Bioengineering and Health Technologies: Our team
The Bioengineering and Health Technologies Group leads research into all aspects of the use of biomaterials and medical devices for the repair of human tissues to restore functionality and aesthetics. The Group brings together basic scientists, dental technicians, and clinicians to form a dedicated team with all the skills necessary to support a broad interdisciplinary programme.
Our project portfolio encompasses research into advanced and nanostructured materials, digital dentistry and advanced manufacturing, and regenerative therapies including tissue engineering. This research programme is directed at providing the scientific and technical advances that underpin the deployment of new technologies and clinical interventions to make a substantial difference to human longevity and improved quality of life.
Our capabilities and impact are further strengthened by international collaboration and industrial partnership. The Bioengineering and Health Technologies Group has contributed significantly to the development of new materials and clinical interventions that make a difference to many thousands of people worldwide, and our current programme will undoubtedly continue to make a difference in the future.
- A message from the team leader: Dr Cheryl Miller
Healthy human tissues and anatomical structures provide superb functionality and incredible longevity. The structural components of the head, neck, face and oral cavity are very important in a wide range of activities that include maintenance of the airway, sensory awareness, communication, eating, and drinking. The face in particular is an important part of our identity, and it is therefore important to achieve a good cosmetic result with any intervention. Not surprisingly, trauma and disease in this region is potentially life-threatening and can substantially undermine quality of life. The aim of our Group is therefore to lead pioneering scientific research into new technologies for the repair and regeneration of tissues in the head, neck and face in order to substantially improve human health and quality of life. Towards this goal, we have three broad objectives:
- To develop and understand new biomaterials with enhanced functional performance for use in clinical applications
- To pioneer the application of new digital technologies and advanced manufacturing technologies to make custom medical devices and scaffolds
- To innovate in the exciting new field of tissue engineering and regenerative dentistry, taking this research forward from the laboratory bench towards clinical application
The group are responsible for numerous advances in biomaterials and devices used in repairing the body and enhancing quality of life. Examples include:
- Advanced Materials: Bioactive bone cements. The B&HT Group, working as part of a European consortium, developed a new biocompatible ionomeric bone cement that is used today in the treatment of thousands of patients worldwide for delicate operations on the bones of the ear, the smallest mineralised structures in the human body.
- Digital Technology, Design and Processing: Custom implants for craniofacial reconstruction. The B&HT Group were one of the first in the world to combine new digital acquisition and design technologies with advanced manufacturing to produce custom medical devices for surgery on the jaw and temporo-mandibular joint.
- Tissue Engineering: Complex 3D tissue models for in vitro testing. Complex in vitro models of oral mucosal have been used in collaboration with industry to test the safety and performance of commercial oral health products, research that has the potential to reduce the use of animals in laboratories throughout the world.
- Principal Investigators
Professor of Biomaterials Science and Honorary Non-Clinical Investigator
Clinical Professor & Honorary Consultant in Restorative Dentistry
Reader in Dental Implantology and Biomaterials (non-clinical)
Senior Clinical Lecturer and Consultant in Restorative Dentistry
Ílida Ortega Asencio
- Associated Staff
Consultant in Prosthodontics and Senior Clinical Teacher in Restorative Dentistry
Christopher W. Stokes
Senior University Teacher
- Postdoctoral Researchers
Postdoctoral Research Associate (2018-present)
I graduated with an MEng degree in Bioengineering in 2015, before starting a PhD split between the Biomaterials & Bioengineering group in Materials Science and the BHT group at the School of Clinical Dentistry, supervised by Dr. Vanessa Hearnden, Dr. Cheryl Miller and Mr. Alasdair McKechnie. My PhD investigated bisphosphonate-related osteonecrosis of the jaw (BRONJ) - using 2D and 3D cell culture to examine bisphosphonate effects on oral soft tissue and whether calcium phosphates could be used to prevent them. I began working as a postdoctoral researcher in December 2018 at the School of Clinical Dentistry, on a project led by Dr. Cheryl Miller, developing an enhanced bone graft material in collaboration with Ceramisys Ltd. In November 2019, I started an EPSRC Doctoral Prize fellowship, in collaboration with Ceramisys Ltd., to continue my PhD research and further develop calcium phosphates as a treatment for BRONJ.
Postdoctoral Research Associate (2019 - Present)
After graduating with an MEng degree in Biomedical Engineering in 2011, I started a PhD at the School of Clinical Dentistry supervised by Prof Paul Hatton and Dr Cheryl Miller. I completed my PhD entitled ‘Nanostructured Medical Ceramics for Bone Tissue Regeneration’ in 2015. This PhD was a CASE studentship in collaboration with Ceramisys Ltd. who manufacture synthetic bone regeneration materials. I am currently continuing multidisciplinary research at the School of Clinical Dentistry with Ceramisys Ltd. to develop materials with enhanced functionality including the stimulation of bone tissue regeneration in combination with antibacterial activity.
Postdoctoral Research Assistant (2015-present)
I began my research career after completing a MEng undergraduate degree in 2012 reading Biomaterials Science and Tissue Engineering, at The University of Sheffield. I embarked on a PhD at the University in the department of Materials Science, investigating synthetic scaffolds for stem cell delivery & guided regeneration of bone. Since arriving in the School of Clinical Dentistry in 2015, I have worked on a variety of projects, mainly themed around biomaterials development for both guided tissue regeneration & antimicrobial purposes.
I specialise in additive manufacturing (CAD and CAM), electrospinning, biocompatibility and antimicrobial testing of biomaterial scaffolds. I have established collaborations with researchers in China, having been on a research exchange and having hosted a researcher. I have lectured on dental materials, manufacturing and digital dentistry to both masters student and undergraduates. I have also run seminars on the use of Autodesk Maya and Materialise Mimics to undergraduates, masters and PhD students.
I am working on two main projects: The first is with the UK EPSRC centre MeDe innovation designing topologically controlled electrospun membranes for bone regeneration. The second with the European consortium MOZART, testing antimicrobial mesoporous matrices against microbial biofilms.
