I hope I can solicit some responses on the subject of restoring an edentulous mandible with an All-on-4 approach. Does anyone have any experiences in restoring an edentulous mandible with an All-on-4 in various retentive overdenture modalities such as:
1. All four abutments are ball abutments
2. Two most distal abutments are ball attachments and the two most anterior abutments are splinted with a Hader bar
3. All four abutments are splinted with a Hader bar
There are several issues to be addressed. The main two are which modality is most retentive? Second, which provides the least amount of stress on implants, and therefore potentially improves long term prognosis? The greatest lateral stresses on the implants occurs during chewing and removal of the overdenture.
Your response based on experience, not opinion, would be greatly appreciated.