Bar Attachments

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

Figure 2A.
Photo showing a Hader Bar fabricated with ERA extensions to support an overdenture
Hader Bar fabricated with ERA extensions to support an overdenture.
Picture courtesy of Dr. Cagna
Figure 2B.
Photo showing Mucosal hyperplasia and mucositis in a bar supported prosthesis due to poor oral hygiene.
Mucosal hyperplasia and mucositis in a bar-supported prosthesis due to poor oral hygiene.
Figure 3.
Photo showing individual stud attachments for easier oral hygiene maintenance
Easier accessibility for oral hygiene maintenance with individual stud attachments.