DENTAL HARD TISSUE DESTRUCTION 143 



size. Furthermore, there is evidence from related experiments that 

 this final submicroscopic maturation of the enamel is to a large ex- 

 tent controlled by the liquid-solid equilibrium between the salivary 

 environment and the enamel structure (Sognnaes, 1955, 1957a). 



On the strength of these observations, the following reasoning 

 suggests itself. If the enamel of erupting teeth, when confronted 

 with a normal salivary environment, is capable of reaching a higher 

 degree of submicroscopic mineralization of its crystals, the question 

 arises whether fully mature enamel which has been reversed to a 

 less completely mineralized stage by superficial pathological demin- 

 eralization is then capable of reassuming the original, supercalcified 

 stage, through contact with a favorable salivary environment. In 

 other words (referring again to Fig. 29), one may ask whether the 

 physiological mechanism which can bring the enamel mineralization 

 from the stage of the recently erupted incisor up to the more highly 

 mineralized stage represented bv the molar enamel (Fig. 29, lower 

 right) may be duplicated if the enamel of fully calcified teeth is 

 experimentally or pathologically drained of some of its lime salt con- 

 tent. It is on the basis of this reasoning that the preliminary re- 

 mineralization experiments described above were caiTied out and 

 included in this report. 



In this writer's view, it would seem that one can now approach 

 this remineralization problem with less skepticism and better scien- 

 tific tools than might have been the case only a few decades ago. 

 For there is emerging both theoretical and experimental support 

 for the hypothesis that incipient biochemical destruction of the 

 enamel — even though it extends along certain susceptible pathways 

 below the external enamel surface — has potentialities for reversibil- 

 ity within certain critical limits, yet to be fully explored in theory 

 and exploited in practice. 



From a chemical point of view it is interesting to note that An- 

 dresen (1926) — prior to these theoretical concepts — proposed a 

 remineralizing salt mixture for topical application to partially de- 

 mineralized enamel surfaces. His prescription was conceived essen- 

 tially as a facsimile of the inorganic ingredients of saliva. Further 

 developments may well be based upon a more selective composition 

 and hence a purer chemical reaction with enamel with due regard 



