Abstract: A dowel post for securing dental and medical prostheses is provided having improved retention when cemented in a parallel-sided blind hole, and which reduces build-up of hydrostatic pressure ahead of the post as it is inserted. The dowel post comprises a head on which said prosthesis is formed or mounted and a shaft extending downwardly therefrom having a channel formed therealong providing a flow path for the cement. The channel is formed by one or more and preferably four or five helical concave flutes wound about the axis of the post at a pitch angle to the axis of 70.degree. or less and preferably at about 45.degree..