RESUMEN
Objective:To evaluate the effect of pinus massoniana bark extract (PMBE) and grape seed extract (GSE) on dentin demineralization caused by acid.Methods:40 root dentin blocks with half of the surface covered were randondy divided into 4 groups (n =10).All samples were subjected to pH cycling for 8 days,and deionized distilled water(DDW),0.1％NaF,12％ PMBE solution and 12％ GSE solution were used as the experimental solutions in the 4 groups.The dentin mineral density(DMD) of the both sides was determined using micro-computed tomography.The D-value of DMD between nn-demineralized and demineralized side (△DMD)was calculated.The samples were observed with field emission scanning electron microscops (FE-SEM).Results:The △DMD of DDW,NaF,PMBE and GSE groups was 198.64 ±59.97,45.94 ±24.21,90.23 ±28.77 and 105.07 ±29.53 respectively.The △DMD between PMBE and GSE groups had no significant difference (P ＞ 0.05),which were both higher than that of NaF group (P ＜ 0.05) and lower than that of DDW group(P ＜ 0.05).The FE-SEM revealed that the dentin tubules in DDW group were completely open,but in NaF group were essentially closed in PMBE group and GSE group were spindle shaped or narrow crack opening.Conclusion:PMBE and GSE had almost the same effect on improving the acid resistance of dentin.