Low-dose lung CT: Optimizing diagnostic radiation dose - A phantom study.

Background/purpose: To investigate a quantitative method for assessing image quality of low dose lung computed tomography (CT) and find the lowest exposure dose providing diagnostic images.

Methods: Axial volumetric lung CT acquisitions (256 slice scanner) were performed on three different sized anthropomorphic phantoms at different dose levels. The maximum steepness of sigmoid curves fitted to line density profiles was measured at lung-to-pleura interfaces.

[Dental fluoriosis].

Increased fluoride intake (more than 2 mg per day) over a longer period of time during tooth development causes dental fluorosis. Depending on the amount and concentration of fluoride ingested, the appearance of dental fluorosis can range from fine white lines to massive defects with loss of substance in the enamel surface.

A quantitative analytical method to test for salt effects on giant unilamellar vesicles.

Today, free-standing membranes, i.e. liposomes and vesicles, are used in a multitude of applications, e.

[Cavity micro-morphology following caries removal].

The objective of this research was to observe the effect of different caries removal techniques on human dentin topography. Thirty-six dentin samples of bisected carious human molars were treated with six different caries removal techniques, replicated and then examined by using a scanning electron microscope. The surfaces were observed before and after the smear layer removal at a magnification of 200- and 1000-fold.

[Heat propagation in dentin during cavity preparation in vitro with oscillating instruments].

The purpose of this work was to study the temperature rise caused by preparation of human dentin using two different types of oscillating instruments. A newly designed tungsten carbide tip (Cariex TC, KaVo) and a diamond-coated tip (Cariex D, KaVo) in combination with an airscaler (Sonicflex 2003L, KaVo) and two different flow rates of two coolants were investigated. For both tips significant differences in temperature rise were found between cooling with waterspray or with Plakout Gel (Kerr, HaWe) and using no coolant.

[Influence of magnification tools on the recognition of simulated preparation and filling errors].

37 mistakes or filling defects were mounted onto a phantom model. Three groups--each consisting of thirteen dentists--examined the jaws under clinical conditions using either no visual aid, magnifying glasses or a microscope. They were further asked if using magnifying tools had a positive effect on pains such as neck and back pain, headaches or sore eyes.

[The operating microscope in dental practice: minimally invasive restorations].

With the visualization provided by the operating microscope (OM), it is now possible to place fillings in formerly inaccessible areas and work in a way that preserves the most enamel and/or dentin. The OM enables working with full overview in interdental areas or in hard-to-reach areas around crowns. The good view not only enables new forms of therapy, but reduces stress while working.