Objective
It was found that formation of SiF(4) could be prevented by incorporation of at least one non-bridging oxygen per silicon and sufficient aluminium to bond the fluorine present. Strong correlations were found between the fluorine content of the glass and the fluoride released from the set cements. Ion release studies demonstrated that the major mechanism of ion release was via ion exchange where a fluoride ion in the cement is exchanged for a hydroxyl ion in the aqueous medium, rather than the accepted counter ion model where an alkali cation is released in conjunction with a fluoride ion from the set cement.
Strong correlations were established between the glass composition and the setting and working times of the resulting cement pastes as well as with the mechanical properties. Sodium and phosphate were shown to disrupt the crosslinking of the polyacrylate matrix. The aluminium to silicon ratio of the glass was not found to be as significant as previously thought and this is believed to result from PO(4) tetrahedra locally charge balancing AlO(4) tetrahedra, as well as glass degradation occurring via phosphorus-oxygen bond hydrolysis in addition to aluminium-oxygen bond hydrolysis.
Biocompatibility studies in vivo with decalcified sections indicated the cements were osteoconductive and the osteoconductivity increased with the sodium and fluorine content of the glass.
Implant studies using a rabbit model and undecalcified sections indicated that the bone formed near the implant was poorly mineralised and had the appearance of osteomalacia. This was associated with the aluminium content of the cement. Aluminium was found at sites distant from the implant particularly with implants placed in the unset state. The ability of the cements to bond to bone in push-out tests was no better than existing acrylic bone cements, largely as a result of the inhibition of mineralisation adjacent to the implanted cement.
The planned research is directed at developing a new generation of glass polyalkenoate cements formed from reacting ion leachable fluoro-alumino-silicate glass with poly(acrylic acid). The new cements will be based on novel glass compositions and will be designed for use as:
1. Posterior dental filling materials that can bond to dentine and enamel and have a fracture toughness comparable to the existing amalgams.
2. Bone cements that stimulate bone growth and can chemically bond to bone as well as the alloys used for prosthesis.
3. An insitu setting bone substitute that can bond to bone and be readily moulded to shape by the surgeon.
Completion of this project should yield major social benefits for elderly edentulous patients and for the younger arthritic patient, as well as resulting in improved posterior dental fillings.
The project may also result in environmental benefits for the ceramic tile industry in reducing hydrofluoric acid emmissions.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- natural sciences chemical sciences inorganic chemistry alkali metals
- natural sciences chemical sciences inorganic chemistry post-transition metals
- engineering and technology materials engineering amorphous solids
- natural sciences chemical sciences inorganic chemistry halogens
- medical and health sciences medical biotechnology implants artificial bone
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
LIMERICK
Ireland
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.