BACKGROUND Mineral trioxide aggregate (MTA), white and gray, has many uses in endodontic therapy but is limited by its difficult handling characteristics. This study compared the physical and chemical properties of white MTA (WMTA) with three experimental root-end filling materials: Capasio (Primus Consulting, Bradenton, FL), Ceramicrete-D (Tulsa Dental Specialties/Argonne National Laboratory, Argonne, IL), and Generex-A (Dentsply Tulsa Dental Specialties, Tulsa, OK). METHODS The setting time and radiopacity were tested using International Organization for Standardization (ISO) 6876 methods. Compressive strength was measured following the ISO 9917 method. The pH of the materials was measured after mixing. A novel test was developed for washout resistance of the materials immediately after placement. Data were compared by analysis of variance and Sidak post hoc analysis (p<0.05) for compressive strength and washout resistance. RESULTS The setting time of Generex-A was half that of WMTA. All materials met the ISO 6876 requirements for radiopacity. The compressive strengths after 7 days decreased in this order: Generex-A>Capasio>WMTA>Ceramicrete-D. The initial pH of Capasio and Generex-A were alkaline, similar to WMTA, whereas that of Ceramicrete-D was acidic. Significantly, alternative materials remained in situ after the washout test, whereas WMTA was displaced from the retropreparations. CONCLUSIONS The clinical handling and washout resistance of the alternative materials were far superior to WMTA. The radiopacity, compressive strength, and washout resistance make Generex-A and Capasio materials suitable for further study. Ceramicrete-D was weaker, less radiopaque, and initially acidic.