ABSORPTIONPROCESSING STRESESS

Denture warpageIT IS THE DEFORMITY OR CHANGE OF SHAPE OF THE DENTURE WHICH CAN AFFECT THE FIT OF THE DENTURECAUSED BY THE RELASE OF STRESSES INCORPORATED DURING PROCESSING STRESSES OCCUR AS A RESULT OF:-CURING SHRINKAGEUNEVEN OR RAPID COOLINGPACKING OF RESIN DURING RUBBERY STAGE CAN ALSO INDUCE STRESSSTRESESS INCORPORATED DURING IMPROPER FLASKING

Warpage contdTHESE STRESESS RELEASED SUBSEQUENTLY:-DURING POLISHING A RISE IN TEMPERATURE CAN CAUSE WARPAGEIMMERSION OF DENTURE IN HOTWATERRECURING OF DENTURE AFTER ADDITION OF RELINING MATERIAL

CrazingSTRESS RELAXATION MAY PRODUCE SMALL SURFACE FLOWS THAT CAN ADVERSELY AFFECT THE AESTHETIC & PHYSICAL PROPERTY OF A DENTURE PRODUCTION OF SUCH SURFACE FLOWS OR MICROCRACKS IS TERMED CRAZINGIMPARTS A HAZY OR A FOGY APPEARANCESURFACE CRAKS PREDISPOSE A DENTURE RESIN TO FRACTURECRAZING RESULTS FROM:--STRESS APPLICATION-PARTIAL DISSOLUTION OF RESIN-PRODUCED BY MECHANICAL SEPERATION OF INDIVIDUAL POLYMERCHAIN ON APPLICATION OF TENSILE STRESS

Water absorption

POLYMETHYMETHACRYLATE ABSORBS SMALL AMOUNTS OF WATER WHEN PLACED IN AQUEOUS MEDIUMSIGNIFICANT EFFECT ON MECHANICAL & DIMENSIONAL PROPERTY OF THE POLYMERSPRODUCE 2 IMP EFFECTS:--SLIGHT EXPANSION OF THE POLYMERIZED MASS-INTERFERS WITH THE ENTANGELMENT OF POLYMER CHAINS & ACT AS PLASTCIZERSPOLYMER CHAINS BECOME MOBILE PERMITS RELAXATION OF STRESESS INCURED DURING POLYMERIZATION SHAPE CHANGE

Finishing & polishingOVER TRIMMING OF THE DENTURE

NO ADEQUATE RETENTION OF THE DENTURETRIMMING & POLISHING OF THE TISSUE SURFACE LEADING TO IRRITATIONSHARP MARGINS LEAD TO TRAUMA

bibliographyPhilips science of dental material by Anusavice 11th editionPrsothodontic treatment for edentulous patients by Zarb-bolender 12th editionSyllabus of complete dentures by Charles M Heartwell 4th editionText book of complete denture prosthodontics by Winkler 2nd editionClinical dental prosthetics A.Roy Macgregor 3rd editionComplete denture prosthetics by Neil