Objective To compare the effect of Biodentine versus MTA on dentine fracture resistance.Methods Thirty swine cuspid teeth were used in this study.The crowns were removed at the cementoenamel junction

and the roots were removed about 30 mm to the cementoenamel junction

resulting in 30 teeth samples of the same length.Based on a random number table

these teeth samples were divided into the Bio group（Biodentine for rootcanal sealing

n=10）

MTA group（MTA for rootcanal sealing

n=10）and control group（no rootcanal sealing

n=10）.After 3 months

mechanical testing was performed

and the maximum load

3-point bending strength

and bending modulus were compared among the three groups.Results The maximum load was statistically different among the three groups（P<0.05）;the maximum load in the Bio group was higher as compared with the MTA group or the control group（P<0.05）;and that in the MTA group was higher than the control group（P<0.05）.The 3-point bending strength also varied significantly among the three groups（P<0.05）;the bending strength in the Bio group was higher than that in the MTA group

but the difference was not statistically significant（P>0.05）;the bending strength in the Bio group and MTA group were both higher than that in the control group（P<0.05）.The bending modulus was also statistically different among the three groups（P<0.05）;the bending modulus in the Bio group was higher when compared with the MTA group or the control group（P<0.05）;and that in the MTA group was higher than the control group（P<0.05）.Conclusion Both Biodentine and MTA can improve dentine fracture resistance

but Biodentine seems to be superior to MTA.Clinical use of these materials depends on the specific condition of each individual patient.