Dentifrices, mouthwashes, and remineralization/caries arrestment strategies

While our knowledge of the dental caries process and its prevention has greatly advanced over the past fifty years, it is fair to state that the management of this disease at the level of the individual patient remains largely empirical. Recommendations for fluoride use by patients at different levels of caries risk are mainly based on the adage that more is better. There is a general understanding that the fluoride compound, concentration, frequency of use, duration of exposure, and method of delivery can influence fluoride efficacy. Two important factors are (1) the initial interaction of relatively high concentrations of fluoride with the tooth surface and plaque during application and (2) the retention of fluoride in oral fluids after application

Contrast, noise and blur affect performance ad appreciation of digital radiographs

We have studied the effect of the simultaneous variation of contrast, noise, and blur on the perceived quality of digital radiograph images. Three images were processed with different levels of roentgen photon noise, different luminance (gray-level) ranges, and different amounts of Gaussian blur. Observers had to rate the quality of the images on a numerical scale. To study how the quality judgment is related to the visibility of small details (diagnostic quality), an artificial detail was added to each image. The detail could be in two possible locations. The visibility of this detail was measured in a two-alternative forced-choice experiment. One of the conclusions is that the quality judgment was based mainly on blur, whereas the visibility of details was affected mostly by noise