Ms. Altair Contreras JaimesAltair Contreras
Research Assistant (2011-2014)
I worked as Research Assistant in glass ionomer bone cements. I did my undergraduate degree in Metallurgical Engineering, when I became interested in Biomaterials after developing my thesis on porous hydroxyapatite scaffolds, specifically studying their mechanical properties and the correlation with porosity variation. After working in business related jobs, I decided to start a Master in Bioengineering at The University of Nottingham in 2009. For this course, I had the chance to work on the biological Response of MG63 cells on Red Algae derived hydroxyapatite, which gave me a better insight on the applications of bone scaffolds and motivated me to continue my career on this field.
Postdoctoral Research Associate (2016 - 2018)
Worked collaboratively with the University and industry to develop, manufacture and characterise surface modified calcium phosphate bone grafts after finishing a related PhD in 2017. Interests in orthopaedics, regulatory affairs, biomechanics, biomaterials and engineering carried forward from an MEng awarded at The University of Sheffield in 2012.
Post Doctoral Research Associate (IEF Marie Curie Fellowship and MeDe Innovation 2012-2015)
Piergiorgio Gentile graduated with a Master Degree in Biomedical Engineering from the Politecnico di Torino (Turin, Italy) in 2006 and he gained his PhD in Biomedical Engineering in 2010 for studies into the investigation of physico-chemical properties of photoactive copolymers (photozymes) and the evaluation of the biological response to these newgeneration polymers into scaffolds or functionalized surfaces.The research interests are focused on biomedical materials (polymers and composites) and tissue engineering & regenerative medicine. Specifically, my research deals with nano and micro-scale design and manufacturing of biomimetic scaffolds for tissue engineering with an emphasis on the optimization of the chemico-physical and mechanical properties suitable for cell growth and differentiation.
Carolina Herranz Diez
Post-doctoral Research Associate (IMCOSS 2013-2014)
I hold a PhD in Biomedical Engineering from the Universitat Politècnica de Catalunya. My research is focused on the interaction of cells with biomaterials. My areas of expertise include recombinant protein techniques, surface biofunctionalisation techniques, physico-chemical characterization of surfaces, mechanical response of cells to surfaces and in vitro studies for cell growth and differentiation.
Post-doctoral Research Associate (IMCOSS 2013)
I started a postdoctoral research associate position in January 2013. I work closely with Dr Cheryl Miller and Dr Aileen Crawford in the tissue engineering group investigating the in vitro biocompatibility and osteogenic potential of nanomaterials. Work is performed in collaboration with the Department of Materials Science and Engineering, at the University of Sheffield, the Ludwig Bolzmann Institute in Vienna and industrial partners, Ceramisys, Fluidinova and Primequal. The aim is to develop a new injectable bone graft substitute, with a dedicated delivery system, for the European and global medical devices/health technologies sector.
Post-doctoral Research Associate (IMCOSS 2013-2014)
I obtained my MSc degree in Chemistry from Tula State University, Russia in 2005 followed by PhD in Physical Chemistry in 2012 from Cardiff University, UK. I joined the University of Sheffield as a post-doctoral research associate in 2013. Originally being appointed at the Department of Materials Science and Engineering I work in close collaboration with the Dental School and biomaterials research group in particular. My research interests lie in the field of materials characterization using a wide range of spectroscopic tools (FTIR, Raman), X-ray techniques (XPS, XRPD) as well as electron microscopy (TEM, SEM). I am currently involved in a variety of projects spanning from bone grafts synthesis and characterization to understanding kinetics and mechanisms of restorative cements formation and setting.
Martin Santocildes Romero
Post-doctoral Research Associate (2014-2017)
I joined the School of Clinical Dentistry as a PhD student in 2009, after completing the degree of MEng in Biomedical Engineering at the University of Sheffield. The aim of my PhD research, supervised by Dr Cheryl Miller, Prof Paul Hatton and Prof Ian Reaney, was the development of membranes for bone tissue repair using a combination of biocompatible polymers and bioactive glasses, and manufactured using electrospinning. Following the PhD I worked as a postdoctoral researcher at the School of Clinical Dentistry on a couple of projects for 3 years and 1 month. The first project was a commercial collaboration of the School with the Danish company Dermtreat ApS for the development of mucoadhesive electrospun patches for localised drug delivery in the oral cavity. The second project was a MeDe Innovation funded research aimed to develop membranes with enhanced properties for musculoskeletal repair. In October 2017 I moved back to Spain, where I am taking a short break from research and I am spending my time refurbishing an old village house in El Bierzo, a region in northwest Leon. Regarding future plans, I will be moving to Copenhagen in February 2018, where I have been employed by Dermtreat ApS to work on the development of their new line of products.
Post-doctoral Research Associate (2010-2013)
I joined the University of Sheffield in 2010 as a post-doctoral research associate, undertaking research in 3D colour reproduction for soft tissue prosthesis. I then moved to new post as a Discipline Hopping Fellow, working in social psychological impact of living with facial prostheses. My research interests are colour and appearance measurement, 3D image capturing and processing and quality of life assessment in Dentistry.
- Postgraduate Researchers
PhD student (2014-2018)
PhD title: 3D-printing technique for development of composite alveolar bone and oral mucosal model.
Supervisors: Dr Keyvan Moharamzadeh, Dr Robert Bolt, and Prof. Ian Brook
Recent advances in three-dimensional printing technology have led to a rapid expansion of its applications from printing patient-specific constructs for therapeutic applications, to creation of complex, reproducible in vitro tissue models for research purposes. The aims of this project are to develop and characterise a composite human alveolar osteo-mucosal model using both conventional and advanced printing bone scaffolding techniques. The second aim is to explore the feasibility of using the printed model in oral cancer investigations or for the evaluation of novel diagnostic or therapeutic approaches to manage oral cancer in the future.
PhD student: (2015-2019)
PhD title: The effect of the topology of electrospun scaffolds on the behaviour of alpha-tanycyte cells
Supervisors: Dr Ilida Ortega, Prof Paul Hatton and Prof Marysia Placzek
I graduated with a first in Biochemistry and Genetics (MBiolSci) from the department of Molecular Biology and Biotechnology at The University of Sheffield in 2015. Following this, I began my PhD which involves manufacturing electrospun scaffolds with different topologies in order to investigate how the alpha tanycyte population of the hypothalamus respond differently to these structures. This project involves interdisciplinary research between The School of Clinical Dentistry and Biomedical Sciences, combining manufacturing techniques with cell biology.
