Sealing properties of a calcium aluminate luting agent

To determine the self-sealing properties of Ceramir C&B, a new calcium aluminate-based luting material and to compare it to two commercially available cements, using a bacterial model system.

30 premolars were prepared in a standardized fashion with a total angle of convergence of approximately 10-12 degrees for complete cast restorations. All margins were placed in dentin. Gold copings were fabricated in a Type III alloy using standardized laboratory methods. Thirty teeth were randomly assigned to three groups of 10: Group 1: Ceramir C&B (CM), a calcium aluminate/glass ionomer hybrid (formerly XeraCem), Group 2: Ketac-Cem (KC), a glass-ionomer cement (control) and Group 3: Rely X Luting Plus (RX), a resin-modified glass-ionomer cement. After cementation the samples were allowed to bench set for 10 minutes, after which they were subjected to thermal cycling (x2000, between 5 and 55 degrees C, dwell time 35 seconds) and then stored in sterile phosphate buffer for 7 days at 37 degrees C. Subsequently the occlusal surface was carefully reduced exposing the dentin. Finishing on wet sand paper removed the gold flash from grinding. After sterilization the specimens were subjected to bacterial microleakage in a dual chamber apparatus for a period of 60 days. Turbidity was recorded daily. The data were analyzed using the Kaplan-Meyer survival analysis and the log-rank test (P<0.05).

A statistical analysis demonstrated that the groups cemented with CM and RX showed no significant difference in microleakage patterns (P>0.05), while both recorded significantly lower microleakage scores (P<0.05) than the group cemented with KC.