A Study of Certain Prevail Implants Used for the Preservation of Crestal Bone in Short Fixed Bridge Cases.

Inclusion Criteria: * patients of either sex and any race greater than 18 years of age * patients for whom a decision has already been made to use dental implants for treating an existing condition specifically: A partially edentulous short-span fixed case of less than 4 implants in the maxilla or mandible; the prosthesis may be anterior, posterior, or transitionally anterior-posterior; no cantilevers allowed but one interior crown may be a pontic * patients must be physically able to tolerate conventional surgical and restorative procedures * patients must agree to be evaluated for each study visit, especially the yearly follow-up visits Exclusion Criteria: * patients with active infection or severe inflammation in the areas intended for implant placement * patients with a \>10 cigarette per day smoking habit * patients with uncontrolled diabetes mellitus * patients with metabolic bone disease * patients who have had treatment with therapeutic radiation to the head within the past 12 months * patients in need of allogenic bone grafting a the site of the intended study implant * patients who are pregnant at the screening visit * patients with evidence of severe para-functional habits such as bruxing or clenching * patients with cantilevers and more than one pontic per bridge