Evaluation of Immediate Versus Delayed Loading of Dental Implants With a Modified Surface

Inclusion Criteria: * Males and females must be at least 18 years of age * Have at least one missing tooth in positions FDI 4, 5, 6, or 7 in any quadrant (ADA positions 2, 3, 4, 5; or 12, 13, 14, 15; or 20, 21, 22, 23; or 28, 29, 30, 31.) * Subjects desire an implant supported restoration on1 to 4 implants per quadrant * The tooth/teeth position(s) at the proposed implant site must have been extracted or lost at least 4 months before the date of implantation and be fully healed * Adequate bone quality and quantity at the implant site to permit the insertion of a Straumann standard 4.1 mm diameter implant of at least 8 mm length without the use of concurrent bone augmentation techniques. If more bone is available and is indicated a Straumann standard 4.8 mm diameter implant with a wide neck of at least 8 mm length may be used, i.e. implant insertion sites must have sufficient bone height such that the implant will not encroach on vital structures and sufficient width that a minimum of 1 mm of bone lingual and buccal bone will remain * The opposing dentition must be natural teeth or fixed crowns or bridges on natural teeth or implants. Removable prostheses or dentures opposing the study implants are not allowed * Patients must be committed to the study for its full duration. Exclusion Criteria: * Presence of conditions requiring chronic routine prophylactic use of antibiotics (e.g., history of rheumatic heart disease, bacterial endocarditis, cardiac valvular anomalies, prosthetic joint replacements) * Medical conditions requiring prolonged use of steroids * History of leukocyte dysfunction and deficiencies * History of bleeding disorders * History of neoplastic disease requiring the use of chemotherapy * History of radiation therapy to the head and neck * Patients with history of renal failure * Patients with severe or uncontrolled metabolic bone disorders * Uncontrolled endocrine disorders * Physical handicaps that would interfere with the ability to perform adequate oral hygiene * Use of any investigational drug or device within the 30 day period immediately prior to implant surgery on study day 0 * Alcoholism or drug abuse * Patients infected with HIV * Patients who smoke \>10 cigarettes per day or cigar equivalents, or who chew tobacco * Conditions or circumstances, in the opinion of the investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, or unreliability * Local inflammation, including untreated periodontitis * Mucosal diseases such as erosive lichen planus * History of local irradiation therapy * Presence of osseous lesions * Unhealed extraction sites (less than 4 months post extraction of teeth in intended sites) * Bone surgery (bone grafts, guided tissue regeneration techniques for bone enhancement) prior to implant placement unless performed more than 6 months prior to implant placement and the site fully healed. Note: Minor bone enhancement using harvested bone from the implant site and a resorbable membrane is allowed at the time of implant placement * Patients requiring bone grafting at the surgical sites at the time of surgery. * Severe bruxing or clenching habits * Persistent intraoral infection * Lack of primary stability of one (or more) implant(s) at surgery. In this instance the patient must be withdrawn and the patient treated accordingly * Patients with inadequate oral hygiene or unmotivated for adequate home care