First-in-Human Pilot Study to Assess Methodology for Using a Mineral-Organic Bone Adhesive for Optimization of Primary Stability and Implant Success for Implants Glued into Immediate Extraction Sockets and Immediately Temporized: Pilot Study.

Abstract

To assess the handling properties and clinical function of a new class of material, a so-called mineral-organic bone adhesive (Tetranite; TN), which as yet has no precedent in orthopedic or oral and maxillofacial surgery, for clinically unstable implants placed in immediate extraction sockets and immediately temporized in the anterior maxilla. A cohort of up to 15 patients requiring between one and four immediate dental implants placed into maxillary extraction sockets from canine to canine were eligible for inclusion. Implants had to be unstable with an insertion torque of < 15 Ncm. Implants were then stabilized using TN, which was allowed to set before reassessing stability using both torque and resonance frequency measurements. Implant stability quotients (ISQs) taken after TN setting were compared to ISQs taken prior to its application, and the implants had to demonstrate resistance to a forward torque of 20 Ncm to be considered stable. ISQs were monitored at 1 week and 1, 3, 7, and 12 months postplacement. In addition, peri-implant tissue health was monitored, adverse events were recorded, and implant success was determined at 1 year postplacement. Eleven patients received a total of 14 implants. Three out of the first six implants failed within 1 month (50%), and thus a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments, only one further failure was experienced for the next eight implants placed (12.5%). Mean ISQ data averaged for buccolingual and mesiodistal measurements demonstrated a baseline value before TN application of 59.1 Ncm (SD: ± 9.7; range: 40.5 to 73.0). After final setting of the TN, mean ISQ measured 71.9 Ncm (± 6.5; 56.0 to 80.0). At 3 months, just prior to restoration placement, mean ISQ measured 71.0 Ncm (± 6.6; 57.0 to 78.0). Thereafter, the mean ISQ continued to increase at both the 7- and 12-month follow-ups with scores of 78.9 (± 4.6; 72.0 to 84.5) and 80.3 (± 3.8; 74.5 to 85.0), respectively. The surviving 10 implants went on to be fully restored and remained in function beyond the end of the study period to yield a final success rate of 71.4%. The purpose of a first-in-human study is to demonstrate an extrapolation of preclinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard, the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of the protocol amendments identified, the user handling experience learned, and the opportunity to modify the material to better perform in the human patient, as all represent important lessons learned. The notable increase in ISQ sheds light on the nature by which the glue was substituted for bone to yield a stable implant by the end of the study period.