LA CONNER, Wash. — Going to the dentist evokes a special anxiety for Verne McLeod. He grew up on the Swinomish Indian reservation here in northwest Washington State in the 1950s and vividly remembers the dentist who visited periodically. The doctor worked from a trailer, and did not bother with painkillers.

“They just strapped us down and drilled,” said Mr. McLeod, 70.

Poor oral health a has plagued tribal lands across the nation. Indian preschool-aged children had four times the rate of untreated tooth decay as white children in a recent study. Poverty, diet and a decades-long lack of access to good care on remote reservations compound the problem.

But Indians and health experts now see hope: If formally trained dentists are scarce, they ask, can people who master many of a dentist’s skills but lack the professional degree get the job done just as well?

Daniel B. Kennedy is out to prove that they can.

Mr. Kennedy, 56, a soft-spoken Tlingit Native Alaskan, is a dental therapist, the rough equivalent of a physician assistant. He is trained to perform the most common procedures that dentists do, from fillings to extractions. Since January, when he started at the Swinomish Dental Clinic, over 50 miles north of Seattle, he has been the only dental therapist on tribal land anywhere in the lower 48 states. He studied in Alaska, which has the nation’s only program — patterned after one in New Zealand — aimed at training therapists specifically to work in underserved tribal areas.