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Dentifrices

The question of denitrifies necessarily arises. If one's hands are soiled with food and other objectionable material, he washes them with soap and water. A touch of soap (toilet soap) on the brush helps to clean similar material from the teeth. Nothing else is necessary for routine purposes.

The teeth of many people become stained with various substances such at tobacco, tar, certain stains in food and beverages, sometimes stains produced by chromogenic bacteria. Such stains are retained by the bacterial film but do not pass through it into the tooth. They may be removed and minimized by a mildly abrasive powder on the brush. Ordinary prepared chalk is effective. When used with the right kind of brush here suggested, it is harmless. It may be used as frequently as the individual requires. The teeth of some individuals stain much worse and in shorter time than others. Each person should use prepared chalk as often as necessary to prevent objectionable discoloration of his teeth. Some will require it every day, others only once in several days or longer.

The sweetening and strong mint or other flavors which most dentifrice's contain serve no useful purpose and are more or less harmful.

Cleaning The Proximal Surfaces

No matter how much or what kind of brushing is done, it is not possible for the bristles to reach and clean the proximal surfaces between the teeth. It is simply imagination to think otherwise. At the contact point the teeth are in direct contact and there is no space between them. For a variable distance extending outward from the contact plane in all directions there is a gradually widening space which is filled with a pack of bacteria, mostly long rod and filamentous type. This material has the form of a somewhat irregularly outlined biconcave disc (Figure 10) with the center corresponding to the contact point. When heavily inoculated food material is lodged upon the outer part of this biconcave disc where there are large numbers of growing ends and fruiting heads of the rods and filaments of which it is composed, acids may be produced there and may be carried, as if by a sponge or wick, deeper into the space. If the acid production continues long enough, ultimately there is partial decalcification—early stage caries—and later perhaps breaking down, cavity formation— advanced stage caries. In order to surely prevent these events it is absolutely necessary to clean the proximal surfaces of the teeth in this area every night before retiring. When done right this removes most of the bacteria and the food material in which they could grow and produce acids. There is not sufficient time from the time food is put in again the next day, for maximum growth of bacteria and for production of harmful amounts of acid, before time to clean the teeth again at night before retiring.

The only way now known, and the only way likely to ever be known, whereby the bacterial film on the proximal sides of the teeth can be removed is by the proper use of the right kind of dental floss. Elsewhere (4) the author has specified the optimum characteristics of dental floss for personal oral hygiene, indicating the necessity or basis for each characteristic specified. This right kind of dental floss consists of 170 very fine filaments of high tenacity nylon. It is not waxed, and is only slightly twisted (3 turns to the inch). When drawn across the surface of the tooth, each of the 170 separate filaments is potentially capable of mechanically dislodging and removing some part of the microscopic bacterial material thereon. Also the bundle of loosely held together filaments is capable of receiving and holding in the spaces between the filaments (Figure 17), large numbers of microscopic particles (bacteria).