According to a recently-released survey,

...in March 2015, the percentage of adults who had been covered by health insurance for a full year, but reported an unmet need for dental care due to affordability, by income level, was:

• 30.8% of low-income adults
• 23.8% of adults with family income between 139% and 399% of the federal poverty level
• 11.4% of adults with family income at or above 400% of the federal poverty level

Source: "Health Reform Monitoring Survey," The Urban Institute, September 24, 2015, http://hrms.urban.org/quicktakes/Gaps-in-Dental-Care-for-Insured-Adults-Remain-under-ACA.html