Résumé
Objective:To study the coronal microleakage of flared root canal teeth restored with computer aided design and computer aided manufacturing (CAD/CAM)fiber post and core.Methods:60 extracted human mandibular premolars with single canal were divided into 3 groups randomly(n =20).The roots of the teeth were restored with CAD/CAM glass fiber post and core(group A), prefabricated glass fiber post(group B)and gold alloy dowel-and-core(group C)respectively.The specimens were immersed in India ink for 4 weeks.Subsequently all teeth were demineralized,dehydrated and rendered transparent.Then coronal microleakage was ob-served with stereomicroscope.Nonparametric data were analyzed.After that,All the specimens was demineralized completely in nitric acid,Then the interface between the post,resin cement and canal wall was observed and recorded.Results:The microleakage was found in all the 3 groups,group A and C showed less microleakage than group B(P 0.05).Microleakage mostly appeared at the interface between post and resin cement in group A and C,while in group B,it appeared between resin cement and the wall of root canal totally.Conclusion:CAD/CAMfiber post and core demonstrates less coronal microleakage than prefabricated glass fiber post.
Résumé
Objective:To investigate the expression of dental matrix protein 1(DMP1)in carious human permanent teeth and its possible role during the reparative process after pulp injury.Methods:10 of noncarious third molars (NC),10 of shallow carious (SC),10 of intermediate carious (IC) and 10 of deep carious (DC) were prepared for the detection of DMP1 in odontoblasts by immunohistochemical staining. DMP1 expression in odontoblasts was analyzed by image analysis system and expressed as integral optical density (IOD).Results:DMP1 was majorly detected in cytoplasms and processes of odontoblasts and odontoblast-like cells.The IOD values in the groups of NC,SC,IC and DC were 0.265?0.018,0.309?0.021,0.678?0.031 * and 0.691? 0.033 * respectively;that in the reparative dentin in DC group was 0.856?0.045 ** ( *vs NC P