Gingival reaction on crowns with cast and sintered metal margins: a progressive report

Sintered metals have been developed recently for the construction of metal ceramic crowns (Degusint U). An unbalanced, randomized double-blind study was conducted to compare the gingival response to artificial crowns with sintered noble metal margins and cast noble metal margins (Degudent U) by measuring the sulcus-fluid-flow rate (SFFR) in highly motivated patients. In a prior study marginal opening of 20 microns were recorded for cast metal crowns, whereas two sintered metal crowns had marginal openings of 40 microns. Three metal ceramic crowns (Renaissance, Degusint U, and Degudent U for the copings and VMK 68 porcelain) with subgingival margins were prepared and fabricated for 12 intact natural teeth. The SFFR was measured for teeth with artificial crowns and adjacent natural teeth after provisional insertion of each crown. Significantly elevated SFFRs were recorded for all artificial crowns compared with the adjacent natural teeth, but there were no variations recorded for the different types of crown margins.