Marouf N et al. This case-control study aimed to investigate the impact of periodontitis on Covid-19 complications. Data were collected from the national electronic health records of the State of Qatar.

The case population was defined as patients with registered Covid-19 complications in their records, including death, ICU admissions or need of assisted ventilation due to the disease. The control group consisted of patients also diagnosed with Covid-19 but without major complications.

568 patients were included in the analysis, of which 40 belonged to the case group and 528 to the control group. 258 patients of the total study population were diagnosed with periodontitis, and 33 of these presented severe complications associated with Covid-19, while only 7 in the case group were patients not diagnosed with periodontitis.

The study concluded that Covid-19 complications were significantly higher among patients with moderate to severe periodontitis compared with those with milder or no periodontitis, an observation also true after adjusting for possible confounders. The adjusted odds ratio for the different complications was 8.81 for death, 4.57 for the need for assisted ventilation, and 3.54 for ICU admission.

It was also shown that the group with Covid-19 and periodontitis presented a significantly higher level of inflammatory markers than the group not diagnosed with periodontitis, an observation suggesting that the systemic inflammation might contribute to complications.

The authors conclude that periodontitis could be a risk factor for Covid-19, but also that the results must be taken with caution due to the limitations of the study; further research is needed