Autometallography for histochemical visualization of rat incisor polyanions with cuprolinic blue.

Autometallography was applied to semi-thin sections of rat incisors fixed a solution of cuprolinic blue-aldehyde. The resulting reduction of silver ions to metallic silver amplifies the copper sulfide signal of the cationic dye. Silver grains were seen over the cell bodies of ameloblasts and odontoblasts but not over their processes. This was owing to the interaction of cuprolinic blue with the DNA and RNA of these cells. In the extracellular matrix, silver grains were unevenly distributed over the predentin, dentin, and forming enamel. The distal predentin near the mineralization front and a thin band of dentin located near the dentino-enamel junction displayed unexpectedly intense accumulation of silver grains, whereas all other portions of the extracellular matrix exhibited the distribution of glycosaminoglycans expected from previous studies. The present investigation constitutes a new application of autometallography to glycosaminoglycan histochemistry.

Calcium and phosphate uptake of human dental enamel treated with sodium bicarbonate.

Enamel cylinders, submitted to the action of NaHCO3 solutions or kept in water, were immersed in a remineralizing solution containing radioactive calcium and phosphate. The calcium uptake was increased in NaHCO3 treated samples, but not the phosphate uptake. Less calcium adsorption was found in 72 h--NaHCO3 treated samples, than after 1 h and 24 h respectively.

[Surface treatment of mineralized tissue: different approaches and prospects]. / Traitement de surfaces de tissus minéralisés: les différentes approches et prospectives.

This paper review the effects of orthophosphoric acid and other acidic agents on dental enamel. The effects of other treatments such as proteolytic agents or of mixture able to remove the lipids are also described. Specific problems are related to the dentine treatment. Acids and chelators should be avoided, because of the dentine tubules, the odontoblasts and pulp. We review also the problem of the smear layer, the surface of the carious dentine and the consequences for dental treatment. Researches which are still in progress are reported including the use of enzymes and alcali gels submitted to feeble electrolysis, this latter being able to prepare dentine, cementum and bone surfaces in order to increase the adhesion of biomaterials.