Framework Try in

Question 1

what are the tips for the framework try in

Answer 1

• the completed RPD must be passive
• should not exert forces on the teeth or soft tissues
• the tip of each retentive clasp should lie passively in a measured undercut
• short time between impression and frameowkr try in is desirable
• allow adequate time for appointment

Question 2

what cast will the lab return the framework on

Answer 2

the duplicate or fitting cast

Question 3

what is the order of prep for RPD

Answer 3

• patient
• preliminary impressions
• diagnostic casts
• mounted diagnostic casts
• practice tooth prep on dx cast then natural tooth prep on patients, survey cronws, custom tray, final impression
• master cast
• clinical procedures- fit framework
• mandibular distal extension RPDs
• altered cast impression
• record base
• jaw relation records
• set denture teeth
• trial insertion
• insert RPD and remount

Question 4

what cast is block out and relief wax placed on

Answer 4

master cast

Question 5

master cast is duplicated using

Answer 5

hydrocolloid
- one poured in stone
- one in high heat refractory material

Question 6

the wax up of the RPD framework is completeted on what cast

Answer 6

refractory

Question 7

describe the refractory cast

Answer 7

• wax relief and block out
• usually white and the material is high heat investment

Question 8

what areas should be evaluation the fit of framework on master cast before appointment

Answer 8

• path of placement
  -action of retentive and reciprocating arms
• areas of interference/scraping of cast
• accuracy of seating
• evaluate external/ internal surfaces for proper finish and construction

Question 9

describe the intraoral fit of framework

Answer 9

• armamentarium: good light, magnification, mirror and explorer
• fitting and occlusion

Question 10

how should the framework fit to the teeth

Answer 10

• position direct retainers over abutments
• place fingers over rests and push along the path of placement
• framework should move smoothly with minimal resistance
• balanced resistance should exist

Question 11

what is balanced resistance

Answer 11

• a more rigid retentive tip on one abutment than another will cause tilting

Question 12

if the framework is not fully seated:

Answer 12

the retainers will not be passive and will exert forces against the teeth

Question 13

what external surfaces of RPD should be evaluated

Answer 13

• rests
• major connector and minor connectors
• direct retainers
• indirect retainers
• external finish lines

Question 14

what should the finish of the intaglio surface look like

Answer 14

• remove bubbles, blebs and artifacts
• surface should be smooth and free from irregularities
• surface is not highly polished

Question 15

what are possible causes for framework misfit

Answer 15

• faulty impression technique
• faulty casts
• tooth movement
• casting inaccuracy

Question 16

what is a faulty impression

Answer 16

• lack of uniform thickness of impression material
• intraoral distortion due to tray movement
• extraoral distortion due to faulty handling

Question 17

what are faulty casts

Answer 17

• improper water to powder rati o
• improper spatulation
• failure to use double pour cast formation technique when making impressions in irreversible hydrocolloid

Question 18

what is the concern with excessive time lapse from impression to framework try in appointment

Answer 18

tooth movement

Question 19

what are examples of tooth movement due to occlusal disharmonies or periodontally involved teeth

Answer 19

• mesially inclined mandibular molars
• lone standing premolars

Question 20

what is tooth movement due to

Answer 20

• excessive time lapse from impression to framework try in appointment
• tooth movement due to occlusal disharmonies/periodontically involved teeth
• recent extractions

Question 21

what is casting inaccuracies from

Answer 21

• expansion of investment
• shrinkage of Ni-chrome alloys is 2.2 -2.4% during casting

Question 22

how can you fit the RPD framework intraoraly

Answer 22

• adjust the framework
• adjust the direct retainers
• adjust the occlusion

Question 23

what are common areas of framework interference

Answer 23

• internal surfaces of direct retainer shoulders
• internal surfaces of direct retainer bodies
• internal surfaces of minor connectors
• interdental papilla areas

Question 24

what are other areas of framework interference

Answer 24

• reciprocating arms
• lingual plating
• soft tissue

Question 25

what are disclosing material to identify interferences

Answer 25

• ney spray
• Kerr disclosing wax
• occlude

Question 26

what is the procedure to locate interferences

Answer 26

• dry the framework
• place thin layer of indicating material
• insert framework along path of insertion
• apply finger pressure
• remove framework and note areas of interference
• adjust area of interference with a small bur or stone
• wipe framework clean and repeat procedure until the framework is seated
• evaluate contact of direct retainers and reciprocating arms
• check for wedging- mod spaces
• adjust the occlusion

Question 27

what would tell you the framework is seated

Answer 27

• no space around rests and plating
• use air to visualize

Question 28

the framework should seat without:

Answer 28

a click

Question 29

what is the objective for adjusting the occlusion with the framework

Answer 29

assure that the same relationship exists in CR and eccentric functional movement with the framework in the mouth, as exists between the teeth when the framework is not present

Question 30

how should you adjust the occlusion of the RPD framework

Answer 30

• adjust for CR
• maintain bulk of rests for strength
• opposing teeth may need modification

Question 31

how much should the investment expand

Answer 31

as much as the metal shrinks
- 2.2-2.4%