On the cutting edge: marginal integrity.

This paper reviews a number of recent University of Southern California School of Dentistry clinical and laboratory research studies on marginal integrity. Marginal integrity was comprehensively investigated in many different ways. A series of studies examined cement physical properties, casting seating and microleakage, from basic laboratory investigations to multicenter clinical trials. New strong adhesive cements were shown to have many important advantages, but they have a short clinical track record and appeared to be less user-friendly than the more traditional zinc phosphate cement. Casting adjustment techniques markedly improved crown seating. Conventional and new technologies for crown fabrication were evaluated in-vivo with respect to marginal integrity. Although science and art have progressed tremendously, the perfect margin was not achieved.