THE MICRO MACROPOROUS BIPHASIC CALCIUM PHOSPHATE CONCEPT FOR BONE RECONSTRUCTION AND TISSUE ENGINEERING - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 104

mental physical properties are interconnecting macroporosity and appropriate
microporosity [19,20].
Macroporosity in BCP ceramic is introduced by incorporating volatile mate-
rials (e.g., naphthalene, hydrogen peroxide or other porogens), heating at tem-
peratures of less than 200 °C and subsequent sintering at higher temperatures
[19,21-25]. Macroporosity is formed as a result of the release of the volatile ma-
terials (Figure 4.1). Microporosity is a consequence of the temperature and dura-
tion of sintering [20]: the higher the temperature, the lower the microporosity
content and the lower the specifi c surface area (Figure 4.2).
At present, commercial BCP products of different or similar HA/

- TCP
ratios are manufactured in many parts of the world and their successful use in
medicine and dentistry has been reported [11,26-31]. The total porosity (macro-
porosity plus microporosity) of these products is reported to be about 70% of the
bioceramic volume. Current BCP commercial products with HA/

β

β - TCP ratios

Figure 4.1. Macroporosity of MBCP observed with SEM.

Figure 4.2. SEM of discs sintered at 1050 °C (D1, D2, and D3) and at 1200 °C (D4, D5).