Not difficult. It is not difficult to stay in the stomatological hospital affiliated to Sun Yat-sen University, because it is necessary to achieve a master's degree, and postdoctoral students have less competition in the master's degree. The Stomatological Hospital affiliated to Guanghua School of Stomatology, Sun Yat-sen University is a key university stomatological teaching hospital directly under the Ministry of Education, a specialized hospital directly under the Ministry of Health and a training base for dentists, and a hospital managed by the Ministry of Health of Guangdong Province.