title: Si complexes in calcium phosphate biomaterials.
abstract: Silicon complexes in silicon doped calcium phosphate bioceramics have been studied using (29)Si magic angle spinning nuclear magnetic resonance spectroscopy with the objective of identifying the charge compensation mechanisms of silicon dopants. Three different materials have been studied: a multiphase material composed pre-dominantly of a silicon stabilized alpha-tricalcium phosphate(alpha-TCP) phase plus a hydroxyapatite (HA) phase, a single phase Si-HA material and a single phase silicon stabilized alpha-TCP material. NMR results showed that in all three materials the silicon dopants formed Q(1) structures in which two silicate tetrahedra share an oxygen, creating an oxygen vacancy which compensated the substitution of two silicon for phosphorus. This finding may explain the phase evolution previously found where silicon stabilized alpha-TCP is found at low temperature after sintering.
authors.affiliation: Department of Physics, Queen's University, Kingston, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Gillespie
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
authors.forename: M
authors.initials: M
authors.lastname: Sayer
authors.forename: M J
authors.initials: MJ
authors.lastname: Stott
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry* / Q000378:metabolism*; D017886:Durapatite / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D017655:Silicon Compounds / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D046911:Macromolecular Substances; D017655:Silicon Compounds; C485828:alpha-tricalcium phosphate; D017886:Durapatite; C020243:calcium phosphate