title: [In-vitro research on the precision of the marginal adaptation of computer-milled titanium crowns (I). Scanning electron microscopy marginal fissure analysis].
abstract: 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.
authors.affiliation: Abteilung für Prothetik, Universität Basel.
authors.forename: A
authors.initials: A
authors.lastname: Schlegel
authors.forename: C
authors.initials: C
authors.lastname: Besimo
authors.forename: R
authors.initials: R
authors.lastname: Guggenheim
authors.forename: M
authors.initials: M
authors.lastname: Düggelin
mesh_terms: D003196:Computer Graphics / Q000295:instrumentation; D003442:Crowns; D003779:Denture Design; D006801:Humans; D008838:Microcomputers; D008855:Microscopy, Electron, Scanning; D003765:Models, Dental; D013499:Surface Properties; D013674:Technology, Dental / Q000295:instrumentation; D014025:Titanium
chemical_list: D014025:Titanium
vernacular_title: In-vitro-Untersuchung zur marginalen Passgenauigkeit von computergefrästen Titankronen (I). Rasterelektronenmikroskopische Randspaltenanalyse.