The shear bond strength of glass ionomer cement sealers to bovine dentine conditioned with common endodontic irrigants

Aim The aim of this in vitro study was to evaluate the shear bond strength of commercially available and experimental glass ionomer cement (GIC) sealers to dentine exposed to common endodontic irrigants, Methodology The enamel of 90 bovine incisor crowns, randomly divided into nine equal groups, was ground to expose the superficial dentine layer. The exposed surface was conditioned with either: (i) distilled H2O; (ii) 2.6% NaOCl; or (iii) 17% EDTA followed by 2.6% NaOCl. Five cc of each irrigant was applied over a 30-second period. The following GIC sealers were tested: (i) Ketac-Endo: (ii) KT-308, an experimental sealer; and (iii) ZUT, a combination of KT-308 and an antibacterial agent (0.2% by weight). The test sealers were applied to form cylinders with a standardized contact surface area (17.8mm(2)) on the conditioned dentine surfaces. Specimens were bench set for 90 min and stored in distilled water at. 37 degrees C for 48h, then tested to failure for shear bond strength (MPa) in an Instron machine. Results KT-308 and ZUT had significantly higher MPa values than Ketac-Endo (two-factor ANOVA, P < 0.0001), regardless of the dentine conditioning. All specimens conditioned with 17% EDTA smd 2.6% NaOCl combined had significantly lower MPa values than those conditioned with water or 2.6% NaOCl alone (P < 0.02). Conclusions it was concluded that the experimental sealers KT-308 and ZUT bonded better to bovine dentine than Ketac-Endo, and that the bond of all three GIC sealers was better with the smear layer present.