In a study of 1566 community-dwelling Japanese elderly who were followed for 5 years, the risk of developing dementia was elevated in individuals with fewer remaining teeth.

Individuals with 10-19, 1-9, and no teeth had 62%, 81%, and 63% higher risks of dementia, respectively, than individuals with >20 teeth. Likewise, an inverse association was observed between the number of remaining teeth and the risk of developing Alzheimer’s disease.

Source:Society for the Study of Addiction

If cost is a factor for why you do not see a dentist regularly, remember that by having dental insurance you are able to have dental care services at a much more affordable cost.  In addition most dental insurance plans provide free preventive dental care hopefully so you will not need to have larger more costly dental care services.