PhD student (2015-2018)
PhD title: Tissue engineering solutions for the treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ)
Supervisors: Dr Vanessa Hearnden, Dr Cheryl Miller, Mr Alasdair McKechnie
I graduated with a Master’s degree in Bioengineering from the University of Sheffield in 2015, before starting a PhD project split between the Biomaterials & Bioengineering group in Materials Science and the BHT group at the Dental School. My project focuses on the development of a tissue engineered solution for BRONJ. This involves the study of the soft tissue effects of BRONJ with in vitro 3D oral mucosa models, and investigating potential ways to mitigate the effects using hydroxyapatite.
PhD Student (2016-2019)
PhD Title: 3D Printing Smart Materials for Cleft Palate Repair
Supervisors: Dr Cheryl Miller, Dr Ilida Ortega, Dr Robert Moorehead & Prof Julian Yates
I graduated with a degree in bioengineering from the University of Sheffield in 2015 specialising in biomaterials science and tissue engineering. I am currently in the 2nd year of my PhD project, the aim of which is to produce patient-specific palatal obturators as an alternative to the traditional corrective surgery. One of my supervisors, Prof Julian Yates from the University of Manchester, is a surgeon in this field which ensures the project remains clinically relevant.
PhD student (2015-2019)
PhD title: The development of electrospun polymer devices for drug delivery to the oral mucosa
Supervisors: Prof. Paul Hatton, Dr. Sebastian Spain, Dr. Craig Murdoch
I graduated with a first class degree in Mechanical Engineering from the University of Warwick in 2015. Currently I am a PhD student based in the Dental School funded by the Polymer CDT EPSRC and an industrial sponsor, Dermtreat ApS. My PhD project is in developing an electrospun polymer patch incorporating a therapeutic agent to target oral mucosal diseases. This highly multi-disciplinary project involves work in manufacturing, material characterisation, analytical chemistry, microbiology, and mammalian tissue culture. My PhD involves a placement at the University of Copenhagen Pharmacy Department to measure drug diffusion through ex vivo tissue from the electrospun patches. Working in collaboration with industry gives this project both clinical and commercial relevance.
PhD Student (2015-2019)
PhD title: Investigating the Validity of the ISO 6872:2015 ‘Dental Ceramics’ for Chemical Solubility.
Supervisors: Dr. Christopher Stokes, Dr. Cheryl Miller, Dr. Robert Moorehead.
I am working on investigating the validity of the ISO standard method of measuring the chemical solubility of dental ceramics. In addition to expertise in chemical solubility testing I have been trained in many techniques to prepare and finish dental ceramics, including CAD-CAM, and in analytical and imaging methods such as SEM. I have always had an interest in teaching, and have attended a number of teaching courses and tutoring in the University of Sheffield. My main interests are in dental materials and their processing methods.
Beatriz J.C. Monteiro
A*STAR PhD Programme Student (2016-2020)
PhD title: Development of biofunctional and bioinspired scaffolds for the control of stem cells fate
Supervisor: Dr. Ilida Ortega, Prof. Paul Hatton, Dr. Simon Cool
I am currently a 2nd year PhD student at the University of Sheffield working on an interdisciplinary project in collaboration with A*STAR Institute in Singapore. I have a background in cellular and molecular biology, however, I developed my interest in tissue engineering strategies during my master degree in biotechnology at Universidade de Lisboa, Portugal. My PhD project is focused on the development of bioinspired hierarchical and biofunctional scaffolds for the control of stem cell behaviour by combining advanced manufacturing techniques (Sheffield) with glycotherapeutics (Singapore) to ultimately create an innovative platform for studying bone regeneration.
PhD Student (2016-2020)
PhD title: Development of Additively Manufactured Stratified Custom Ceramic Implants for Maxillo- and Cranio- facial Reconstruction
Supervisor: Dr Cheryl Miller, Dr Robert Moorehead and Dr Candice Majewski
I developed my passion for bone regeneration during my master’s degree which was in biomaterials and regenerative medicine at the University of Sheffield. I wanted to further my knowledge in this topic and thus decided to carry out a PhD in the development of additively manufactured implants for the reconstruction of the orbital floor. The aim of my project is to fabricate a 3D printed ceramic composite scaffold with antibacterial and osteogenic properties. I will focus on selective laser sintering of polyamide (PA) with hydroxyapatite (HA) and zinc (Zn). PA is a biocompatible material with an increased mechanical strength that makes it ideal for bones restoration when combined with a bioactive ceramic such as HA. Biomaterial infections have been associated with bacterial colonization. Zinc ions have antimicrobial properties which have been found effective against such infections.
Amnael (Carlos) Orozco Diaz
PhD Student (2015-2018)
PhD title: 3D-printing of custom prostheses for maxillofacial reconstruction.
Supervisors: Dr. C. Miller, Dr. R. Moorehead, Dr. G. Reilly
I graduated in 2008 as BSc in Biomedical Engineering from the Monterrey Institute of Technology and Higher Education (ITESM) in Mexico City. I am currently a fellow of the National Council for Science and Technology (CONACyT) from Mexico, who have awarded me a full scholarship for a PhD degree in the UK. My PhD project looks into the development and initial characterisation of a 3D-printing composite filament which is compatible with currently-available commercial grade 3D-printers. This new material consists of a polylactic-acid polymer phase with embedded micro-scale hydroxyapatite particles. This material is aimed to produce therapeutic bone implants that promote new bone formation while being fully absorbable post-implantation.
Danilo Villanueva Navarrete
PhD Student (2016 - 2020)
Supervisors: Dr. Ilida Ortega Asencio, Prof. Sheila MacNeil and Dr. Frederik Claeyssens
I am a Biotechnology Engineer from the Universidad de Santiago (Chile) with a MSc degree in Biological and Bioprocess Engineering (University of Sheffield). Before starting my current PhD position, I worked for 2 years as a project engineer in Chile linking universities research with industry. Since October 2015 I have been working as a PhD student (funded by CONICYT) developing my research between The School of Clinical Dentistry and at The Department of Materials Science and Engineering in Sheffield. My project involves the development of biofunctional microfabricated scaffolds for corneal repair including both their manufacture (using a combination of additive manufacturing techniques and electrospinning) and their in vitro evaluation using rabbit corneal models.
