OP 1 Final Flashcards
shape of the preparation itself
outline form
What do these 4 factors establish?
- Access to the lesion (allows to visualize extent of caries and for burs to reach all carious lesions)
- Extent of the lesion (the extent of the caries in the dentin is what ULTIMATELY determines the preparation size)
- Restorative material to be used (ie amalgam or porcelain need a 90 degree cavosurface margin but composite or gold need a beveling of the margin)
- Esthetics
Outline form
T/F Outline form should be made so that occlusal contact NEVER hits the margin of the restoration
True
shape given to the prep to prevent fracture of either the restoration or the tooth
resistance form
What are these 3 things examples of?
- adequate bulking of amalgam
- rounding of internal line angles
- horizontal pulpal and gingival floors being prepared perpendicular to the tooth’s long axis
resistance form
Why is the prep placed 0.5 mm into the dentin?
- Avoid the sensitive DEJ
- Provide adequate bulk of restorative material
- Take advantage of the dentin’s resilient nature
What prevents fracture?
Resistance form
shape that prevents the restoration from being displaced by tipping or lifting forces
retention form
What are these 5 things examples of?
- undercuts
- truncations
- grooves
- pins
- dovetails
Retention form
What prevents displacement?
Retention form
What will come from converging walls, and sometimes the dovetail?
Primary retention
What helps retain the restoration in case the primary retention fails?
Secondary retention
What are these 11 things examples of?
- grooves
- coves
- extensions
- skirts
- beveled margins
- pins
- slots
- steps
- amalgam pins
- etchants
- adhesives
Secondary retention
What can also sometimes be considered a secondary retention factor?
Dovetails
shape that allows the needed procedure to be performed
convenience form
what allows for vision, access, etc. and is what influences the outline form itself?
convenience form
Why do amalgam preparations tend to have to have a few extra things done to them in order to be appropriate?
Amalgam does not directly adhere to the tooth
Because amalgam does not directly adhere to the tooth, what is usually necessary in order to maintain proper strength of amalgam restorations?
expansions of the prep
T/F Although dovetails are always beneficial on any preparation, they are VERY important for amalgam
True
What do amalgam preparations for class IIs require in order to minimize undermined enamel rods?
(while with composite, it is not necessary)
Reverse S curve
What is very vital in order to have maximal strength in amalgam restorations?
Compacting
T/F Amalgam does not need to be triturated to activate
FALSE, amalgam must be triturated in order to activate!!
T/F Amalgam cannot be added onto set amalgam and must be redone if necessary
True
Amalgam cannot be polished/finished until at least ____________ after placing placing (use _________ first and then ________; on slow speed); Has _______ tensile strength.
24 hours; brownie; greenie; low