After crown prep Flashcards
what is the next step after crown prep?
make a temporary by taking an impression
why is a temporary important?
- protects prep
- stops opposing tooth from drifting
temp falls off, what are you going to anticipate?
- opposing tooth
- adjacent tooth and prep itself could drift
if opposing tooth has drifted, what is this called?
extrusion/overeruption
if adjacent tooth has drifted then crown might be tight what will you do then?
- squeeze in or
- polish proximal surfaces of adjacent teeth or crown itself
what else could happen if temp has fallen off?
- temp protects prep so prep is exposed and more risk to pulp
- sensitivity
- pt could damage prep whilst eating
what material do you cement a temporary crown with?
zinc oxide eugenol based
if crown needs adhesive cementation e.g. resin based then use non-ZOE based
what material do we use to take impressions with?
putty
whats good about putty?
- dimensionally stable (sets without changing shape)
it is important that the material does not change shape otherwise it will be less accurate
what are important qualitities for impression material?
- accuracy
- dimensionally stable
- good elastic recovery
- good tear strength
- biocompatible with oral mucosa
- good flow
- low viscosity
when taking impressions for crowns, what materials can you use?
light body and heavy body, since light body flows through all the structures hence increases accuracy
