Following the loss of teeth, the alveolar bone formed in response to the eruption of the teeth is gradually resorbed by the body. In conventional dental implant therapy, a wide safety margin of uninterrupted healing (3-6 months) following placement of the implants is used to assure a predictable survival of the implants (on the order of > 90%). In the past few years, there have been multiple studies documenting with improved implant surface technologies available, that dental implants can be put into function far sooner than conventionally thought. The investigators are currently performing recalls on subjects treated in a research protocol at the University of Iowa (YAOSS-0001; IRB 200305001). Since this initial study, a shortened version of the implant device has been developed and has obtained FDA clearance (FDA 510k 063779 clearance letter dated April 27, 2007) for a 4mm diameter by 6mm in length dental implant. In a case study the investigators are proposing to repeat the same protocol as used in the initial trial with the following exceptions: only this one implant type will be used, no bone compression surgical techniques will be used (referred to as "osteotome" indirect sinus lifting). Our initial trial has documented good performance with minimal bone loss and a 98.3% cumulative survival rate.

This will be an open, prospective case-series clinical documentation study to document the clinical efficacy of the 4.0mm diameter x 6 mm in length implant (Astra Tech Dental Implant, Fixture OsseospeedTM ) in the treatment of subjects missing teeth in the upper jaw. A minimum of two but preferably three implants shall be considered for each surgical site. A total of 20 subjects fulfilling all inclusion criteria will be enrolled. Subjects will have a complete diagnostic work-up performed and assessment for eligibility in the study by both a Prosthodontist and Surgeon. Subjects will then have the implants placed in an out patient basis at the College of Dentistry. The subjects will not wear a conventional removable partial during the initial six weeks of healing. At six weeks, an assessment of the implants shall be made by the surgical and restorative team and if a set of safety benchmarks are met, provisional crowns will be made to place the implants into clinical function (mastication). Over the first year, the provisional crowns will be periodically removed and a series of clinical measurements and mobility measurements made. At the end of 1 year following placement, the permanent crowns or bridgework will be constructed and the subject followed annually for another four years (five years total from placement). A total of 15 clinical visits are estimated per subject.