The aim of this study was to evaluate the biocompatibility of the regeneration of the dentin–pulp complex in a murine model with different treatments with MTA Angelus, NeoMTA, and TheraCal PT. An in vivo controlled experimental study of 15 male Wistar rats forming three study groups, the upper and lower central incisors were selected where pulpotomies were conducted, leaving a central incisor as control at 15, 30, and 45 days. For data analysis, these were expressed as mean ± standard deviation and were examined by Kruskal–Wallis test. Three factors were analyzed as follows: “inflammatory infiltrate; disorganization of pulp tissue, and the formation of reparative dentin”. No statistical significance was found between the different groups (p > 0.05). Treatment with these three biomaterials (MTA, TheraCal PT, and Neo MTA) presented an inflammatory infiltrate and slight disorganization of the odontoblast layer in the pulp tissue of a murine model, with normal coronary pulp tissue and the formation of reparative dentin in the three experimental groups. Thus, we are able to conclude that all three are biocompatible materials.