Her tooth throbbed painfully for months, as Sandy Abrahamson alternated between taking maximum doses of Tylenol, Motrin and aspirin.

When she finally got herself through the door of a dentist’s office after avoiding an appointment for years, she was informed the molar had decayed to its roots and would have to be pulled. But she was so afraid of injections that she insisted the tooth be yanked out with nothing for the pain.

She withstood the attempt for three hours until she gave in and faced the terror of an injection, tears leaking onto her dental bib. At that point, Abrahamson, a nurse practitioner who lives in Edmonds, Wash., was in the fierce grip of her dental phobia.

“It is not easy to give over control to someone who is going to crawl inside your mouth and do some work, in your mouth, where you breathe and swallow,” Abrahamson said.

Roughly five to 10 percent of the population suffers from dental phobia, but as many as 40 to 75 percent of people experience fear and anxiety related to dentistry that contributes to postponing and cancelling appointments, or avoiding the dentist altogether, according to extensive research on the subject.

A typical response to phobia and fear is avoidance — unless, as in Abrahamson’s case, there is help, which for her came at the intersection of dentistry and psychology. Her dentists work with psychologists at the Dental Fears Research Clinic in Seattle, where the first step of her treatment for several years was meeting with a counselor.

Last week researchers at King’s College in London released the latest study in support of this approach to treating dental phobia and anxiety. They reported that cognitive behavioral therapy — a combination of behavioral modification and talk therapy that is designed to challenge negative or harmful beliefs, known as C.B.T. — offered a reliable long-term solution to dental phobia, anxiety and avoidance.

The British study looked at the experiences of 130 patients — though it did not include a control group with patients who had no C.B.T. treatment — who were considered to be anxious enough about going to the dentist to qualify as phobic. Fear of injections and drilling was the reason for the phobia in a majority of the patients, according to the study.

The 130 patients, 99 of them women, were given five CBT sessions at a dental hospital at King’s College. The study found that 79 percent of the patients treated between Jan. 2009 and May 2013 went on to have dental care without sedation and that only 6 percent requested sedation at the dentist after the therapy.

The sessions began with an evaluation of the patient’s level of fear or anxiety and slowly incorporated aspects of seeing the dentist, said one of the study’s authors, Tim Newton, professor of psychology as applied to dentistry at King’s College London Dental Institute.

The patients would be given homework, he said, including the practice of relaxation exercises and then, by week three patients would be shown the “injection equipment, photos of the injection equipment and a video of someone else having an injection.” That is an aspect of behavioral therapy known as “exposure therapy,” or desensitization, which aims to make the patient feel at ease in the presence of the source of a phobia by repeated exposure to it.

Dental phobia is considered a “specific phobia,” in the psychiatric bible of disorders, known as the Diagnostic and Statistical Manual. One phobia “subtype” is known as fear of “blood-injection-injury,”and this phobia can cause the blood pressure to drop so low that the person experiencing it faints.

“People can feel very out of control,” Newton said. “So we talk to people about control. You can signal to dentist that you want to stop; you can get as much information you want; you are in charge of how often you get breaks — tell the dentist.”

Newton said the five therapy sessions were structured so that the drilling part came last. Since the program started at King’s College, eight more public and quasi-public facilities have followed suit to offer patients CBT in the dental setting, he said.

Teams of psychologists and dentists in one practice are much more common in Europe and Scandinavia than in the United States, researchers say. That is partly because of insurance issues: the psychological services are a mental health benefit that may not be covered by a patient’s health plan.

The increasing use of cognitive behavioral therapy for dental phobia comes at a time of great popularity for “sedation dentistry,” which involves the use of anti-anxiety and other drugs to put fearful patients into a state of conscious sedation for dental procedures. Some dentists say the potentially costly sedation can create amnesia so patients do not have to remember the noise and vibrations of the oft-dreaded drill, the saliva suction, the needles plunging into cheeks and gums.

Although it may be novel in the U.S., the idea that behavior modification and therapeutic approaches to dental phobia have more long- term benefits than medication is not new. Several studies in Sweden, which opened one of the first dental clinics using psychologists, showed that anxious dental patients who participated in therapy were much more likely to continue dental treatment than those who underwent general anesthesia for procedures. Another study, published in 2004, examined all the research on the subject up to that point and concurred.

Lisa J. Heaton, a psychologist on staff at the Dental Fears clinic in Seattle and an assistant professor at the University of Washington School of Dentistry, said the clinic offers sedation and therapy and, often, a combination.

“Patients will call and say, ‘I want to be knocked out and done with it,’” she said. “But these people will wake up with the same fear they went to sleep with. Their teeth are fixed, but they then fall into the same pattern of avoidance. And then they need all this dental treatment done.”

Once her molar emergency was settled, Abrahamson, 63, and her psychologist at the Dental Fears Center began to work on undoing the power of her phobia, using various cognitive and behavioral therapy techniques.

She would talk about her anxiety and then try sitting in the chair. Then she would talk some more and try having a tiny drop of analgesic placed on her gums, the topical solution given before an injection of Novacaine.

Dentists and psychologists acknowledge that it is not easy to sell the idea of therapy for dental phobia or fear, given the time commitment and, in the United States, the possibility of having to pay out of pocket for the extra service.

The extra time was worth it to Abrahamson, because facing her dental phobia led her to seek treatment for trauma from an abusive marriage. She came to see the awful state of her teeth as a sign that things within had to change.

“I felt out of control, and I wanted it to be different,” she said. “Anybody who engages in cognitive behavioral therapy, whether the goal is dental procedures or if it’s to change your life, the only people who can be successful are people who are willing to go back in and go through it and struggle with it and fight with it and relive whatever you need to relive and say what you need to say.”

She has a dental check up on the 15th of this month and said she was not nervous about it.

“I go into it understanding that it’s uncomfortable,” she said. “To this day tears will fall out of my eyes — it’s still there — but it isn’t causing me to behave in a way that is unhealthy.”

Want more inspiring news and ideas to improve your life? Sign up for the Saturday Inspired Life newsletter.

If you liked this story on Inspired Life, you may also enjoy: