7 - Denture try in

Question 1

What should you check before inserting the try in?

Answer 1

• are the try in bases stable on the cast
• are the borders smooth, rounded with no sharp edges
• is the borer extension shaped to the width and depth of the sulcus
• are the centre lines correct
• is there proper contact with the pin on the table
• are the teeth set in the correct position eg over the ridge in the mandibular
• correct shade and mould
• has the post dam been cut

Question 2

What should you check when you put in the try in?

Answer 2

• retention and stability
• base extensions
• LIMBO
• position of teeth
• vertical dimension and FWS
• even contacts
• speech
• aesthetics

Question 3

How should you assess the try ins?

Answer 3

• assess individually then together
• allow time to settle
• moisten before inserting
• insert mandibular before maxillary

Question 4

How do you assess retention and stability?

Answer 4

• manipulate soft tissues and ask patient to speak
• will not be as good as final denture (due to wax)
• ensure effective communication with patient regarding this

Question 5

How do you assess base extension?

Answer 5

• hold the tissues away from denture, if it drops then likely underextended
• manipulate the tissues, if it drops then likely overextended
• if there is too much lip support then it will drop

Question 6

How do you assess LIMBO?

Answer 6

• lip support
• incisal level
• midline
• buccal corridor
• occlusal planes (anterior/posterior)

Question 7

How do you assess position of teeth?

Answer 7

• ensure teeth are in the neutral zone
• mandibular teeth should be set over the ridge
• maxillary teeth should be set just buccal to the ridge

Question 8

How do you assess vertical dimension?

Answer 8

Ensure patients FWS has not changed dramatically from previous denture or from what is comfortable for them

Question 9

How do you assess speech?

Answer 9

• ask patient to speak, ensuring all different sounds are checked including f, v, s, sh etc
• teeth should be slightly apart when speaking

Question 10

How do you assess aesthetics?

Answer 10

• allow patient to look in the mirror, leave them alone to form their own appearance
• get specifics if there is an aspect they do not like
• reassure that try in gingiva is much redder than final

Question 11

What are the options if something is wrong with the denture at try in?

Answer 11

• re-try appointment
• correct at chairside
• prescribe for the lab to make a change before finish
• correct at insertion appointment

Question 12

How do you correct the teeth touching during speech?

Answer 12

• insufficient FWS
• OVD needs to be reduced
• re-reg jaws and lab will reset all teeth except the upper anteriors

Question 13

How do you correct a whistling sound during the “s” sound?

Answer 13

• OVD may need to be increased or anterior tooth position changed
• re-reg jaws and lab will reset all teeth

Question 14

How do you correct the incorrect mould or shade?

Answer 14

• choose again
• prescribe to lab to reset

Question 15

How do you correct the incorrect midline?

Answer 15

• mark new midline
• prescribe to lab to reset with same teeth

Question 16

How do you correct minor changes to tooth position?

Answer 16

• alter at chairside until patient is happy
• send to lab to finish

Question 17

How do you correct major changes to tooth position?

Answer 17

• LIMBO problems
• re-reg jaw and prescribe to lab for re-try in

Question 18

How do you correct minor overextension?

Answer 18

• modify wax
• mark on master cast max extent of flange
• prescribe lab with instructions for insertion

Question 19

How do you correct major overextension?

Answer 19

Master impressions

Question 20

How do you correct minor underextension?

Answer 20

• wash imp material and try in (closed mouth technique), prescribe to lab for casting/mounting for re-try
  OR
• proceed to insertion but do not insert, reline denture at this stage

Question 21

How do you correct major underextension?

Answer 21

Master impressions

Question 22

How do you correct an error in vertical dimension?

Answer 22

• always triggers re-try
• if OVD is too great, teeth removed from one denture and wax rim added
• if OVD is too small, wax rim can be added to teeth or teeth removed and replaced with larger wax rim

Question 23

How do you correct major occlusal discrepancies?

Answer 23

• measure OVD and decide if correct or not
• if correct, some or all teeth removed and replaced with wax rim, re-reg, prescribe to lab for re-try
• if incorrect, remove all teeth from one denture and place wax rim to eliminate error, re-reg, prescribe to lab for re-try

Question 24

How do you correct minor occlusal discrepancy?

Answer 24

• selective grinding at try in or insertion (use BULL)
• use articulating paper

Question 25

What is the BULL rule?

Answer 25

Buccal Upper Lingual Lower
- adjust the contacting surfaces rather than the cusps