Aim: To develop, apply, and evaluate a virtual learning object (VLO) for teaching undergraduate dental students and paediatric dentists to diagnose and manage molar incisor hypomineralization (MIH). Design: This controlled educational intervention included 170 undergraduate dental students and 50 paediatric dentists. The student intervention group (VLOG) was trained by the VLO, the control group of students (CG) received a synchronous virtual class, and the group of paediatric dentists (PDG) was trained by the VLO. Pre-test and post-test data were analyzed with a mixed one-way and Tukey’s post hoc ANOVA test (α = 0.05). The answers to the questionnaire were analyzed with the one-way ANOVA test and Tukey's post hoc test (α = 0.05). Results: The values obtained in the pre-test were significantly lower than those obtained in the post-test for all groups. The specialists showed a higher level of knowledge before and after the MIH training compared with the students (p <.001). Similarly, statistical differences were found in the level of knowledge, which increased after MIH training (p <.001). There were no differences between the CG and VLOG. Conclusions: The level of knowledge increased in all groups after training regardless of the method used. VLOG works similar to traditional teaching approaches.