Porcelain Jacket Crowns: Back to the Future Through Bonding

More than 50 years before bonding to tooth structure (and especially to dentin) was available, metal-free porcelain restorations were used in the anterior dentition and cemented without adhesion, ie, so-called porcelain jacket crowns. Those restorations yielded favorable esthetic results at the cost of high failure rates, due to the lack of cohesion between the brittle restorative material and the tooth. Their popularity recovered in the early 1990s, when fourth-generation dentin bonding agents were introduced to the cementation procedure, significantly strengthening the restored teeth and leading to very high patient satisfaction. Later in the same decade, the dentin bonding procedures were further optimized. Significant improvements of the dentin bond stability were obtained through the immediate dentin sealing (IDS) technique, which involves the application of the dentin adhesive to the freshly cut dentin before making the final impression. The ability of feldspathic porcelain to be etched and silanated to produce reliable resin bonding makes it the perfect material for use with the IDS technique. Further, the porcelain bond has been refined by meticulous post-etching cleaning techniques and heat drying of the silane. Associate Professor, Herman Ostrow School of Dentistry, University of Southern California, Oral Health Center, Los Angeles, California, USA. 901 Michel Magne LA, Los Angeles, California, USA.