Correction of nonparallel implants for an implant-retained overdenture.

An implant-retained overdenture is less expensive than a fixed implant-retained prosthesis; however, using ball attachments on abutments that are nonparallel and/or outside the path of insertion may result in loss of retention. As described in this case report, alignment devices can be used as a mandibular overdenture retainer to diminish the lack of parallelism between two implants. The treatment plan involved the use of an alignment device on each implant to ensure correct alignment among ball attachments and its retentive component. These devices can be used to fabricate overdentures retained by implants that are misaligned by as much as 14 degrees.