The intent of this study was to quantify the fracture surface area of dental composites subjected to different aging media. Dental composites, a combination of a resin and glass filler particles, were examined using a high resolution microtomography system developed at beamline 2-BM of the Advanced Photon Source (APS). The composite specimens were 2 mm in diameter and 3 mm in height subjected to a compression load. The initial data set of images was taken with no load, then the load was incrementally increased, a new scan taken, repeatedly, until failure occurred. The images obtained from the tomography scans were reconstructed and analyzed to provide a 3D representation of the crack. This reconstruction involved determining the total solid area, the total area which includes the crack interfaces, and then just the total crack interface area. A ratio was then determined between the control and the loaded specimen. The specimens were aged in various media for 3 months. Preliminary 3D analysis corresponded to previous studies with respect to the aging media and load, i.e., higher loads and aging in ethanol resulted in weaker materials and in this case increased crack areas and compression of the material. When sufficient samples are processed (at present N=6) this 3D analysis will allow statistical comparison of crack area. Supported by NIDCR grant DE07979. Use of the APS was supported by the U.S. DOE, Office of Science, Basic Energy Sciences, under Contract No. W-31-109-ENG-38.