The prognosis of replanted teeth depends on several factors, the most important being the length of extra-oral dry time. Studies show that after 60 min dry time, root resorption is predicted. Immediate intracanal placement of Ledermix, a paste containing triamcinolone (corticosteroid) and demeclocycline (tetracycline) has been shown to inhibit root resorption after extended dry time. However, discoloration is possible from the tetracycline in Ledermix. To evaluate the individual influence of corticosteroid and tetracycline on external root resorption after extended extra-oral dry time. Sixty-nine premolar roots of four beagle dogs were extracted and instrumented with NiTi files. Group 1 (negative control) was immediately replanted after root filling with GP and sealer; Group 2 (positive control) was root filled with GP and sealer and replanted after 60 min dry time; In groups 3-5, the canals were filled with Ledermix, Triamcinolone, and Demeclocycline, respectively, and replanted after 60 min dry time. After 4 months, the dogs were sacrificed and the roots were examined histologically for type of healing (favorable or unfavorable) and remaining root diameter. The groups treated with Ledermix, Triamcinolone and Demeclocycline had statistically significantly more favorable healing (75.8%; 69.8%; 52.4%) and more remaining root structure (5.59; 5.48; 5.09) than the group filled with GP and sealer (positive control) (0; 1.15). Corticosteroids were as effective as Ledermix at inhibiting external root resorption.