Osseointegrated implants have been used to improve denture support, stability and retention. Currently, the placement of 2 implants and the fabrication of an implantretained overdenture is considered by some to be the standard of care. The influence of various types of attachments on stress distribution of 2-implant-retained mandibular overdenture designs has not been sufficiently assessed. The purpose of this study was to compare the load transfer characteristics of 5 attachment systems for 2-implant-retained mandibular overdenture designs. One photoelastic model was fabricated having 2 screw-type implants (3.75 X 13 mm) embedded in the interforaminal region and implants were parallel to each other and vertically oriented. Five retention mechanisms were studied on model; a bar with yellowcolored clips, a milled galvanoformed bar, a bar with two clear distal locator attachments, a bar with two distal ceka attachments, clear locator attachments. For measurements of stress a vertical load 135 N was applied unilaterally to the central fossa of the right first molar. The resultant stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. A bar with two clear distal locator attachments and,clear locator attachments showed higher stress than other attachments
Osseointegrated implants have been used to improve denture support, stability and retention. Currently, the placement of 2 implants and the fabrication of an implant-retained overdenture is considered by some to be the standard of care. The influence of various types of attachments on stress distribution of 2-implant-retained mandibular overdenture designs has not been sufficiently assessed. The purpose of this study was to compare the load transfer characteristics of 5 attachment systems for 2-implant-retained mandibular overdenture designs. One photoelastic model was fabricated having 2 screw-type implants (3.75 X 13 mm) embedded in the interforaminal region and implants were parallel to each other and vertically oriented. Five retention mechanisms were studied on model; a bar with yellow-colored clips, a milled galvanoformed bar, a bar with two clear distal locator attachments, a bar with two distal ceka attachments, clear locator attachments. For measurements of stress a vertical load 135 N was applied unilaterally to the central fossa of the right first molar. The resultant stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. A bar with two clear distal locator attachments and,clear locator attachments showed higher stress than other attachments.