Effect of different bonding strategies on ceramic/resin shear bond strength

Objectives: Investigation of the effect of different adhesives on feldspathic machinable ceramic / luting resin shear bond strength. Methods: 7 groups of 20 ceramic specimens each were machined from Vita Mark II blocks. Their surfaces were uniformly treated with 1000 grit paper. Group 1 (control) was etched for 60 s, group 2 CoJet- and group 3 PyrosilPen-treated and silaned. Group 4 and 5 were etched for 60 s and silaned with 2 experimental silanes. Variolink II was used as luting resin for groups 1 to 5. Group 6 was treated with Nexus, group 7 with Panavia F 2.0 system and their respective silanes. All specimens were stored dry for 24 h at 37 °C. Shear bond strength was measured prior to and after 5000 thermocycles (TC) between + 5 / + 55 °C in water. ANOVA was calculated with p < 0.05. Results: Shear bond strength values 24h/TC in MPa (sd) are for group 1: 11 (3,0)/12 (5,3), group 2: 22 (3,9)/25 (7,3), group 3: 26 (9,0)/30 (8,0), group 4: 12 (5,9)/8 (2,0), group 5: 8 (2,4)/7 (3,4), group 6: 16 (6,1)/3 (1,6) and group 7: 15 (8,6)/15 (4,3). CoJet and PyrosilPen significantly performed best prior to and after TC. Bond strength of one experimental silane and Nexus significantly decreased after TC. Conclusions: Silicoating technology and tribochemistry are fast, trouble free and effective surface treatment methods to achieve very good bond strength between feldspathic ceramics and luting resins. Uncomfortable etching with H₂F₂ can be avoided.