Immunohistochemistry examination showed that SOX-2 was expressed in all 23 cases of odontogenic cyst and in 2 cases of poly-cystic ameloblastoma.

Objective:To study the influences of sucrose,citric acid and sodium bicarbonate on the adhesion of 3 kinds of adhesives.Methods:60 extracted tooth and 60 zirconia blocks (3 mm × 3 mm × 3 mm) were randomly divided into 3 groups (n =20),namely PULPDENT group,3M ESPE RelyxTM Veneer group and RelyxTM Luting group.Then,the samples of each group fell into 4 subgroups(n=5),namely subgroup A for artificial saliva,subgroup B for 10％ sucrose,subgroup C for 0.2％ citric acid,and subgroup D for 0.03 ％ sodium bicarbonate.After completing the adhesion of the specimens with corresponding adhesives,the specimens of subgroups A,B,C and D were submerged into artificial saliva(the control),sucrose,citric acid and sodium bicarbonate solutions for 2 times/day and 5 min/time,respectively.For the rest of time,all the specimens were submerged in artificial saliva.3 months later,shear bond strength of the specimens was tested,the fracture surface was observed under SEM,20 × microscope,and the fracture model was observed by stereoscopic microscope.SPSS 17.0 software was adopted for statistical analysis of the data.Results:The bond strength of PULPDENT,3M ESPE RelyxTM Veneer groups were higher than that of RelyxTM Luting group(P ＜ 0.05);the bond strength of subgroups B,C and D was lower than that of subgroup A(P ＜0.05);and the difference between the remaining groups was not statistically significant(P ＞0.05).SEM observation displayed that in group RelyxTM Luting,subgroups B,C and D showed increased crack depth,width and length when compared with subgroup A;there was no obvious difference between the remaining groups and the control group;in groups PULPENT,3M ESPE RelyxTM Veneer and RelyxTM Luting,all samples in their subgroups showed interface failure.Conclusion:Compared with PULPDENT and 3M ESPE RelyxTM Veneer adhesive,RelyxTM Luting is more susceptible to the influence of sucrose,citric acid and sodium bicarbonate,so it is not suitable for bonding zirconia blocks.