Aims are to assess periodontal health and salivary stress/ immunity responses in COVID-19 survivors

There are lack of data concerning oral health in COVID-19 survivors, nevertheless, many middle-aged patients with oral symptoms of Post-acute COVID-19 report xerostomia and taste impairment and suffer from oral hypofunction, thus may be susceptible to periodontitis and oral frailty. Post-acute or long COVID-19 is/would be the health hallmark of post-COVID-19 era, manifested as a multiplicity of clinical problems and requiring conceptual framework aiming at multidisciplinary health preserving activities. There are various factors which may affect oral and periodontal health in post-COVID-19 era, such as disruption of dental professional care due to the fear of infection, virus-induced disturbance of oral homeostasis and, as a common denominator- COVID-19-induced psychological stress. Expected results would not just offer epidemiological data but also, mechanistic background for defining risks and modified measures aiming to preserve oral health in post-COVID-19 era.

Inclusion Criteria:

• self-reported good general health, ≥ 14 erupted teeth excluding third molars. For periodontally healthy: Bleeding on probing score ≤10%, without attachment loss and radiographic bone loss and probing depth ≤ 3 mm in every site (Trombelli L et al., 2018). For periodontitis patients: periodontitis in stages II-IV.

Exclusion Criteria:

• history of periodontal treatment in previous six months, acute oral infection, presence of systemic disease(s), pregnancy, lactation, smoking ≥ 10 cigarettes per day

Groups I and III will include COVID-19 survivors in late convalescent stage (one to six months post onset of symptoms accompanied by SARS-CoV-2- positive nasopharyngeal swab result) who had non-severe COVID-19 (no or mild pneumonia - less than 50 percent lung involvement on imaging within 24 to 48 hours, absence of dyspnea and hypoxia). Groups II and IV will include participants who report to had no symptoms of COVID-19 and had no SARS-CoV-2- positive nasopharyngeal swab result