Dr Tony Johnson is Senior Lecturer in the Academic Unit of Restorative Dentistry and Head of the Dental Technology Unit at the School of Clinical Dentistry at the University of Sheffield, UK.

Dr David G. Patrick is a University Teacher in the Dental Technology Unit, Academic Unit of Restorative Dentistry at the School of Clinical Dentistry at the University of Sheffield, UK.

Dr Christopher W. Stokes is Senior University Teacher in the Academic Unit of Restorative Dentistry at the School of Clinical Dentistry at the University of Sheffield, UK.

Mr David G. Wildgoose until his retirement in 2009 was a Dental Instructor in the Dental Technology Unit, Academic Unit of Restorative Dentistry at the School of Clinical Dentistry at the University Sheffield, UK.

Dr Duncan J. Wood is a Senior University Teacher in the Dental Technology Unit, Academic Unit of Restorative Dentistry at the School of Clinical Dentistry at the University of Sheffield, UK.