Those having dental insurance may take for granted a twice-yearly preventive-care visit to the dentist. But for many seniors on a fixed income—and even more so for seniors on the lower end of the economic spectrum—a routine cleaning is a luxury. Forty-nine percent of seniors 65 and older who have not seen a dentist in a 12-month period cite cost as the No. 1 reason for not visiting the dentist more frequently. That number skyrockets to 69 percent of low-income seniors, according to the American Dental Association’s Health Policy Institute.