title: Glass Polyalkenoate Cements Designed for Cranioplasty Applications: An Evaluation of Their Physical and Mechanical Properties.
abstract: Glass polyalkenoate cements (GPCs) have potential for skeletal cementation. Unfortunately, commercial GPCs all contain, and subsequently release, aluminum ions, which have been implicated in degenerative brain disease. The purpose of this research was to create a series of aluminum-free GPCs constructed from silicate (SiO₂), calcium (CaO), zinc (ZnO) and sodium (Na₂O)-containing glasses mixed with poly-acrylic acid (PAA) and to evaluate the potential of these cements for cranioplasty applications. Three glasses were formulated based on the SiO₂-CaO-ZnO-Na₂O parent glass (KBT01) with 0.03 mol % (KBT02) and 0.06 mol % (KBT03) germanium (GeO₂) substituted for ZnO. Each glass was then mixed with 50 wt % of a patented SiO₂-CaO-ZnO-strontium (SrO) glass composition and the resultant mixtures were subsequently reacted with aqueous PAA (50 wt % addition) to produce three GPCs. The incorporation of Ge in the glass phase was found to result in decreased working (142 s to 112 s) and setting (807 s to 448 s) times for the cements manufactured from them, likely due to the increase in crosslink formation between the Ge-containing glasses and the PAA. Compressive (σc) and biaxial flexural (σf) strengths of the cements were examined at 1, 7 and 30 days post mixing and were found to increase with both maturation and Ge content. The bonding strength of a titanium cylinder (Ti) attached to bone by the cements increased from 0.2 MPa, when placed, to 0.6 MPa, after 14 days maturation. The results of this research indicate that Germano-Silicate based GPCs have suitable handling and mechanical properties for cranioplasty fixation.
authors.affiliation: Department of Mechanical &amp; Industrial Engineering, Ryerson University, Toronto, ON M5B 2K3, Canada. basel.khader@ryerson.ca.
authors.forename: Basel A
authors.initials: BA
authors.lastname: Khader
authors.affiliation: Department of Mechanical &amp; Industrial Engineering, Ryerson University, Toronto, ON M5B 2K3, Canada. curran@ryerson.ca.
authors.forename: Declan J
authors.initials: DJ
authors.lastname: Curran
authors.affiliation: Division of Oral &amp; Maxillofacial Surgery &amp; Anaesthesia, Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada. Sean.Peel@dentistry.utoronto.ca.
authors.forename: Sean
authors.initials: S
authors.lastname: Peel
authors.affiliation: Department of Mechanical &amp; Industrial Engineering, Ryerson University, Toronto, ON M5B 2K3, Canada. mtowler@ryerson.ca.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Towler
keywords: biaxial flexural strength; compressive strength; cranioplasty fixation; germanium; glass polyalkenoate cemets; ovis aries bone; tensile strength; titanium miniplate