ABSTRACT INTRODUCTION: Mineral trioxide aggregate (MTA) used for pulpotomy procedures in immature permanent teeth can reduce treatment to 1 session as opposed to classic calcium hydroxide therapy, which necessitates multiple appointments. The main disadvantage of MTA use is crown discoloration after treatment. The aim of this study was to characterize 3 materials that are used for pulpotomy procedures in immature permanent teeth and assess their color stability in the presence of sodium hypochlorite solution. METHODS: Hydrated Neo MTA Plus (Avalon Biomed Inc, Bradenton, FL), MTA Plus (Avalon Biomed Inc), and Biodentine (Septodont, Saint-Maur-des-Fossés, France) were characterized after immersion in Hank’s balanced salt solution for 1 day and 28 days using a combination of scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction analysis. The color stability of the 3 materials in contact with water or sodium hypochlorite was evaluated by photography, spectrophotometry, and X-ray diffraction analysis. RESULTS: All the materials hydrated and produced calcium hydroxide as a by-product of hydration at early age. All materials interacted with synthetic tissue fluid, forming a calcium phosphate phase. MTA Plus exhibited discoloration in contact with sodium hypochlorite. CONCLUSION: All the materials tested are suitable to be used in the treatment of immature teeth because they all produced calcium hydroxide, which is necessary to induce dentin bridge formation and continued root formation. Neo MTAPlus and Biodentine are suitable alternatives to MTA, and they do not exhibit discoloration.