By Deborah Kotz Globe Staff

Have you ever been to the dentist for a routine cleaning only to be told that you need some expensive maintenance work such as replacing all your old mercury fillings or removing impacted wisdom teeth? It’s hard not to wonder whether these procedures are truly needed, and a new Cochrane analysis published last week underscores the problem of overtreatment.

The Cochrane researchers found no benefit to removing impacted wisdom teeth that aren’t causing pain or swelling, nor negatively affecting surrounding teeth, making the case for a watchful waiting approach rather than immediate surgery.

Other research found that dentists who perform annual X-rays -- rather than getting bitewings every two or three years as is recommended for healthy adults -- may be slightly raising their patient’s risk of having a meningioma, a common though usually benign brain tumor, according to a recent study from Brigham and Women’s Hospital. And, no, it’s usually not necessary to replace those mercury fillings, says a dentist from the Mayo Clinic, unless they’re defective or covering underlying tooth decay.

How can you avoid unnecessary dental procedures? I found some great tips on a website devoted to calming dental fears and managing anxiety that keeps some people from setting foot in a dentist’s office, which can be extremely damaging to their teeth and gums.

Here’s an excerpt of their tips.