Immediate Dental Implant Stabilization in a Canine Model Using a Novel Mineral-Organic Adhesive: 4-Month Results

Purpose: This study evaluated a novel injectable, self-setting, osteoconductive, resorbable adhesive that provides immediate implant stabilization. Materials and Methods: Twenty-six large canines had the mandibular second through fourth premolars and the first molar removed bilaterally. After 3 months, oversized osteotomies were prepared with only the apical 2 mm of the implant engaging native bone. One site had a novel resorbable, self-setting, mineral-organic adhesive (TN-SM) placed around the implant, a second site received bone graft, and a third site received only blood clot. Removal torque, standardized radiography, and histology were used to evaluate implant stability and tissue contact after 24 hours, 10 days, and 4 months. Results: Mean removal torque values after 24 hours were 1.4, 1.3, and 22.2 Ncm for the control, bone graft, and mineral-organic adhesive, respectively. After 10 days, these values were 5.7, 6.2, and 45.7 Ncm and at 4 months increased to 88.7, 77.8, and 104.7 Ncm, respectively. Clinical, radiographic, and histologic evaluations showed a lack of inflammatory reaction. Control defects were initially radiolucent in the coronal area; grafted sites revealed particles in the gap, with both conditions gradually filling with bone over time. At 10 days, histologic evaluation demonstrated excellent biocompatibility and intimate contact of mineral-organic adhesive to both the implant and bone, providing an osseointegration-like bond; control sites revealed no bone contact in the defect area, while the bone-grafted sites revealed unattached graft particles. At 4 months, much of the mineral-organic adhesive was replaced with bone; the control and grafted sites had some bone fill, and many of the defects demonstrated no bone-to-implant contact and were filled with soft tissue or isolated graft particles. Conclusion: The mineral-organic adhesive provides immediate (osseointegration-like) and continued implant stabilization over 4 months in sites lacking primary stability. Experimental sites demonstrated maintenance of crestal bone levels adjacent to the mineral-organic adhesive and soft tissue exclusion without the use of membranes in this canine model. These results demonstrate that this novel mineral-organic adhesive can enable implant osseointegration in a site where insufficient native bone exists to allow immediate implant placement. Parole chiave: bone adhesive, calcium phosphate, dental implants, integration, phosphoserine, resorbable, stability