Two hundred individuals will be formed according to the study and control groups: Group-1: coronavirus 2 (Covid-19) (+) patients (n=100) and Group-2: Healthy individuals (in which the volunteers will be included due to group-1) (n=100). Oral examinations including DMFT scores, salivary flow rate, visible gingival index scores and radiographs (OPG) will be performed on both groups on the 1st appointment. Oral swap samples will be collected with sterile swap brushes (Six sample for each person) on the 1st, 7th and 30th days to evaluate the salivary immunoglobulins (Immunoglobulin A (IgA), Immunoglobulin G (IgG), Immunoglobulin M (IgM)) and cytokine (IL-1, IL-6, IL-10) levels. Blood samples will be collected to validate the oral swap test results.

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is the virus responsible for coronavirus disease 2019 (COVID-19) which also affects all systems of the body including the oral environment. Recent studies have demonstrated the association between oral health status and systemic diseases. including systemic infections and respiratory diseases. Aim of this study is to analyze the immunoglobulin and cytokine levels of SARS-CoV-2 patients and correlate the oral health status of these patients. Our hypotheses are, 1) Covid-19 affects individuals with low oral hygiene (high DMFT score) more severely, 2) Oral cytokine levels will increase similarly to blood levels in patients with Covid-19, 3) Oral immunoglobulin levels in patients with Covid-19 decreased similarly to those in blood. Oral examination of 100 Covid (+) patients which were hospitalized due to acute respiratory failure will be performed in the dental department of each faculty hospital. Decay-Missing-Filled Tooth (DMFT) scores, visible gingival plaque index (Löe-Silness), Bleeding on Probing (BoP) scores, and orthopantomographs (OPG) will be collected for each participant. Oral swap specimens will be collected (6 sample for each person) to evaluate the levels of salivary immunoglobulins (IgA, IgG, IgM) and cytokines (IL-1, IL-6, IL-10) on 1st, 7th, and 30th days. ELISA test will be performed for immunological analysis with ready-made kits (SunRed Biotech. Co, Shanghai, China). Full blood analyses will be performed to validate and correlate the actual cytokine and immunoglobulin levels.

Inclusion Criteria:

• Covid (+) patients,
• Patients who were hospitalized due to Acute Respiratory Deficiency,
• Conscious patients in ICU (intensive care unit) or IDMC (Infectious Diseases and Microbiology Clinic).

Exclusion Criteria:

• Patients with Cancer,
• Patients with Autoimmune System diseases,
• Pregnant women,
• Patients with Immune Deficiency diseases (Acquired immune deficiency syndrome - AIDS, Autoimmune lymphoproliferative syndrome - ALPS , Chronic granulomatous disease - CGD, etc.).

Care provider, investigator and outcome assessors are chosen from separate specialists (Intensive Care Unit, Dentistry, Infectious Disease Departments).