OVERDENTURE
Locator abutments
Overdentures can be
divided in to two categories, type "A" and type "B". A type
"A" overdenture is the most simple and a preexisting
denture may be retrofitted to engage the attachment abutments.
Another benefit for the type
Bredent bar
"A" overdenture
is that it can conform to a limited inter arch space situation.
The attachment abutments screw directly to the implant and come
in several configurations, from Locator, ERA and o-ring.
Depending on the type of attachment the implants need to be
placed quite parallel with the exception of Locators which can
accommodate up to 20 degrees of divergence. All attachments come
in different collar height configurations to adapt to varying
tissue depths around the implant.
Hader bar
A type "B" overdenture consists of a traditional cast bar or
milled titanium bar to which a denture will attach itself. These
bars can be designed as a hader bar or with attachments.
Almost any kind of stud style attachment can be utilized for a bar.
Locator bar
Due to height requirements of the bar substructure and the
attachments, interarch space dimensions need to be carefully
evaluated during the treatment planning phase. The bar type set
up can compensate for divergent implant angulation better than a
type "A" overdenture set up.