Provisional Extra-Coronal Restorations

Question 1

when are provisional extra coronal restorations provided
and why

Answer 1

between tooth prep and fit of indirect restoration

immediate, long term health of tooth and structures

Question 2

what characteristics should provisionals restore
[after tooth prep]

Answer 2

aesthetics
degradation in tooth function
sensitivity reduction
coronal seal of RCT

Question 3

a poorly fitting/contoured provisional can cause…

Answer 3

unable to clean
caries
gingival inflamamtion
poor moisture control
gingival overgrowth

Question 4

characteristics needed for materials in provisionals

Answer 4

non irritant
low temp rise during setting
dimensionally stable
adequate working and setting time
adequate strength and wear resistance
good aesthetics

Question 5

types of provisionals

Answer 5

custom formed
- preferable, technically demanding
- resin

preformed
- standard shape/size
- adjust to fit chairside

Question 6

establishing occlusion and aesthetics

Answer 6

tooth wear - reestablish shape, pilot occlusion and aesthetic

guidance - diagnostic wax up, articulated study models, facebow registration

once satisfactory - lab

pt trial - wear until happy with form and function

Question 7

types of preformed provisional crowns

Answer 7

tooth coloured -
- polycarbonate
- clear plastic filled with composite

metal -
- aluminium
- stainless steel

Question 8

adv and disadv of preformed provisional crowns

Answer 8

adv -
- no prior impression
- trauma

disadv -
- unlikely to fit accurately
- large bank of crowns needed to accommodate variations of pts which is costly