Purpose: This article describes the development of a three-dimensional finite element model of a premolar based on a microscale computed tomographic (CT) data-acquisition technique. The development of the model is part of a project studying the optimal design and geometry of adhesive tooth-colored cusp-replacing restorations. Materials and Methods: The premolar was digitized with a micro CT scanner with a resolution of 13 µm. Surface contours were fitted to the various materials, after which a 3-D finite element mesh was constructed to the contours. To demonstrate the potential use of the resulting model, it was applied to a cusp-replacing resin composite restoration. Results: The stress patterns generated in the composite material were truly 3-D. Stress concentrations were found at the surface where the load was applied and in the vicinity of the dentin-composite bonding surface, where the interface had its complex geometry. Conclusion: The described procedure is an easy method to produce a highly detailed 3-D finite element model of a premolar with an adhesive cusp-replacing restoration.