Bars are usually planned to accommodate non-parallel implant trajectories.31 Bars provide excellent stabilization, retention, and force distribution (due to splinting effect) (Figure 2A). There are various designs of bars such as Ackermann Bar (spherical shape), Dolder Bar (ovoid or “U” shape), and Hader Bar (keyhole shape).31 Bars may be casted, milled, or fabricated by CAD-CAM (computer-aided designing/computer-aided manufacturing) technology.31 Fabrication of a prosthesis supported by a bar attachment requires substantial planning and is technique sensitive.28,31-35 Bars require more vertical restorative space (minimum 13‑14mm) compared to individual stud attachments.36 Patients with bar-supported prostheses may develop mucosal hyperplasia beneath the bar and mucositis around the implants when optimal oral hygiene is not maintained (Figure 2B).31 Individual stud attachments are preferred attachments (due to reduced tissue coverage) for patients with poor oral hygiene (Figure 3).37
Your session is about to expire. Do you want to continue logged in?
WARNING! You did not finish creating your certificate. Please click CONTINUE below to return to your previous page to complete the process. Failure to complete ALL the steps will result in a loss of this test score, and you will not receive credit for this course.