Bioactive Ceramics: Cements

Abstract

Bioactive cement may be a breakthrough for the biomaterials aimed at the reconstruction of bone defect as they set in situ and form bioactive set mass. As a result of the setting reaction, the bone defect can be filled with the bioactive materials without leaving a gap between the cement and surrounding bone. Also, the setting reaction allows minimum invasive surgery when the bone cement is injected to the bone defects using a syringe. On the contrary, bioactive cements show an inflammatory response when they fail to set. Therefore, understanding the setting reaction is key to their clinical use. The setting reaction of apatite cement, brushite cement, and gypsum is classified as a dissolution–precipitation reaction, where components of the powder phase dissolve into their mixing liquid, and the dissolved compounds precipitate as other compounds. Due to the interlocking of precipitated crystals, the cement sets. Portland cement and mineral trioxide set based on hydration reaction and the resulting formation of amorphous calcium silicate hydrate and calcium hydroxide. Further improvement of bioactive cement is also awaited, based on the understanding of the setting reaction.