Saja Muhsin Ali
PhD Student (2013-2016)
PhD title: Biologically active surface modifications to scaffolds for bone tissue regeneration.
Supervisor: Dr C Miller
I am a TERM-DTC student with a previous 1st class masters in biomaterial science and tissue engineering (Tissue Engineering & Regenerative Medicine Doctoral Training Center). My project involves research into improving the capacity, consistency and speed of bone regeneration through surface modification of alloplastic bone grafts. My PhD is also currently CASE supported, enabling collaborative research and supervision towards relevancy in industry.
PhD Student (2011-2015)
PhD title: Nanostructured medical ceramics for bone tissue regeneration.
Supervisor: Prof. Paul Hatton.
My PhD project involves the synthesis and characterisation of nanoscale hydroxyapatite products. I have been trained to carry out a variety of specialist materials characterisation techniques including X-ray diffraction and transmission electron microscopy. In the future I will carry out biocompatibility assays to determine how cells respond to the materials I have synthesised. Since my PhD is a CASE studentship, I also work closely with my industrial supervisor to ensure my experiments are relevant to the biomaterials industry.
PhD student (2011-2015)
PhD Title: The remineralisation of eroded or carious dentine by infiltration with nanoparticles
Supervisors: Dr Nicolas Martin, Dr Cheryl Miller and Prof. Chris Deery
I graduated with a degree in Biochemistry and Microbiology from the University of Sheffield in 2010. I then went on to work for a company which specialises in developing, manufacturing and marketing synthetic calcium composite devices for tissue regeneration. This is where I developed an interest in dental materials. I am currently undertaking a four year CASE studentship which is sponsored by BBSRC and GlaxoSmithKline. My project is focused on infiltrating dentine collagen with nanoparticles as part of a strategy to re-mineralise dentine that has been affected by caries or acid erosion. Having an industrial sponsor means that I really appreciate the potential clinical outcomes. Overall, I am enjoying being involved in the world of dental materials research.
PhD Student (2011-2015)
PhD title: The effect of the interface lute on the structural integrity of the tooth-ceramic crown system
Supervisors: Dr N. Martin, Dr E. Tsitrou, Dr E. Ghassemieh
My PhD project is going to:
- Determine the effect of the interface in adhesively cemented all-ceramic crowns on the structural integrity of the restored tooth in-vitro mechanical testing and FE analysis.
- Explore the correlation between the two analytical techniques used to determine the structural performance of the adhesively-bonded all-ceramic crown-tooth complex.
Hawa M Fathi
PhD Student (2008-2012)
PhD title: Development of apatite-mullite glass-ceramic materials for use as dental restorations.
Supervisors: Dr Anthony Johnson, Dr Christopher Stokes, Dr Cheryl Miller
My project is concentrating on evaluating the effect of adding two nucleating agents (ZrO2 and TiO2) on the properties of apatite-mullite glass-ceramic material to try and improve the durability and the strength of the material to comply with the ISO standard recommendations for dental ceramics.
PhD Student (2010-2013)
PhD Title: Functional and tribological properties of tissue engineered cartilage
Supervisors: Prof .Paul Hatton, Dr. Aileen Crawford (University of Sheffield), Prof. John Fisher and Dr. Sophie Williams (University of Leeds)
Tissue engineering techniques have the potential to provide a patient specific treatment for the repair and regeneration of secondary osteoarthritic cartilage defects following traumatic soft tissue injury. The aim of my PhD is to produce high quality cartilage constructs using bovine chondrocyte seeded matrices, with particular focus on some of the biological factors that influence its mechanical properties. Functional investigation of tissue engineered cartilage in vitro is vital in predicting its performance in vivo, therefore my work involves producing tissue with enhanced lycosaminoglycan, collagen II and surface zone protein content and assessing their relationship with compression resistance and surface tribology.
PhD Student (2011-2015)
PhD title: Electrospun membranes for bone tissue repair and regeneration
Supervisors: Prof. Paul Hatton, Dr Cheryl Miller, Mr Wayne Austin (Ceramisys Ltd) and Dr Paul Genever (University of York)
Membranes are used in dental implant and periodontal surgery to exclude soft tissues from the surgical site where bone tissue healing is required. There is a gap in the current market for a synthetic and resorbable membrane, and the aim of this project is to fabricate series of electrospun modified synthetic bioresorbable membranes, characterise their structure and physical properties, and evaluate specific properties related to their use as membranes and scaffolds in bone tissue regeneration (e.g. biocompatibility). This project has CASE funding from Ceramisys Ltd.
PhD Student (2009-2012)
PhD title: The rapid manufacture of facial soft tissue prostheses using CAT/CAM technology
Supervisors: Prof. Julian Yates, Prof. Richard van Noort
The general disadvantages of the conventional methods of fabrication of soft tissue facial prostheses include high cost and shortage of technical staff. The increasing demand for this kind of prosthetic led our research team to provide a simple system for data capture, design and reproducible manufacture method with a clinically acceptable material. This will deliver a relatively low cost process that will be accessible to the global patient community. My project focuses on the manufacturing aspect of the digital processing of soft tissue facial prostheses by layered fabrication method. The project could be summarised as; 3D data capturing, 3D designing and layered printing using Z510-3D colour printer.
Martin Eduardo Santocildes Romero
PhD Student (2010-2013)
PhD Title: Electrospun polycaprolactone/strontium-substituted bioactive glass scaffolds for bone tissue engineering
Supervisors: Dr Cheryl A Miller, Prof. Paul Hatton, Prof. Ian Reaney
The aim of this project was to fabricate an electrospun composite material using a bioresorbable polymer and particulate bioactive glass and then to study its potential use as a scaffold for bone tissue engineering. For this purpose we used polycaprolactone and strontium-substituted bioactive glass, which is reported to encourage the formation of new bone tissue thanks to the action of the strontium ion. Once production of the composite material is completed, our intention is to study their cytotoxicity and their effect on osteoprogenitor cells.
