Onlays Flashcards
An \_\_\_\_\_\_ is a restoration covering at least one cusp on the occlusal surface where the morphology is replaced by another material including ceramic, gold, amalgam, zirconia.
Onlay
Indications for an _____
-When cusps have been undermined by caries
-When enamel is available for etch and bonding
-When there is the presence of horizontal cracks which
are too far apart to repair with composite or amalgam
-Lack of supporting dentin under a cusp
-Heavy occlusion
-Discolored cusps in an esthetically oriented patient.
-When remaining tooth structure is less than 1/3 to ½ of the inter-cuspal distance
-Done well, research has shown that an onlay with appropriate cusp coverage
greatly increases the strength of the natural tooth prior to the onlay
Onlay
Contraindications for an ______
-Patient has poor oral hygiene
-Patient is severe bruxer
-More than 2/3 of the occlusal table requires restoration to
support the onlay, a complete crown is generally
recommended.
-Inability to create sufficient bulk for ceramic material in the
preparation and with opposing occlusion. Need 2mmof
reduction for ceramics.
-Inability to maintain a dry field.
-In general, the adhesive resin cements used for onlays are
technique sensitive and may not be appropriate for every
scenario.
Onlay
Why choose an Onlay?
Conservation of tooth structure is the
primary reason.
With an ____, there is still tooth structure
available to extend the onlay or move
to a crown if the restoration fails.
onlay
Now, with more and more dentists purchasing and
using digital scanning with an in office milling,
_____ are used more because the digital scanning
and milling without the temporization issues have
brought back this more conservative restoration by
eliminating the more challenging previous
concern.
onlays
What is the material used in onlays that provides the best marginal adaptation?
Gold
____ mm minimal thickness of all-ceramic onlay restorations
2
T/F: The margin of the onlay preparation should not be in
occlusion.
True
