PSEN2 and early-onset autosomal dominant Alzheimer disease: We used forebrain-specific conditional presenilin 1 (PS1) and presenilin 2 (PS2) double knockout mice (dKO mice) that exhibit symptoms of neurodegenerative diseases, especially Alzheimer’s disease, to investigate whether ibuprofen can rescue brain and periodontal tissue abnormalities by attenuating the inflammatory response.