Elvira Dingeldein

Evaluation of a novel nanocrystalline hydroxyapatite paste Ostim in comparison to Alpha-BSM - more bone ingrowth inside the implanted material with Ostim compared to Alpha BSM.

BackgroundThe purpose of this study was to evaluate the performance a newly developed nanocrystalline hydroxyapatite, OSTIM® following functional implantation in femoral sites in thirty-eight sheep for 1, 2 or 3 months. Ostim® 35 was compared to an established calcium phosphate, Alpha BSM®.MethodsBiomechanical testing, μ-CT analysis, histological and histomorphological analyses were conducted to compare the treatments including evaluation of bone regeneration level, material degradation, implant biomechanical characteristics.ResultsThe micro-computed tomography (μCT) analysis and macroscopic observations showed that Ostim® seemed to diffuse easily particularly when the defects were created in a cancellous bone area. Alpha BSM® remained in the defect.The performance of Ostim was good in terms of mechanical properties that were similar to Alpha BSM® and the histological analysis showed that the bone regeneration was better with Ostim® than with Alpha BSM®. The histomorphometric analysis confirmed the qualitative analysis and showed more bone ingrowth inside the implanted material with Ostim® when compared to Alpha BSM ® at all time points.ConclusionsThe successful bone healing with osseous consolidation verifies the importance of the nanocrystalline hydroxyapatite in the treatment of metaphyseal osseous volume defects in the metaphyseal spongiosa.

Parameters Influencing the Properties of Calcium Phosphate Cements

A calcium phosphate cement based on alpha TCP, Monetit, CaCO3 and Hydroxyapatite was investigated regarding the influence of milling procedure and attributes of raw materials on setting times. Both parameters were shown to influence the CPC powder properties significantly. The milling procedure determines via the particle size distribution the setting characteristics of the final powder. Reduction of particle size results in a decrease of setting times. Nano-sized particles which were also shown to depend on the milling procedure seem to markedly influence the final setting time. In addition the applicability is improved when particle size is reduced.