This revised application is a clinical trial designed to evaluate crestal bone level changes when implants are placed into extraction sites and immediately provisionalized. Extraction of maxillary incisor teeth is a common procedure as documented in our school clinics. Traditional treatment when a tooth is extracted includes a period of healing followed by placement of an implant. Our preliminary data indicates that the delayed approach results in labial bone loss with resultant horizontal deficiency in over 50% of cases, requiring hard and soft tissue grafting to achieve a functional result. Additional preliminary data indicates that grafting the extraction site and/or immediate implant placement and provisionalization results in a functional restoration, without the need for additional adjunctive grafting procedures. It is unclear how the crestal bone levels change during healing of the extraction site prior to implant placement, in contrast to immediate implant placement, with immediate provisionalization with a crown. We hypothesize that there will be differences in the crestal bone levels (primary endpoint), and differences in soft tissue levels and indices (secondary endpoints) between implants immediately temporized, placed either delayed or immediately after tooth extraction, with more bone loss in the immediate placement group (experimental) compared to the delayed placement group (control). The long-term goal is to determine if the crestal bone remodeling after tooth extraction or the apical position of the implant determines the final level of the crestal bone. Two groups of 45 patients will be evaluated. All subjects will have a single rooted maxillary tooth extracted. One group will have the socket grafted with mineralized bone and allowed four months prior to implant placement. The crestal bone in this group will have remodeled during the four months of healing prior to implant placement. The second group will have the implant placed immediately after tooth extraction, thus the crestal bone will remodel in the presence of the implant and the immediately placed temporary restoration, as a one-stage procedure. For both groups, the implants will be immediately temporized with a crown after implant placement. Standardized hard and soft tissue data will be collected preextraction as baseline, and then prospectively for at least two years in this trial, to compare and contrast the methods.
