IMPRESSION MATERIALS AND TECHNIQUE Flashcards

Question

Elastic Non-aqueous elastomers (4)

Answer 1

Polysulfides Polyethers Addition silicone Condensation silicone

Answer 2

-water major component -hydrocolloid

Answer 3

-irreversible (alginate): not for fixed -reversible (agar): used for fixed (not commonly used today)

Answer 4

-polysulfide -vinyl polysiloxane -polyesther

Answer 5

-polysulfide -vinyl polysiloxane (VPS) -polyether (PE)

Answer 6

* FEEL COMFORTABLE TO THE PATIENT * EXTENDS SLIGHTLY BEYOND THE FACIAL SURFACES OF THE TEETH * EXTENDS APPROXIMATELY 2 TO 3 MM BEYOND THE THIRD MOLAR. RETROMOLAR. OR TUBEROSITY AREA OF THE ARCH. * IS SUFFICIENTLY DEEP TO ALLOW 2 TO 3 MM OF MATERIAL BETWEEN THE TRAY AND INCISAL OR OCCLUSAL EDGES OF THE TEETH.

Answer 7

1 RIGIDITY IMPORTANT 2 STOCK TRAYS a. PLASTIC, METAL; PERFORATED/RIMMED b. COMPLETE ARCH, QUADRANT DUALARCH 3. CUSTOM ACRYLIC RESIN TRAYS (MADE 24H IN ADVANCE) a.PHOTO-CURED (TRIAD) THERMOFORMED AUTO-CURED b. BETTER FIT c.LESS MATERIAL WASTE d. CONTROLLED THICKNESS OF MATERIAL e. INCREASED ACCURACY, ESPECIALLY FPD'S 4 ADHESION TO TRAY a. PREVENT IMPRESSION DISTORTION DUE TO MATERIAL PULLING AWAY FROM TRAY b. MECHANICAL PERFORATIONS c. ADHESIVE MATERIAL 1) SPECIFIC FOR EACH MATERIAL (INCLUDING ALGINATE) 2) SHOULD ALWAYS USE, EVEN WITH PERFORATED TRAY 3) APPLY AND DRY ~ 15 MIN

Answer 8

for polyvinyl siloxane and polyether impression materials

Answer 9

used with rubber base impression materials

Answer 10

used with silicone impression materials

Answer 11

*CARRY THE IMPRESSION MATERIAL iNTO THE ORAL CAVITY *HOLD THE MATERIAL IN CLOSE PROXIMITY TO THE TEETH * AVOID BREAKING DURING REMOVAL * PREVENT WARPING OF THE COMPLETED IMPRESSION

Answer 12

a filly or overextended impression of the arch, with all the anatomical landmarks

Answer 13

made, taken

Answer 14

WAS DEVELOPED AS A SUBSTITUTE FOR THE AGAR IMPRESSION: MATERIAL WHEN ITS SUPPLY BECAME SCARCE DURING WORLD WAR II BASED ON A NATURAL SUBSTANCE From SEAWEED RACTED FROM CERTAIN BROWN WHEN THE SOLUBLE ALGINATES ARE MIXED WITH WATER, THEY FORM A SOL QUITE READILY ALGINATE IMPRESSION MATERIALS ARE HYDROPHILIC, SO MOIST TISSUE SURFACES ARE NOT A PROBLEM.

Answer 15

THE MATERIAL SELECTED DEPENDS UPON THE DENTIST'S PREFERENCE AND THE TYPE OF IMPRESSION REQUIRED FOR THE PROCEDURE THE DENTIST PREPARES THE TOOTH OR TEETH FOR THE IMPRESSION THE LIGHT-BODIED MATERIAL IS PREPARED AND LOADED INTO THE SYRINGE AND TRANSFERRED TO THE DENTIST THE DENTIST PLACES THE LIGHT-BODIED MATERIAL OVER AND AROUND THE PREPARED TEETH AND ONTO THE SURROUNDING TISSUES. 5 THE HEAVY-BODIED MATERIAL IS PREPARED AND LOADED INTO the tray and transferred TO THE DENTIST 6 WHEN THE IMPRESSION MATERIAL HÀS REACHED FINAL SET. THE IMPRESSION IS REMOVED AND INSPECTED FOR ACCURACY 7 THE IMPRESSION IS DISINFECTED, PLACED IN A BIOHAZARD BAG, LABELED, AND READIED FOR THE LABORATORY TECHNICIAN.

