Does an incremental filling technique reduce polymerization shrinkage stresses

It is widely accepted that volumetric contraction and solidification during the polymerization process of restorative composites in combination with bonding to the hard tissue result in stress transfer and inward deformation of the cavity walls of the restored tooth. Deformation of the walls decreases the size of the cavity during the filling process. This fact has a profound influence on the assumption-raised and discussed in this paper-that an incremental filling technique reduces the stress effect of composite shrinkage on the tooth. Developing stress fields for different incremental filling techniques are simulated in a numerical analysis. The analysis shows that, in a restoration with a well-established bond to the tooth-as is generally desired-incremental filling techniques increase the deformation of the restored tooth. The increase is caused by the incremental deformation of the preparation, which effectively decreases the total amount of composite needed to fill the cavity. This leads to a higher-stressed tooth-composite structure. The study also shows that the assessment of intercuspal distance measurements as well as simplifications based on generalization of the shrinkage stress state cannot be sufficient to characterize the effect of polymerization shrinkage in a tooth-restoration complex. Incremental filling methods may need to be retained for reasons such as densification, adaptation, thoroughness of cure, and bond formation. However, it is very difficult to prove that incrementalization needs to be retained because of the abatement of shrinkage effects.

Living sustainably: changing cultures and behaviours

2007 was a turning point on what sustainability meant for the construction industry with its new regulation and initiatives. The Government defined sustainability in terms of environmental objectives that can be measured, monitored and met. Last year was also the introduction of the Code for Sustainable Homes. This seminar explores the lessons learnt and the next stage of sustainability in terms of policy and practice.

Law in the community: the University of Greenwich/Greenwich Association of Disabled People Centre for Independent Living (GAD) research project

The GAD Advocacy Service is funded by the London Borough of Greenwich Directorate of Neighbourhood Services; its remit to support disabled people experiencing Hate Crime, Domestic Violence and Harassment. Run by disabled personnel and giving advice to all disabled people it is unique in London. Since its inception in 2004, the Advocacy Service has been stretched to its limit - there is a need to extend the remit of the Advocacy Service to give specialist legal advice on other issues. In 2003, the CEDRM-UK project was set up in the University of Greenwich Law Department as part of the Disability Rights Promotion International Legal Education and Research Project; its objectives were firstly, to facilitate the collection of data on the effectiveness of legislation in promoting the rights of disabled persons; and secondly, to pilot new methods in teaching and training in Human Rights Law – students acquire an expertise in Human Rights Law through research into the practical application of legislation relating to civil and human rights in the daily life of the community. In July 2007, GAD and CEDRM-UK embarked on a joint project to report on the work of the Advocacy Service and to create a database to support its caseload. The 2008-9 Project team will report on their work and findings relating to facilitating equality in the workplace; the inclusion of cancer, HIV and multiple sclerosis within the legal definition of disability and the implications of the statutory duty to promote disability equality for the provision of extracurricular activities for schoolchildren. [From the Author]

Fact, fiction and nostalgia: an assessment of heritage interpretation at living museums

This paper aims to explore and discuss the role of nostalgia (a concept that is inherently grounded within a psychological framework) in heritage interpretation from both provider and consumer perspectives. Whilst many cultural practitioners recognise the relationship between sentimentality and authenticity, particularly within a folk-heritage context, few have sought to examine the effect this has on the visitor experience. This paper questions visitors’ ability to objectively assess objects and experiences at heritage sites, and the role of practitioners in presenting often blurred views of social history that may sometimes negate historical fact. Drawing on case study research at two UK living museums, Blists Hill Victorian Town in Shropshire, England, and the Big Pit: National Coal Museum in Wales, notions of reminiscence, authenticity, myth and intangibility are considered within the framework of the interpretive experience. Findings suggest that the visitor experience is inherently subjective, highly individual and that the concept of intangibility is integral to an understanding of the nostalgia-authenticity debate.