Izvorni znanstveni članak
[Scanning electron microscopical investigation of marginal crevice]
Vera Njemirovskij
; Zavod za morfologiju Stomatološkog fakulteta , Zagreb, Hrvatska
Sažetak
Between the classic filling and cavity margins an interspace exists. The term leakage indicates a rather small crevice but it can be identified by the use of radioisotopes and observations with scanning electron microscopy. Using the means of SEM it was the intention to find the diference between the mechanical and mechanica-chemical preparation of cavo-surface margins and to investigate the marginal dehiscence along amalgam and composite fillings. Observed have been 48 cavities in extracted teeth, 48 filled with composites and 20 amalgam fillings. All observations have been made using Stereoscan Cambridge 600 apparatus, after shadowing with gold and palladimu particles. The results indicate that mechanical beveling 'using diamond
DICA 580 causes an Uneven surface. The beveled and cavosurface enamel walls etched with 37% phosphoric acid have produced three different appearences. The measurements of the marginal interspace under magnification from 200 x up to 2000 x in cavities filled with amalgam have given various width values from 12 up to 15 micrometers. Cavities after beveling the cavosurface enamel walls and etched using 37% phosphoric acid and filled with composites in two layers did not show a noticeable marginal interspace or it as in same parts up to 3 micrometers only. In conclusion it is stressed that
the new conception of an additional etching of beveled cavity margins increases the adhesive ability of the composites and the marginal crevice is thereby reduced to a minimum or does not exiist at all. Although some problems concerning composites are not yet solved (the toxicity upon the pulpal tissue, the adherence to dentin, the micnofillers and resistance upon wear on the surface, the radioopacity) the restorative dentistry is now on the eve of a new and more promising technique.
Ključne riječi
marginal interspace; SEM; composites
Hrčak ID:
117036
URI
Datum izdavanja:
15.9.1983.
Posjeta: 917 *