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ePaper created 2017-12-06, 12:03:50 | version 1.38.0
| industry A clinical comparison β-tricalcium phosphate vs hydroxyapatite ceramics Authors: Private lecturer Dr Dr Arwed Ludwig & Dr Gregor Thomas, Germany Literature Figs. 1a–c: Comparative tests of different ceramic bone-substitute materials with the human osteo- blast-cell line SAOS-2: morpholog- ical differences after 24 hours of osteoblast cultivation. The topic of bone substitution or bone regeneration, xenografts, allografts or biomimetic materials are discussed very controversially in the OMF surgery at times. However, the progress and good clinical expe- riences made with biomimetic materials during the last two decades are undisputed. The present obser- vational study compares two established bone aug- mentation materials of different chemistry and struc- ture in a direct, indication-related way. The mentioned study cases show that both material types are able to support the surgical work substantially, considering the respective task. The essential questions related to the product group of the biomimetic materials are about the structure preserving its volume without resorption, or complete degradation of the applied material. The restructuring into vital new bone tissue holds the in- evitable side effect of a controlled, yet existing vol- ume loss. The materials used for the comparison are manufactured and distributed by the company curasan (Kleinostheim, Germany) under the names CERASORB® M and Osbone®. CERASORB® M is a -tricalcium phosphate (-TCP) with a phase purity of 99 % in spongy, polygonal broken form. The open- celled structure with interconnected micro-, meso- and macropores allows a fast ingrowth of osteoblasts and a complete transformation into new vital bone tissue. Due to the lack of any biological and organic content the material can be safely used. The manufac- turing process guarantees complete sterility and ab- sence of pyrogens. Osbone® is a purely biomimetic hydroxyapatite with a porosity of 80 % and a likewise polygonal broken granular form with interconnected pores. This leads to a very spongy-like structure of the product. The hydroxyapatite is resorbed extremely slow and therefore guarantees a high volume stability over time and early mechanical endurance. Both products have a clear advantage over xeno- geneic materials with the early osteoblastic coloni- sation and therefore an early bone formation, as the examination of Bernard A. et al. of 2010 shows (Figs. 1a–c). Further important parameters for the evaluation of bone augmentation and bone regen- eration materials are: Primary particle size A bone augmentation material with a particle size higher than 10 µm is ideal to avoid cellular decompo- sition and phagocytosis. It ensures the mechanical stability of the fabric as well as the interconnecting microporosity. A particle size of less than 10 µm stim- ulates the phagocytosis by macrophages. This leads to an unwanted and premature loss of the bone augmentation material in the defect and a complete biological bone regeneration cannot take place. Scaffold stability The granules must not dissolve and disintegrate into small particles or lose stability due to the solu- tion process when the product is applied. A prema- ture disintegration into microparticles provokes an activity of phagocytizing macrophages and poly- morphic polynuclear cells. Thereby increased un- specific immunoreaction interferes with the regen- eration process. In some cases this can lead to an exuberant inflammatory reaction. Fig. 1a Fig. 1b Fig. 1c 38 implants 4 2017