Impressions and Occlusion for Complete Dentures

Question 1

what is the first clinical stage

Answer 1

impressions - make special trays

Question 2

how big is a spacer normally

Answer 2

3mm

Question 3

what is the second clinical stage

Answer 3

master impressions - master casts and record blocks

Question 4

what is the third clinical stage

Answer 4

jaw reg
choose shade, mould and setting
mount casts and set up

Question 5

what is the fourth clinical stage

Answer 5

try in - retry or finish

Question 6

what are the try in checks

Answer 6

vertical dimension of occlusion
even contact in RCP
lip support
occlusal planes - anterior/posterior
lower teeth over ridge
speech
retention and stability
base extensions
appearance

Question 7

what is the fifth clinical stage

Answer 7

insertion (finish)

Question 8

what is the insertion checks

Answer 8

vertical dimension of occlusion
even contact in RCP
speech
retention and stability
base extensions
appearance
comfort

Question 9

what is the sixth clinical stage

Answer 9

review

Question 10

what are the review checks

Answer 10

pain/redness/ulceration
function
aesthetics
speech
recheck occlusion/vertical dimension

Question 11

how do you know if an impression tray is too small

Answer 11

flanges hit the ridge

Question 12

how do you know if an impression tray is too large

Answer 12

stretches the mouth or feels uncomfortable or cannot get it in the mouth

Question 13

what are the limitations of stock trays

Answer 13

rarely fit mouth accurately
often require modification
difficult to obtain necessary border seal

Question 14

how do you evaluate the impression

Answer 14

general adaptation and surface detail
appropriate sulcus depth and shape
ensure ridge is in centre of tray
appropriate landmarks included
anterior lingual sulcus
impression fixed to tray

Question 15

what are special trays made in

Answer 15

light cure acrylic resin

Question 16

what are advantages of special trays

Answer 16

need less impression material
custom made
ensures even thickness of impression material
less bulky

Question 17

what are tissue stops used for

Answer 17

ensure uniform thickness of impression material
help localise tray during impression taking

Question 18

where do you place tissue stops in upper and lower trays

Answer 18

upper - place in canine region and along post dam area
lower - place in canine region and over retromolar pads

Question 19

what is used to make tissue stops

Answer 19

greenstick or incorporated into tray in acrylic

Question 20

when are finger rests used

Answer 20

in lower special trays

Question 21

where are finger rests placed

Answer 21

in region of 2nd premolar/1st molar

Question 22

what do finger rests allow

Answer 22

fore finger to be placed on either side of tray, thumb under mandible for support to ensure it is fully seated posteriorly and ensure more even distribution of pressure to the tissues
helps stabilise tray in mouth

Question 23

what is mucocompression

Answer 23

pressure is applied to the mucosa so that the shape of tissues under load is recorded

Question 24

what is mucostasis

Answer 24

minimum pressure is applied to the tissues to record their shape at rest

Question 25

what technique do you do avoid compression of flabby ridge

Answer 25

use impression with perforated tray with both high and low viscosity material

Question 26

what are the 3 types of record block

Answer 26

wax block only shellac base heat cured base

Question 27

what is the equipment used for jaw reg

Answer 27

no air/hot plate/bunsen wax knife/palate knife foxes bite plane willis bite gauge/callipers tooth shade and mould guide bite registration paste

Question 28

what does LIMBO stand for

Answer 28

lip support incisal level midline buccal corridor occlusal plane

Question 29

when do you use LIMBO

Answer 29

when adjusting the upper record block for tooth position

Question 30

what is the recommended nasiolabial angle

Answer 30

90 degrees

Question 31

what do you use to check tooth position

Answer 31

alma gauge

Question 32

what do you use to check incisal level

Answer 32

visual judgement photographs of natural teeth lip level lip during speech age 1-2mm of show

Question 33

what should you get the patient to do when checking incisal level

Answer 33

fricatives

Question 34

what lines are marked onto the record block

Answer 34

lip line, canine line, midline line

Question 35

what is the buccal corridor

Answer 35

space between teeth and buccal mucosa shown when smiling

Question 36

what references do you look for when looking at the occlusal plane

Answer 36

interpupillary ala-tragus

Question 37

what is the neutral zone

Answer 37

space between lips and cheeks on one side and tongue on other

Question 38

where should the teeth be in the neutral zone

Answer 38

anterior teeth = over ridge posterior teeth = over ridge

Question 39

what happens if the teeth and buccal flange are too close to the cheek

Answer 39

dislodges denture with cheek movement

Question 40

what happens if the teeth are too lingually placed

Answer 40

poor tongue space and tongue lifts denture when it moves

Question 41

what happens if the lingual flange is an incorrect shape

Answer 41

tongue lifts denture when it moves

Question 42

what is retruded contact position

Answer 42

guided occlusal relationship occurring at the most retruded position of the condyles in the joint cavities

Question 43

what is muscular position

Answer 43

position of closure produced by balanced muscle activity raising the mandible from rest to initial contact

Question 44

what is occlusal vertical dimension

Answer 44

distance between a set point on the maxilla and a set point on the mandible when the teeth are in maximum intercuspation

Question 45

what is the resting vertical dimension

Answer 45

when the mandible is at rest with patient upright

Question 46

what can affect the RVD measurement

Answer 46

stress pain anxiety tensing of facial muscles

Question 47

what should the ideal freeway space be

Answer 47

2-4mm

Question 48

what would be the effects of excessive FWS

Answer 48

reduced masticatory efficiency overclosed facial appearance and cheek biting TMJ symptoms

Question 49

what would the effects of reduced FWS be

Answer 49

excessive load on denture bearing area continuous muscular activity results in pain aesthetic complaints noisy dentures

Question 50

how do you measure vertical dimension

Answer 50

willis bite gauge

Question 51

what are the final checks before recording registration

Answer 51

are blocks trimmed se teeth will be in neutral zone even contact with upper block? OVD correct for patient with adequate FWS centre line correct occlusal planes appropriate