PhD student (2011-2014)
PhD title: Resin bonded polymer fixed partial dentures (FPD) made with CAD/CAM and 3D printing technologies for Temporary and Permanent application
Supervisors: Dr Effrosyni Tsitrou, Prof Richard van Noort, Dr Sarah Pollington
CAD/CAM opened the gate for the very recent 3D rapid prototyping manufacturing methods. 3D printing or Rapid prototyping is a growing approach for medical applications. Rapid prototyping can be through laser sintering, layered fabrication or Inkjet printing. However, these fabrication methods are still in their infancy in the dental field and success of these restorations are not assessed yet. It is therefore of interest to investigate the performance of these restorations. For that reason CAD/CAM CEREC, and 3 methods of 3D printing will be compared. Accuracy of fit and geometry followed by mechanical testing and Finite element analysis models.
Research masters student (2010-2012)
Project title: Investigating and optimising composite veneered zirconia laminates
Supervisors: Dr David Patrick, Dr Duncan Wood, Dr A Johnson
All-ceramic crowns is an example of recently developed methods for producing dental restorations. An attempt to optimise metal-free crowns and overcome all-ceramic restorations disadvantages led to the idea of the project; combine the advantages of zirconia (strong core capable of protecting underlying tooth), and light-cured composite (aesthetic, easy to handle and repair, and less abrasive to opposing natural teeth). Investigations was carried out on specimens shaped as discs and crowns (n=10) made out of different restorative materials. Mainly, CAD/CAM milled coping of yttrium partially-stabilised zirconia, veneered with in-lab light cure composite. Different assessments such as: Fracture Resistance, Biaxial Flexural Strength and Finite Element Analysis using ANSYS software, were used with specimens both single laminate groups.
PhD Student (2010-2014)
PhD title: Development of titanium powder metallurgy for dental restorations.
Supervisors: Dr Tony Johnson, Dr Christopher Stokes
The aim of my project is to implement the concept of powder metallurgy into dental technology. Titanium metal powder is cold uniaxially pressed and sintered in an inert atmosphere. Samples are characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). I will be performing some milling to produce some metallic dental copings using CAD/CAM technologies. Mill-ability of titanium was analysed using industry standards and was compared with some current dental materials.
PhD Student (2010-2013)
PhD title: Recapitulating endochondral ossification to produce hypertrophic cartilage constructs for bone
Supervisors: Dr Aileen Crawford, Prof. Paul Hatton, Prof. Ian Brook
I am investigating the ability for chondrocytes isolated from the nasal septum to follow the path of endochondral ossification and become hypertrophic before producing a mineralised cartilage. It is hoped that these mineralised constructs can be implanted into maxillofacial defects where they will be remodelled into bone. The techniques used in this project include cell culture, microbiology and immunohistochemical techniques.
PhD Student (2011-2014)
PhD title: Remote Clinical Consultations using super-fast broadband connectivity and Virtual Reality in dentistry
Supervisors: Dr Nicholas Martin, Dr Daniela Romano, Dr Chris Stokes
My project is in telemedicine research. It involves examining the feasibility of undertaking patient-centred clinical consultations remotely using super-fast internet connectivity. This is being compared to the face-to-face modality currently undertaken. It will involve the use of sophisticated web enablement, 3D graphic online manipulations and Virtual Reality, using a novel interdisciplinary approach, and emerging technologies. Initially focussed within dentistry, the project has the scope to spread to lots of other areas of medicine.
PhD Student (2011-2015)
PhD Title: Fabrication and Evaluation of Complex or Custom Scaffolds for Skeletal Tissue Engineering
Supervisors: Prof. Paul Hatton, Dr Frederik Claeyssens.
Healthy craniofacial bone and connective tissues contribute significantly to many aspects of human health including communication, respiration, vision, and aesthetics. Damage to these tissues is frequently associated with loss of functionality, pain, and disfigurement. The shape and anatomical structure of bones in the head, neck and face often plays a crucial role in supporting function. Therefore, there is significant interest in the fabrication of custom prostheses or scaffolds that can promote tissue regeneration in a desired 3D shape. While a range of rapid manufacturing techniques are now available to produce custom shapes, the biomaterials associated with these crude systems are not always suited to human implantation.
My project is focused on developing and evaluating craniofacial custom porous scaffolds made of novel biomaterials which are capable of promoting rapid and successful healing of craniofacial defects using Solid Freeform Fabrication technologies.
PhD Student (2011-2015)
PhD Title: Bone Tissue Engineering on 3D Scaffolds in a Bioreactor Chamber (CASE)
Supervisors: Prof. Paul Hatton (School of Clinical Dentistry, University of Sheffield), Prof. Ben Varcoe (School of Physics and Astronomy, University of Leeds), Prof. Sheila MacNeil (Kroto Research Institute, University of Sheffield), J Malcolm Wilkinson (Kirkstall Ltd.) & Stefan Przyborski (Reinnervate Ltd.)
My PhD is an exciting mix of biology and physics with an aim to improve technologies for tissue engineering bone. My background is in physics and I graduated with a first class physics degree from the University of Leeds in 2011. I then started my 4 year PhD program at the White Rose Consortium Doctorial Training Centre in Tissue Engineering and Regenerative Medicine which is funded by ESPRC, and I have just completed a training year. I am just beginning my project which is split between the University of Sheffield and the University of Leeds with industrial partnerships with Kirkstall (Ltd) and Reinnervate (Ltd). In my project I am hoping to create a new bone culture bioreactor which can be used as a simulation tool to help us understand how materials and drugs interact with the body. I am also working on methods for non-destructively analysing tissue cultures which will hopefully help to make tissue engineering in research and industry more time and cost efficient.
PhD Student (2009-2013)
PhD Title: Aligned fibre matrices for use as scaffolds in periodontal ligament engineering
Supervisors: Dr. Aileen Crawford, Prof. Gareth Griffiths and Prof. Paul Hatton.
Periodontal tissue engineering is a relatively new field with enormous potential to fully regenerate the lost periodontal tissues and may also overcome some of the limitation in the existing periodontal therapies. Much interest has been directed towards the construction of aligned scaffolds, as this feature may influence cell behavior. The overall aim of the project is to investigate the effect of fibre alignment of electrospun poly-L-lactic acid (PLLA) mats on the biological response of periodontal ligament fibroblasts (PDLFs). As a Periodontist, the project gave me the chance to increase my knowledge on the periodontal molecular and cellular biology as well as to develop my research skills.
