This study determined the effect of a modification of the drilling technique on the retention of self-threading pins. The drilling technique in two stages significantly increased the retention of self-threading pins.
Van Nieuwenhuysen, J.-P., & Vreven, J. (1992). A drilling technique to improve the retention of self-threading pins. Journal of Prosthetic Dentistry, 68(2), 255-256. https://doi.org/10.1016/0022-3913(92)90324-4 (Original work published 1992)