A method of forming a three-dimensional object comprised of a silicone polymer is carried out by: (a) providing a silicone dual cure resin; (b) forming a three-dimensional intermediate from that resin, where the intermediate has the shape of, or a shape to be imparted to, the three-dimensional object, and where the resin is solidified in that intermediate object by irradiating with light; and then (c) further reacting the three-dimensional intermediate to form the three-dimensional object. The silicone dual cure resin includes: (i) a light polymerizable first reactant; (ii) a photoinitiator; (iii) at least one additional reactant(s), and (iv) optionally a catalyst. At least one of the first reactant and the additional reactant(s) contains a siloxane linkage.
