title: [The in-vitro study of the marginal fit accuracy of computer-milled titanium crowns. II. A histological-morphometric marginal-gap analysis].
abstract: The Digitising Computer System (DCS) can be mechanically programmed to produce computer-milled titanium dentures for veneered ceramic single crowns using three-dimensional computer models. A first analysis by electron scanning microscope of the marginal leakage in titanium framework on 12 extracted teeth showed a marginal accuracy of fit of 68.3 +/- 61.1 microns for the shoulder, and 95.7 +/- 83.2 microns for the chamfered preparation. Owing to limited indicative value of recordings by electron scanning microscopes, the crown edges of the 9 teeth with shoulder preparations were subjected to histological-morphometric measurements. Using this more accurate investigational system, a distinctly higher arithmetic mean of 89.2 +/- 69.1 microns for the marginal accuracy of fit was achieved. It also enabled the marginal leakage of cement (96.5 +/- 85.1 microns), the marginal adaptation (37.4 +/- 93.3 microns) and the shoulder formation (44.4 +/- 58.9 microns) to be judged.
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: K
authors.initials: K
authors.lastname: Donath
mesh_terms: D003198:Computer Simulation; D003442:Crowns; D003738:Dental Cements; D003779:Denture Design; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D003765:Models, Dental; D013499:Surface Properties; D014025:Titanium
chemical_list: D003738:Dental Cements; D014025:Titanium
vernacular_title: In-vitro-Untersuchung zur marginalen Passgenauigkeit von computergefrästen Titankronen. Teil II: Histologisch-morphometrische Randspaltenanalyse.