Optimizing resin cement removal around esthetic crown margins

Objective. To quantify luting cement at the crown-tooth interface of esthetic crowns fabricated using four different techniques and two methods of excess cement removal. Material and Methods. Four methods of crown fabrication were used: the feldspathic porcelain and platinum foil technique, the feldspathic porcelain and refractory die technique, the resin composite crown and CAD/CAM technique, and the feldspathic porcelain crown and CAD/CAM technique. Half of the cemented crowns were allocated to Group A: removal of excess cement by flicking-off with a plastic instrument 3 min after initial polymerization, or Group B: removal of excess cement using a wiping action with cotton pellets. Morphologic measurements, using non-destructive digital profilometry, were made of the volume of excess cement (mm³), mean maximum and mean depth of excess cement (μm), and surface area of excess cement (mm²). Results. ANOVA and Duncan post-hoc tests revealed no statistical differences (p <0.05) between the four types of crown fabrication with respect to volume and mean depth of retained luting cement. There was a significantly greater volume, mean depth, and mean maximum depth of luting cement retained using the "flick off" method compared to the cotton pellet "wiping" method for excess cement removal, but no statistical differences in mean surface area between the two methods. Conclusions. Following removal of excess luting cement, as judged clinically, using two methods, subclinical amounts of cement remained adherent to the tooth surface of all specimens at the crown-tooth interface.