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Impression Material

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Impression Material. IMPRESSION MATERIALS, TYPES and TRAYS. Impression are negative reproduction of teeth and surrounding structure Preliminary Impression done by the assistant poor dimensional stability stock impressions trays Final Impressions done by the doctor only - PowerPoint PPT Presentation

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Page 1: Impression Material

Impression Material

Page 2: Impression Material

IMPRESSION MATERIALS, TYPES and TRAYSImpression are negative reproduction of

teeth and surrounding structurePreliminary Impression

◦done by the assistant◦poor dimensional stability◦stock impressions trays

Final Impressions◦done by the doctor only◦good dimensional stability◦stock impressions trays /custom trays

Page 3: Impression Material

Preliminary Impression Material◦Irreversible Hydrocolloid/Alginate◦Thermo-dots◦Polyvinylsiloxane Condensation

materialUses:

◦Diagnostic models◦Opposing arch models◦Fabrication of custom trays◦Fabrication of provisional

restorations

Page 4: Impression Material

IMPRESSION TRAYSFull arch

◦custom made◦preformed plastic◦perforated rim

lock◦max/mand

Quadrant◦custom made◦preformed plastic ◦perforated rim

lock

Triple Tray◦quadrant◦sextant◦take upper and

lower in oneSextant Tray

◦custom made ◦preformed plastic◦perforated rim

lock◦ant/post

Page 5: Impression Material

INITIAL IMPRESSIONSNegative is poured

in gypsum to create a positive model.

Models can be articulated together, articulator recreates the TMJ.

Models can be used as opposing for bite registration

Page 6: Impression Material

FINAL IMPRESSIONSNegatives poured in

gypsum to create positive model

Models are articulated together and the prep tooth is cut out of the model to create a die

A die is a replication of the prepared tooth or teeth or the edentulous mouth

Page 7: Impression Material

CUSTOM TRAYSAcrylic light cured or self cured

resin material◦need a polymer and monomer◦polymerization = setting

Page 8: Impression Material

CUSTOM TRAYSVacuum formed custom trays

◦resin sheets are heated and formed over the initial impression using heat and vacuum

Page 9: Impression Material

CUSTOM TRAYSThermoplastic tray material

◦beads or buttons that are pliable when heated

Page 10: Impression Material

Preformed rim lockLocks impression material into

tray

Page 11: Impression Material

Preformed Plastic Need tray

adhesive

Page 12: Impression Material

Triple TraysTakes final impression, opposing

impression, and bite registration

Page 13: Impression Material

CUSTOM TRAYSAcrylic resin trayMuch like the

thermoplastic beads

Needs spacer and stops because of the custom fit

Spacer can be pink wax, aluminum foil or wax paper

Page 14: Impression Material

ELASTOMERIC MATERIALSRubberlike qualitiesUsed when precise duplication is

neededNo distortion, great dimensional

stabilitySupplied in a two paste system

◦base and catalystSupplied in either a two tube system

or extruder gunCan be one or multiple body types

Page 15: Impression Material

Polysulfide ◦ Advantages good stability,accuracy sharpness in detail light = syringe, wash

medium, heavy = tray material

long shelf life used for crown, bridge,

partial, denture impressions

◦ Disadvantages stains, tastes bad and

stinks ten minute setting

time

Page 16: Impression Material

Polyether◦ Advantages

excellent accuracy great dimensional

stability medium body only,

used as both syringe and tray material

used for crown, bridge, denture and partial impressions

◦ Disadvantages only one body type

Page 17: Impression Material

Silicone◦ Polysiloxane

Condensation – putty

used for bite registration, custom tray

◦ Polyvinylsiloxane addition silicone advantages

high degree of accuracy and dimensional stabilty

three body types disadvantages

expensive

Page 18: Impression Material

Bite Registration◦ Polysiloxane bite

registration material open bite (shown) closed bite

◦ Wax bite registration material pink wax horseshoe wax bees wax aluwax

Page 19: Impression Material

Preparation for ImpressionSelect materialSelect type of

tray or traysObtain an

opposing arch, if necessary

Apply adhesive as directed to impression tray

Mix syringe material, deliver to provider

Mix tray material, place in tray and deliver to provider

Remove impression. disinfect and evaluate

Prepare provisional if necessary

Page 20: Impression Material

What to send to LabLab slipFinal ImpressionOpposing archBite registration

◦ It is important to give the lab tech everything they will need to produce a quality product

Page 21: Impression Material

Deliver AppointmentProsthetic should be due two

days before appointment. Any adjustments can be done

outside the mouth before cementation or placement

Final adjustment of cemented appliance can be done in the mouth

Oral hygiene instructions