F.C. Besic

Electron Probe Microanalysis of Noncarious Enamel and Dentin and Calcified Tissues in Mottled Teeth

A quantitative chemical distribution of five elements in several undecalcified sections of teeth was determined by the electron microprobe method. The calcium (Ca)/ phosphorus (P) weight percent ratios were determined in scans through the enamel and dentin, and characteristic curves for the concentration of the trace elements magnesium (Mg), sodium (Na), and chlorine (Cl) were obtained.

Carieslike Enamel Changes by Chemical Means

TN MY opinion, typical early caries of the enamel is characterized by (1) 1 change in color, to either white or brown; (2) softening of the enamel, as determined by pressure with a sharp metal probe; (3) radiographic rarefaction of the affected tissue; and (4) in most instances preservation of surface contour and gloss while penetration of the process proceeds toward and into the dentin. The purpose of this article is to show that similar macroscopic changes are produced in vitro by acid solutions when they contain both calcium and phosphate ions in concentrations which are considerable, but not sufficient to suppress entirely the solution of the enamel. The findings in this report appear to be in general agreement with the observations of Hardwick.1 McIntosh,2 Dietz,3 Hurst, Frisbie, and Nuckolls,4 and Besic5 have demonstrated by in vitro experimentation carieslike changes of the enamel in solutions supporting bacterial growth. Enright, Friesell, and Trescher6 have shown by chemical methods, at least in some instances, a similarity between their artificially produced enamel changes and true dental caries.

Detailed Electron Probe Microanalysis of Three Teeth Sections with Early Enamel Caries

A detailed electron microprobe analysis of Ca, P, Na, Cl, and Mg in three early carious lesions is compared with data of these elements found in noncarious enamel of the same three specimens.

An aspect of diffusion; its possible association with dental caries.

IN 1943 the writer began some experiments to determine the effects of corrosion by various acids upon extracted teeth. Close observation of teeth so treated showed a lack of corrosion of the enamel in (1) the region where the crown of the tooth touched the vessel containing the acid and (2) the deepest parts of fossae and sulci. This same result was noted in the contact area when two teeth touching each other were subjected to acid treatment.

Dispersion Staining, Dispersion, and Refractive Indices in Early Enamel Caries

Dispersion staining and the Becke Line Method were used to obtain refractive index values from undecalcified sections of 20 human tooth specimens that exhibited early carious lesions. Characteristic dispersion staining curves and dispersion curves for noncarious enamel, the zone of deepest penetration in carious enamel, and carious enamel external to the deepest zone, are presented.

Some Physical Problems Involved in the Application of Solutions to Teeth for the Purpose of Reducing Dental Caries

TN VIEW of the common clinical practices of using bacteriostatic mouthwashes and topically applied solutions in attempts to reduce dental caries, it appears worth while to examine certain theoretical considerations limiting the effectiveness of such practices. There are two factors opposing the penetration of the active molecules or ions of topically applied solutions into contact and similar areas: (1) the presence (in pits, grooves, and contact areas) of saliva or air which must be displaced if the solution is to wet these areas completely and (2) the fact that diffusion of substances in solutions into small spaces is slowed down by the mechanism discussed by Rashevskyl and Besic.2 The following experiments illustrate the operation of these factors.

Application of Dispersion Staining to the Study of Refractive Index of Dental Enamel

Dispersion staining is a unique microscopic technic that imparts color to the edges of transparent substances immersed in liquid mediums with refractive index values near that of the solid substances. The historic aspects, theory, methods, apparatus, and applications can be found in Brown et al (The Microscope and Crystal Front 13:311 and 14:39, 1963); Crossman (Stain Techn 24:61, 1949); and McCrone (J Roy Micr Soc 83:217, 1964). Undecalcified teeth sections prepared by the method of Gray and Opdyke (I Dent Res 41: 172, 1962) varying in thickness from 75 to 100 im were blotted dry on paper toweling, placed on microscope slides, wetted to the slide by capillarity with several drops of Cargille Standard Index of Refraction Liquid (Series A) 1.618* and then fractured from the enamel edge (EE) to the pulp-dentin junction (PDJ) by light pressure applied to the exposed surface with the cutting edge of a surgical scalpel blade. After carefully coverslipping, additional refractive index medium was added by capillarity to fill any voids left between the coverslip and the microscope slide. Fractures were then viewed orthoscopically by means of transmitted white light adjusted for Kohler Illumination through a Zeiss Photomicroscope axially aligned with an attached McCrone dispersion staining

Molecular Transport in Micro-Volumes Simulating Salivary Retention Areas:

SYNOPSIS IN INTERLINGUA TRANSPORTO MOLECULAR IN MICRO-VOLUMINES SIMULANTE AREAS DE RETENTION SALIVARI.—I spatios restringite, solutiones es retenite e protegite contra displaciamento per capillaritate. Le transporto in tal areas es multo lente quando le solution del area de retention e le medio circumjacente es iso-osmotic. Differentias del concentration osmotic inter solutiones interne e externe esseva utilisate pro determinar le velocitates del transporto. Esseva constatate que tal differentias osmotic es multo efficace in le transporto de massa. In un micre compartimento le proportion del existente grande superficie con le micre volumine pare esser un obstaculo pro le alteration o le protection del parietes continente si un transporto de massa non occurre frequentemente.

Infrared Microscopic Study of Early Enamel Caries and Caries-like Enamel Changes Produced in Vitro

Comparison of known penetrating characteristics of infrared, visible, and ultraviolet radiations through certain opaque materials suggested the use of infrared, due to its greater penetration, in the microscopy of enamel. The limited use of an infrared microscope* (Fig. 1) with wave lengths of 0.76-1.20 p enabled the authors to examine undecalcified tooth sections prepared by the method of Gray and Opdyke (J. D. Res., 41:172, 1962) and evaluate the instruments use in caries research. Results indicated that areas transmitting the least amount of infrared radiation (dark areas on the luminous screen) corresponded to areas transmitting the least amount of light in visible-light and polarizing microscopes. There was less clarity of detail and less contrast in decalcified or hypocalcified areas indicating greater penetration of infrared rays through such areas. Some carious specimens, which showed a deep zone to be positively birefringent in the polarizing microscope, displayed only

Human Salivary Arborization Patterns

Papanicolaou (Almer. 1. Obstet. Gynec., 51:316-28, 1946) noted patternization of cells while making microscopic examinations of cervical smears. A lack of l)atternization or tlisorganized cell patterns indicated estrogen deficiency or pregnancy. Zondek and Rozin (Obsfef. and Gynec., 3:463-70, 1954) reported that negative-reacting specimens of cervical mucus will arborize if mixed in a dried state with isotonic NaCI, KCI, or KBr anti allowetl to dry again. They concluded a negative reaction is, therefore, due to insufficient electrolyte content. Andreoli anil lorta (J. cin. Endocr.. 17 :913-14. 1957) relate arborization of saliva in females with estrogen activity. This investigation consists of two parts: (I) Microscopic examination of human saliva from both males and females. A tdrop of paraffin-stimulated saliva was placed on a clean slide and allow cd to dry in air at room temperature. Unfiltered specimens protluced erratic results Some slides from the same