Transcript Slide 1

Hader
Spark Erosion
Round
Andrews
Ovoid
Dolder
Bar Designs
Double Bar
Branson
Custom Milled
Rectangular
Square
Attachments and Bars
•Intra Bar
•Extra Bar
•Circum Bar
Extra Bar
Attachment placed on the superior aspect of
the bar
•Increases strength of bar
•Requires more interarch space
Intra-Bar
Connection between the two components
directs the forces of mastication closer to
the crest of the ridge
•Decreases lever arm mechanics
on the supporting teeth
•Bar strength may be
compromised
Circum-Bar
Attachment wraps itself around the bar
•Allows for rotation around bar
The Milled Bar
Main Advantage
Final prosthesis is extremely stable because
lateral forces are best managed by an
intimately fitting primary and secondary
bar
This minimizes stress on the attachments
The Bar Overdenture
Advantages
• Increased stability and retention than an
attachment retained overdenture
• Accomodates a wide variety of implant
angulations
• Bar splints implants together
• Provides better resistance to lateral forces when
in function
• Pose less of a chance of failure at
bone-implant interface
The Bar Overdenture
Disadvantages
• More costly
• More technique sensitive