Timing of Soft Tissue Grafting Following Immediate Implant Placement

Buccal bone resorption (mm)

Patients undergoing single immediate implant placement (IIP) in the premaxilla will be
 invited to participate in this randomized controlled trial (RCT). Prior to surgery, a small-
 field low-dose cone beam computed tomography (CBCT) is taken to verify the integrity of the
 facial bone wall and an adequate amount of apical and palatal bone availability for implant
 anchorage.
 
 In all of the patients, a connective tissue graft (CTG) will be harvested and inserted into
 the buccal mucosa to increase soft tissue thickness around the immediately installed implant.
 However, included patients will be randomly allocated to either receive the CTG immediately
 after implant installation (Immediate soft tissue grafting, ISG = control group) or 3 months
 after implant installation (Delayed soft tissue grafting, DSG = test group).
 
 Forty sealed envelopes are prepared for that purpose, of which 20 are internally labeled as
 DSG and 20 as ISG. Following IIP, a sealed envelope will be opened to reveal the
 treatment concept In both groups, a cutting implant is installed in an optimal 3D position.
 Socket grafting is performed with deproteinized bovine bone mineral to limit buccal bone
 resorption and to optimize soft tissue stability.
 
 In the ISG group, a pouch is made in the buccal mucosa using microsurgical instruments.
 Thereupon, a free gingival graft is harvested from the palatal mucosa in the premolar area
 and de-epithelialized to arrive at a CTG of about 1 mm thickness. Height and length are
 tailored to the dimensions of the site. Then, the CTG is brought into the pouch and fixed
 with two single sutures onto the buccal mucosa. Finally, a healing abutment is installed,
 which is replaced by a provisional implant crown 2 days later.
 
 In the DSG group, implant placement, socket grafting and installation of a provisional
 implant crown occur as described above. In contrast, a buccal pouch is performed 3 months
 after implant installation. Graft harvesting, adaptation and fixation are performed as
 described above.
 
 A small-field low-dose CBCT is taken at the 1-year and 5-year follow-up in order to measure
 buccal bone resorption as compared to the baseline dimensions in designated software.