In vivo Performance of Biodegradable Calcium Phosphate Glass Ceramics using the Rabbit Model: Histological and SEM Observation

Abstract

Two MK5 (45CaO-45P 2 O 5 -5MgO-5K 2 O, in mol%) and MT13 (45CaO-37P 2 O 5 -5MgO-13TiO 2 , in mol%) glasses are prepared in the meta-and *Author to whom correspondence should be addressed. E-mail: jdsantos@fe.up.pt pyrophosphate regions and crystallized to obtain MK5B and MT13B, respectively. MK5B was obtained by controlled crystallization, and MT13B by powder sintering. As a result of these heat treatment processes, the crystalline phases precipitated in the glassy matrix are KCa(PO 3 ) 3 , -Ca(PO 3 ) 2 , -Ca 2 P 2 O 7 and Ca 4 P 6 O 19 phases for MK5B and CaTi 4 (PO 4 ) 6 , TiP 2 O 7 , -and -Ca 2 P 2 O 7 phases for MT13B. To assess the in vivo biological behavior of these glass ceramics, a mixed granulometry in the range 250-355 mm and 355-425 mm with a ratio of 1/1 was implanted for 2, 4, and 12 weeks in the tibiae of Japanese white rabbits. The results showed that the in vivo behavior was strongly affected by their solubility. All implanted materials, MK5B and MT13B, and -tricalcium phosphate (-TCP) as control material, showed signs of degradation in vivo. However, the levels of degradation were quite different throughout the implantation periods. The highest degradation was observed for MK5B glass ceramic and the lowest for MT13B with -TCP in-between. All implanted materials allow for new bone formation in the bone defect area. At the longest implantation period (12 weeks), the MT13B and -TCP materials were almost completely surrounded by new bone tissue, whereas MK5B showed some unfilled spaces. This behavior is discussed in terms of the high degradation observed in previous studies. JOURNAL OF BIOMATERIALS APPLICATIONS

Incorporation of bioactive glass in calcium phosphate cement: Material characterization and in vitro degradation

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Biocompatibility of a porous alumina ceramic scaffold coated with hydroxyapatite and bioglass

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