Objective: Due to the high rate of dental caries in our country, and specifically in the SERODU Clinic, we sought to determine the prevalence of this pathology in permanent first molars, in children aged 6 to 9 years who attended the Clinic of the Faculty of Dentistry from the Equatorial Technological University-Quito-Ecuador and to know which of the first permanent molars has the highest exposure of dental caries, in which gender is more predominant and if there was any previous, preventive or restorative treatment. Materials and methods: An observational, retrospective and descriptive study was conducted in the Clinic of the Faculty of Dentistry of the Technological University Equinoccial-Quito-Ecuador, during the period 2016-2017, reviewing each of the Clinical Histories entered in the interval of proposed time, with a previously calibrated staff. In History the information of the Odo...