Tooth Shade Assessment:

Colour change was evaluated with a reflectance spectrophotometer at 6 time points: day 0 (T0), day 1 (T1), day 7 (T7), 1 month (T30), 2 months (T60), and 6 months (T180) after material placement. T0 was the baseline value after tooth preparation but before the placement of the materials. The colour measurement was made using the L*a*b* value. Using these L*a*b* values, the differences between the colour measured at the initial time point (time 0) and those measured at the various time points (∆E) was calculated as follows:

ΔE=[(ΔL) 2+(Δa) 2+(Δb) 2]1/2

where ΔL, Δa, and Δb are the changes in L*, a*, and b*, respectively, between the initial time point and the next time point being compared.

The study was designed to compare the degree of tooth discolouration that occurs over time in specimens filled with ProRoot MTA, Biodentine and MTA repair HP in presence and absence of blood contamination. All the prepared specimens were subjected to spectrophotometric analysis using spectrophotometer (X Rite Gretag Macbeth, Berlin, Germany). The colour differences were evaluated at six-time intervals; T0, T1, T7, T30, T60 and T180 using the CIE L*a*b*[Commission Internationale de l’Eclairage (CIE)] colorimetric system.