In situ hydroxyapatite/apatite-wollastonite glass ceramic composite was fabricated by a three dimensional printing (3DP) technique and characterized. It was found that the as-fabricated mean green strength of the composite was 1.27 MPa which was sufficient for general handling. After varying sintering temperatures (1050-1300 degrees C) and times (1-10 h), it was found that sintering at 1300 degrees C for 3 h gave the greatest flexural modulus and strength, 34.10 GPa and 76.82 MPa respectively. This was associated with a decrease in porosity and increase in densification ability of the composite resulting from liquid phase sintering. Bioactivity tested by soaking in simulated body fluid (SBF) and In Vitro toxicity studies showed that 3DP hydroxyapatite/A-W glass ceramic composite was non-toxic and bioactive. A new calcium phosphate layer was observed on the surface of the composite after soaking in SBF for only 1 day while osteoblast cells were able to attach and attain normal morphology on the surface of the composite.

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Hydroxyapatite/bis-GMA composites were processed by new technique which comprised three dimensional printing (3DP) of hydroxyapatite and then impregnation by bis-GMA based resin. Two types of composites which used either as-fabricated green 3DP samples or 1,300 degrees C sintered 3DP samples were studied. It was found that both 3DP composites have higher flexural modulus, strength and strain at break than the initial 3DP hydroxyapatite sample. Composites produced from sintered sample has higher hydroxyapatite content, higher density and greater modulus, but lower strength and strain at break than composite produced from green 3DP sample. In vitro toxicity shows that 3DP hydroxyapatite/bis-GMA based composites are non-toxic. Osteoblast cells were observed to attach and attain normal morphology on the surface of composites.

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