question 42

Question 1

what to put on lab sheet

Answer 1

o Patients details, operators details
o Date and time for lab work to be completed
o Stage of treatment
o Instructions
 Please pour up impressions in improved stone and mount on a semi-adjustable articulator using occlusal registration provided
 Please construct a metal ceramic adhesive cantilever bridge to replace 22. Use 23 as abutment. Please provide ridge lap pontic for 22 in shade XX
 Please construct a metal ceramic conventional fixed-fixed bridge to replace 35 and 36. Use 34 and 37 as abutments. Please provide dome-shaped pontic for 35 and wash-through pontic for 36 in shade XX
 Include any specific details like surface staining, features and finish
o Signature

Question 2

types of pontic designs

Answer 2

o Wash-through – lower molars
 No contact with soft tissue, functional rather than for appearance
o Dome-shaped – lower incisors, pre-molars or upper molars
 Point contact with soft tissue, aesthetically unpleasing in high smiles
o Modified ridge lap – moderate-low smile line anteriors
 Buccal surface flush with gingiva, palatal/lingual cut away for cleansability
 Problems with food packing on palatal/lingual surface
o Ridge lap – long span anteriors, high smile line anteriors
 Cleansable if designed carefully, less food packing
 Greatest contact with soft tissue – avoid blanching and displacement of soft tissue
o Ovate – long span anteriors, high smile line anteriors
 Presses into the ridge to give illusion that the tooth is emerging out of the gingiva
 Not utilised commonly by clinicians

Question 3

explain ridge lap

Answer 3

o Ridge lap – long span anteriors, high smile line anteriors
 Cleansable if designed carefully, less food packing
 Greatest contact with soft tissue – avoid blanching and displacement of soft tissue

Question 4

explain wash through

Answer 4

o Wash-through – lower molars
 No contact with soft tissue, functional rather than for appearance

Question 5

explain dome shaped

Answer 5

o Dome-shaped – lower incisors, pre-molars or upper molars
 Point contact with soft tissue, aesthetically unpleasing in high smiles

Question 6

explain modified ridge lap

Answer 6

o Modified ridge lap – moderate-low smile line anteriors
 Buccal surface flush with gingiva, palatal/lingual cut away for cleansability
 Problems with food packing on palatal/lingual surface

Question 7

types of materials for bridges

Answer 7

o All metal – gold (ideal for lower posterior), nickel/cobalt chromium, stainless steel
o Metal ceramic
o All ceramic – zirconia, lithium disilicate
o Ceromeric
o Implant retained

Question 8

indications for bridges

Answer 8

o General – function, stability, appearance, speech, psychological, systemic disease (epilepsy), cooperative patient
o Local – big teeth, heavily restored teeth, favourable abutment angulations, favourable occlusion

Question 9

contraindications for bridges

Answer 9

o General – uncooperative pt, MH, poor OH, high caries rate, perio, large pulp horns
o Local – high possibility of further tooth loss, prognosis of abutment poor, length of span too great, ridge form and tissue loss, tilting, rotations, PA status, periodontal status, degree of restoration (how much tooth structure), poor crown to root ratio (minimum 1:1, ideally 2:3)

Question 10

types of pontic designs

Answer 10

o Wash-through – lower molars
 No contact with soft tissue, functional rather than for appearance
o Dome-shaped – lower incisors, pre-molars or upper molars
 Point contact with soft tissue, aesthetically unpleasing in high smiles
o Modified ridge lap – moderate-low smile line anteriors
 Buccal surface flush with gingiva, palatal/lingual cut away for cleansability
 Problems with food packing on palatal/lingual surface
o Ridge lap – long span anteriors, high smile line anteriors
 Cleansable if designed carefully, less food packing
 Greatest contact with soft tissue – avoid blanching and displacement of soft tissue
o Ovate – long span anteriors, high smile line anteriors
 Presses into the ridge to give illusion that the tooth is emerging out of the gingiva
 Not utilised commonly by clinicians