Introduction: Mineral trioxide aggregate (Pro Root [PR]; Dentsply, Tulsa, OK) has been shown to have high rates of success in various endodontic applications. A major drawback is its tendency to discolor dentin. Two new bioceramics (BD, Biodentine [BD]; Septodont, Saint Maur des Fosses, France; and Endo Sequence [ES]; Brasseler, Savannah, GA) have been developed that claim to not discolor teeth. The aim of this study was to compare tooth discoloration between these 3 materials. Methods: Forty-eight bovine mandibular incisors (4 groups, n = 12) were obtained and prepared from the apical aspect after root resection. Canals were prepared with sequentially larger Para Post drills (Coltene/Whaledent Inc, Cuyahoga Falls, OH) to size 7 to 3 mm coronal to the cementoenamel junction. Experimental materials were condensed into the crowns and the access sealed. Color was assessed at various times up to 2 months according to the CIE L*a*b* color space system. Change in color, Delta E, was compared among groups and over time using analysis of variance. Results: For all materials, there was a sharp increase in Delta E after placement. There was a rebound effect on day 1. After a rebound toward the initial color, all materials displayed a trend toward discoloration through the experimental period. At the end of 8 weeks, both BD and ES had discolored significantly more than either control or PR. BD and ES were not significantly different from each other. Control and PR were not significantly different from one another at the end of the experimental period. Conclusions: BD and ES discolor bovine tooth structure to a perceptible degree. At 8 weeks, this was significantly more than PR.