Ultrasound-based Imaging to Detect Early Changes of Hard and Soft Tissue Around Immediately Placed Implants With or Without Soft Tissue Augmentation

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.