Dentine microstructure in hypoplastic deciduous teeth by collagenase etching

Abstract

A new method is described for studying the microstructure of dentine by treating a polished surface with collagenase. The removal of collagen in this way allows high-resolution observation of the mineral component of dentine, and in this paper scanning electron micrographs are presented of dentine surfaces from , ‘normal’ teeth and caries-free hypoplastic teeth. In both cases, dentine is shown to consist of small rounded units ∼ 10–20 mn across which coalesce to form spheroids ∼ 100 nm in diameter which themselves aggregate to form a continuous mineral phase. The main difference between normal and hypoplastic teeth is that the inter-tubular dentine of the latter displays many more spaces, produced by the removal of greater numbers of collagen fibres from between the spheroidal particles. Thus the presence of less mineral would suggest that the carious process, once generated in such a tooth, may advance more rapidly than in normal teeth. The appearance of spheroids composed of smaller building units provides further evidence in support of the theory that calcification of dentine occurs at least in part by the apposition of mineral on the surface of calcospherites.