In-vitro research on the precision of the marginal adaptation of computer-milled titanium crowns (I) . Scanning electron microscopy marginal fissure analysis
Schlegel, A.; Besimo, C.; Guggenheim, R.; Düggelin, M.
Schweizer Monatsschrift für Zahnmedizin 101(10): 1273-1278
1991
ISSN/ISBN: 0256-2855 PMID: 1947970 Document Number: 370583
The Digitising Computer System (DCS) can be mechanically programmed to produce computer-milled titanium frameworks for veneered ceramic single crowns using three-dimensional computer models. Titanium frameworks were constructed in this way during the present in-vitro investigation involving twelve extracted teeth with shoulder or chamfered preparation. An electron scanning microscope was used to evaluate the marginal accuracy of fit of the cemented crowns. The total length of 42.7 cm comprised by the crowns enabled 397 measuring points to be used. The arithmetical mean marginal leakage for the shoulder preparation amounted to 68.3 +/- 61.1 micrometers, and 95.7 +/- 83.2 micrometers for the chamfered one. From these results, it can be affirmed that the marginal accuracy of fit in constructing crowns by the Digitising Computer System is comparable to that of the conventional method.