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The purpose of this study is to test the shear-bond-strengths of auto-mixed and manual-mixed self-adhesive resin cement to dentin on long-term high-altitude pressure.

Human molars were embedded in acrylic resin. Sixty composite resin discs were obtained. The composite resin discs were bonded to dentin using hand-mixed and auto-mixed self-adhesive resin cement. After cementation, the samples were stored in artificial saliva and divided into two subgroups (n = 30), hypobaric pressure and the atmospheric pressure group. The specimen underwent three pressure cycles per day for 100 days. The failure types were evaluated after debonding with scanning electron microscopy. The shear bond strength was tested with Universal Testing Machine. Analysis of variances/Tukey post hoc tests were used for statistical analysis. Groups were also evaluated by the Weibull modulus.

Regardless of hypobaric pressure changes, the highest bond strength was examined in auto-mixed Panavia SA samples. A significant difference was found in both auto-mixed MaxCem EC and hand-mixed RelyX U200 group after exposure to hypobaric pressure compared to the control group.

The luting cement-type, mixing methods of cements and environmental pressure changes significantly influence the bond strengths. Dentists can use auto-mixed self-adhesive resins in patients likely to be exposed to hypobaric pressure.

The purpose of this study was to investigate the effect of the environmental pressure changes on the bond strength between zirconia ceramics and adhesive resin cement.

In total, 40 rectangular-shaped zirconium-oxide ceramic specimens were prepared. For surface modification, all zirconia specimens were sandblasted with 50 μm alumina particles. The composite resin discs were bonded to modified zirconia surfaces with resin cement. The specimens were divided into four groups; hyperbaric, hypobaric, hyperbaric + hypobaric and control group. The specimen underwent pressure cycles for 30 days. The shear bond strength test was performed by using the universal testing machine, and failures of the debonded samples were examined with scanning electron microscopy and light microscope.

No significant difference in bond strength was found between the hyperbaric, hypobaric and control groups after 30 days (p > 0.05). However, there was a significant difference in the hyperbaric + hypobaric group compared to the control group (p = 0.022). Also, the Weibull modulus was highest in control group and lowest in the hyperbaric + hypobaric group.

Barometric changes due to flying followed by diving may have an adverse effect on the retention of zirconia ceramics. Care should be taken in the selection of materials for dental treatment of people who are exposed to environmental pressure changes.

Discusses environmental factors which may have harmful effects on the cardiovascular system and cause acute or chronic disease. Classifies these factors as chemical, physical, biological and psychosocial. Concentrates on describing the chemical, physical and biological elements which directly cause cardiovascular diseases, such as nicotine and carbon monoxide (chemical); temperatue and electricity (physical) and viral infections such as maternal coxsackie (biological). Concludes by stressing the need for more intensive studies on this subject.

Understanding how health status and physiological factors affect performance is a daunting task. This chapter will discuss physiological, behavioral, and psychological factors that influence or determine the capacity to fight, and will consider metrics that can be used to measure their status. The premise of this discussion is that there is a set of physiological and psychological factors that intimately affect performance and that the relative contribution of these variables is individually unique. These factors can be identified and assessed, and are amenable to modification. A fuller understanding of these variables can lead the effort to maintain and improve performance in the adverse and challenging environments of military operations.

Aeromedical training is meant to train aircrew in combating physiological problems that they might face in flight. Given the importance of the training, there are limited studies in the literature investigating the anxiety levels during aeromedical training along with training outcomes. This study aims to assess the untrained participants’ anxiety levels before and after aeromedical training, investigate the differences in anxiety levels across different physiological training devices and determine whether participants’ anxiety levels affect their G tolerances.

This study was carried out on 61 healthy male subjects (n = 61) who had applied for initial aeromedical training. Anxiety surveys and visual analog scales were administered before and after the practical aeromedical training. In addition, blood pressure and heart rate measurements were carried out.

Participants had significantly higher anxiety levels before human centrifuge training (pre-Glab) than before the altitude chamber training (pre-hypobaric). Participants who experienced G-induced loss of consciousness (G-LOC) had slightly more anxiety reported than the non-G-LOC group. There was a significant decrease between pre-Glab and post-Glab (after the human centrifuge training) and between pre-hypobaric and post-hypobaric (after the altitude chamber training) anxiety levels. The incidence of G-LOC was lower in participants having higher pre-G-Lab blood pressure. However, the difference in anxiety levels between the G-LOC group and the non-G-LOC group was not statistically significant.

In this study, state anxiety inventory was not performed after human centrifuge training as centrifuge training lasted for around 5 min only, and it is not advisable to repeat state anxiety inventory in such short periods. Blood pressure was not measured after G-Lab training because human centrifuge training is hard training and has an impact on blood pressure. Hence, it would have been difficult to distinguish whether the blood pressure change was due to anxiety or hard physical activity. These limitations, especially for the G-Lab, caused us to evaluate state anxiety only with VAS. It would be worthwhile to repeat similar studies with objective measurements before and after the training.

This information suggests that instructors who train the applicants on aerospace medicine be ready for the possible consequences of anxiety.

There are only a few centers in the world that include all the physiological training devices (practical aeromedical training laboratories) together. To the best of authors’ knowledge, there are no studies in the literature investigating the differences in anxiety levels across various physiological training devices. The studies about the effect of anxiety levels on aeromedical training outcomes and anxiety levels before and after the training are scant.