Elastomeric impression materials
Sponsored Links
This presentation is the property of its rightful owner.
1 / 23

Elastomeric Impression Materials PowerPoint PPT Presentation


  • 557 Views
  • Uploaded on
  • Presentation posted in: General

Elastomeric Impression Materials. DA 122 Dental Materials. Elastomeric Impression Materials. Polysulfide Polyether Polyvinylsiloxane (known as addition silicone ) All are supplied as 2-paste systems (tubes): Base + catalyst

Download Presentation

Elastomeric Impression Materials

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Elastomeric Impression Materials

DA 122 Dental Materials


Elastomeric Impression Materials

  • Polysulfide

  • Polyether

  • Polyvinylsiloxane (known as addition silicone)

    • All are supplied as

      • 2-paste systems (tubes): Base + catalyst

      • Automix: Extruder guns (catalyst + base) with cartridge and mixing tips

    • Base and Catalyst are mixed to homogeneous consistency

      • Base = paste in tube, cartridge, or putty

      • Catalyst = paste in tube, cartridge, or liquid in bottle with dropper (AKA “accelerator”)

    • Self-curing (chemical action)


Mixing elastomeric impression material

  • Objective when mixing elastomeric impression materials is:

    • To obtain a homogenous mix

    • To obtain a uniform cure of the mix

    • Wear non-latex gloves


Tubes

  • Base and catalyst tubes

  • Narrow stiff

    impression spatula

  • Large mix pad (6X6)

  • Syringe for light-body

    material

  • Adhesive-prepared

    tray for heavy-body

    material


Cartridges

  • Light-body cartridge with

    applicator tip or

    syringe

  • Heavy-body

    cartridge

  • Extruder gun; one

    for each cartridge;

    hand-held or mechanical


Automatic Mixing

  • Mechanical device for

    mixing cartridges

    Ex. MixStar

    Pentamix


Putty-Polyvinyl SiloxaneAddition Silicone

  • Base = jar or bucket

  • Catalyst = jar or liquid

  • Large mix pad (6X6)

  • Narrow, stiff spatula

  • Non-latex gloves

  • Impression tray

    • Prepared with adhesive


Curing Stages

  • Self-cure = polymerization

  • Initial set: includes mix and work time until

    material stiffens and you cannot manipulate

    it

  • Final set: in mouth; material goes from elasticity phase into rubber phase

  • Final cure: takes place from 1 – 24 hours after final set; slight dimensional changes can occur


Viscosities

  • Light-bodied = syringe type

    • “wash”

    • Thin body, can flow in and around tooth structure

    • Used in syringe or extruder gun and placed directly on tooth or structures in mouth

  • Regular or heavy-bodied = tray type

    • Thicker

    • Used to fill tray to make chairside custom tray which will hold light-bodied material against teeth for better detail


Polysulfide Impression Material

Common Uses

Characteristics:

Known as “rubber base” or mercaptan

Unpleasant odor (sulphur)

Long setting time

Stains clothing (mercaptan)

Shrinkage after setting (disadvantage-lacks dimensional stability)

Greater strength and tear resistance than colloids

Flexible

  • Final impressions for dentures and partial dentures

  • RATIO:

    • Equal amounts

    • Mix to homogeneous consistency


Polysulfide

Armamentarium

Clean-up

Orange solvent

2x2 gauze squares

Wait until set to peel set material off spatula

Remove used sheet of mixing pad

Recap impression materials

MIX Surface: paper mixing pad

MIX instrument:

Stiff, narrow spatula

  • Stiff, narrow impression spatula

  • Paper mixing pad

  • Catalyst and base

  • 2x2 gauze squares

  • Adhesive-painted custom impression tray

  • Syringe to apply light-bodied material


Polysulfide

Times

Appearance

Shiny light blue or

chocolate brown

Homogenous end product

COMMON BRAND NAMES:

Permlastic

Coe-flex

Kerr

  • Mix = 60 seconds

  • Work = 3-6 minutes

  • Set = 10 – 20 minutes in mouth


Polysulfide Impression material


Polyether Impression Material

Common Uses

Special Properties

Accuracy

Stability

Stiff enough to be used without putty on tray

Shorter working time

  • Final impression for crowns, bridges, indirect inlays or onlays

  • RATIO:

    • Base : Catalyst

    • Equal amounts


Polyether Impression Material

Armamentarium

Clean-up

Wait until material sets and then peel it off of spatula or other non-porous surfaces

Wipe item clean with rubbing alcohol

MIX surface: paper pad

MIX instrument:

Narrow, stiff spatula

**automatic mix units available **

  • Impression tray prepared with adhesive

  • Narrow, stiff spatula

  • 6x6 paper mix pad

  • Base and catalyst

  • Syringe for application


Polyether Impression Material

Times:

Appearance

Shiny color

Common Brand Names:

Impregum

Polyjel NF (we use)

  • Mix = 30 – 45 seconds

  • Work = 2 – 3 minutes

  • Set = 6 – 7 minutes in mouth


Polyether Impression material


Polyvinylsiloxane Impression Material (also known as addition silicone)

Common Uses

Special Properties

Available in range of viscosities (“bodies”) or forms:

Light, medium, heavy body

Highly accurate

Easy to spatulate

Odor-free

Tends to bubble on setting

Latex gloves may inhibit set; use vinyl or nitrile gloves

  • Final Impressions: crowns, bridges, indirect inlays or onlays, implant crowns

  • Bite registrations

  • RATIO:

    • equal amounts of base and catalyst


Polyvinylsiloxane Impression Material

Armamentarium

Clean-up

Immediately on porous surfaces; can stain

Wait to set to peel off non-porous surfaces

Mix surface/instrument:

Not necessary because extruder gun is used

  • Extruder gun with

    • Cartridge

    • Tips

  • Adhesive-prepared impression tray (custom or stock)

  • Also available in automatic mix machine


Extruder gun dispenser

  • Extruder gun dispenser for impression materials:

    • Impression material moves plunger forward to force the:

      • Base and accelerator from the individual chambers

      • Then the pastes move into mixing tip

      • They blend and exit tip as a uniform paste


Polyvinylsiloxane

  • Disadvantage of polyvinylsiloxane (also known as silicone)

    • Expensive

    • Short shelf life


Polyvinylsiloxane Impression Material

Times:

Appearance:

Brightly colored, shiny, rubbery when set

Common Brand Names:

Take 1

Express

President

  • Mix = 30 seconds

  • Work = 2 minutes

  • Set = 5 minutes in mouth


Techniques for Polyvinylsiloxane

Wash Technique

  • Heavy body + light body

  • Heavy body = putty in tray

  • Light body=put in syringe


  • Login