PhD student (2006-2009)
PhD Title: Ceramic Scaffolds for Bone Tissue Engineering
Supervisors: Prof. Paul Hatton, Dr. Aileen Crawford, Dr. Kathryn Hurrell-Gillingham and Prof. Dr. Ralph Muller (ETH Zurich).
The requirement for bone tissue engineering has evolved from the limitations of biological and synthetic grafts. Hydroxyapatite and calcium phosphate ceramic scaffolds are highly suited to bone tissue engineering due to their chemical similarity to bone mineral and extensive track record as bone graft substitutes. This EPSRC CASE project is being undertaken in collaboration with a local medical ceramics company, Ceramisys Ltd. We aim to develop and evaluate porous hydroxyapatite, other calcium phosphates and composite scaffolds for bone tissue engineering.
PhD student (2002-2005)
PhD Title: The Development of Canasite Glass-Ceramic Bone Substitutes
Supervisor(s): Prof. Ian M Brook, Prof Paul Hatton and Prof Ian Reaney (Engineering Materials)
Fluorcanasites are quadruple chain silicate glass- ceramic, have a highly crystalline microstructure of interpenetrating laths that give rise to high flexural strength (>300 MPa) and fracture toughness (>5 MPa m-2). Early commercial compositions were bioinert or even irritant to bone tissue (da Rocha Barros et al. 2002). In the same year, Miller et al. demonstrated that the addition of excess CaO and P2O5 to the stoichiometric (Ca5Na4K2Si12O30F4) composition induced the early formation of an apatite layer in simulated body fluid. However, no quantitative data regarding their biocompatibility has been published to date, and knowledge of structure-property relationships in these materials remains limited.
The aim of this research was therefore to further characterise these modified fluorcanasite glass-ceramics after controlled two stage heat-treatment and to compare their in vitro biocompatibility with parent and commercial bioactive glasses. Properties of the fluorcanasite glass and glass-ceramics including ion release were also studied and the data related to biocompatibility.
PhD student (2006-2009)
PhD Title: Nanoparticulate materials for re-mineralising dental caries
I am working on using nanoparticulate materials to infiltrate dental caries to encourage or promote re-mineralisation. The intent its to prevent decay reaching the pulp cavity in the first place, and re-build some of the inorganic dentine/enamel structure that protects it.
PhD student (2003-2007)
PhD Title: Evaluation of restoration bonding systems using microtensile bond strength tests and finite element analysis
Supervisor(s): Prof. Richard van Noort and Elahel Ghassemieh (Mechanical Engineering)
Laboratory bond strength measurement is a widely used method of evaluating commercial dentine bonding systems and predict their clinical performance. Therefore, a thorough understanding of the stress patterns involved in bond failure is an important factor in evaluating usefulness of a specific bond strength testing method. Different specimen designs are used in the microtensile bond strength testing method; these are stick, dumbbell and hourglass shape. However, so far little attention has been paid to the details of methodology of the test procedures used. The aim of this study is to compare three dentine bonding systems utilizing three experimental microtensile bond strength test designs (µTBS) and correlating the outcomes with finite element stress analysis (FEA).
PhD student (2006-2009)
PhD Title: Characterisation and Evaluation of Glass Ceramics for applications in Implantology and Maxillofacial Surgery
Supervisor(s): Prof. Paul Hatton, Prof. Ian Reaney (Engineering Materials), Prof. Ric van Noort and Prof. Ian Brook
My research comprises of characterisation and evaluation of compositions from the Fluorrichterite Group of glass ceramics that have been selectively modified to be osteoconductive. These compositions have promising mechanical properties and their potential applications include single unit bioceramic dental implants and custom prostheses for repairing maxillofacial bony defects. Currently there are no all bioceramic dental implant systems available and most maxillofacial reconstruction is done using autogenous bone which can cause significant co-morbidity. Therefore, the potential for an osteoconductive bioceramic material which has good mechanical properties is very good.
My work till date has included XRay Fluoresence Spectroscopy (XRF), XRay Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), Solubility measurement, Ionic Release Measurement using ICP and Ion Selective Electrodes. I am currently carrying our in-vitro biocompatibility assessment and osteoconductivity prediction using Simulated Body Fluid (SBF). This assessment includes Thin film XRay Diffraction (TF-XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and possibly Raman Spectroscopy along with SEM. This work will then lead onto in-vivo assessment.
PhD student (2002-2005)
PhD Title: Development of Thermoresponsive Hydrogels for Cell Expansion
Supervisor(s): Dr Steve Rimmer (Department of Chemistry) and Prof Paul Hatton
Bioresorbable polymer scaffolds are frequently described in studies of cartilage tissue engineering. However, to date there has been no single biomaterial or design universally accepted for this purpose. Existing scaffolds suffer from uncontrolled degradation, and it remains difficult to recover tissues from agarose and alginate gels. A biocompatible thermoresponsive polymer would be desirable for culturing chondrocytes, and would have applications in the recovery of intact chondrocytes with their pericellular matrix for further tissue engineering applications. The aim of this study was therefore to develop and investigate a novel, thermoresponsive 3D scaffold based on Poly(N-isopropylacrylamide) (pNIPAAm). This macromonomer was used in the synthesis of cross-linked graft copolymer networks with glycerol methacrylate (GMA).
PhD student (2005-2008)
PhD Title: Chondrocyte expansion on thermoresponsive polymers
Supervisor(s): Prof. Paul Hatton and Dr Aileen Crawford.
One critical step of the tissue engineering process is the expansion of cells from a small biopsy. Convention methods for cell expansion use enzymes that may be sourced from animal tissue. This introduces a risk of infection, and there is some evidence that enzymes and EDTA might injure cells and contribute to their loss of phenotype during expansion. The aim of my research is to develop and evaluate a novel thermoresponsive route for cell expansion using modified hydrogels. This route takes advantage of changes in surface chemistry and dimension to release cultured chondrocytes from surfaces without potentially harmful enzymes. I am also investigating whether or not this approach will help to maintain the chondrocytic phenotype in expanded cell populations.
