More benefits in brushing teeth

It may seem contradictory, but the cell damage caused by brushing your teeth may help keep your gums healthy, U.S. researchers say. Toothbrush bristles tear holes in the epithelial cells that line the gums and tongue, causing a momentary rupture, explains a team at the Medical College of Georgia.

"It's very clear that brushing your teeth is a healthy thing to do; no one questions that brushing removes bacteria and that's probably it's main function," corresponding author and Dr. Paul L. McNeil, a cell biologist, said in a prepared statement.

"But we are thinking that there might be another positive aspect of brushing. Many tissues in our bodies respond to mechanical stress by adapting and getting stronger, like muscles. We think the gums may adapt to this mechanical stress by getting thicker and healthier. It's the 'no pain, no gain' theory, the same as exercising," McNeil said.

For this study, he and his colleagues injected fluorescent dye into the bloodstream of rats and then brushed the rats' teeth, gums and tongues. Calcium (which is abundant in saliva) then moves into the cells and triggers internal membranes to move up and patch the holes, the researchers reported in the August issue of the Journal of Dental Research. This repair takes a few seconds. During that time, growth factors that promote the growth of collagen, new blood cells and blood vessels leak out of the damaged epithelial cells. The injury to these cells also turns on expression of a gene (c-fos) that's often activated under stress and may be the first step in a response such as cell division or growth, the researchers said.

Dealing with Dandruff

Dandruff, also known as seborrheic dermatitis, occurs when flakes of skin develop on the scalp or inside the ear. The skin condition, which can run in families, may be triggered by stress, fatigue, oily skin, acne or using hair or skin products that contain alcohol, the U.S. National Library of Medicine says. Infrequent showering or shampooing may also trigger dandruff.

To treat the condition, over-the-counter dandruff or medicated shampoos should be used daily. Active ingredients in these shampoos include salicylic acid, coal tar, zinc, resorcin, ketoconazole or selenium. The hair and other affected areas should be washed for about five minutes before rinsing thoroughly.

- HealthDay news