Answer 16

*POTASSIUM OR SODIUM ALGINATE: *CALCIUM SULPHATE DIHYDRATE: *ZINC OXIDE: *POTASSIUM TITANIUM FLUORIDE: *DIATOMACEOUS EARTH: *TRISODIUM PHOSPHATE: *COLORING AGENTS *FLAVORING AGENTS

Answer 17

DISSOLVES IN WATER AND REACTS WITH CALCIUM IONS

Answer 18

A REACTOR, REACTS WITH POTASSIUM ALGINATE TO FORM A DIHYDRATE INSOLUBLE ALGINATE GEL

Answer 19

FILLER PARTICLES, AFFECTS PROPERTIES AND SETTING TIME

Answer 20

ACCELERATOR, COUNTERACTS THE INHIBITING EFFECT OF THE HYDROCOLLOID ON THE SETTING OF STONE; ENSURES GOOD QUALITY SURFACE OF THE CAST

Answer 21

FILLER PARTICLES, CONTROLS THE CONSISTENCY OF THE MIX AND THE FLEXIBILITY OF THE SET ALGINATE

Answer 22

RETARDER, CONTROLS THE SETTING TIME TO PRODUCE EITHER REGULAR OR FAST-SET ALGINATES

Answer 23

THE FIRST STEP OF MANIpulation OF WATER AND POWDER ATION IS TO PREPARE A PROPER MIX THE MEASURED POWDER IS SIFTED INTO PREMEASURED WATER THA HAS ALREADY BEEN POURED INTO A CLEAN RUBBER BOWL E THE WATER IS ADDED FIRST TO WET THE MIXING BOWL AND TO ENSURE COMPLETE WETTING OF POWDER PARTICLES CARE SHOULD BE TAKEN TO AVOID INCORPORATING AIR INTO THE MIX. THE MIXING TIME IS PARTICULARLY IMPORTANT; 45 SEC TO 1 MIN IS GENERALLY SUFFICIENT, DEPENDING ON THE BRAND AND TYPE OF ALGINATE (FAST-SET OR REGULAR-SET) CONTAMINANTS, SUCH AS SMALL AMOUNTS OF GYPSUM LEFT IN THE BOWL FROM A PREVIOUS MIX OF PLASTER OR STONE, CAN ACCELERATE THE SET. THE TRAY MUST FIT THE PATIENT'S ARCH SO THAT THERE IS SUFFICIENT BULK OF MATERIAL. THE THICKNESS OF THE ALGINATE IMPRESSION BETWEEN THE TRAY AND THE TISSUES SHOULD BE AT LEAST 3 MM MOST MANUFACTURERS RECOMMEND A SPECIFIC DISINFECTANT SUCH AS IODOPHOR, BLEACH, OR GLUTARALDEHYDE, WHICH SHOULD BE USED ACCORDING TO THE MANUFACTURER'S DIRECTIONS. THE CURRENT PROTOCOL FOR DISINFECTING HYDROCOLLOID IMPRESSIONS RECOMMENDED BY THE CENTER FOR DISEASE CONTROL IS TO USE HOUSEHOLD BLEACH (1 TO 10 DILUTION), IODOPHORS, OR SYNTHETIC PHENOLS AS DISINFECTANTS. AFTER THE IMPRESSION IS RINSED THOROUGHLY, THE DISINFECTANT CAN BE SPRAYED LIBERALLY ON THE EXPOSED SURFACE. THE IMPRESSION IS THEN WRAPPED IMMEDIATELY IN A DISINFECTANT- SOAKED PAPER TOWEL AND PLACED IN A SEALED PLASTIC BAG FOR 10 MIN. FINALLY, THE WRAPPED IMPRESSION IS REMOVED FROM THE BAG, UNWRAPPED, RINSED, AND SHAKEN TO REMOVE EXCESS WATER. THE STONE CAST SHOULD BE KEPT IN CONTACT WITH THE IMPRESSION PREFERABLY FOR 60 MIN, BEFORE THE IMPRESSION IS SEPARATED FROM THE CAST, IT IS WISE TO SEPARATE THE CAST FROM THE IMPRESSION WITHIN À REASONABLE PERIOD OF TIME SO THAT DESICCATION OF THE HYDROCOLLOID DOES NOT OCCUR, THEREBY CAUSING ABRASION OF THE GYPSUM CAST DURING ITS REMOVAL. TWO MAJOR FACTORS THAT AFFECT THE SHELF LIFE OF ALGINATE IMPRESSION MATERIALS ARE STORAGE TEMPERATURE AND MOISTURE CONTAMINATION FROM AMBIENT AIR.

