Abstract: A measuring device for calculating sample volumes and changes in sample volumes is disclosed. The device includes a rotatable platform upon which the sample is placed and rotated in increments with an image of the sample being recorded at each rotational position to which the sample is rotated. The recorded images are digitized and outlined such that the outline can be divided into a plurality of parallel slices. The volume of each slice is calculated by calculating the volume of each portion of the slice represented by each image. The portions are then summed to provide the volume of each slice with the volume of each slice then being summed to provide the volume of the total sample. The device further includes a display apparatus to enable an operator to not only view before and after calculated volumes, but to be provided with a graphical display of the shape of the sample both before and after an event which changes the volume of the sample.

Abstract: Novel unsaturated carboxy esters for use in dentistry as bonding agents are produced by a reaction of unsaturated alcohols with cyclic acid dianhydrides. The dianhydrides which can be used in the invention are in general symmetrical compounds having an aromatic nucleus substituted with four carboxylic acid groups from which two moles of water have been removed to form two cyclic anhydride groupings. The unsaturated alcohols used for making the unsaturated carboxy esters have the formula ##STR1## wherein R is H or CH.sub.3, R.sub.1 is H, CH.sub.3, or .dbd.CH.sub.2,n is an integer from 1 to 4 inclusive, andx is 0 or 1.