TNF and Alzheimer disease: Consistent with the study by Kamer et al., which showed a higher expression of antibodies against periodontal bacteria (A. actinomycetemcomitans, T. forsythia, and P. gingivalis) and TNF-α in the serum of AD patients than controls [47]; Cestari et al. noted a significant association between periodontitis and increased serum levels of TNF-α and IL-6 in AD patients [48].