Michael G. Buonocore

Comparative Dissolution Rates of Enamel, Dentin, and Bone. I. Effect of the Organic Matter

SYNOPSIS IN INTERLINGUA RAPIDITATES COMPARATIVE DEL DISSOLUTION DE ADAMANTE, DENTINA, E OSSO. I. EFFECTO DEL MATERIA ORGANIC.—Le rapiditate del dissolution de adamante, dentina, e osso varia con le pH del medio discalcificatori. A pH 5,0, le dissolution de osso esseva le plus rapide, sequite per illo de dentina e, postea, de adamante. A pH 3,5, le dissolution de adamante esseva le plus rapide e illo de osso le plus lente. Iste observationes contrastava con illos notate quando le tissus studiate esseva isolate ab substantia organic. Alora-intra le gamma de valores de pH includite in le studio-osso se dissolveva semper le plus rapidemente, sequite semper de dentina e, alora, de adamante. Le materia organic de osso e de dentina retardava le dissolution de iste tissus. In plus, il pareva que iste effecto retardatori cresceva con un declino del pH. Le materia organic de adamante, del altere latere, habeva pauc effecto super le rapiditate de dissolution.

Air Pressure Device for Thickness Measurement of Undecalcified Tissue Sections

IN THE PAST two decades, air pressure devices have found increasing use 1 where rapid and accurate thickness measurements are required, particularly in machine control and automatic gauging application. The ability of this type of instrument to measure the thickness of small areas without contact pressure suggested its use with thin brittle sections of calcified tissue. This paper describes the construction of an air pressure device specifically designed for such an application. There are several basic designs for commercially available air gauges, employing different types of measuring technics, such as the back pressure, flow, venturiand bellows-type circuits. In the apparatus described here, the back pressure circuit is used, and the discussion will be limited to this type, although the basic principles are the same for all air gauges.