Lesion Formation and Lesion Remineralization in Enamel under Constant Composition Conditions

Abstract

A new apparatus for the de- and remineralization of enamel in vitro under constant composition conditions is described. A de- or remineralizing solution flows over the specimens at a controlled rate. During artificial lesion formation (using an acetate buffer containing methylhydroxydiphosphonate, MHDP), the composition of the solution is constant. The Ca and phosphate variation is less than 3%, pH variation is less than 0.03 pH unit. For enamel these variations are within the biological variations between enamel specimens. Experimentally it was found that the liquid streaming over the enamel surface does not measurably remove material from the surface (erosion) with the experimental error of 0.1 μm. This was measured by following microhardness indentations during demineralization. The effect of various MHDP concentrations on demineralization was investigated in the range of 2–50 μM. Even low concentrations of MHDP prove to be effective in the microhardness increase and lesion depth reduction during demineralization. In the demineralization experiment it is shown by means of microradiography, hardness measurements as well as light microscopy that the method described quickly produces reproducible lesions. In a remineralization experiment of demineralized enamel effective remineralization of the lesions occurs in 360 h, giving a threefold increase in microhardness and a twofold decrease in lesion depth.

Remineralization of initial carious lesions in deciduous enamel after application of dentifrices of different fluoride concentrations

“…Subsequently, the specimens were kept in a demineralizing solution containing: 3 mM CaCI 2 . 2H 2 O, 3 mM KH 2 PO 4 , 50 mM CH 3 COOH (acetic acid), 6 µM Methylendiphosphonate, amounts of KOH to adjust the initial pH to 5.0, Thymol (traces) [5] and positioned on a shaking table for 3 days. After the demineralization period a control slice was obtained and underwent a TMR (transversal microradiography) evaluation in order to check the demineralised specimens for minimum variation of mineral loss.…”

Inhibition of Lesion Progression by the Penetration of Resins In Vitro: Influence of the Application Procedure

“…Subsequently, the specimens were stored in a demineralizing solution (Buskes, Christoffersen & Arends, 1985) at pH 5 (37°C) for 14 days. After demineralization, each specimen showed three initial enamel lesions (A, B, C) separated by two lines of nail varnish.…”

Resin Infiltration of Artificial Enamel Caries Lesions with Experimental Light Curing Resins

“…The working hypothesis was that penetration depth (PD) correlates linearly with the square root of the product of the PC of an infiltrant and penetration time (i.e., PD PC t ). To create artificial enamel lesions in the uncovered areas, specimens were exposed to five liters of a demineralizing solution containing 50 mM acetic acid, 3 mM CaCl2 2H2 O, 3 mM KH2 PO4 , 6 M methylhydroxydiphosphonate 18) for 50 days (pH 5.0; 37 ). The pH was checked daily, and if necessary, adjusted with a small amount of either hydrochloric acid (10 ) or potassium hydroxide solution (10 M) (all chemicals from Sigma-Aldrich, Steinheim, Germany).…”