Gerontologist
Gerontologists are health care professionals who specialize in working with elderly patients. They provide their services to people in nursing homes, senior citizen centers, and other similar facilities.
This answer is incorrect. There is no such thing as a "geriantologist." A gerontologist is someone who specializes or studies aging, generally from a social perspective. For example, they may study statistical trends and Demographics associated with aging issues. A geriatrician is a physician who specializes in treating older adults. Every geriatrician is a gerontologist, but not every gerontologist is a geriatrician!