µTBS of Self Adhesive Resin Luting Cements to Ceramic
Objectives: To test the null hypothesis that µ-tensile bond strength (µ-TBS) of three self adhesive resin luting cements bonding ceramic discs to perfused teeth was the same. Methods: 9 ceramic discs (IPS Empress 2, Ivoclar Vivadent) were conditioned with 5% Hydrofluoric acid (IPS Ceramic Etching Gel, Ivoclar Vivadent) and primed with a silane (Monobond-S, Ivoclar Vivadent). Then, discs were luted to perfused (30 cm of deionized water) crown segments with one of three self adhesive resin luting cements: Multilink System (Ivoclar Vivadent), RelyX Unicem (3M Espe) and Panavia F Light (Kuraray Medical Inc). After 30 minutes of perfusion, specimens were cut into square bars (range of tested areas = 0.53 to 1.36 mm2), and each bar was submitted to tension (500 N, 1 mm/minute), until debonding. Results: An inverse relationship between µ-TBS and tested areas was found. ANOVA test showed statistically significant differences (p < 0.00001) among materials’ mean distances (M = -1.2, R = -8,1, P = 9.2) to the regression line that related tested area and µ-TBS, representing the null hypothesis. Mean calculated µ-TBS for 1 mm2 of tested areas (SD) were M = 16.5 (5.7), R = 9.6 (6.4), P = 26.9 (9.7) . Conclusions: null hypothesis was rejected. Materials showed different µ-TBS (Panavia F > Multilink > Relyx Unicem), when IPS Empress 2 discs were luted to perfused teeth.