M. I. El-Anwar, K. E. AL-Azrag, M. H. Ghazy, and L. E. Dawood, “Influence of implant-abutment angulations and crown material on stress distribution on central incisor: a 3D FEA”, Braz. J. Oral Sci., vol. 14, no. 4, pp. 323–329, Sep. 2016.