Med-Tech Innovation Materials
Table I I: Comparison of S82 fluorcanasite with a commercially available lithium silicate dental ceramic
S82 Fluorcanasite
Chemical solubility Biaxial flexural strength Fracture toughness Hardness % Total transmittance Micro tensile bond strength (ceramic-composite) Micro tensile bond strength (ceramic-dentine) Durability: Micro tensile bond strength
(ceramic-composite) Coefficient of thermal expansion
722 ± 177 µg/cm2 250 ± 26 MPa 4.2 ± 0.3 MPa m1/2 5.16 ± 0.24 GPa 72.5%
27.6 ± 6.9 MPa 29.9 ± 10.1 MPa 15.2 ± 5.5 MPa
9.7 ppm/0 C
Lithium disilicate (Commercial standard) 40 µg/cm2 266 ± 37 MPa 3.3 ± 0.8 MPa m1/2 5.94 ± 0.19 GPa 37.3% 24.8 ± 9.4 MPa
24.77 ± 7.8 MPa 12.3 ± 3.3 MPa
11.4 ppm/0 C
consumables is big business. Pictet Research estimated in 2008 that the global market for dental restorations had reached $3 billion/year and was growing at a rate of 25% per annum. With established players marketing branded ceramic preparations, it was decided that the most sensible route to commercialisation was to license the new technology to one of the leading suppliers in the market. So great was the interest in the material’s improved
properties that demand for evaluation of the new composition quickly grew. Several months of testing followed, during which time the University's laboratory became a small production facility, manufacturing and shipping samples of the new material to locations across Europe.
Initial feedback from potential licensees has been
extremely encouraging. The aesthetic properties of the new material have been particularly well received, and industry partners have provided direct feedback on how the material could be improved to align with their manufacturing processes. The team commercialising fluorcanasite received a further boost in January 2011 when the Food and Drug Administration (FDA) approved the material for marketing in the US.
Finished crown as a completed restoration
Although the chemical durability of the new composition could not be improved to the levels of lithium disilicate, it was significantly improved over previous fluorcanasite formulations and fell well within the accepted ISO standard for use as a core dental restorative material (EN ISO 6872:1999 for chemical stability). On seeing these results, it was clear to Ric van Noort,
Professor of Dental Materials Science, and Dr Sarah Pollington, Clinical Lecturer at the University of Sheffield, that the new material had the potential to rival the dental ceramics currently available on the market. Professor van Noort recalled, “I think many members of the dental materials research community thought what we tried to do could not be done. To produce a fluorcanasite glass-ceramic that had a chemical solubility reduced from in excess of 6000 µg/cm to one with a solubility of less than 1000 µg/cm2
was a major achievement.”
Having achieved this technical success and proven that the material could be milled on a laboratory scale, the next challenge was to identify a suitable route to market.
The road to market Commercial opportunities at the University of Sheffield are managed in partnership with Fusion IP, an AIM-listed company that works with Sheffield and Cardiff Universities to commercialise intellectual property. Working with Fusion IP, the research team secured funding from the Yorkshire Proof of Commercial Concept Fund (
www.yorkshireconcept.org) to further develop the ceramic and a patent application was filed in June 2008. Fusion IP then undertook detailed assessments of the dental materials market and supply chain to ascertain the best route to market for the technology. The supply of CAD/CAM technologies and ceramic
14 ¦ April 2011
Dr James Lapworth is Business Manager for Healthcare Innovations
Dr Sarah Pollington is Clinical Lecturer in Restorative Dentistry, and
Professor Ric van Noort is Professor of Dental Materials Science, all at the University of Sheffield,
www.shef.ac.uk/dentalschool.
Dr Andrew Tingey is Portfolio Licensing Manager for Fusion IP plc, The Sheffield Bioincubator, 40 Leavygreave Road, Sheffield S3 7RD, UK, tel. + 44 (0)114 275 5555, e-mail:
andrewtingey@fusionip.co.uk,
www.fusionip.co.uk
www.med-techinnovation.com
A bright future Andrew Tingey, Portfolio Licensing Manager for Fusion IP said, “We are extremely encouraged by the level of industry interest that we have had in this material, and that we have been successful in obtaining FDA approval for it. We think that fluorcanasite has the potential to be a real commercial success story.”
The technical team has embarked on another round of development of fluorcanasite to perfect the manufacturing process and balance the material’s aesthetic and physical properties. The future for fluorcanasite as a dental material looks very bright.
References
1. G.H. Beall, “Chain Silicate Glass-Ceramics,” J. Non-Cryst Solids, 129, 163–173 (1991).
2. C.W. Stokes, “Canasite Glass-Ceramics for Dental Restorations,” PhD Thesis, University of Sheffield (2003).
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