After the try-in in the dental practice, the secondary impression is taken and the fabrication of a milling base as described in the previous chapter about telescopic crowns follows. Before beginning with the metal-milling, the primary parts are surveyed with a parallel scraper both for undercuts as well as for avoidance of a 0° angle wall which would result in unwanted friction and therefore a telescopic fit. After this check, the primary crowns are milled one after another with 2° burs.