Impression Taking for Dentate Pt/s

Question 1

An impression of dentate arch MUST record…

Answer 1

accurately the anatomic form of the teeth AND surrounding tissues

Question 2

WHY should the impression be accurate?

Answer 2

Impressions bridge dental practice and labarotary

The ACCURACY of the model and final restoration DEPENDS on using a RELIABLE IMPRESSION MATERIAL that consistently produces a highly detailed impression

Question 3

PURPOSE of impression taking…

Answer 3

to accurately record the teeth relevant clinical landmarks (soft tissues) w/o xsive tissue distortion

Question 4

Functions of impression taking…

Answer 4

to provide a CAST to construct a required dental restoration or prosthesis

Question 5

Impression Material Overview

Answer 5

> TYPE(mucosa) + LEVEL(accuracy req) = determine PROPERTIES(impression material) needed

> extent of soft tissue displacement varies DEPENDING on PRESSURE applied by operator AND CONSISTENCY of material

Question 6

Impression Material Types

Answer 6

can be grouped into various ways

-viscosity/density of material (heavy/med/light-bodied)

Question 7

Impression Material Matrix

Answer 7

• Rigid

- Elastic > hydrocolloids (ir/rev) vs. elastomers

Question 8

Commonly Used Materials

Answer 8

> Alginate (elastic -> hydrocolloids -> iirev)
Condensation silicone (elastic -> elastomer)
Addition silicone (elastic -> elastomer)

Note: Adv and Disadv on Anki

Question 9

Impression Tray Requirements

Answer 9

• tray should be RIGID and STRONG, but NOT too thick

- tray should RETAIN ITS SHAPE throughout impression procedure and pouring of impression

Question 10

Types of Impression Trays

Answer 10

can be of various types

• according to the MATERIAL used to fabricate trays
• according to the METHOD of tray fabrication
• according to TEETH present/absent in the mouth
• according to the METHOD OF INTERLOCKING of material

Question 11

Factors affecting in selection of stock trays

Answer 11

• MATERIAL TYPE used in the primary impression procedure (ex. alginate - use perforated tray)
• SIZE of arch
• FORM of arch (round, square, taper)
• stock tray must cover all ANATOMICAL LANDMARKS needed
• stock tray should give SUFFICIENT SPACE for impression materials to squeeze out

Question 12

After taking the impressions out - what do I need to do?

Answer 12

1. ) Assess your impression!

2. ) Disinfect and store the impressions to be sent to the lab

Question 13

1.) Assess your impression!

Answer 13

• free or minimal voids
• no distortion; clear and distinct impression
• adequately extended
• adequate details and all structures must be recorded
• stable material that is sufficiently attached to tray

Question 14

Managing gag reflex

Answer 14

Gag reflex = reflex contraction(back of throat) evoked by touching the:

 - ROOF(MOUTH)
 - BACK(TONGUE)
 - AREA AROUND TONSILS
 - UVULA
 - BACK(THROAT)

Management:

• reassurance and kind handling
• upright position of the patient
• distract patient’s mind - talking, raising one foot
• avoid overloading the tray

Question 15

Cause of grainy material

Answer 15

• improper mixing
• prolonged mixing
• unfin setting rxn
• water:powder incorrect

Question 16

Cause of tearing of materials

Answer 16

• removed fr mouth too early

- prolonged mixing

Question 17

Cause of too many bubbled

Answer 17

• unfin setting rxn
• air incorporated during mixing
• too much saliva left in mouth before taking impression

Question 18

Cause of distortion

Answer 18

• premature removal of impression

- movement of tray during setting