Evaluation of Ti/Al alloy coated with biogenic hydroxyapatite as an implant device in dogs’ femur bones

The main target of the present research was a full assessment of the toxicity effects and biocompatibility of a Ti/Al-alloy device coated with biogenic hydroxyapatite (bHA) when implanted in dogs in comparison with those of an uncoated Ti/Al-alloy device. The coating of the alloy was carried out using controlled high-velocity suspension flame spray (HVSFS) technique. Both coated and uncoated devices were implanted in dogs’ femur bones for different time periods (45 days and 90 days). Bone-formation ability and healing were followed up, and blood analysis was performed, at Time zero (immediately post surgery), and then at 3 days, 45 days, and 90 days post surgery. Bone mineral density checks, radiological scans of the femur bone, and histological analysis were also conducted. The in-vivo study results proved that implantation of a device made from bHA-coated Ti/Al alloy in dogs’ femur bones is completely safe. This is due to the high osteoconductivity of the coated alloy, which enables the formation of new bone and a full connection between new and original bone material. At 90 days post surgery, the coated alloy had been completely digested within the original bone; thus, it appeared as a part of the femur bone and not as a foreign body. Both the scanning electron microscopy with energy-dispersive X-ray and histology analysis findings affirmed the results. Furthermore, the blood tests indicated no toxicity effects during the 90 days of implantation.

Temperature effect in physicochemical and bioactive behavior of biogenic hydroxyapatite obtained from porcine bones

Biogenic hydroxyapatite (BHAp) is a widely used material in the biomedical area due to its similarities with the bone tissue mineral phase. Several works have been spotlighted on the thermal behavior of bone. However, little research has focused on determining the influence of calcination temperature in the physicochemical and bioactive properties of BHAp. In this work, a study of the physicochemical properties’ changes and bioactive response of BHAp produced from porcine femur bones using calcination temperatures between 900 to 1200 °C was conducted. The samples’ structural, morphological, and compositional changes were determined using XRD, SEM, and FTIR techniques. XRD results identified three temperature ranges, in which there are structural changes in BHAp samples and the presence of additional phases. Moreover, FTIR results corroborated that B-type substitution is promoted by increasing the heat treatment temperature. Likewise, samples were immersed in a simulated biological fluid (SBF), following the methodology described by Kokubo and using ISO 23317:2014 standard, for 3 and 7 days. FTIR and SEM results determined that the highest reaction velocity was reached for samples above 1000 °C, due to intensity increasing of phosphate and carbonate bands and bone-like apatite morphologies, compared to other temperatures evaluated.

Comparative analysis of the prevention of caries by toothpastes with different compositions and their effect on the mineral structure of the oral fluid

Introduction. One of the most attractive materials in the composition of toothpastes is hydroxyapatite with nanoscale crystals that contribute to the prolongation of remineralization due to the release of calcium and phosphorus. In some cases, macro- and micronutrients are introduced into preventive toothpastes; however, the dynamics of increasing their concentration in the oral fluid has not been studied enough.The objective was to study the effect of bioactive toothpaste with natural hydroxyapatite, enriched in nanodispersed particles of iron, zinc and copper, on the dynamics of the dental status and the level of copper, iron, zinc, magnesium and calcium in the oral fluid.Methods and materials. 26 patients were examined: 19 patients used the toothpaste being studied, and 7 patients used toothpaste, which did not have macro- and microelements. The determination of the Green-Vermilion hygiene index and the papillary-marginal-alveolar index was carried out, followed by calculation of the effectiveness of the cleansing and antiinflammatory effects. In the oral fluid, the method of electrothermal atomic absorption spectrometry was used for determination of the content of cations of copper, iron, zinc, magnesium and calcium.Results. One month after the start of the use of toothpaste with natural hydroxyapatites enriched with macro- and microelements, a statistically significant increase in the oral fluid of patient, levels of copper, iron, zinc and calcium was established. The effectiveness of the cleansing effect was 85 %, anti-inflammatory effectiveness – 90 %.Conclusion. The increase in the level of macro- and microelements in the oral fluid is due to the composition of the toothpaste containing, along with biogenic hydroxyapatite, nanodispersed particles of iron, zinc and copper.Authors declare no conflict of interest.The authors confirm that they respect the rights of the people participated in the study, including obtaining informed consent when it is necessary, and the rules of treatment of animals when they are used in the study. Author Guidelines contains the detailed information.