Association between Apical Periodontitis and Autoimmune Diseases: A Systematic Review with Meta-analysis

The aim of this study was to perform a qualitative and quantitative synthesis of the available studies evaluating the possible relationship between apical periodontitis and autoimmune diseases.

The literature search was conducted across 6 electronic databases (PubMed/MEDLINE, Embase, SciELO, Web of Science, Cochrane Library, and Scopus). The search covered articles published up to September 2023. There was no disagreement between the 2 reviewers. The RevMan software (V5.3) (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014) was used for the meta-analysis. A dichotomized analysis was performed using the Mantel-Haenszel statistical method with a fixed-effect model and the risk ratio as the effect measure. A 95% confidence interval was adopted, and the significance level was set at P < .05. The presence of apical periodontitis was predefined as the event, with the experimental group consisting of patients with autoimmune disease and the control group consisting of patients without autoimmune disease (healthy individuals). The data used included the number of individuals presenting the event vs the total number of study participants.

Nine studies were included and considered eligible. The methodological quality of the studies was classified as moderate in 5 of the 9 included studies, while 2 were rated as low, and 2 were rated as high-quality. The relative risk was 1.24 with a 95% confidence interval (1.08-1.62), in which the prevalence of apical periodontitis in comparing patients with autoimmune diseases and healthy patients yielded statistically significant results (P < .0001). Thus, patients with autoimmune diseases had a 24% higher relative risk of developing apical periodontitis compared to the healthy/control group.

The analysis of the studies included in this review suggests a potential association between apical periodontitis and autoimmune diseases. However, it is important to consider that the selected studies have limitations, primarily because they are observational studies.