title: Preparation of tricalcium phosphate/calcium pyrophosphate structures via rapid prototyping.
abstract: Custom made tricalcium phosphate/calcium pyrophosphate bone substitutes with a well-defined architecture were fabricated in this study using 3D powder printing with tricalcium phosphate (TCP) powder and a liquid phase of phosphoric acid. The primary formed matrix of dicalcium phosphate dihydrate (DCPD, brushite) was converted in a second step to calcium pyrophosphate (CPP) by heat treatment in the temperature range 1,100-1,300 degrees C. The structures exhibited compressive strengths between 0.8 MPa and 4 MPa after sintering at 1,100-1,250 degrees C, higher strengths were obtained by increasing the amount of pyrophosphate formed in the matrix due to a post-hardening regime prior sintering as well as by the formation of a glass phase from TCP and calcium pyrophosphate above 1,280 degrees C, which resulted in a strong densification of the samples and compressive strength of >40 MPa.
authors.affiliation: Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, 97070 Wurzburg, Germany. uwe.gbureck@fmz.uni-wuerzburg.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
authors.forename: Tanja
authors.initials: T
authors.lastname: Hölzel
authors.forename: Isabell
authors.initials: I
authors.lastname: Biermann
authors.forename: Jake E
authors.initials: JE
authors.lastname: Barralet
authors.forename: Liam M
authors.initials: LM
authors.lastname: Grover
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002131:Calcium Pyrophosphate / Q000737:chemistry*; D019245:Compressive Strength; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011312:Pressure; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; C018392:tricalcium phosphate; C494366:calcium phosphate, dibasic, dihydrate; D002131:Calcium Pyrophosphate