Abstract – Ledermix Paste® is a paste containing triamcinolone and demeclocycline with demonstrated anti-inflammatory activity that may slow down resorptive processes after severe traumatic injuries to the dentition. A total of 29 premolar roots of six mongrel dogs were extracted and instrumented with rotary nickel titanium files. Fifteen of these roots were then filled with a calcium hydroxide (Ca(OH)2) slurry and 14 roots were filled with Ledermix Paste® paste. All accesses were sealed with glass ionomer and the roots replanted after an extraoral dry time of 60 min. After 4 months, the dogs were killed and the roots prepared for histological evaluation. Five-micrometer thick cross-sections of the root and surrounding tissue taken every 90 µm were evaluated for healing. In addition, residual root mass was also measured to determine the extent of root structure loss for each treatment method. The Ledermix Paste®-treated roots had statistically significantly more healing and less resorption than the roots treated with Ca(OH)2. Root filling with Ledermix Paste® also resulted in significantly less loss in root mass due to resorption compared to those roots filled with Ca(OH)2. Immediate intracanal placement of Ledermix Paste® at the emergency visit after an avulsion injury appears to decrease resorption and increase favorable healing.