My Auckland dentist emailed through my dental records so a Hawke's Bay dentist could perform emergency root canal on a crowned tooth. My patient file was peppered with instances of my refusing x-rays. Evidently this occurred in July 2000, August 2001, September 2006, November 2010 and December 2011. Once it was recorded in capital letters and once they wrote "still didn't want x-rays"; the disapproval was thinly disguised. Reading between the lines, I was a difficult patient.

Each time I visited the dentist for a check-up, and usually before I'd even made it to the dentist's room, they'd casually ask me if I'd like x-rays. "No, thanks," I'd reply cheerfully as if they'd offered tea or coffee or some other kind of hospitality. Once my reply was countered with: "But we've got a brand new x-ray machine" - to which I responded: "Cool." Surely they didn't imagine I'd say: "Oh, well, in that case then, yes. A little dose of radiation does sound tempting. Count me in."

I must have given the impression of being some hippy-ish advocate of natural therapies, suspicious of modern medicine, but in fact I was just surprised that an x-ray had taken on the guise of a routine process rather than something to be harnessed as a tool for assessing problems. I happily had an x-ray in 2009 when I was experiencing some serious teeth problems. But when exactly did x-rays become gratuitous, something to be performed on a whim?

A US doctor interviewed for Yearly dental X-rays raise brain tumor risk, study finds echoed my general attitude: "For folks experiencing severe tooth pain or other dental symptoms, an X-ray's benefits may outweigh the risks, he said. If a person is not having symptoms, he doesn't think the X-rays are necessary."

Last month I took my nine-year-old for a routine check-up with her paediatric dentist and I requested that no x-rays be taken this visit. To my surprise I was asked to sign a consent form. That's right. X-rays have become so normalised that I had to consent to her not having any. I'd have thought it should be the other way around. Lucky I mentioned it up front.

The Washington Post reported on a study that found "people with meningioma [a common form of brain tumour] were more than twice as likely as people without the brain tumor to have had a bitewing X-ray sometime in their life. For a bitewing X-ray, the patient holds the film in place by biting down on a tab." The article went on to say that the study was based on x-rays performed in the 1960s which "delivered higher doses of radiation than today's do" and also noted that the American Dental Association recommends dental x-rays are limited to about every one to two years for children and two to three years for adults.

The significance of the study was downplayed locally too. "[E]xperts note that advances in x-ray equipment, regulations and the low actual incidence of the disease mean that people should not be worried about the health risks," says the Wellington-based Science Media Centre.

Even so, I'll be proceeding with my usual caution by authorising dental x-rays only if indicated. And if my dentist plans to offer me an optional extra unconnected with clear and present dental concerns it had better be in the form of a decaf skinny mocha.

What are your thoughts on dental x-rays? Does your dentist offer them even if there's no pressing issue? Do you have them willy-nilly or do you try to adopt a more measured approach?