PhD student, (2000-2003)
PhD Title: Characterisation of Tissue Engineered Hyaline Cartilage
Supervisor(s): Prof. Paul Hatton and Prof. Ian M Brook
There is a great deal of expectation that tissue engineering will revolutionize medicine in the next decade and beyond. This expectation is based firmly on recent developments in cell biology, biomaterials science and clinical techniques. While it will ultimately affect most or all branches of medicine, certain tissues are more suitable than others for pioneering research with a good likelihood of clinical impact in the very near future.
Cartilage is one such tissue for a number of reasons that include the fact that it is synthesised by only one cell type, we have a good understanding of chondrocyte biology and there is an urgent clinical need for improved cartilage tissue repair. This PhD aims to compare and contrast the structure of engineered cartilage with natural tissue (both articular and nasal) at the level of both light and electron microscopy. Light level studies will include immunohistochemisty of the chondron (in particular, localisation of Type VI collagen).
PhD student (2003-2009)
PhD Title: Computerised iris reproduction
Supervisor(s): Dr A. Johnson & Mr D Wildgoose
The nature of this work involves developing a new method of artificial eye construction for people who have lost eyes due to trauma, disease or congenital deformity. It investigates the feasibility of using digital technology to reproduce a human iris, that accurately conforms to the patient's remaining eye, and to standardise the production of artificial eye prosthesis construction whilst providing a natural exact replica of the remaining eye.
PhD student (2005-2008)
PhD Title: Polymer-Ceramic Composite Scaffolds for Osteochondral Tissue Engineering
Supervisor(s): Prof. Paul Hatton, Prof. Ian Reaney (Engineering Materials) and Prof. Tony Ryan (Chemistry).
Biphasic scaffolds based on the combination of ceramics and polymers may have potential in the repair of osteochondral defects, for example by improving the integration of the engineered tissue into the defect site. In simple terms, the polymer component is used to support tissue engineered cartilage while the ceramic is intended to act as an osteoconductive biomaterial for bone "anchoring" or integration. The aim of my project is therefore to develop and evaluate polymer-ceramic composite scaffolds formed by combining 45S5 bioglass with electrospun polymers. The suitability of these scaffolds for osteochondral tissue engineering will be assessed by the culture of chondrocytes and mesenchymal stem cells on the scaffolds.
PhD student (2002-2005)
PhD Title: Glass-Ceramics for Bone Reconstruction
Supervisor(s): Prof. Ian Reaney (Engineering Materials) and Prof. Paul Hatton
Glass-ceramics have great potential for use as biomaterials in bone and tooth repair. The aim of this project is to develop and evaluate novel glass-ceramics with potential for these biomedical applications.
PhD student (2005-2008)
PhD Title: Development of tissue engineered hypertrophic cartilage for bone repair
Supervisor(s): Dr Aileen Crawford, Prof. Ian Brook, Prof. Paul Hatton
Hypertrophic cartilage is an altenative to using bone grafts. This type of cartilage has the advantage of being able to survive at low concentrations of oxygen, allowing time for vascularisation to occur after implantation. As a consequence this approach is particularly attractive where large grafts are required.
My work is looking at the feasibility of preparing hypertrophic cartilage using nasal chondrocytes, as these can be obtained easily, and relatively painlessly from the nose, as opposed to using bone marrow detrived stem cells. I am also investigating the use of 3D culture environments and growth factors to prepare functional tissues.
PhD student (2005-2008)
PhD Title: Smart polymers for use in cell culture of human chondrocytes
Supervisor(s): Dr Steve Rimmer (Department of Chemistry) and Prof Paul Hatton
Aims: To develop novel thermo responsive materials for use as cell culture substrates or scaffolds for tissue engineering.
The availability of suitable cells is potentially a limiting factor for cartilage tissue engineering. Existing cell and tissue culture techniques involve the expansion of cells on a modified polystyrene surface and the use of animal derived products in cell recovery.
A thermo responsive material, which undergoes a large physical change in response to a small change in temperature, may be useful as an alternative method of cell recovery, and may be suitable for culturing cells in a 3D environment.
In this project, candidate materials based on the thermo responsive polymer poly(N-isopropylacrylamide) are prepared and characterised in the Department of Chemistry before assessing their suitability as surfaces or scaffolds for cell culture.
PhD student (2002-2005)
PhD Title: The Evaluation of Spider Silks for use as Tissue Engineering Scaffolds
Supervisor(s): Prof Paul Hatton and Dr Aileen Crawford
"Tissue engineering" describes the use of cultured, live cells for the treatment of human disease and injury. In general, vital cells are delivered to the target site on a carrier material or matrix. There is great interest in biological materials for use as tissue engineering scafolds. The aim of this project is to evaluate the suitability of spider silks (from Nephila edulis) for use as scaffolds for cartilage tissue engineering.
PhD Title: Development of Regenerative Therapies for Periodontal Bone Loss
Supervisor(s): Prof. Andrew Rawlinson and Prof. Paul Hatton
Biomaterials are widely employed in the treatment of bone loss. Synthetic bone substitutes do not however always work as well in patients as in vivo data suggests. The aim of this research project is to investigate potential methods to improve the regenerative capacity of alloplastic biomaterials for treatment of periodontal bone loss.
PhD student (2004-2007)
PhD Title: A 3D oral mucosal model for treatment development and evaluation
Supervisor(s): Prof. Ian M Brook, Dr Andy Scutt (Eng Mat) and Prof. Richard van Noort
The aims of this project are to characterise and assess tissue engineered reconstructed oral mucosa for in vitro use as a pre-clinical model for mucotoxicity and biocompatibility studies of dental materials. An effective model of this type will reduce or avoid the need for animal testing, and permit the development of more specific oral health products, with greater safety and more rapidly than has been possible to date.
In a study approved by the South Sheffield Research Ethics Committee, human oral fibroblasts and keratinocytes have been isolated from consenting patients having oral surgery. After expansion in vitro, these cells have been re-seeded into a dermal scaffold and grown at the liquid air interface to construct an oral mucosal model.
