Dr. Chris Chin sees Victoria Herrera, 6, who is visiting a dentist for the first time in this 2017 file photo.

Dental therapists — a midlevel provider similar to a physician assistant or nurse practitioner — will be a new, licensed profession in Arizona.

Arizona is the seventh U.S. state to allow dental therapy as a profession, said Kristen Mizzi Angelone, dental campaign manager for Pew Charitable Trusts.

Under the law signed Wednesday by Gov. Doug Ducey, dental therapists will be allowed to practice only in certain settings — tribal settings, federally qualified health centers and other nonprofit community health centers treating low-income patients. The law will take effect Aug. 3.

Dental therapy is seen by supporters as a way of addressing Arizona’s oral health needs because therapists will be able to perform a limited scope of procedures such as fillings, extractions and crowns at a lower cost.

Members of the Tohono O’odham Nation southwest of Tucson were among the most vocal supporters of the legislation, as they see it as offering a career path for tribal members to remain on the reservation without spending as much money as it costs to go to dental school. Tribal members have also indicated interest in setting up dental therapy coursework at Tohono O’odham Community College.

While Arizona tribes may hire federally certified dental therapists from out of state once the new law takes effect in August, it’s expected to be several years before Arizona schools start graduating dental therapists.

The original dental therapy bill was sponsored by Sen. Nancy Barto, a Republican from Phoenix who has long said adding dental therapists is a “free market solution” to meeting oral health needs in the state.

“Dental therapists are a proven workforce model that will increase affordable care options without creating new, burdensome regulations,” Barto said.

The law says that for someone to become a dental therapist, they must first be licensed as a dental hygienist and graduate from a three-year dental therapy training program accredited by the Council on Dental Accreditation, and complete a clinical competency examination.

The Arizona Dental Association had been highly critical of creating a new dental profession but in the end agreed to the amended law that was passed. “We still have doubts about it. We really believe it’s not the answer it’s being touted as,” said Kevin Earle, the association’s executive director.

The legislation requires the Department of Health Services to do a study once the dental therapists are working in Arizona, to track whether they are making a difference. “We’ll look at it again when the study is done,” he said.

The association worked with Dental Care for Arizona to ensure dental therapists enter into a written collaborative agreement with an Arizona-licensed dentist. All billing will go through that dentist or the dentist’s clinic.

The final version of the law also rolls back the type of extractions a dental therapist can do under supervision. The law stipulates dental therapists may not extract permanent teeth unless under the direct supervision of a dentist.

“Though we made significant improvements to the original version of the bill, we still do not believe dental therapy is the answer to Arizona’s oral health care challenges,” said Dr. Robert Roda, a Scottsdale endodontist and president of the Arizona Dental Association.

The dentists had argued there are other ways to improve oral health, such as adding more teledentistry, removing administrative barriers within the managed care system for Medicaid (the Arizona Health Care Cost Containment System, AHCCCS), and attracting more dentists to rural areas.

The bill also does not address policy issues that are preventing Arizonans on AHCCCS from getting comprehensive oral health care. Adults on AHCCCS are not covered for routine care — only dental emergencies.

One in seven Pima County adults ages 35 to 44 have periodontal (gum) disease, Pima County’s 2015 Health Needs Assessment says. A statewide 2015 Healthy Smiles Healthy Bodies survey says 52 percent of Arizona’s kindergarten children have a history of tooth decay, compared with the national average of 36 percent.

The rate of practicing dentists in Arizona is 53.89 per 100,000 population — below the national average of 60.79, the American Dental Association’s 2016 data shows.

And that rate, while it has improved in the last 15 years, doesn’t reflect the way the dentists are clustered, with big gaps in some areas, including Santa Cruz, Pinal, Greenlee and Yuma counties.

State. Rep. Pamela Powers Hannley, a Tucson Democrat, said the new law will create high-quality jobs while increasing access to safe, quality and affordable oral health care to Arizonans who currently lack access.

Dental therapists are already practicing in Minnesota and on tribal lands in Alaska, Oregon and Washington state. Maine and Vermont passed dental therapy laws and are developing training programs. About 12 other states are considering laws that would allow dental therapists, Mizzi Angelone said.

“I think Arizona is going to be a model for other states,” she said. “What is included in the Arizona law is really modeled on a national standard.”

Contact health reporter Stephanie Innes at 573-4134 or email sinnes@tucson.com. On Twitter: @stephanieinnes