Abstract: A method for detecting the presence of active and inactive caries in teeth and diagnosing periodontal disease uses non-ionizing radiation with techniques for reducing interference from scattered light. A beam of non-ionizing radiation is divided into sample and reference beams. The region to be examined is illuminated by the sample beam, and reflected or transmitted radiation from the sample is recombined with the reference beam to form an interference pattern on a detector. The length of the reference beam path is adjustable, allowing the operator to select the reflected or transmitted sample photons that recombine with the reference photons. Thus radiation scattered by the dental or periodontal tissue can be prevented from obscuring the interference pattern. A series of interference patterns may be generated and interpreted to locate dental caries and periodontal tissue interfaces.

Abstract: A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising:a) source means for providing a source of parallel x-ray beams,b) staging means for staging and sequentially rotating a sample to be positioned in the path of thec) x-ray image magnifier means positioned in the path of the beams downstream from the sample,d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means, ande) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor.

Abstract: A selective call control center is provided for transmission of calls to selective call receivers, such as paging receivers. In a first aspect, priorities are assigned to call sources and to call receivers and the order of transmission of calls is determined by the control center as a function of the priorities of the source and the receiver for each call. In a second aspect, at least one call receiver is provided having at least two addresses and the address to be selected from the at least two addresses for calling that receiver is determined dependent on the priority of the source of the call.