The Accessibility of the Organic Dentinal Matrix

Abstract

A method, based on the diazotization reaction, was derived to determine the accessibility of the organic matrix of dentin for lysis by proteolytic enzymes, and applied to intact, untreated dentin, to acid decalcified and naturally rarious dentin, to dentin exposed to moist heat and to dentin partially decalcified in equimolar and nonequimolar organic and inorganic acids to determine specific chemical groups indicative of proteins accessible to lysis. Application of this method to the residual matrix of completely acid-decalcified dentin showed that a constant amt. of accessible protein/unit of wt. was present, but this amt. was twice that present in the organic matrix of nautrally carious dentin. Decalcification by various organic and inorganic acids liberated the organic matrix in proportion to the degree of decalcification. Partial decalcification of dentin by various organic and inorganic nonequimolar acids at a constant pH liberated a constant amt. of the matrix /unit of decalcification. Similar acids at equimolarity rendered the organic matrix of different teeth accessible in different amts./unit of decalcification. At a constant pH, many of the acids decalcified dentin at different rates whether the acid soln. was non-equimolar or equimolar.