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Objective:To assess the influence of different surface treatment on the adhesion of the zirconia-veneering ceramic systems.Methods:28 zirconia specimens were divided into 4 groups(n =7) and treated by non-treatment(group A,the control),sandblaste(group B),hot-etching(group C) and sandblaste + hot-etching(group D).2 specimens randomly selected from each group were examined under SEM and XRD for the observation of surface structure.The veneering porcelain was layered on the remaining specimens of the 4 groups (n =5),then the shear strength of the interface was tested by a universal testing machine.Data were statistically analyzed by SPSS 13.0 software.Results:Different degrees of micro pore structure was observed on the zircomia surface of the 4 groups by SEM observation.The XRD analysis showed that all specimens emerged monoclinic phase.The shear bond strength of group A,B,C and D was (15.96 ± 3.44) MPa,(20.58 ± 2.21) MPa,(26.28 4-2.86) MPa and (22.51 ± 1.94) MPa respectively.group A vs group B,C and D,P ＜ 0.05;group C vs group A,B and D,P ＜ 0.05.Conclusion:The surface treatment of sandblaste,hot-etching and sandblasted + hot-etching can improve the shear bond strength of the zirconia-veneering ceramic systems,and the hotetching method is the most effective.
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Objective:To evaluate the accuracy of Cerec Bluecam and Cerec Omnicam with 3D printed resin models.Methods:A metal master model including 4 cylindrical metal preparations on the model base,respectively simulating the maxillary canine and the first molar preparations,was prepared.The right canine and the right first molar were respectively marked as A and B,and the left as C and D.The master model was scanned respectively by Cerec Bluecam and Cerec Omnicam for 10 times,10 digital models were genera-ted in Bluecam group and Omnnicam group respectively.Resin models were obtained by a 3D printer based on the digital models,the distance of AB,AC,BD and the diameter(d)of A were respectively measured.Statistical analysis was conducted by SPSS 13.0 soft-ware.Results:The distance of AB,AC,BD of master model and Bluecam group showed significant difference(P 0.05);the distance of AC,BD of master model and Omnicam group showed significant difference(P 0.05).All the distances of the Bluecam group and Omnicam group showed significant difference(P <0.05).Conclusion:The scanning accuracy of Cerec Bluecam is higher than that of Cerec Omnicam in a single preparation scanning.When the scanning area ex-tending,the scanning accuracy of Cerec Omnicam is higher than that of Cerec Bluecam.
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Objective To investigate the status of personality disorder and the relationship with childhood trauma in heroin addicts.Methods 108 heroin dependent patients were investigated by Personality Disorder Ques-tionnaire -4 +(PDQ -4 +)and Childhood Trauma Questionnaire -Short From (CTQ -SF).Results The comor-bidity rate of heroin dependence and personality disorder was between 47.2% and 10.2%,which had a higher posi-tive rate of for borderline (47.2%)and antisocial (38.0%)personality disorder and the lowest for depression (10.2%).The borderline personality disorder score was highest[(4.63 ±2.16)points]and the lowest was histrionic personality disorder [(2.65 ±1.49)points]in 12 subscales,which were significantly higher than those in the national norm,and the differences were statistically significant (t =13.54,2.57,all P <0.05).It had significantly positive correlation between borderline and antisocial personality disorder and the each five factors of childhood trauma experi-ence (r =0.265,0.390,0.207,0.303,0.276;0.225,0.219,0.228,0.236,0.287,all P <0.05 ).In addition, depressive personality disorder and physical abuse,emotional neglect and body ignored showed significantly positive correlation (r =0.226,0.227,0.196,all P <0.05).Conclusion There was the comorbidity rate of personality disorders and heroin dependence,and the higher positive rate was borderline and antisocial personality disorders.It was a certain correlation of childhood traumatic experience and personality disorders,especially borderline,antisocial and depressive personality disorder.
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Objective:To determine the fluorine content in enamel before and after besmearing fluoride varnishes or fluorinated bubbles. Methods:Thirty patients whose deciduous central incisors will be extracted were divided into group a and b randomly. For the same patient, a pair of mandibular deciduous central incisor were chosen. For group a: one tooth was removed, and the other one besmeared with fluoride varnishes and removed 24 h later. For group b: one tooth was removed, and the other one besmeared with fluorinated bubbles and removed 24 h later. The fluorine contents in the enamel of every tooth were determined by neutron activation method and analyzed statistically. Results:For group a: the fluorine content in the experimental group was (142.78?42.25) ?g/g, and that in the control group was(119.62?38.62) ?g/g. For group b: (162.36?31.36) ?g/g and (126.56?38.42) ?g/g respectively. The fluorine content in the enamel of tooth besmeared with fluoride varnishes or fluorinated bubbles was higher than that in the control group(P