What Hygienists Look for During a Cleaning (That You Can't See)

By Dr. Jane Collins | October 15, 2025

For most patients, a dental cleaning feels like a routine of scraping, polishing, and flossing. You leave with that fresh, smooth feeling, but you might not realize that while your hygienist was cleaning, they were also performing a high-level investigation of your overall health.

Your dental hygienist is a highly trained professional who acts as the 'front line' of preventative care. They are often the first to spot issues that have nothing to do with cavities. Here is what they are really looking for.

1. Gum Pocket Depths (The 'Numbers' Game)

You’ve probably heard your hygienist calling out numbers like '3, 2, 3... 4, 3, 5' to an assistant. This is called periodontal charting. They are measuring the depth of the pocket (space) between your gum and tooth in millimeters.

1-3 mm: Healthy gums.
4 mm: Warning sign. Early inflammation (gingivitis) may be present.
5+ mm: Danger zone. This indicates gum disease and bone loss. Deep pockets trap bacteria that a toothbrush can't reach.

2. Hidden Tartar (Calculus)

You can see the plaque on the front of your teeth, but hygienists are hunting for subgingival calculus. This is hardened tartar that builds up below the gum line. It acts like a splinter in your finger, causing constant irritation and infection in the gum tissue. You can't feel it or see it, but their instruments can detect the rough patches on your roots.

3. Signs of Oral Cancer

During your cleaning, your hygienist is also scanning the soft tissues of your mouth—your tongue, cheeks, throat, and the floor of your mouth. They look for red or white patches that don't wipe off, sores that haven't healed, or lumps.

Oral cancer is highly treatable when caught early, making this 2-minute scan one of the most important parts of your visit.

4. Signs of Grinding (Bruxism)

Do you wake up with headaches? Your hygienist might know why before you do. They look for worn-down biting surfaces, flattened canines, or small cracks in the enamel. These are classic signs of nighttime teeth grinding. They might suggest a night guard to protect your teeth from fracture.

The Takeaway

Next time you're in the chair, remember: that 'scraping' is actually a comprehensive health exam. Your hygienist is your partner in catching silent problems before they become painful ones.