De dentium affectibus

XXXIIX.

That we strive to ward off diligently. Although, therefore, already eroded and broken teeth can in no way be restored to their original integrity; we give effort, however, that they are not affected further by external injuries, and the evil increased by this reason.

XXXIX.

Such injuries, however, are not of one kind, but are clearly manifold. Therefore, first of all, we order that excessively hot things, for example, be avoided, for the reason that they finally split the teeth by their power of burning, or at least weaken them so that they fall out more easily afterward: in which kind our Germans sin greatly by ingesting hotter foods and as if boiling into the mouth.

XL.

Into the same class should also be placed the often-repeated use of sweets. For it is sufficiently established that by this, teeth are blackened and wonderfully deformed.

XLI.

On the other hand, we also interdict things that are too cold (whether the environment be cold, or the things to be consumed), just as they are to all bones by their nature cold and bloodless, so also are they vehemently hostile to the teeth.

XLII.

To which we add that they should abstain from gnawing and breaking very hard things; likewise, that they preserve their teeth clean as much as possible, free them from every impurity which promptly adheres and collects therein, cast far away metals by which bones are easily exasperated and vitiated, and in their place substitute rather woods endowed with the power of drying and astringency, such as the wood of the mastic tree; and other things of the same flour which are also commonly known.

But