Synthesis and Properties of Bone Cement Containing Dense ß-TCP Granules

Abstract

Effort was made to enhance the compressive strength and to suppress temperature rise during setting of b-Ca 3 (PO 4 ) 2 (TCP) based cement through the control of powder to liquid ratio. To increase the powder to liquid ratio, highly dense granules of b-TCP with the size around 300 mm were prepared and blended with monocalcium monophosphate (MCPM) and calcium sulfate hemihydrate (CSH). Due to the decrease of the liquid necessary for setting, compressive strength was remarkably increased from 3.9 to 20.6 MPa. The use of granular b-TCP was also affirmative in heat evolution, since temperature rise was virtually negligible during setting.

Hydroxyapatites Produced by Wet‐Chemical Methods

“…The liquid/powder (L/P) ratio of 0.6 mL/g used in the preparation of cylindrical bioceramic samples resulted in compressive strengths of 26–30 MPa after sintering (BIO‐S). If this L/P ratio decreases to around 0.35–0.40 the density of the hardened sample should increase and the porosity should decrease resulting in a higher compressive strength 36 . Although the value of 0.6 mL/g seems to be slightly high, it was suitable to obtain a paste with appropriate workability that could be poured into molds after mixing and removed from them for heat treatment.…”

“…The BIO‐S samples showed a structure with less porosity and a number of dense regions being visible. An increase in strength can be effectively achieved through a decrease in porosity, because theoretical prediction indicates that strength is proportional to the inverse of porosity 36 …”

“…These cements are very compatible with bone and are then resorbed and gradually replaced by newly formed bone 34,35 . For the numerous calcium phosphate cements based particularly on α‐TCP and tetracalcium phosphate, HAp is the end product with a variation in the degree of crystallinity and carbonation 36 …”

“…34,35 For the numerous calcium phosphate cements based particularly on a-TCP and tetracalcium phosphate, HAp is the end product with a variation in the degree of crystallinity and carbonation. 36 Here, we have used a combination of known wet-chemical methods: ''method A,'' which was actually designed to produce poorly crystalline HAp powders and ''method B,'' which was actually intended for the production of ''amorphous calcium phosphate'' powders, which are typically used in the preparation of self-setting cement formulations. 30 Therefore, the mixing of the corresponding powders obtained in methods A and B in a certain composition and a certain liquid-to-powder ratio could be regarded as a new processing route, which enables the acquisition of carbonate HAp cements with carbonates in phosphate positions as in biological apatites.…”

Effects of fine aggregate on the properties of calcium phosphate cements

“…4 Two other studies used dense tricalcium phosphate (TCP) granules in calcium phosphate bone cement systems and both noted improved workability at lower liquid-to-solid ratios. 5, 6 Oh et al 5 incorporated 300-450 ìm â-TCP granules in cement produced by the reaction of monocalcium phosphate monohydrate and calcium sulfate hemihydrate and found significant improvements in compressive strength. Cho et al 6 produced mortars incorporating dense AE-TCP particles, sieved to 45-90 ìm, when HAp formed according to equation (2).…”