Cyanoacrylates as Coupling Agents for Glass-Ceramic Priming
Objectives: Silanization is widely used for surface treatment due to chemical interactions between organo-silanes and glass-ceramic surfaces. However, organo-silane undergoes stability issues. The aim of this study was to investigate cyanoacrylates as possible coupling agents on the aspect of bonding strength on lithium disilicate. Methods: Lithium disilicate (Ivoclar e.max) was polished (600 grit SiC), non-etched or etched (4% hydrofluoric acid/5 min), rinsed with deionized water and air-dried. A thin layer of experimental primer was applied. Shear bond strength was tested using the Ultradent jig method (bonding area 4.5mm2). A resin composite material, Duo-link Universal (Bisco), was used to fabricate the posts (2mm-high), and light cured (20sec/1000mW/cm2). The specimens were then stored either in dry condition or in water at 37 °C/24 hr and tested by Instron tester (crosshead-speed 1mm/min). Porcelain Primer (Bisco) was used as control. Results: Table 1 shows mean shear bond strength (SBS) of different cyanoacrylates on polished and etched e.max. SBS of resins-formulated butyl cyanoacrylate on etched e.max reached 36.66 (8.89) MPa under dry condition. Conclusions: Cyanoacrylates are chemically interacted with lithium disilicate surfaces. Butyl cyanoacrylate based experimental primer showed comparable bond strength as current silane primer under dry condition.
Table 1. Mean shear bond strength in MPa (standard deviation) (n=5-8) of experimental primers with Duo-link Universal resin luting cement at dry conditions