You know those handheld beeping laser probes that some dentists use? They are a scam. At least that’s been my experience with them. And I’ve had 10 fillings!

Here’s how they work: Four years ago, after acquiring his first “diagnodent,” my old-old dentist said my x-ray and visual tests came back negative, but this newfangled beeping pencil-like thing said I had a cavity. Confused, I asked him: “Is this the same as an x-ray verified cavity.” No, he replied, but it did mean decay was starting. I asked if we could watch it with regular check ups. He agreed. Then retired later that year before I could follow up.

So I went to a new dentist. He too used a diagnodent. And each and every year, he would find more and more cavities with the device, while the xrays and visual tests all came back negative. Still doubtful, I pressed him on the issue each and every time. He always dodged my questions and politly replied, “If I were you I would get them filled.” He did this for not one, not two, but three consecutive years with an increasing amount of beeping teeth.

(As an aside, this dentist also said my root canal tooth should be replaced, as it could “crack and break at any time and injure my mouth.” Yep, I have a weaponized tooth, people. Keep your distance. It may attack at any moment.)

Long story short, I called this guy’s bluff each and every year through regular checkups. He kept saying my beeping teeth would get worse. They never did. Having enough, I went to my new dentist this year.

“You’re cavity free and have some of the cleanest teeth I’ve worked on,” he said this week, after using digital x-rays and visual probes to examine my teeth. No diagnodents. He also complimented how well my 20 year old root canal tooth looked. For what it’s worth, he had a very nice, clean, and remodeled office with digital technology — on par with my old dentist (although his lobby couches weren’t as plush).

Here’s the rub: Diagnodents are not suppose to be used independently from x-ray and visual dentist test. Furthermore, when they do beep, it often means the tooth MAY develop into a cavity. It doesn’t necessarily mean start drilling right now, according to one informed patient (which is consistent with my retired dentist’s prognosis).

“I talked to my neighbor, who is a retired dentist, and he said that with fluoride drops and better hygiene, it’s likely the teeth can remineralize and those won’t become cavities,” she said. “Then I read the laser is susceptible to false-positives. THEN I read an article from a dentist in Australia that said a lot of dentists are using diagnodents to drum up business and do unnecessary work!”

Moral of the story: Avoid diagnodents as a primary diagnosis. They’re shady. Tell your dentist you plan on using regular check ups and cleanings to take care of teeth, and that you will only fill cavities that are x-ray, visual, or pain positive.

P.S. I used to go to the dentist twice a year, until I heard that it was actually dentists that invented this twice a year custom in an effort to boost business. For people with healthy teeth, one examination per year should suffice. In some cases, once every two years will do. It just depends on the quality of your teeth. The more you know.

See also: Please don’t talk to me while cleaning my teeth