Human Histological evaluation of a new dental implant multisurface topography after four and eight weeks of healing on .

Aim:, It has been demonstrated that the undersized osteotomy could improve the osseointegration process. To the author best knowledge there is no data in the literature treating the bone healing near dental implants with a multisurface topography using this protocol. The present study aimed to histologically evaluate the performance of a new multisurface topography dental implant placed in humans after four and eight weeks of healing. Materials and Methods: Histological evaluation was performed on two multisurface topography dental implants of 4/3 x 10 mm inserted with a torque of 70 ± 10 Ncm. Both implants were retrieved through patients’ request to remove them due to “feeling of foreign body presence in their jaw”. Notwithstanding the patients were discouraged and informed about the risks of implants removal they insisted on their decision. However before removing, the patients agreed to sign an information consent form on the retrieved implants to be included in a study. One implant was retrieved after four weeks of healing while the other was retrieved eight weeks after. Both specimens were fixed in 10% buffered formalin at pH 7.1, dehydrated in an ascending series of alcohol rinsed and embedded in a glycolmethacrylate resin. After polymerization, the specimens were sectioned, along their longitudinal axis, with a high-precision diamond disc at about 80 µm, and ground down to about 30 µm with a custom built sawing and grinding apparatus. The evaluation was performed under brightfield light microscope, confocal scanning laser microscope (CSLM), and a scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). Results: Histological findings showed after 4 weeks a BIC rate of 42.7 % with a high level of cellular activity near the implant surface associated to areas of newly formed bone. SEM evaluation showed osteoid seems directly laid-down over the implant surface. After 8 weeks the BIC rate was of 60.1 % with some area of bone remodelling process in action. The EDX investigation measured as weight % in five areas of each sample showed a Ca/P ratio of 0.9 ± 1.2% for implant retrieved after four weeks and 1.3 ± 0.2% for implant retrieved after eight weeks. Conclusions: The histological results demonstrated that the new multisurface topography dental implants, when placed in undersized osteotomy sites, showed an adequate bone healing after only four weeks (42.7% of BIC). Moreover, EDX investigation demonstrate a predominance of immature bone matrix under mineralization process.