Resistance to Fracture of Two All-Ceramic Crown Materials Following Endodontic Access

Statement of problem There is currently no protocol for managing endodontic access openings for all-ceramic crowns. A direct restorative material is generally used to repair the access opening, rendering a repaired crown as the definitive restoration. This endodontic procedure, however, may weaken the restoration or initiate microcracks that may propagate, resulting in premature failure of the restoration. Purpose The purpose of this in vitro study was to evaluate how an endodontic access opening prepared through an all-ceramic crown altered the structural integrity of the ceramic, and the effect of a repair of this access on the load to failure of an all-ceramic crown. Material and methods Twenty-four alumina (Procera) and 24 zirconia (Procera) crowns were fabricated and cemented (Rely X Luting Plus Cement) onto duplicate epoxy resin dies. Twelve crowns of each were accessed to simulate root canal treatment therapy. Surface defects of all accessed specimens were evaluated with an environmental scanning electron microscope. The specimens were repaired with a porcelain repair system (standard adhesive resin/composite resin protocol) and were loaded to failure in a universal testing machine. Observations made visually and microscopically noted veneer delamination from the core, core fracture, shear within the veneer porcelain, or a combination thereof. A Kruskal-Wallis test was used to determine if a significant difference (α=.05) in load to failure existed between the 4 groups, and a Mann-Whitney test with a Bonferroni correction (P Results All specimens exhibited edge chipping around the access openings. Some displayed larger chips within the veneering porcelain, and 4 zirconia crowns showed radial crack formation. There was a significant difference in load to failure among all groups with the exception of the alumina intact and repaired specimens (P=.695). The alumina crowns generally showed fracture of the coping with the veneering porcelain still bonded to the core, whereas the zirconia copings tended not to fracture but experienced veneering porcelain delamination. Conclusion Endodontic access through all-ceramic crowns resulted in a significant loss of strength in the zirconia specimens but not in the alumina specimens

A laser-doppler velocimeter with ocean applications

Difficulties of intrinsic and environmental origins are still being experienced in the use of ocean currentmeters. The recently developed laser-Doppler technique of flow measurement offers advantages over existing techniques and the application of the laser-Doppler technique to ocean flow measurements is proposed. In particular, a laser-Doppler system which has been used in the laboratory and which is suitable for ocean applications is described...

State Quality-Adjusted Life Expectancy for U.S. adults from 1993 to 2008

Purpose: Quality-Adjusted Life Expectancy (QALE) is a summary measure of mortality and health-related quality of life (HRQOL) across different stages of life. This study developed a method to calculate state-level QALE for U.S. adults. Methods: Population HRQOL data came from the Behavioral Risk Factor Surveillance System (BRFSS). Using age-specific deaths from the Mortality Summary File, this study constructed life tables to estimate life expectancy and QALE for all 50 States and the District of Columbia by sex and race from 1993 through 2008. Results: From 1993 to 2008, the QALE of an U.S. adult at 18 years old had increased from 51.2 to 52.3 years. In 2006, states with the highest QALE were Hawaii (56.2), Minnesota (55.2), North Dakota (54.9), Iowa (54.7), and Nebraska (54.4), while the states with the lowest QALE were West Virginia (47.1), Mississippi (48.2), Alabama (48.5), Kentucky (48.5), and Oklahoma (49.0). Conclusions: Because population HRQOL values and mortality statistics are available from existing and publicly accessible data and because formulas for the calculation of QALE and its standard error are easy to incorporate in a spreadsheet, State and local Health Departments can calculate QALE as a routine surveillance measurement for tracking their population’s health over time

Escape for Boone & Crocket

Eber Crocket is the owner of Boone & Crocket Trapper Supply (B&C). He feels like the environmental forces that are impacting his business are like a trap slowing closing on him. He is considering ideas to improve his store’s profitability. Demand for furs as fashion goods is a multi-million dollar industry. Twenty percent of this demand is met by wild fur which is harvested by trappers. Trapping suppliers serve as the middleman between small individual trappers and auction houses. These auction houses collect the raw fur pelts from trappers and trapping stores and hold them until one of their auctions. Members of the international fashion community are the principle buyers of wild fur. These firms are involved in the tanning, finishing and design work needed to turn a fur pelt into a finished garment. The fur industry is impacted by many environmental forces. Among them, sociocultural, regulatory and economic forces are key. Boone & Crocket Trapping Supply is small family-owned business located in central Minnesota It offers a wide selection of trapping-related goods and services. The majority of B&Cs profits come from the sale of traps, baits and other goods. The remaining profit comes from fur handing and auction fur sales. Your friend Eber wants your perspective on some of the new product and service ideas he is considering to make B&C more profitable. His ideas are to produce trapping baits, expand the condition of furs B&C buys, differentiate the store’s product line, enter the nuisance animal control business, or become involved in trapper’s education

