Shear Bond Strength of Lining Materials to Calcium-silicate Cements at Different Time Intervals

To compare the shear bond strength of three different light-curing, flowable composites (Ionoseal [IS], Vertise flow [VF], and Futurabond NR + Grandio Flow [GF]) on MTA-Angelus [MTA] or Biodentine [BD] at three different time intervals.

Freshly mixed MTA or BD was applied into 180 identical plaster molds. Three minutes, 15 min, and 2 days after mixing, specimens of IS, VF, and GF with standardized size and diameter were applied on MTA and BD specimens (n = 10 per material and time interval). Subsequently, all specimens were stored at 36°C and 100% humidity for 28 days. The shear bond strength was determined using a universal testing machine. Statistical evaluation was performed using multifactorial ANOVA and post-hoc Tukey's Test (p < 0.05).

Multifactorial ANOVA did not show any significant influence of the combinations "lining material × time" (p = 0.257) and "calcium-silicate cement × lining material × time" (p = 0.241). Significant influences were detected for the interactions "calcium-silicate cement × lining material" (p = 0.000) and "calcium-silicate cement × time" (p = 0.009) and for the parameters calcium-silicate cement (p = 0.000), lining material (p = 0.000), and time (p = 0.008). The predominant failure mode of the restorative materials to the cement surfaces was mixed.

Already 3 min after mixing, IS, VF, and GF achieved shear bond strengths on MTA or BD that were similar to those after 15 min and 2 days.