PREFACE

There is ample evidence, from many places and over many years, that fluoridation of the public water supply leads to a substantial reduction in dental caries, with all that means in prevention of suffering, inconvenience and unnecessary cost. It can be shown that the beneficial effect of fluoride is significant, whatever other measures are taken in relation to sound nutrition and preventive dental practice. There are several other ways in which fluoride can be used in the prevention of dental caries but each of the alternatives has substantial disadvantages compared with the fluoridation of water. The justification for such a measure as the addition of fluoride to the water supplies of entire communities must rely on strong scientific evidence pointing not only to its effectiveness but to its safety, even though the recommended level in the public water supply is similar to that yielded by many natural sources. From the first, therefore, the safety of the fluoridation of water to the optimum concentration (1 milligram per litre) has been a paramount consideration, and fluoridation programmes were both preceded and accompanied by investigations ofthe healt