Bond strength of porcelain to cobalt chromium dental alloy fabricated by selective laser melting and casting methods

Abstract

This study aimed to compare the bond strength of porcelain to cobalt-chromium dental alloy fabricatedby selective laser melting (SLM) and casting methods.Twelve rectangular barsmeasuring 25x3x0.5 mmwere fabricated of cobaltchromium alloy for each of the SLM and casting groupsaccording to ISO9693:1999. Porcelain was appliedat the center of each bar measuring 3  8 mm with 1 mm thickness. Three-point fl exural bond strength test was performed to assess the bond strength of porcelain to alloy. Data were analyzed and compared between the SLM and casting groups via Independent sample t-test (alpha=0.05). Mode of failure was also determined by visual inspection of samples. The mean bond strength of porcelain to SLM alloy (35.26±1.22 MPa) was signifi cantly higher than that to casting alloy (33.21±3.02 MPa) (P<0.05). Most failures in both groups were mixed and no sample showed adhesive failure. The SLM metal-ceramic system showed higher bond strength than the required threshold by ISO9693:1999. Compared to alloys fabricated by the casting method, the SLM method showed higher bond strength to porcelain. This relatively new technology is promising for dental application and can serve as a suitable alternative to the conventional casting method for the fabrication of metal-ceramic restorations.