First-in-Human Pilot Study to Assess Methodology for Using a Mineral-Organic Bone Adhesive for Optimization of Primary Stability & Implant Success for Implants Glued into Immediate Extraction Sockets and Immediately Temporized. Pilot Study 1.

PURPOSE: The purpose of this First-in-Human pilot study was to assess the handling properties and clinical function of a new class of material, so-called mineral-organic bone adhesive (Tetranite, TN), that as yet has no precedent in orthopedic or oral & maxillofacial surgery, for clinically unstable implants, stabilized by this bone adhesive, in immediate extraction sockets and immediately temporized in the anterior maxilla.

MATERIALS & METHODS: A cohort of up to 15 patients requiring between 1 and 4 immediate dental implants inserted into maxillary extraction sockets from canine to canine could be enrolled to the study. Implants had to be unstable, <15Ncm. Implants would then be stabilized by the use of a TN, which was allowed to set and the stability re-assessed using both torque and resonance frequency. Implant Stability Quotients (ISQ) taken after TN set were compared to ISQs taken prior to its application and the implants had to demonstrate resistance to a forward torque of 20Ncm. ISQs were monitored at 1 week and 1, 3, 7 and 12 months post-placement. In addition, peri-implant tissue health was monitored, adverse events recorded and implant success determined 1-year post-placement.

RESULTS: 11 patients received a total of 14 implants. Three out of the first 6 implants failed within one month (50%), subsequent to which a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments only 1 further failure was experienced for the next 8 implants placed (12.5%). Mean ISQ data averaged for bucco-lingual and mesio-distal measurements, demonstrated a baseline value before TN application of 59.1 (Std Dev: ±9.7; Min: 40.5; Max: 73.0). After final set of the TN, mean ISQ measured 71.9 (Std Dev: ±6.5; Min: 56.0; Max: 80.0). At 3 months, just prior to restoration, mean ISQ measured 71.0 (Std Dev: ±6.6; Min: 57.0; Max: 78.0). Thereafter mean ISQ continued to increase at both the 7- and 12- month reviews with scores of 78.9 (Std Dev: ± 4.6; Min: 72.0; Max: 84.5) and 80.3 (Std Dev: ± 3.8; Min: 74.5; Max: 85.0) respectively. The surviving 10 implants went on to be fully restored and remain in function beyond the end of the study period to yield a final success rate of 71.4%.

CONCLUSION: The purpose of a first-in-human study is to demonstrate an extrapolation of pre-clinical 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 protocol amendments identified, user handling experience learned, and the opportunity to modify the material to better perform in the human subject, as all represent important lessons learnt. The notable increase in ISQ sheds light on the nature by which the glue is substituted for bone to yield a stable implant at the end of the study period.