Students are back to school, however this year will bring more than just math tests and oral examinations. The toughest test is the one that scientists will have to face to prevent virus transmission within schools. Data collected in Italy show that of the diagnosed cases of COVID-19, 2.1% involved children aged 0-9 years and 4.0% children aged 10-19 years, with a mortality rate close to zero. In recent weeks, however, there has been a considerable increase in cases in the paediatric and adolescent population-many of which are asymptomatic-and 16% of the cases reported to the health surveillance system were of subjects under the age of 19. Schools account for 2.5% of new outbreaks, therefore the focus must be shifted to prevention measures such as daily temperature checks, management of suspicious cases at school, and the possibility of using rapid tests at school, due to the high frequency of febrile episodes during winter, in order to distinguish suspected Covid cases from the seasonal flu. Data at hand, scientific studies confirm that children of all ages can be infected with the coronavirus and spread it to others and that in the school environment the spread of the virus can become critical especially in the presence of "super-spreaders". In fact, it has recently been shown that the majority of patients (70%) with Covid-19 have never infected anyone else, while only 8% of patients are linked to 60% of new infections. Prevention is crucial and it represents the only way to win the fight against coronavirus, a fight that will also be fought in the classroom during fall. Paediatric dentists, who come into contact with a large number of children and are aware of their health status, are once again called to give their contribution to help safeguard the health of young patients, their parents, their classmates and the community as a whole.