\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Material** & **Manufacturer** & **Ingredients** & **Preparation Procedure** \\ \hline \multirow{4}{*}{ProRoot MTA} & \multirow{4}{*}{Dentsply, Tulsa, OK, USA} & \multicolumn{2}{c}{tricalcium silicate,} \\  & & & tricalcium aluminate, \\  & & & tetracalciumaluminoferrite, free calcium \\  & & & oxide, and bismuth oxide \\ \hline \multirow{4}{*}{Biodentine} & \multirow{4}{*}{Septodont, Saint} & powder: tricalcium silicate, calcium \\  & & carbonate and oxide filler, iron oxide shade, \\  & & & and zirconium oxide \\  & & & liquid: calcium chloride as accelerator, \\  & & & hydrosoluble polymer water-reducing \\  & & & agent, water \\ \hline \multirow{4}{*}{MTA Plus} & Avalon Biomed Inc, & powder: tricalcium silicate, dicalcium \\  & by Prevest Denpro & silicate, bismuth oxide, calcium sulfate, \\  & Limited, Jammu, India & & \\  & & & liquid: hydrated polymer gel \\ \hline \multirow{4}{*}{MTA Repair HP} & Angelus, Londrina, \\  & & PR, Brazil & powder: tricalcium silicate, dicalcium \\  & & & silicate, dicalcium aluminate, calcium \\  & & & oxide, and calcium tungstate \\  & & & liquid: water and plasticizer \\ \hline Ortho MTA & BioMTA, Seoul, Korea & calcium carbonate, silicon dioxide, \\  & & aluminium oxide, and dibismuth trioxide \\ \hline \multirow{4}{*}{Retro MTA} & \multirow{4}{*}{BioMTA, Seoul, Korea} & calcium carbonate, silicon dioxide, \\  & & aluminium oxide, and calcium \\  & & zirconia complex \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Compositions of the CSCs considered in this study. Regenerative Procedures, for pulp regeneration treatment, the canal should be prepared with 1.5% NaOCl solution for disinfection and then EDTA solution [19]. EDTA increases surface roughness and thus improves adherence and growth of cells. The above guidelines are currently considered to represent the gold standard in regenerative endodontic procedures [20]. However, EDTA can be replaced by citric acid (CA) at concentrations of 10-40% [18; 21; 22]. Anhydrous CA is a tricarboxylic acid found in citrus fruits that is frequently used as an excipient in pharmaceutical preparations owing to its antioxidant properties. It maintains the stability of active ingredients and is used as a preservative. It is also used as an acidulant to control pH and acts as an anticoagulant by chelating the calcium in blood [23]. CA exhibits good chemical stability and shows slight anti-microbial effects. Upon irrigation with 10% CA, almost twice as much TGF-\(\beta\)1 is released when compared to irrigation with 17% EDTA. The viabilities of stem cells from the apical papilla (SCAP) after root canal irrigation with 17% EDTA and 10% CA are similar [21; 22]. Furthermore, conditioning root canals with CA significantly increases dentin roughness compared to EDTA treatment [24; 25]. However, until now, no work on the influence of citric acid on CSCs has been published, nor have the effects of the aforementioned root canal irrigants on MTA Repair HP been studied. Thus, the aim of the present study was to investigate the effects of 10% and 40% CA in comparison to those of irrigation solutions such as 15% EDTA, 2% NaOCl, 2% CHX, and 0.9% sodium chloride (NaCl) as a control group on the color change of the CSCs Biodentine, ProRoot MTA, Retro MTA, Ortho MTA, MTA Plus, and MTA Repair HP. The null hypothesis is that CA does not discolor these bioceramic materials.