Sugar and fruit acids do not injure the enamel of normal teeth. Sound teeth have been immersed in a sugar solution and in fruit acids for months without suffering any erosion. Dr. E. Howard Turison and others have proved this.

Sugar can hurt the teeth only by entering the stomach and blood and perverting metabolism. Free sugar (commercial sugar) possesses a strong affinity for calcium. When eaten in considerable quantities it leaches the tissues, including the teeth, of their calcium. Dr. Howe says, "only when general derangement follows sugar feeding does caries occur." Starches, sugars, including candies and syrups, must be eliminated from the diet in treating pyorrhoea.

Lactic acid does not injure the enamel of the teeth. No experiments have been able to show that bacteria of any type, when cultured on the teeth, are responsible for dental caries. Bacteria, even if they enter into the production of dental decay, play a very subordinate part and, in conditions which seem to be most favorable to their activity and growth, they are powerless to produce dental decay so long as the resistance of the body is normal.

Tooth decay is attributed to the action of bacteria and their acids upon the teeth. In recounting his experiments on monkeys in which dental caries was produced by a deficient diet and, incidentally, referring to the lactic acid theory of tooth decay, Dr. Howe says: "Before we examine the effects of vitamin-C deficiencies upon the teeth of monkeys, let me remind you that all of our efforts to affect these teeth by fermentation in the mouth for long periods of time by the feeding and injection of microorganisms associated with caries have been unavailing, so long as the diet was normal."

Experiments by Drs. Howe and Hatch (1917) in America, and by Sir James Mclntosh, Warwick James and Lazarus-Barlow, working together in England, in trying to produce dental caries by using acid forming bacteria all resulted negatively. Dr. Howe says that "so long as the diet is normal it has been found impossible to cause caries or pyorrhoea by maintaining fermentation in the mouth or by feeding or injecting the bacteria believed to be most actively associated with dental caries."

There is a deeper cause for tooth decay than the germs that get onto the surfaces of our teeth. That cause exerts its baneful influence upon the growth and development of the teeth. That cause reaches back into the prenatal life of the child when the tissues of the teeth are being formed and developed.

If these things are not so, why then are so many teeth plainly defective when they erupt. They are small, distorted, overlapped, notched, have cavities in them and present other evidences of faulty structure and of lack of resistance to the forces of decay. It is so common to see the six-year molars, the first permanent teeth to erupt, come through with cavities in them.

Something more fundamental than a tooth brush and a biannual dental examination is required to prevent such a condition as this. Something more than these things are essential to the preservation of such teeth.

The ocean of dental decay is so large and its causes such that it can never be coped with by cleaning and filling the teeth. No amount of scrubbing and polishing can preserve them if nutrition is inadequate. Only a radical program will avail us here.

Cleaning the teeth of tartar, which is intended to save the gums and not the teeth, avails little unless a change in food and water is made. The calcific (lime salts) and food debris deposits (tartar) collecting about the necks of teeth come from the saliva and excess lime in free use of lime water. It often collects rapidly.