Answer 24

removing the material from the undercut areas

Answer 25

should be removed

Answer 26

THESE ARE ELASTIC IMPRESSION MATERIALS CALLED *NON-AQUEOUS" ELASTIC IMPRESSION MATERIALS: DISTINGUISHED FROM THE HYDROCOLLOIDS WHICH ARE AQUEOUS MATERIALS.

Answer 27

- POOR TEAR RESISTANCE - POOR DIMENSIONAL STABILITY

Answer 28

IS AN ELASTOMER THAT IS ALSO KNOWN AS "MERCAPTAN" OR SIMPLY "RUBBER BASE" THE IMPRESSION MATERIAL IS PACKAGED IN TWO TUBES: A BASE AND AN ACCELERATOR

Answer 29

THE BASE CONTAINS A LIQUID POLYSULFIDE POLYMER MIXED WITH AN INERT FILLER THE ACCELERATOR WHICH IS USUALLY LEAD PEROXIDE MIXED WITH SMALL AMOUNTS OF SULFUR AND ACTS AS AN OXIDATION INITIATOR.

Answer 30

base: poly dimethyl siloxanr cross linking agent: alkyl ortho silicate or organo hydrogen siloxane catalyst: organo tin compounds filler: silica

Answer 31

THE MATERIAL HÀS A LIMITED SHELF LIFE THE TRAY REOUIRES À SPECIAL TRAY ADHESIVE NO SYNERESIS OR IMBIBITION BUT DOES RESPOND WITH SHRINKAGE OVER TIME THE MATERIAL IS MORE FLEXIBLE, SO THERE IS MORE CHANCE FOR DISTORTION DURING REMOVAL * WAIT 20 TO 30 MINUTES BEFORE POURING OF MODELS FOR STRESS RELAXATION TO OCCUR.

Answer 32

* FOR DIMENSIONAL STABILITY, THIS IS THE BEST IMPRESSION MATERIAL * POURING OF THE MODEL CAN BE DELAYED UP TO 7 TO 10 DAYS * STIFFNESS OF THE MATERIAL MAKES REMOVAL OF THE TRAY DIFFICULT. * MATERIAL DISPENSED USING AUTO-MIXING UNIT AND MIXING TIPS.

Answer 33

BEST IMPRESSION MATERIAL FOR DIMENSIONAL STABILITY POURING SHOULD BE DELAYED AT LEAST 4 HOURS FOR H2 OUT-GASSING POURING CAN BE DELAYED UP TO 7-TO-10 DAYS B. (OR INDEFINITELY) STIFFNESS MAKES REMOVAL DIFFICULT. C. MOST MATERIAL DISPENSED USING AUTO-MIXING GUN AND MIXING TIPS

Answer 34

1.ADDITION REACTION: A + B- C NO BY-PRODUCTS 2. LIGHT, MEDIUM, OR HEAVY-BODIED PASTES, HEAVY-BODIED PUTTY OR 3.AUTOMATIC MIXING, UNIFORM MIX a. LESS AIR b.DECREASED MIX TIVE C.MIXING TIPS NOT ALWAYS INTERCHANGEABLE (CHECK COLOR CODE) 4. HYDROPHOBIC a. DRY ORAL FIELD b. SURTACTANTS ADDED, IMPROVED POURING LESS CAST BUBBLES 5. SULFUR, POLYMERIZATION INHIBITION a. LATEX GLOVES, RETRACTION CHEMICALS 6. H, GAS RELEASE a. SECONDARY REACTION NOT A BY-PRODUCT b 15-30 MIN POUR DELAY C. PLATINUM H, SCAVENGERS 7. excellent elastic recovery from undercuts 8. dimmensionally stable a. poor delay b. multiple pours

