A new report from J.D. Power finds that overall dental plan customer satisfaction is declining—driven by challenges with cost and in-network dentist availability.

The J.D. Power 2017 Dental Plan Satisfaction ReportSM finds that, in 2017, satisfaction declined to 770 (on a 1,000-point scale) from 781 in 2016. The decline in satisfaction is primarily driven by challenges with cost—755 in 2017 versus 767 in 2016—and coverage—787 in 2017 versus 802 in 2016. The biggest decline was in in-network dentist availability, down 1.29 satisfaction points from 2016.

And while the study found that the number of times a member contacted the dental plan insurer to resolve their problem or question decreased to 1.78 in 2017 from 2.46 in 2016, the length of time to resolve the problem or question increased to 4.61 days in 2017 from 3.53 days in 2016.

The report also notes that 9 in 10 (94%) of “delighted” dental plan members—those with an overall satisfaction score above 900—say they “definitely will” recommend the insurer to others, compared with the report average of 44%. And given the choice, more than half (93%) of delighted members say they “definitely will” select the same dental plan insurer, compared with the report average of 40%.

Dental insurance provider DentaQuest ranked highest, performing particularly well in the cost and communications factors, according to the report. Aetna Dental ranked second and UnitedHealthcareDental ranked third.

The study was fielded in October 2017.