The clue to the cause of of JM's husband's periodontitis (WDDTY vol 7 no 11) may lie in her statement: "He is meticulous in his dental hygiene."

Ten years ago I was sent an article published in Germany: "Zahnausfall aus der Tube" tooth loss from the toothpaste tube. I enclose the full article, but the salient points are these.

Some toothpaste may contribute to, if not cause, tooth loss. Sodium lauryl sulphate (SLS) is used mainly as a foaming agent, but it is a fierce detergent. It may cause severe swelling of the gums and is listed as a poison in America and as a primary irritant. It binds to tissues, so is not removed by simply rinsing the mouth with water. SLS also damages the friendly bacteria in the mouth, while leaving others such as E coli and streptococci unharmed. At the time of publication (1987), 38 out of 55 brands of German toothpaste contained SLS, some of them in high concentrations.

Another group of chemicals: formaldehyde, bromchlorophen and chlorhexidin, were included in some toothpastes as antibacterials. They are undesirable, upsetting the balance of mouth flora. Some toothpastes were too acid, etching the teeth and making them more vulnerable to decay. Some were too alkaline, harmful to the gums.

My dentist reckons that brushing teeth with a little plain salt sodium chloride is perfectly effective and will do no harm. Out of interest I looked at the ingredients in toothpastes on a supermarket shelf yesterday SLS is still to be found among them.

The article recommends that anyone suffering from periodontitis should avoid toothpaste with SLS or any detergent, or with formaldehyde or chlorhexidin. The article recommends checking the size of the cleaning particles the smaller they are, the kinder to the teeth. A McCosh, Biggan, Lanarkshire.......