Convergence angles for full veneer crown preparation completed by undergraduate students in a dental teaching hospital

Objectives: To determine the degree of taper and the average angle of convergence (AOC) accomplished for full veneer/coverage crowns (FVC) by supervised undergraduate students at a dental teaching hospital. Methods One hundred and twenty-five stone dies of FVC preparations (25 full-metal [FMCs] and 100 metal-ceramic [MCCs]), prepared by dental students were included in this study. To measure AOC, standardised buccal and mesial photographs were taken when dies were mounted onto a custom silicone jig after careful positioning. 2D digital analysis software (ImageJ) was used to calculate the average mesio-distal (MD), bucco-lingual (BL) and overall AOC for each die. Differences between groups were tested for significance at 95% confidence using t-tests and analysis of variance (ANOVA). Findings were compared to the recommended 6°–15° range. Results: The average AOC was 24.2° ± 11.95°. As few as one-in-four preparations (26.4%, n = 33) complied with the recommended standards. The MD plane (24.7° ± 15.53°) was more tapered than the BL plane (23.0° ± 13.84°) (p >0.05) and FMCs preparations (34.7° ± 15.10°) more than MCCs (21.6° ± 9.38°) (p <0.001). Molars (31.6° ± 12.56°) had the greatest AOC, followed by premolars (20.7° ± 7.81°), canines (19.4° ± 6.37°) and incisors (17.0° ± 9.62°) (p <0.001). Additionally, mandibular teeth (28.8° ± 13.76°) exhibited a greater AOC than those in the maxilla (21.7° ± 10.08°) (p <0.05). Conclusion: The findings of this study suggest that within a dental school teaching environment, crown preparations completed by undergraduate students are over-tapered. Tooth type, inter and intra-arch position and crown material significantly impact taper, with mandibular molar FMCs displaying the greatest AOC. Contemporary dental school teaching should help support students in this important aspect of their clinical training

The European Union and a Changing Europe: Establishing the Boundaries of Order

This article seeks to explore the relationship between the European Union (EU) and the changing European order, with particular respect to the ways in which the EU structures and shapes the boundaries between itself and the broader European arena. It evaluates a range of available international relations theories, and adopts a 'critical neoliberal-institutionalist' approach to the problem. It applies this approach by assessing the EU's boundary-constructing and boundary-maintaining behaviour in a number of areas, before developing two models of the EU's role: the 'politics of exclusion' and the 'politics of inclusion'. After spending most of its life practising the 'politics of exclusion', the EU has moved towards a 'politics of inclusion' to reflect the changing demands of the European order. Nevertheless, the tensions between the two types of politics will continue to be a central feature of the EU's role. Copyright 1996 BPL.

Agricultural Interests and the Origins of Capitalism: A Parallel Comparative History of Germany, Denmark, New Zealand, and the USA

Addressing the literature on the historical origins of capitalism, this study analyses the role agriculture played in the formation of non-market economic coordination in economic and social affairs around 1900. It argues that the dominant rural production profile dictated whether farmers did exert a significant impact on socio-economic institution and policy formation outside the rural sector. By applying the method of parallel demonstration of theory, we illustrate the plausibility of these theoretical considerations through juxtaposing the historical record of Germany, Denmark, New Zealand and the USA. The article highlights the limits of a dichotomous view on the origins of capitalism because the coordination effect of rural economies varies within the later coordinated and the later liberal cluster of market economies