OBJECTIVES: To investigate the association between hospitalization for COVID-19 and oral changes, and to evaluate whether oral changes can indicate a higher risk of disease progression to death. MATERIALS AND METHODS: This case-control study analyzed patients hospitalized (university hospital), including those in intensive care unit and clinical wards. The study group comprised 69 COVID-19 positive patients (PCR-test), while the control group included 43 COVID-19 negative patients. A dentist performed oral evaluations, and salivary samples were collected for calcium, phosphatase, and pH analysis. Sociodemographic data, hospitalization information, and hematological test results were collected from electronic-medical records. The presence of oral changes was assessed using chi-square tests, and the predicted risk of death was analyzed using binary logistic regression. RESULTS: COVID-19 positive patients had a significantly higher prevalence of oral changes compared to COVID-19 negative patients. The presence of any oral changes in COVID-19 positive patients indicated a 13-fold higher risk of mortality. "Bleeding ulcers," "pressure ulcers," and "angular cheilitis" were significantly associated with hospitalization for COVID-19. CONCLUSION: There may be an association between hospitalization for COVID-19 and the development of oral changes, including bleeding ulcers, pressure ulcers. and angular cheilitis. These oral changes may serve as potential indicator for disease progression an increased risk of death. CLINICAL RELEVANCE: COVID-19 hospitalized patients have a higher prevalence of oral changes, which indicate an increased risk of mortality. Oral medicine staff should be included in multidisciplinary teams to detect and treat these oral changes promptly.