Use of polypropylene copings to simplify the waxing procedure for mesio-occlusodistal and partial veneer crowns

Although polypropylene copings have been used for porcelain-fused-to-metal patterns and recently for pin-retained castings, their use for partial veneer crowns has not been reported. This paper describes the use of copings for mesio-occlusodistal onlays, three-quarter crowns, and seven-eighths crowns. Some of the problems encountered in the fabrication of such restorations can be eliminated. Pattern fractures are almost nonexistent during the waxing stage. Groove or box adaptation to the preparation is easily maintained, and the internal aspects of the crowns are cleaner and smoother.