The conclusions were: 1. The Cerestore crown system produced an impressive marginal fit without technique sensitivity. However, irregularities on the crown margin due to the porosities of the fired core were noted. 2. The Dicor castable ceramic crown system in this study produced rounded marginal openings because of the shrinkage during ceramming, the treatment of the surface texture after ceramming, and damage from air abrasives. 3. The Ceplatec crown system produced a suitable marginal fit when the distortion of the foil coping during porcelain firing was controlled. The quality of the margin was ultimately determined by the skill of the technician.