An apical sealing material may be exposed to an inflamed environment with low pH levels. The change in physical and chemical properties of mineral trioxide aggregate has been well-documented in the presence of low pH. However, on literature search there is no documentation of the effect of low pH on Biodentine™.

To compare the effects of various levels of acidic pH on the push-out bond strength of Biodentine™.

Forty root dentin slices from single rooted human teeth were sectioned horizontally. The canal lumens were instrumented to obtain a standardized diameter of 1.3 mm and filled with Biodentine™. The specimens were then randomly divided into four groups (n = 10) and wrapped in pieces of gauze soaked in phosphate buffer saline solution (pH = 7.4) and butyric acid buffered at pH values of 4.4, 5.4 and 6.4 respectively. They were incubated at 37°C for 4 days. Push-out test were then carried out using universal testing machine. The data was analyzed using one-way analysis of variance (ANOVA) technique with Tukey's correction for multiple group comparisons.

Data was subjected to one-way ANOVA using Tukey's post hoc test. Group I (control, pH = 7.4) showed greatest bond strength of 19.5 ± 0.9 MPa. The least push-out bond strength of 11.7 ± 0.5 MPa was observed in Group IV where the specimens were soaked at pH 4.4. A p-value less than 0.05 were considered to be statistically significant.

The force needed to displace Biodentine was significantly lower in samples stored at lower pH values.

Poplai G, Jadhav S, Hegde V. Effect of Acidic Environment on the Push-out Bond Strength of Biodentine™. World J Dent 2012;3(4):313-315.