This model has been evaluated before and after exposure to dental materials using Alamar Blue assay, inflammatory markers measurements (IL-1β and TNF-α ELISA), basic histology and electron microscopy. Further work is underway to refine the model, and assess it's usefulness in other pre-clinical trials.
PhD student (2005-2011)
PhD Title: To determine the validity of c-factor in composites
Supervisor(s): Prof. Richard van Noort
Composite dental materials have been in clinical use since the late 1950s. One of the characteristics of dental composites is shrinkage during free radical polymerization as monomer molecules are converted into a polymer network, reducing intermolecular spaces. Dental composite polymerization shrinkage ranges between 2 - 6% by volume. Several properties affect the performance of this dental material. Configuration factor (C-factor) is a theoretical concept, which attempts to explain the nature of polymerisation shrinkage of composites. Literature is replete with mention of this factor, however evidence of the validity of this factor is lacking. Volume of the cavity is also a factor that affects the properties of composite.
My study attempts to determine whether there is validity in the c-factor concept. Microleakage is a consequence of polymerisation shrinkage of composites and this has clinical repercussions. This study attempts to determine if the c-factor or volume is more of a predictor of microleakage in composites.
PhD student (2004-2008)
PhD Title: High impact resins
Supervisor(s): Dr. A. Johnson and Prof. R. Van Noort
Plastic dentures are amongst the most important dental interventions, at least in terms of numbers fitted. The vast majority of these are manufactured from a blend of poly(methyl methacrylate) resin with about 50% filler particles and/or reinforcing fibres.
My research is looking into optimising processing conditions of these dentures, to ensure they have good appearance and durability. To do this I have been synthesising polymer beads, and I am currently developing techniques for including a range of fillers such as nano and micro sized TiO2 ZrO2, silicate glass flakes and nano sized clays e.g. Laponite clay.
The new materials are evaluated at the School by biaxial flexural strength (BFS) impact strength (Charpy impact strength test) and micro-indentation hardness tests. Preliminary results indicate that some improvement in BFS of PMMA has been achieved by adding filler particles.
PhD student (2002-2005)
PhD Title: The Effect of Expansion on Chondrocyte Phenotype
Supervisor(s): Dr. Adrian Jowett and Prof Paul Hatton
Progressive expansion of chondrocytes is known to lead to loss of phenotype. The aim of my research is to investigate the specific details of this process in order to identify the optimum expansion conditions for this important cell type.
PhD student (2005-2008)
PhD Title: Investigation of the tribological properties of tissue engineered cartilage
Supervisor(s): Paul Hatton, Aileen Crawford, John Fisher (University of Leeds) and Zhongmin Jin (University of Leeds)
Articular cartilage is a specialised tissue responsible for the smooth and effortless quality of motion. The main functions of articular cartilage are to provide low friction between joint surfaces and protect the bones from high compressive loads. Natural cartilage is however sometimes subject to degradation and trauma and because it does not have a blood supply, its capacity for repair is relatively poor. Regenerative medicine today offers promising solutions in the repair and replacement of articular cartilage. It is now possible to develop cartilage in-vitro, with a composition and a structure relatively close to native cartilage. The frictional and mechanical properties however, still remain uncertain. The characterisation of these properties is highly important to understand the process of articular friction and to be able of implanting engineered tissue in the human body.
PhD student (2003-2006)
PhD Title: Restoration design using CAD-CAM
Supervisor(s): Prof. Richard van Noort
Ceramic and composite materials are the most popular restorative materials in dentistry. The introduction of CAD/CAM technology to the dental field brought forward the option of more sophisticated restorations. These studies explore the scope and limitations of these new materials and technologies. This includes evaluations of minimal milling margins using a CAD/CAM machine, a proper understanding of the tollerances involved will allow the dentist to develope minimal tooth preparation designs, and offer less invasive restoration work.
PhD student (2001-2004)
PhD Title: Glass-Ionomer Cements for Medical Applications
Supervisor(s): Prof. John Sharp and Prof. Paul Hatton
Glass-ionomer cements have recently been developed for use as bone cements in otorhinolaryngology. However, they would benefit from further improvements to their radio-opacity and handling properties. A systematic substitution of SrF2 for CaF2 within a commercial glass composition (SerenoCEM®) was carried out. The glass compositions were verified using x-ray fluorescence and the glass morphology was observed using electron microscopy. A variety of methods were applied to study the working and setting times of the cement, including the Gilmore needle (dental standard BS 29917 & 6039) and calorimetry.
- Emeritus and Retired Staff
Professor of Oral Surgery and Oral Medicine
Professor Brook graduated with a dental degree from the University of Liverpool in 1978. Hospital posts in Liverpool, London (The Middlesex and St. Bartholomew´s), Truro and Aberdeen followed. Appointed to the University of Sheffield in 1983 he gained his MDS in 1986 for `In vitro studies into the development of intra-oral inserts for the controlled delivery of drugs´, and PhD in 1994 for studies into the biocompatibility of Glass-ionomer cements.
Qualified as a Dental Technician in 1972 and obtained advanced dental technology qualifications in ceramics and crown and bridge work (1974) and general dental work (1975). I was also awarded the City and Guilds of London Further Education Teaching Certificate (1976), LCGI (1988) and MCGI (1992). After qualification as a dental technician I worked in the NHS (Charles Clifford Dental Hospital, Sheffield) from 1972 until 1976 when I then joined the staff of the University of Sheffield Dental School as a dental instructor. In 2007 I was appointed Senior Lecturer. I completed my MMedSci in 1991 and my PhD in 1995.
Richard van Noort
Professor of Dental Materials Science
I joined the University of Sheffield, Department of Medical Physics in 1976 as an EPSRC funded post-doctoral research assistant, undertaking research in soft tissues for prosthetic heart valve fabrication. In 1980 I moved to a new post as lecturer in Dental Materials Science in the Department of Restorative Dentistry in the Dental School, and have been there ever since. I was promoted to a professorial chair in 1997. I was Head of the Department of Adult Dental Care from September 2003 until August 2007. My contribution to dental materials research was recognized by the University of Sheffield with the award of the DSc in 2008. My general contribution to dental materials was recognized by the British Dental Association with the award of the John Tomes Medal for Services to Dentistry in 2009.
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