RESUMO
Accurate prenatal diagnosis of complex congenital cardiovascular anomalies,vascular ones in particular,is still challenging.A fetal cardiovascular cast model can provide a copy of the cardiac chambers and great vessels with normal or pathological structures.This study was aimed to demonstrate three-dimensional anatomy of complex congenital cardiovascular anomalies in fetuses by means of corrosion casting.Twenty fetuses with prenatal-ultrasound-diagnosed complex cardiovascular anomalies were enrolled in this study (19 to 35 gestational weeks).Fetal cardiovascular cast models were made by a corrosion casting technique.The specimens were injected with casting material via the umbilical vein,and then immersed in strong acid after casting fluid was solidified,to disclose the geometries of cardiovascular cavities.Nineteen cast models were successfully made from 20 specimens.The casts distinctly showed the morphological malformations and spatial relationship between cardiac chambers and great vessels.One hundred and eleven abnormalities were revealed by casting in the 19 specimens,including 34 abnormalities located in the cardiac chambers (3,4 and 27 anomalies in the atria,atrioventricular valves and ventricles,respectively),and 77 in the great vessels (28,20,24 and 5 anomalies in the aorta and its branches,the pulmonary artery,the ductus arteriosus and the major veins,respectively).Corrosion casting can display three-dimensional anatomy of fetal complex cardiovascular anomalies.This improves our understanding of related pathomorphology and prenatal diagnosis.
RESUMO
BACKGROUND: Researchers in China and abroad have done a lot of experiments to study the bond strength of dentine adhesives from generation one to six,which have received satisfied results. However,there are still no reports about the bond strength of the seventh generation adhesive (Adper EasyTM one). OBJECTIVE: To evaluate the bond strength of the Adper EasyTM one to normal dentine and caries-affected dentine,and to compare the results with total-etching adhesives. METHODS: A total of 12 healthy posterior teeth were randomly divided into group A and B; 12 posterior teeth with chronic occlusal caries were divided into group C and D. Adper EasyTM one was applied for group A and C,while Single bond 2 for group B and D. The modes of group A,B,C,D were subjected to microtensile bond strength test. Interfacial morphologies were analyzed by Stereo-Microscopy. RESULTS AND CONCLUSION: The microtensile bond strength of group A and B was (21.84±3.98),(27.10±4.85) MPa,which was (16.44±3.46) and (21.48±4.85) MPa in the group C and D. The differences between group A and B,group C and D,group A and C,as well as group B and D were statistical significant (P < 0.05). Failures mostly occur along the resin-dentine interface. The total-etching adhesives performed more effectively to both normal dentine and caries-affected dentine than Adper EasyTM one. For the same adhesive,the healthy dentine yielded higher bond strength than the caries-affected dentine.