A single center, prospective clinical trial is planned to investigate the effect of different emergence angles of implant restorations on peri-implant soft tissue recession and implant marginal bone loss.

The primary outcome is to systematically evaluate the association of implant-, peri-implant tissue-, and restoration-related factors with facial mucosal level changes.

Facial mucosal recession still poses a threat to long-term success of implant therapy especially esthetic appearance. To study the timing and extent of mucosal recession and the associated risks, a prospective study is strategically important. This will allow the collection of valuable longitudinal data about facial mucosal level changes, peri-implant tissue dimensions, and implant/restoration parameters that are considered critical for determining the mucosal level. Forty adult patients who meet the inclusion criteria will be recruited to participate in this study. Patients that had an implant crown placed a minimum time frame of 6 months and have existing relevant clinical data (mucosal level and thickness, radiographs, cone beam computed tomogram (CBCT) scans, study casts and intra-oral photographs) at baseline and if possible at other follow-up visits will be invited to participate in this study. Patients that volunteer to be screened will not be examined for study eligibility until an informed consent has been obtained. Patient information will be protected according to HIPAA. The enrolled subjects will have research measurements taken, an ultrasound scan, intraoral photos and an impression of the arch including the study implant. One dental cone beam computed tomography (CBCT) scan will be taken to evaluate the implant position in relation to the alveolar ridge and to evaluate relative bone quality. The primary outcome will analyze the changes in the facial mucosal level, by superimposing the digital images of the stone models that were taken previously. On ultrasound images, peri-implant tissue parameters, implant positions, restoration contour, etc., will be measured and recorded. The primary outcome will then be equated with clinical and radiographic readings, and ultrasound parameters, along with timing of provisionalization or final restoration, in regression analysis to identify factors related to facial mucosal recession.

Inclusion Criteria:

• Subjects 18 years old or older
• One immediate maxillary implant placement with 2 adjacent neighboring teeth
• Available pre-surgery model
• Radiographic documentation (either peri-apical x-rays or CBCT)
• Have final restoration for at least 6 months.

Exclusion Criteria:

• Are under 18 years of age.
• Are unwilling or unable to read and sign this informed consent document.
• Have any medical conditions that we believe may influence the outcome of the study.

Subjects who had a single implant restoration in the maxillary anterior position with sufficient baseline data will be recruited for this study.