Book Reviews

Reviews of the following books: Pamphlets for the People: A Review Essay on the Publications of the Maine Historic Preservation Commission; Arthur Spear, 1879-1959 by Arthur Spear, Jr.; Army Engineers in New England: The Military and Civil Works of the Corps of Engineers in New England, 1775-1975 by Aubrey Parkma

Life, Death, and IQ: It\u27s Much More than Just a Score: Understanding and Utilizing Forensic Psychological and Neuropsychological Evaluations in Atkins Intellectual Disability/Mental Retardation Cases

This article highlights best practices for assessing MR and ID in capital cases with an emphasis on Atkins trial preparation and potential problems the authors have noted through experience. These best practices in Atkins hearings concern issues for the lawyers, forensic psychologists, and neuropsychologists, which include: 1. Practice effects and IQ testing 2. Consistency of IQ scores over time 3. Flynn Effect 4. Malingering versus cognitive suboptimal effort 5. Lack of records indicating pre-age 18 diagnosis of MR/ID 6. Retrospective assessment of adaptive behaviors 7. Death row trends of increasing IQ over the years while incarcerated 8. Maladaptive behaviors versus symptoms of conduct disorder and antisocial personality disorder 9. There need be no nexus between an Atkins finding of mental retardation and the adaptive behavioral aspects of criminal and homicidal behavior 10. Potential bias of collateral informants 11. Cultural issues inherent in IQ and adaptive testing 12. Considering the utilization of different experts within a particular case, i.e., assessment of adaptive functioning versus assessment of intelligence 13. Videotaping assessments 14. Litigation strategies expanding MR/ID findings. Due to the length requirement of this article, some of these issues will be addressed and not to the extent of their respected complexities

How Regional Employment in the U.S. Automobile Industry Influences Consumer Ethnocentrism

The past three decades lay witness to major geographical evolution of the automobile industry in the United States. This study analyzes exactly how CETSCALE scores differ among a population that is currently either more or less economically impacted by automobile production and marketing. The analysis presented in this study illustrates a direct correlation between ethnocentric dispositions among consumers and employment opportunities in the automobile sector across U.S. Census Bureau geographical regions and divisions in each region. Comprehensive statistical details are provided that arguably demonstrate a change in what the phrase “Made in America” means, at least where automobile production is concerned

Elevated Temperature Thermal Properties of ZrB2-B4C Ceramics

The elevated temperature thermal properties of zirconium diboride ceramics containing boron carbide additions of up to 15 vol% were investigated using a combined experimental and modeling approach. The addition of B4C led to a decrease in the ZrB2 grain size from 22 µm for nominally pure ZrB2 to 5.4 µm for ZrB2 containing 15 vol% B4C. The measured room temperature thermal conductivity decreased from 93 W/m·K for nominally pure ZrB2 to 80 W/m·K for ZrB2 containing 15 vol% B4C. The thermal conductivity also decreased as temperature increased. For nominally pure ZrB2, the thermal conductivity was 67 W/m·K at 2000 °C compared to 55 W/m·K for ZrB2 containing 15 vol% B4C. A model was developed to describe the effects of grain size and the second phase additions on thermal conductivity from room temperature to 2000 °C. Differences between model predictions and measured values were less than 2 W/m·K at 25 °C for nominally pure ZrB2 and less than 6 W/m·K when 15 vol% B4C was added

Quality-adjusted life expectancy (QALE) loss due to smoking in the United States

Purpose: Estimate quality-adjusted life expectancy (QALE) loss due to smoking and examine trends and state differences in smoking-related QALE loss in the U.S. Methods: Population health-related quality of life (HRQOL) scores were estimated from the Behavioral Risk Factor Surveillance System. This study constructed life tables based on U.S. mortality files and the mortality linked National Health Interview Survey and calculated QALE for smokers, non-smokers, and the total population. Results: In 2009, an 18-year-old smoker was expected to have 43.5 (SE = 0.2) more years of QALE, and a non-smoker of the same age was expected to have 54.6 (SE = 0.2) more years of QALE. Therefore, smoking contributed 11.0 (SE = 0.2) years of QALE loss for smokers and 4.1 years (37%) of this loss resulted from reductions in HRQOL alone. At the population level, smoking was associated with 1.9 fewer years of QALE for U.S. adults throughout their lifetime, starting at age 18. Conclusions: This study demonstrates an application of a recently developed QALE estimation methodology. The analyses show good precision and relatively small bias in estimating QALE––especially at the individual level. Although smokers may live longer today than before, they still have a high disease burden due to morbidities associated with poor HRQOL