A new long-term study of dental therapists in Alaska's Yukon-Kuskokwim Delta has found they are making a difference in the oral health of children and adults.
In villages served the most by dental health aides, children and adults had more preventive care and fewer extractions, cutting down on one of the worst outcomes in dentistry, the study found. Teeth are pulled when they can't be restored, usually because of decay.
"That tells us the therapists are really making a difference in these communities. And the more care they are providing in these underserved communities, the more preventative care and the fewer extractions people are getting," said the lead researcher, Donald Chi, an associate professor at the University of Washington School of Dentistry in Seattle and a pediatric dentist with clinical experience in the Y-K Delta.
The study was released Friday by the University of Washington.
Dentists had challenged the therapists in court, asserting they weren't as competent as fully licensed dentists, but gave up in 2007 when they lost their case.
Chi said he was approached by Dane Lenaker, then the dental director at the Yukon-Kuskokwim Health Corp., to study the dental therapist program. It had intrigued him since his dental school days, when it was just starting and already attracting controversy.
The new study was funded by Pew Charitable Trusts, the W.K. Kellogg Foundation and Alaska's Rasmuson Foundation, all of which have supported the dental therapy program or studies of it.
Chi and other researchers evaluated a decade of data, from 2006 through 2015, that came from patient electronic health records and Medicaid, the federal-state insurance program. Other studies have looked at the quality of care and patient access, but this is the first to assess long-term health impacts in communities.
Researchers focused on the relationship between the number of days dental therapists were in communities and three health outcomes for children and two for adults.
For both children and adults, they assessed the amount of preventive care and extractions and for children only, added in incidents of care under general anesthesia. That generally is done when children need a high number of teeth pulled because of extensive decay.
Dental therapists aren't dentists, but in Alaska and in growing numbers of places, they can perform some of the same work. They examine patients and fill cavities, set temporary crowns and conduct root canals in baby teeth.
In addition, they take X-rays, do cleanings and apply sealants and fluoride.
Their supporters say they fill a need in communities that otherwise have no regular dentist. The Alaska Native Tribal Health Consortium has a two-year specialized training program for dental therapists, who work under the supervision of a dentist.
Advocates for dental therapists said that not enough dentists practice in rural Alaska to meet the needs of residents.
Alaska's first dental therapists had to go to New Zealand for training and started working in 2005. Now most do their studies in Alaska.
The American Dental Association and Alaska Dental Society sued to stop the program, saying some of the work should be done by licensed dentists. But after a judge ruled it was legal, they dropped the suit and agreed to help improve dental care in Alaska.
In communities without access to a dental therapist, the study found young children were nearly three times more likely to have one of their front teeth extracted compared with those that had the most access. Without a therapist, they were less likely to get preventive care such as fluoride, a cleaning or sealants.
Outcomes for adults were similar though the differences weren't as extreme.
Sixteen communities were studied that had no treatment by dental therapists and 10 were studied with the highest level of treatment.
Specifically, almost 23 percent of children under age 3 without a dental therapist had a front tooth extracted, compared to about 7 percent of those with good access to a therapist, according to the electronic health record data quoted in the study.
Baby teeth start forming at about 6 months of age. Decay in baby teeth is a strong predictor of decay to come in permanent teeth, Chi said.
While 47 percent of the children in communities where dental therapists visited most often received preventive care, just 30 percent did in those with no access to a therapist, according to the study.
The 47 percent figure might sound low but that is line with Lower 48 communities with high poverty rates, as found in the Y-K Delta, said Chi, who has regularly traveled to the region to practice.
That's an average figure over the 10 years. The portion of children receiving preventive dental care has been growing in the region, along with the number of dental therapists.
YKHC, which serves about 50 villages with 25,000 people, currently has 10 dental therapists, two each in Bethel, Aniak, Hooper Bay and Emmonak and one in Mountain Village and Toksook Bay.
Therapists also must commit to spend 14 weeks a year traveling to nearby villages. Their focus is school screenings and treatment of school-age children and pregnant women.
The Alaska Native-run health agency is working to have health therapists cover every village, said Tiffany Zulkosky, YKHC vice president of communications. It is sponsoring four students this year and expects to do the same next year, she said.
Besides Alaska, dental therapists also are authorized in Minnesota, Maine and Vermont. They work with tribes in Washington and Oregon. Other states are exploring the program too.
The study doesn't establish that the presence of a dental therapist is the cause of better oral health, only that there is an association to that factor.
Researchers didn't look at other issues that impact dental health and whether they vary village to village.
"Dental care is not a panacea," the study says. "This underscores the importance of other behaviors relevant in oral health such as limiting sugar intake, optimizing fluoride exposure, and tobacco cessation."