secondary caries and finally results in treatment failure. A study was made to compare between cavity sealing of tooth filled with biodentine manually triturated or by machine trituration. More microleakage was seen when Biodentine was manually manipulated as compared to machine trituration and that is because mechanical trituration produces a more homogenous mix compared to manual mixing. 6.Antibacterial and Antifungal activity: A study aimed to evaluate the antibacterial and antifungal properties of Biodentine, compared to commercial glass ionomer cements (GICs) and mineral trioxide aggregate (MTA). Growth inhibition diameter around each material was recorded after they were fixed in seeded plates. Records were taken within 24-72 hours incubation at 37°C. The tests indicted Biodentine’s antimicrobial activity was superior to that of GIC and MTA, with a mean inhibition zone of 3.2 mm (Table 3). GIC was incapable of inhibiting the growth of Candida. It also indicates that for all three cements, the diameters of the inhibition zones for S. mutans were significantly larger than for E. faecalis, Candida, and E. coli (P < 0.05). Biodentine shares its characteristics and mode of action with calcium hydroxide. However, Biodentine has better mechanical stability and lower resorption rate In this study, Biodentine had a significantly more potent antibacterial effect than MTA. The antimicrobial action of MTA is attributed to its high initial pH of 10.2, which rises to 12.5 in 3 hours. From this study we conclude that: – All materials showed antimicrobial activity against the tested strains except for GIC on Candida. – The largest inhibition zone was observed for Streptococcus group. – Biodentine showed largest inhibition zone. 7.Conclusion BioDentine, among its many other uses, can be applied as a dentine substitute material in endodontic procedures such as direct and indirect pulp capping. What makes clinicians favor it over MTA is its color stability, its superior mechanical properties such as its compressive and flexural strengths, its shorter setting time, its biocompatibility and bioactivity. Although that does not mean MTA and other root-end fillings are not applicable. Push Out Bond strength is the strength of the material that allows it to resist dislodgement.>