Answer 35

medium body, tray and syringe

Answer 36

-heavy/medium -medium/light

Answer 37

-make putty impression prior to preparation -putty used as custom tray -light or medium body, syringe

Answer 38

1. base + caralyn: addition 2. light, medium, heavy body 3. hand, auto-mix or electronic-mix system 4. DIFFICULT REMOVAL FROM MOUTH OR CAST UNDERCUT BLOCKOUT INITIALLY THOUGHT DUE TO HIGHER PE STIFFNESS REFORMULATED, LESS STIFF THAN VPS EVEN THOUGH LOWER STIFFNESS, STILL HIGHER REMOVAL FORCE MATERIAL STIFFNESS AND IMPRESSION REMOVAL DIFFICULTY NOT CORRELATED (WALKER ET AL 2012, J PROS) 5. HYDROPHILIC: LIKELY REASON FOR IMPRESSION REMOVAL DIFFICULTY HIGHER INTERACTIONS FORCES WITH IMPRESSED SURFACE 6. HIGH ELASTIC RECOVERY 7. DIMENSIONAL STABILITY POUR DELAY MULTIPLE POUR

Answer 39

EXCELLENT IMPRESSION ACCURACY AND DIMENSIONAI STABILITY STIFF AND THEREFORE DIFFICULT TO REMOVE WITHOUT ROCKING BREAK SEAL AND ROCK SLIGHTLY TO PREVENT TEARING: LOW TEAR RESISTANCE NEGATIVELY AFFECTED BY H2O, SALIVA, AND BLOOD (1 SINCE IT IS HYDROPHOBIC, MOISTURE INCREASES MARGINAL DISCREPANCY (2) INCREASED WATER ABSORPTION OCCURS IF USE THINNING AGENTS CAN BE DISPENSED FROM AUTOMATED EXTRUDER AND MIXER (ESPE PENTAMIX)

Answer 40

*BASE: POLYETHER * CROSS-LINKING AGENT: SULFATE *CATALYSTS: GLYCOL-BASED PLASTICIZERS * FILLER: SILICA

Answer 41

*MATERIAL IS VERY STIFF WHICH MAKES IT DIFFICULT TO REMOVE WITHOUT ROCKING *WHEN REMOVING THE IMPRESSION, BREAK THE SEAL AND ROCK SLIGHTLY TO PREVENT TEARING. * WATER, SALIVA, AND BLOOD AFFECT POLYETHER MATERIAL * ADDED MOISTURE WILL INCREASE THE IMPRESSION'S MARGINAL DISCREPANCY * INCREASED WATER ABSORPTION OCCURS IF A THINNING AGENT IS USED.

Answer 42

-load reusable intraoral impression syringe -load disposable intraoral syringe -use intraoral syringe tip on automix unit -inject into sulcus, push material ahead of tip to reduce bubbles

Answer 43

1. AIR SYRINGE, DRIVE MATERIAL, INTO SULCUS AND PREP DETAIL 2. TRAY, WITH DRIED ADHESIVE, LOADED FROM DISPENSER. (ASST DOES THIS WHILE DENTIST SYRINGES AROUND PREP 3. TRAY IS SEATED AND HELD WITH NO DOWNWARD PRESSURE FOR ~4-6 MIN 4. ONCE SET, REMOVE AS QUICKLY AND STRAIGHTLY AS POSSIBLE, REDUCE PERMANENT DEFORMATION.ION

Answer 44

Lifting intra-oral tip while syringing or presence of moisture.

Answer 45

Cause: Sulfur contamination from gloves or retraction chemical. Solution: Wash and dry preparation

Answer 46

-disinfectant-soaked paper towel/plastic bag, 10 min -VPS not adversely affected -hydrocolloids (imbition:expansion after 10 min) -polysulfide, polyether (potential expansion, increase exposure time)

Answer 47

*less focus on research and development of impression materials *digital impressions, scan and then send electronic file

Answer 48

* CEREC PRIMESCAN, OMNICAM OR BLUECAM (SIRONA) * ITERO ELEMENT (ALIGN TECHNOLOGY) * LAVA TRUE DEFINITION SCANNER (MIDMARK)

Brainscape's Knowledge GenomeTM

IMPRESSION MATERIALS AND TECHNIQUE Flashcards

Brainscape's Knowledge Genome^TM