| dc.description.abstract | Aims: The aim of this study was to design and synthesise a novel bioactive endodontic sealant that contains a bioactive glass (BAG) with strontium and fluoride embedded in a polydimethylsiloxane (PDMS) matrix. The physical and chemical properties of this sealant were compared with a commercially available, bioactive, endodontic sealant, Guttaflow Bioseal® (GFBS). Method: Physical properties were tested for both sealants against the International Organisation for Standardisation (ISO) 6876 and included: radiopacity, solubility, setting time and flow value. Chemical properties were also assessed after immersion of both sealants in simulated body fluid (SBF) and tris buffer solution (TBS). The following were analysed: pH rise, ion release (via inductively coupled plasma optical emission spectrometry (ICP-OES)) and apatite formation (via Fourier-transform infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD)). Results: Both sealants demonstrated physical properties that met ISO 6876. The novel sealant illustrated improved physical properties (higher radio-opacity, lower solubility, and increased setting time). The rate of the Na+ ion release from GFBS was greater than 50 times that of the novel sealant. This explains why the solubility was higher from the GFBS® than from the novel sealant. The flow values for both sealants appeared similar. Both sealants showed an increase in pH over a period of three months, after immersion in solution. A higher pH rise was seen in GFBS®. Both sealants showed ion release (Ca, Na, P and Si), with additional Sr release from the novel sealant. Strontium has been associated with upregulation of osteoblast and 13 downregulation of osteoclast. GFBS had evidence of apatite formation after a 3-month immersion period in SBF, as seen from XRD analysis. Conclusion: Both the novel sealant and the GFBS® demonstrated bioactive properties with ion release from both sealants and the ultimate formation of apatite from GFBS®. The novel sealant showed improved physical properties with the addition of strontium increasing radiopacity and the reduction of sodium in the bioactive glass minimising the solubility of the sealant. | en_US |
