Novel hydroxyapatite/niobium surface coating for endodontic dental implant

Endodontic dental implants have been used for many years. Many materials have been advocated for use as endodontic implants but a few of them have shown biocompatibility and have been acceptable. The aim of this study was to design and produce a novel biomaterial by producing a new surface coating on metallic substrate in order to achieve two goals, namely, an improvement in the corrosion behaviour of metallic endodontic dental implant and the bone osteointegration simultaneously. Stainless steel (SS) 316L was used as the metallic substrate and a novel double layer hydroxyapatite/niobium (HA/Nb) composite coating was prepared on it. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were utilised to characterise the coating. Electrochemical tests were performed in physiological solutions in order to determine the corrosion behaviour of the coated and uncoated specimens. Two types of endodontic implants were used, including SS with and without novel HA/Nb coating, which were prepared and subsequently implanted in the mandibular canine of 22 cats after completion of root canal treatment and osseous preparation. After a healing period of 4 months, osteointegration evaluation and histopathological interpretation were carried out using SEM and optical microscopy. In vitro tests indicated that the novel HA/Nb composite coating could improve the corrosion resistance and therefore the biocompatibility of SS endodontic dental implant. The clinical evaluation results showed that the average bone osteointegration of coated implants was more than for uncoated implants. The histopathological results and bone tissue response to the coated endodontic dental implants were acceptable. It can be concluded that HA/Nb composite coated SS could be used as an endodontic dental implant material.