I have been placing and restoring modern day dental implants for over 20 years now and for most of that time, I have insisted that the minimum dental implant treatment for the edentulous maxilla (upper jaw with no teeth) is 4 implants splinted with a bar and an overdenture. About ten years ago, I violated this rule (all rules are eventually violated). The restoration was successful for about 8 years, and then we lost two of the four implants that were used. I'll show you what happened and why I originally violated my own "rule" and then see if I can sum up the findings.... SRD