Unforeseen Event - Original PI left the University of Iowa

Mid-facial recession following immediate implant placement (IIP) in the place of a tooth poses a significant challenge for clinicians to treat. Emerging evidence shows that connective tissue graft (CTG) augmentation may mitigate the remodeling of the buccal bone crest (i.e., bone within the gum that supports the tooth), and lessen the soft tissue recession. A recent systemic review suggested a supplemental CTG grafting to IIP as a standard of care, especially for cases that have a high esthetic risk, specifically with a thin gingival biotype (i.e., thin gum tissue) and a thin buccal bone plate. The alternative option to augment the facial contour is the xenogeneic volume-stable collagen matrix (VCMX), which favors avoiding morbidity but hasn't been thoroughly investigated on IIP. Despite that IIP has attracted considerable scientific interest, the dynamic changes of the bone crest and soft tissue, especially during the early healing stage (<3 months following IIP), are little known. Recently, an ultrasonography protocol has been validated for its diagnostic value in dental implant research. High-frequency B-mode imaging and color flow and power Doppler are implemented to display the spatial relation of anatomic landmarks of peri-implant tissues and to visualize the flow velocity and blood volume, respectively. It provides a valuable real-time diagnostic tool to evaluate hard and soft tissue remodeling and tissue perfusion changes during the early healing stage around IIP, comparing CTG and VCMX grafting. Hence, the purpose of this three-arm RCT is to compare the clinical efficacy and longitudinal remodeling of hard and soft tissue around IIP among CTG, VCMX, and control (without soft tissue augmentation) group. This will be the first evidence of the longitudinal tissue changes around immediate implant, and the first RCT comparing the clinical efficacy and esthetic outcome of xenogenic soft tissue substitute (i.e., from the non-living bone of another species) to the gold standard approach (CTG) on the immediate implants.

Inclusion Criteria:

• Age 18-95
• Has a single hopeless tooth in the maxillary esthetic zone (i.e., first premolar to first premolar, tooth #5-tooth #13)
• Adequate oral hygiene (i.e., full-mouth bleeding score (FMBS) and full mouth plaque score (FMPS) of less than 25%)
• Adequate tooth space to support an immediate implant placement (i.e., adequate mesiodistal space of greater than or equal to 6 mm and interocclusal space to support a non-occluding provisionalization).
• Postextraction vertical bone defect of the buccal socket wall was less than or equal to 3mm.

Exclusion Criteria:

• patients taking long-term (more than 3 months) medications affecting bone metabolism
• generalized untreated periodontitis with greater than of 30% of sites with greater than 5mm pocket depths and bleeding upon probing with a dental probe
• medical contraindications for having a surgical procedure (i.e., ASA Status of III, patient with a severe systemic disease that is not life-threatening; ASA Status of IV, a patient with a severe systemic disease that is a constant threat to life).
• history of radiotherapy in the head and neck region
• heavy smoker (greater than 10 cigarettes per day)
• pregnancy
• gingival recession before extraction in relation to the contralateral tooth.