Sir, in 1956 when taking my LDS finals examination I correctly assumed there would be a question about fluoridation of the public water supply!

In 1969, while attending the DDPH course at Leeds Dental School, fluoridation was much in the minds of Professor Jackson and John Murray, which reflected the public debate about the merits of further fluoridation at that time.

In 1975/76, as Area Dental Officer for Sefton AHA, being convinced that fluoridation was effective in lowering the incidence of dental caries, I robustly promoted the fluoridation of the water supply in Merseyside both to the Area Health Authority and in public debate. Nothing happened and now here we are a further 30 years on and Southampton PCT, among others, is discussing whether they should fluoridate the local water supply. But now I am less confident of the cost benefit of the proposal.

A cursory review of the literature (and at age 78 I am not keen on doing more than a superficial trawl of the research) suggests that the marginal benefit gained in caries prevention on top of that already gained by fluoride in toothpaste, in drops and by topical application, is far less clear cut than was the case when the incidence of caries was so much higher as at the time when the measure was first promoted.

It is of consequence to note that reparative treatment today is much less destructive of tooth tissue and also that, to an extent, modern dental practice with its concentration on preventative measures probably has had some impact on the DMF rates.

The limited number of surveys I have perused tend not to show whole lifetimes' experiences of dental caries; indeed sometimes to my surprise they concentrate almost exclusively on the deciduous dentition.

Be that as it may, a key factor that contributes to my unease about supporting the proposal is that the Public Health Authorities seem somewhat less willing now to assert that there are definitely no long term adverse effects (save for dental fluorosis) on the recipients' general well-being than they were when I was actively promoting the measure so long ago!

In conclusion at this time of stringent financial restraints and with much public antipathy, I just wonder now if the marginal benefit of the fluoridation of the public water supply is worth pursuing?