The purpose of this study is to determine the difference in success when placing implants
immediately into an extraction site compared to delaying the implant placement until the
extraction site has healed. In addition, the level of bone around the implants will be
compared to determine if one method leads to better results over time.
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 pre-extraction
as baseline, and then prospectively for at least two years in this trial, to compare the
methods and contrast the effectiveness of the proposed immediate restoration therapy.
- All patients will be willing to be present for examination two times a year for at
least three years, as well as maintenance cleanings twice a year 3 months prior to
the data collection visit.
- All patients will be free of uncontrolled diabetes (any type), existing malignancy,
and will not be receiving any therapy that suppresses their immune system, such as
radiation, chemotherapy, or chronic steroid usage
- Need for extraction of a single rooted maxillary central or lateral incisor, canine,
or premolar, with no signs of acute infection (purulent exudate, erythema, pain, and
- Patients will have bone present on all surfaces of the tooth within 3 mm of the
gingival margin of the planned restoration, in order to provide sufficient bone to
circumferentially cover the implant.
- All patients will have adequate space for satisfactory restoration of the edentulous
- Each patient's dentition will be free of active periodontal disease or exhibit
controllable periodontal disease such that their teeth will clinically be non-mobile
and have probing depths less than 3 mm.
- All prospective sites will have at least 2mm of attached or keratinized gingiva.
- The crestal bone width should be enough to accommodate either a 3.75 diameter implant
for the central incisor, canine, and premolar sites, or a 3.25 mm diameter implant
for the lateral incisor tooth sites. Bone height should be at least 14 mm for
accommodation of the implant.
- Patients with labial dehiscence defects greater than 3 mm from the proposed gingival
margin of the planned restoration will be excluded from this study.
- Patients who cannot come for follow up due to conflicts of schedules will not be
accepted into the study.
- Patients with advanced cardiovascular, pulmonary, renal, liver disease that place
them in an ASA III or IV rating will be excluded. Post-menopausal women with known
osteoporosis as determined by their medical internist, will be excluded. Patients
with known alcohol abuse will be excluded.