Cone beam CT (CBCT) is becoming an increasingly utilized imaging modality for dental examinations in the UK. Previous studies have presented little information on patient dose for the range of fields of view (FOVs) that can be utilized. The purpose of the study was therefore to calculate the effective dose delivered to the patient during a selection of CBCT examinations performed in dentistry. In particular, the i-CAT CBCT scanner was investigated for several imaging protocols commonly used in clinical practice. A Rando phantom containing thermoluminescent dosemeters was scanned. Using both the 1990 and recently approved 2007 International Commission on Radiological Protection recommended tissue weighting factors, effective doses were calculated. The doses (E(1990), E(2007)) were: full FOV head (92.8 microSv, 206.2 microSv); 13 cm scan of the jaws (39.5 microSv, 133.9 microSv); 6 cm high-resolution mandible (47.2 microSv, 188.5 microSv); 6 cm high-resolution maxilla (18.5 microSv, 93.3 microSv); 6 cm standard mandible (23.9 microSv, 96.2 microSv); and 6 cm standard maxilla (9.7 microSv, 58.9 microSv). The doses from CBCT are low compared with conventional CT but significantly higher than conventional dental radiography techniques.

Within the limitations of this study, it was concluded that i-CAT NG (voxel size 0.3) may not produce sufficient resolution of the thin cortical bone adjacent to dental implants and, therefore, the measurements may not be accurate; whereas, Accuitomo 3D60 FPD (voxel size 0.125) may produce better resolution and more accurate measurement of the thin bone.

CBCT is a reliable and valid method of detecting simulated EIR and performs significantly better than intraoral periapical radiography. Small volume CBCT operating with 360° of rotation of the X-ray source and detector is no better at detecting small, artificially created EIR cavities than the same device operating with 180° of rotation.

Electronic copy available at: http://ssrn.com/abstract=1813749This paper offers a critique of the concept of governance as networks. Using the complementary concept of regime governance, it argues that networks are not the primary mode of governance in the politics of urban regeneration in the UK. Drawing on primary and secondary material, it is argued that Central Government is becoming more influential in the local policy arena. In the 'mix' of market, hierarchy and network, hierarchy is more pervasive than network. It is therefore argued that partnerships should be treated as a distinct mode of governance. These conclusions demonstrate that despite the fashion for copying urban policies from the USA, local politics in the UK remain very different. Ironically, the transfer of policies developed in the USA has tended to entrench divergent practices and outcomes. The UK does not, therefore, appear to be moving toward the US model of regime politics. It is concluded that the partnership and network/regime models of governance should be subjected to rigorous comparative studies.

This paper explores neoliberalisation and its counter-currents through a six-case study of austerity urbanism in Spain and the UK. Applying Urban Regime Theory it highlights the role of urban politics in driving, variegating and containing neoliberalism since the 2008 crash. Variegated austerity regimes contribute to strengthening neoliberalism, but with limits. Welfarism survives austerity in felicitous circumstances. And, where contentious politics thrive, as in Spain, it holds out the potential for a broader challenge to neoliberalism. In contrast, austerity regimes in the UK cities are strongly embedded. The legacies of past struggles, and differing local and regional traditions form an important part of the explanation for patterns of neoliberalisation, hybridization and contestation.