An investigation of the composite resin/porcelain interface.

Failures at composite resin/porcelain interfaces under shear-like loading were examined. Porcelain surfaces were treated with hydrofluoric acid and/or one of two silane coupling agents, using two different composite resin cements. The results showed that after seven days storage, bond strengths of specimens which had undergone porcelain surface treatment were greater than the cohesive strength of the porcelain itself, resulting in brittle fracture of the porcelain. The diluted restorative composite resin performed as well as the commercial composite resin cement. Silane pretreatment of porcelain was important as the bond strength of etched/silane primed specimens was significantly higher than the etched only specimens. However, one primer appeared to be more efficient than the other in bond promotion. Some explanations for the differences in bond strengths are offered.     

Genotoxicity of corrosion eluates obtained from endosseous implants

PURPOSE: Commercially pure titanium alloys are currently used as metallic biomaterials in implantology. Corrosion phenomena appear to play a decisive role in metallic implant long-term behavior. Thus, the goal of this study was to examine the genotoxic potential of corrosion eluates obtained from dental implants using Chinese ovary hamster cells in vitro by the single-cell gel (comet) assay. This technique detects deoxyribonucleic acid strand breaks in individual cells in alkaline conditions. MATERIALS AND METHODS: The materials tested included 3 dental implants commercially available. Each of the tested materials was corroded in a solution consisting of equal amounts of acetic acid and sodium chloride (0.1 M) for 1, 3, 7, 14, and 21 days. The Chinese ovary hamster cultures were then exposed to all corrosion eluates obtained from endosseous dental implants for 30 minutes at 37 degrees C. RESULTS: None of the eluates was found to exhibit genotoxicity, regardless of the type of dental implant used. CONCLUSION: The results suggest that all dental implants tested in this study did not induce deoxyribonucleic acid breakage as depicted by the single-cell gel (comet) assay.     

A multifunctional, provisional, implant-retained fixed partial denture

This article describes the modification of a procedure for fabricating a laboratory-processed, metal-reinforced, acrylic resin provisional restoration that becomes an implant-retained fixed partial denture. The modification involves the incorporation of patrix and matrix components into a cast metal framework. The prosthesis can be used as an alternative to a removable radiologic stent and surgical guide. It can function as a surgical guide during implant placement and help retract the buccal mucogingival flap during implant placement. The prosthesis also can be used as an aid in locating the implant during stage II surgery. Finally, the pontics can be converted into an implant-supported provisional restoration immediately after the implant prosthetic components are attached to the uncovered implants.     

A Profile of Black and Hispanic Subgroups'' Access to Dental Care: Findings from the National Health Interview Survey

This study examined which black and Hispanic minority subgroups were least likely to obtain dental care and why, based on logistic regression analyses of the 1986 National Health Interview Survey. Blacks and Hispanics were less apt to have private dental insurance coverage, to be knowledgeable about the purpose of fluoride, to have been to a dentist in the past year, and, when they did go, were more apt to have gone in response to symptoms rather than for preventive reasons, compared to whites. Logistic regression analyses for adults 18 years of age and older and for children and adolescents 2 to 17 years of age showed that the following individuals had the lowest probability of having been to a dentist in the past year: males, members of larger families, adults who were unemployed or in blue-collar jobs, those who lived in the South or nonmetropolitan areas, people who perceived their health to be fair or poor, and those with no private dental insurance. Mexican-Americans were least likely to have been to a dentist regardless of their income or education. In general, the findings confirmed the importance of dental insurance, as well as suggesting a need for more school-based dental programs and public health clinic-based dental health education and outreach efforts for targeting minority children and adults.     

