Fabrication of a functionally graded dental composite resin post and core by laser lithography and finite element analysis of its stress relaxation effect on tooth root.

Laser lithography was applied for Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) fabrication of dental prostheses made of composite resin. First, the conditions to obtain the optimum resolution for photo-curing were determined, and then a composite resin full crown was fabricated by laser lithography. Second, a functionally graded composite resin post and core which had gradient elasticity in the post, was manufactured by the gradual change in the filler contents of the composite resin. Finally, stress analysis of the functionally graded post and core was performed by a two-dimensional finite element method. This demonstrated the effects of reducing the stress concentration around the apex of the post.