Association Between Periodontitis and Alzheimer’s Disease: a Case-control Study

Objectives: Alzheimer’s disease (AD) is a neurodegenerative chronic condition responsible for 60% to 80% of all dementia cases. The goal of this study is to test the hypothesis that periodontitis is associated with AD.
Methods: This study was approved by the Federal University of Rio de Janeiro (UFRJ) IRB (CAAE 81079417.4.3001.5263) and, to participate, each subject or his/her legal representative signed an informed consent form. Clinical oral examinations were carried out and socio-demographic data were collected by a single, trained and calibrated, investigator (ROA) from outpatients with mild to moderate AD (cases, n=50) and from their family caregivers (controls, n=52) at the Psychiatric Institute of the UFRJ, from May 2018 to January 2019. Mean age and full mouth mean probing depth (PD), mean clinical attachment level (CAL), mean number of teeth, and mean percentage of sites with bleeding on probing (BOP), visible plaque (Pl) and calculus were analyzed by the Student’s T or the Mann-Whitney test. Gender, income, education level and smoking habit were compared between groups with the chi-square test.
Results: Gender, age, income, education level and smoking habit were equally distributed between case and control groups. Cases had fewer teeth than controls (11.5±6.2 vs. 20.8±6.1, p=0.000), deeper PD (3.4±0.2 vs. 2.4±0.1, p=0.000) and greater CAL (4.6±0.3 vs. 3.1±0.2, p=0.000). Also, cases had superior percentage of sites with Pl, calculus and BOP than controls (72.6±3.8 vs. 16.7±2.9, p=0.000; 54.4±5.2 vs. 9.5±2.3, p=0.000 and 57.9±4.5 vs. 15.4±2.0, p=0.000; respectively).



Conclusions: Periodontitis seems to be associated with AD. However, the study design does not allow the establishment of a cause-effect relationship.