Crowns

Question 1

retention form

Answer 1

prevents removal of restoration along path of insertion or the long axis of tooth prep

Question 2

resistance form

Answer 2

prevents dislodgement of the restoration by forces directed in an apical or oblique direction and prevents any movement of the restoration under occlusal forces

Question 3

what impression material for crowns

Answer 3

polyether
(impregum - brand name)