Q:What is WDDTY's view on the necessity of the removal of dental plaque on a regular basis? As I understand it, there may be a need for such removal in the case of people with certain gum problems. I have, also heard that some of these gum problems are in fact created by the methods used in plaque removal! E J, Enniscorthy, Ireland......

Thank you, E J, for your citation from the late Dr Robert Mendelsohn's newsletter The People's Doctor (Vol 8 no 9, 1983), which quotes from a recommended periodontal textbook (Periodontal Therapy (sixth edition, Drs Henry M Goldman and Walter Cohen). In the textbook, three investigators showed a positive correlation between brushing teeth and gum recession in animal experiments.

They also found that abrasive toothpastes and hard toothbrushes and excessive toothbrushing destroyed root surfaces, that the inadvertent trauma of dental floss can sever gingival tissues, that patients with periodontitis can have a higher incidence of bacterial infection of the bloodstream from the mechanical action of the toothbrush on bacteria laden gums, and that in patients with inflamed gums, gum abscesses can occur with the use of devices that squirt between your teeth.

You're right that the abrasive methods of plaque removal and poking around gums might be worse than usual brushing and flossing at home. Although all the dentists we spoke with confirmed that periodic gentle descaling and home plaque removal is vital, all agreed that constant, abrasive cleaning does more harm than good.

Both Jack Levenson and Dr Mittelman have found many cases of toothbrush caries, caused by too vigorous brushing and also brushing across the cervical margins next to gums. Although the official dental organ, the J of Periodontology (September/October 1994) reported that "sonic" brushes are more effective in removing plaque than manual toothbrushes, it did not appreciably improve gums; gingivitis and bleeding levels were similar in groups using toothbrushes or sonic brushes. Furthermore, we don't know the effects of a sonic toothbrush's vibrating brushes on the delicate gums.

Dr Mittelman recommends an ultrasoft toothbrush with rounded ends and says to avoid new types of toothbrushes with novel shapes, particularly those with "natural bristles", which can traumatize the gums.

Two possibilities, he says, are the Rotadent toothbrush, with a small head and 5600 filaments like human hair (available only through dentists; write to him at 2653 West End Avenue Apt 2A, New York, NY 10023, if you can't get one through your dentist). Another possibility is the Bass brush, which has soft bristles designed for subgingival plaque removal. Dr Mittleman recommends the Butler No 300 Dr Bass's Right Kind/ Sub-G brush, available in American chemists or by writing for an order form to Oral Health Products, Inc, PO Box 470623, Tulsa, OK 74147. Ask for the no. 1 Adult three row staggered. He also recommends Dr Bass's unwaxed floss.

Both our panel dentists stress that flossing is vital so long as it is done properly without abrasive floss. Good flossing requires substantial manual dexterity, and Dr Mittelman finds that virtually all his patients need flossing lessons from the hygienist. Make sure that you and your children, who can start learning at three to floss, as his own son did, ask for lessons, or find another dentist who will make the time to teach you during cleaning sessions with the hygienist.

If your gums have receded, use a balsa wood wedge toothpick to clean between the gums and teeth (avoid regular toothpicks which are too abrasive).

How often your teeth get de scaled depends upon your teeth and nutritional status.

Although the University of Michigan periodontal clinic pronounced that every three months is optimum to prevent active disease from forming, patients with a low sugar, health food diet containing plenty of raw foods probably could go for six months to a year between cleanings. One dental specialist at University College Hospital has said that a a six month checkup is arbitrary and nonsensical, if your gums are healthy. Make sure also to have a saliva producing food at the end of the meal (such as fruit), which will avoid plaque build up.