Direct comparison of the bond strength results of the different test methods: A critical literature review

Objective. The goal of this paper is to undertake a literature search collecting all dentin bond strength data obtained for six adhesives with four tests ( shear, microshear, tensile and microtensile) and to critically analyze the results with respect to average bond strength, coefficient of variation, mode of failure and product ranking. Method. A PubMed search was carried out for the years between 1998 and 2009 identifying publications on bond strength measurements of resin composite to dentin using four tests: shear, tensile, microshear and microtensile. The six adhesive resins were selected covering three step systems ( OptiBond FL, Scotch Bond Multi-Purpose Plus), two-step (Prime & Bond NT, Single Bond, Clear. l SE Bond) and one step (Adper Prompt L Pop). Results. Pooling results from 147 references showed an ongoing high scatter in the bond strength data regardless which adhesive and which bond test was used. Coefficients of variation remained high (20-50%) even with the microbond test. The reported modes of failure for all tests still included high number of cohesive failures. The ranking seemed to be dependant on the test used. Significance. The scatter in dentin bond strength data remains regardless which test is used confirming Finite Element Analysis predicting non-uniform stress distributions due to a number of geometrical, loading, material properties and specimens preparation variables. This reopens the question whether, an interfacial fracture mechanics approach to analyze the dentin - adhesive bond is not more appropriate for obtaining better agreement among dentin bond related papers. (C) 2009 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Elephants and polity in ancient India as exemplified by Kautilya's Arthasastra (Science of Polity)

After providing some background on the domestication and use of elephants in ancient India, this article concentrates on the role of the elephant in Indian statescraft as outlined in Kautilya’s Arthasastra, reputed to have been written in the fourth century BC (over 2300 years ago). The body of this essay is presented as follows: first background on the nature of Kautilya’s Arthasastra is provided and then his advice is outlined and discussed about the care of elephants. This care involves the duty of the King, the duties of the superintendent of elephants and the law relating to the treatment of elephants. Subsequently, Kautilya’s views about the use of elephants in war are considered. The essay concludes with an overall assessment of the role of the elephant in the polity of ancient India as portrayed by Kautilya. It is argued that the high use value of elephants to ancient Indian rulers, especially in war, had a significant positive impact on the conservation of Asian wild elephants, and incidentally other wildlife in India as well. Today, the conservation of the Asian elephant depends mostly on its use for tourism and its non-use economic values which reflect human empathy with it and which are reinforced in India by social and cultural values.

Odontogenic keratocyst and multiple supernumerary teeth in a patient with Ehlers-Danlos syndrome - A case report and review of the literature

Ehlers-Danlos syndrome (EDS) is a hereditary disorder of the connective tissue related to collagen metabolism. Deficiency or alteration of the collagen present in the tissues results in some classic signs such as skin hyperelasticity, articular hypermobility, and vascular fragility, among others. In addition, EDS oral manifestations are rarely cited in the literature. The aim of this article is to report a rare case of a young female patient with EDS who presented supernumerary teeth and an odontogenic keratocyst. There is no report in the literature of the simultaneous occurrence of these alterations. The article further highlights the importance of EDS diagnosis in patients who need dental treatment and the due care for their assistance.

Fossil trees in ancient fluvial channel deposits: evidence of seasonal and longer-term climatic variability

It has been established that large numbers of certain trees can survive in the beds of rivers of northeastern Australia where a strongly seasonal distribution of precipitation causes extreme variations in flow on both a yearly and longer-term basis. In these rivers, minimal flow occurs throughout much of any year and for periods of up to several years, allowing the trees to become established and to adapt their form in order to facilitate their survival in environments that experience periodic inundation by fast-flowing, debris-laden water. Such trees (notably paperbark trees of the angiosperm genus Melaleuca) adopt a reclined to prostrate, downstream-trailing habit, have a multiple-stemmed form, modified crown with weeping foliage, development of thick, spongy bark, anchoring of roots into firm to lithified substrates beneath the channel floor, root regeneration, and develop in flow-parallel, linear groves. Individuals from within flow-parallel, linear groves are preserved in situ within the alluvial deposit of the river following burial and death. Four examples of in situ tree fossils within alluvial channel deposits in the Permian of eastern Australia demonstrate that specialised riverbed plant communities also existed at times in the geological past. These examples, from the Lower Permian Carmila Beds, Upper Permian Moranbah Coal Measures and Baralaba Coal Measures of central Queensland and the Upper Permian Newcastle Coal Measures of central New South Wales, show several of the characteristics of trees described from modern rivers in northeastern Australia, including preservation in closely-spaced groups. These properties, together with independent sedimentological evidence, suggest that the Permian trees were adapted to an environment affected by highly variable runoff, albeit in a more temperate climatic situation than the modem Australian examples. It is proposed that occurrences of fossil trees preserved in situ within alluvial channel deposits may be diagnostic of environments controlled by seasonal and longer-term variability in fluvial runoff, and hence may have value in interpreting aspects of palaeoclimate from ancient alluvial successions. (C) 2001 Elsevier Science B.V. All rights reserved.

Feasibility of an evidence-based literature search service for general practitioners

Objective: To test the feasibility of an evidence-based clinical literature search service to help answer general practitioners' (GPs') clinical questions. Design: Two search services supplied GPs who submitted questions with the best available empirical evidence to answer these questions. The GPs provided feedback on the value of the service, and concordance of answers from the two search services was assessed. Setting: Two literature search services (Queensland and Victoria), operating for nine months from February 1999. Main outcome measures: Use of the service; time taken to locate answers; availability of evidence; value of the service to GPs; and consistency of answers from the two services. Results: 58 GPs asked 160 questions (29 asked one, 11 asked five or more). The questions concerned treatment (65%), aetiology (17%), prognosis (13%), and diagnosis (5%). Answering a question took a mean of 3 hours 32 minutes of personnel time (95% Cl, 2.67-3.97); nine questions took longer than 10 hours each to answer, the longest taking 23 hours 30 minutes. Evidence of suitable quality to provide a sound answer was available for 126 (79%) questions. Feedback data for 84 (53%) questions, provided by 42 GPs, showed that they appreciated the service, and asking the questions changed clinical care. There were many minor differences between the answers from the two centres, and substantial differences in the evidence found for 4/14 questions. However, conclusions reached were largely similar, with no or only minor differences for all questions. Conclusions: It is feasible to provide a literature search service, but further assessment is needed to establish its cost effectiveness.

Loss as a universal concept: Review of the literature to identify common aspects of loss in diverse situations

It has long been recognized that loss and its associated grief are important elements of many adverse life events that affect the entire global population: death, disability, traumatic events, abuse., terminal and chronic illness, aging, addiction, unemployment, relationship breakdown, war, migration, and educational failure. While there is significant empirical evidence of the potential deleterious effects of specific situations of loss across the global community, systematic discussion concerning the common elements of loss that are associated with adverse life situations in general has been limited. This review of the theoretical and empirical literature concerning various losses and the recommendations for care of those affected by such losses identifies common aspects of situations of loss and common recommendations in the care of those confronted by such losses. These common themes of loss are described by simple summary statements that can be communicated to a broad audience, hence enhancing community education and, potentially, community-wide mental health promotion.