Effects of a hydroxyapatite coating on the stability of endosseous impleants in rabbit tibiae

Background. A dental implant surface which would promote rapid and strong osseointegration is a key factor of success in modern implantology. To achieve this goal, different implant surface modifications are developed. A hydroxyapatite (HA) coating changing a bioinert titanium surface into bioactive is one of them. Objectives. The objective of the study was to investigate the effects on bone osseointegration in rabbits resulting from the application of a HA coating deposited on titanium endosseous implants using a modified electrochemical method. Material and method' Titanium implants with HA coatings and controls with Al2O3 grit-blasted surfaces were embedded into rabbit tibiae. The chemical composition, roughness and morphology of the implants were determined. Implant stability tests were performed, and the Periotest (R) value (PTV) and the implant stability quotient (ISQ) value for Osstell Mentor were recorded in order to evaluate the osseointegration. Results. The surface characterization of the implants revealed a microstructure with an arithmetical mean height (Sa) in the range of 0.71-1.04 mu m. The HA coating was free of contamination, whereas the controls were enriched with corundum. After healing, a statistically significant increase in the mean ISQ and a decrease in the mean PTV for the HA-coated implants was observed. In the case of the control implants, only PTV decreased significantly with time. Conclusions. The present study found that implant surface properties affected implant stability as determined by Osstell and Periotest measurements. The HA coating reported herein was found to have chemical and physical properties which appear to improve osseointegration compared to grit-blasted implants.