Immunohistochemical localization of CEA,EMA and keratin in salivary mucoepidermal carcinoma]

Localizations of CEA,EMA and keration in 19 cases of mucoepidermal carcinomas were investigated using the indirect immunoperoxidase technique.The results showed CEA was negative in normal salivary glands and showed faint reaction in glands near carcinoma tissue.Keratin and EMA were localized in some myoepithelial cells.The positive rates in carcinoma tissue were 78.9%,89.5% and 84.2%,respectively.The positive rates and staining intensity of CEA and EMA in carcinoma tissue gradually decreased with the decline of tumor differentitation,but that of keratin showed no variation.the author consider that CEA and EMA could become good indices in clinically diagnosing mucoepithelial carcinoma and determining tumor differentiation type cell in mucoepidermal carcinoma and have a potential to multiply express the tumor elements of epithelium and/or mesenchyma.     

肺梭形细胞癌1例报告及文献复习

探讨肺梭形细胞癌（SpCC）患者的临床特征、诊断过程和治疗方法,旨在提高临床医生对该病的认识。     

妇科肿瘤患者化疗期症状群与生活质量的动态变化及其相关性研究

目的 分析妇科肿瘤患者化疗期不同时间点的症状群与生活质量的动态变化,并探讨两者间的相关性.方法 采用前瞻性研究方法,以137例妇科肿瘤化疗患者为研究对象,使用一般资料问卷、中文版安德森症状评估量表(MDASI-C)和欧洲癌症研究与治疗组织(EORTC)生活质量问卷(QLQ-C30)量表在化疗后即刻(T1)、化疗后1个月(T2)、化疗后3个月(T3)及化疗后6个月(T4)4个不同时间点进行动态调查.结果 妇科肿瘤患者在化疗期4个时间点的症状严重程度(F=76.31,P=0.00)、生活质量(F=117.65,P=0.00)均有差异.T3时间点的症状最严重、生活质量最差.T1时间点提取出4个症状群,分别为:病感症状群、消化道症状群、神经系统症状群及疼痛相关症状群,与生活质量多个领域得分呈正相关(P<0.05);T3时间点提取出5个症状群,分别为:神经系统症状群、病感症状群、疼痛相关症状群、情感症状群及消化道症状群.以上症状群与QLQ-C30量表多个领域得分呈正相关(P<0.05).结论 在化疗后即刻至化疗后3个月,妇科肿瘤患者化疗期间的症状群越来越严重,生活质量越来越差.     

Electroacupuncture Attenuates Surgical Stress-Induced Reduction of T Lymphocytes through Modulation of Peripheral Opioid System

Objective:To investigate the action mechanisms of electroacupuncture(EA)on postoperative immunosuppression.Methods:Male C57 BL/6 mice(5–7 weeks old)were randomly divided into:the sham injury group,the surgical trauma stressed group,the EA group[surgery+2/100 Hz EA at Neiguan(PC 6)],and the EA+Nal(surgery+EA+intraperitoneal injection of naloxone).Abdominal surgical trauma stress mice model was established.EA was performed on bilateral PC 6 acupoints by an EA apparatus(2/100 Hz)for 20 min once a day for 3 days.The m RNA expressions of MOR,DOR,and KOR in thymus and L3-5 dorsal root ganglions(DRG)were determined by quantitative real-time polymerase chain reaction(q RT-PCR)and the protein expressions of MOR,DOR,and KOR in thymus were measured by Western blot.Flow cytometry assay was used to detect the levels of T lymphocyte subtypes in the peripheral blood.Results:Surgical trauma induced decreased the m RNA expression level of MOR in both thymus(P<0.01)and L3-L5 DRGs(P<0.05).Moreover,EA treatment not only significantly attenuated the MOR protein and m RNA expression in the thymus(both P<0.05),but also markedly increased expression of DOR and KOR opioid receptor in thymus(P<0.01).However,the m RNA expressions of opioid receptors were not regulated by EA in the DRG(all P>0.05).Furthermore,T lymphocyte population of CD3^+ and CD4^+ was decreased in the peripheral blood after surgical trauma(both P<0.01).EA treatment can significantly elevate the population of CD3^+(P<0.01),CD4^+(P<0.05)and CD8^+T cells(P<0.01).Intraperitoneal injection of the non-selective opioid receptor antagonist naloxone blocked the up-regulation of T lymphocytes by EA.Conclusion:EA may improve postoperative immunosuppression through the peripheral opioid system.