Purpose: To compare gray MTA, white MTA and resin-modified glass-ionomer cement ( Fuji ) as barriers to prevent coronal leakage.
N= 78 Teeth
* The difference between grey and white MTA is reduced iron content in white MTA and the particle size is smaller to enhance handling and placement.
Inclusion and exclusion criteria: ✓Extracted anterior human teeth was used in this study.
Materials and methods:
•The extracted teeth were stored in 0.2% thymol solution and debrided of any soft tissue.
•After access cavity, cleaning and shaping, and obturation, the canals were cleaned of GP and sealer (coronal 3 mm)
•The sample was divided into 2 experimental groups ( 36 teeth each ) •Group I : 18 teeth received a 3mm barrier of grey MTA (A) and 18 teeth received white MTA (B).
•Group II : 18 teeth received a 3 mm barrier of Fuji RMGI cement (A) and 18 teeth received gray MTA (B)
•The remaining 6 teeth were used as control groups.
•A dual-chamber leakage model utilizing salivary microbes was used for the evaluation
•The experiment was conducted and groups were compared for a 30 days interval, a total of 90 days ( Table 2 ).
Most highlighted results:
•Group I: leakage was noted in 2 gray MTA samples and 3 white MTA samples
•Group II : leakage was noted in 1 gray MTA sample and 3 Fuji RMGI samples
•There was no significant difference in leakage between gray and white MTA or between gray MTA and Fuji

Clinical significance:
All materials used in this study can be considered materials of choice to be used as a coronal barrier for endodontically treated teeth since they seem to be promising in preventing coronal leakage . ( up to 90 days )