BACKGROUND: Cognitive impairment is the gradual loss of one's ability to learn, remember, pay attention, and make decisions. Cognitively impaired elderly people are a challenging patient population for dental health care professionals and may be at higher risk of developing oral health diseases. The authors systematically reviewed interventions effective at improving dental health in patients with cognitive impairment and described research gaps remaining. TYPES OF STUDIES REVIEWED: In a comprehensive search of multiple databases, the authors identified 2,255 studies published in the English language from 1995 through March 2016. The authors included studies if the investigators evaluated oral health measures after an intervention in patients 65 years or older with cognitive impairment or dementia. Nine full-text articles met the criteria for inclusion. RESULTS: Only 1 study was a randomized control trial, whereas all others lacked appropriate controls. Investigators studied the effects of dental treatments, battery-powered devices for oral hygiene, and training of care staff members. Most interventions improved some aspect of the oral health of patients with dementia, and results were more pronounced when patients required assistance while performing oral hygiene tasks or had poor oral health at baseline. CONCLUSIONS AND PRACTICAL IMPLICATIONS: A basic care plan for patients with dementia should, at the minimum, match prevention strategies recommended for healthy elderly patients. Dental health care professionals should promote oral hygiene education for caregivers for elderly patients with cognitive impairment. There is a wide gap in knowledge regarding effective methods specifically to improve oral health in patients with dementia.