[Spectrophotometric comparison of the influence of porcelain types on shade of metal-ceramic restorations]

Color matching between natural teeth, shade guides and metal-ceramic restorations is a common clinical problem. Difficulties related to color matching arise from structural differences between metal-ceramic crowns and natural teeth, the limitation of range of available ceramic shades, inadequate shade guides, different type of metal alloys, and varying composition of ceramic materials. The aim of this in vitro study was to investigate the influence of various porcelains on the final color of metal-ceramic restorations. Three commercial porcelains for metal-ceramic restorations, Vita VMK[95] [Vident, Brea, CA, USA], ceramco[2] [Dentsply, Burlington, NJ, USA] and Noritake[Noritake, Tokyo, Japan] and alloy T3[Ticonium, Division of CMP Indnstries LLC] were combined in metal-ceramic disks with standardized thickness of layeres.10 disk[10mm] were prepared for each porcelains in A3 shade. the samples were analyzed with a spectrophotometer, and data were obtained in the CLELAB color system. The recorded data were analyzed with One Way Analysis of Variance and Tukey test. The type of porcelains overlying disks had significant effect on color of metal ceramic restoration [P<0.001] in three coordinate dimensions [L, a, b]. The Vita porcelain had most similar to the control group [delta E=1.58] and the ceramco[2] porcelain was least similar to the control group [delta E=2.65]. The data of this study indicated that type of porcelain had significant effect on metal-ceramic restoration color

Evaluation of the stability of coated plates with antigen at different temperatures and times by ELISA test to diagnose fasciolosis

Considering that ELISA method presently is the test of choice for diagnosis of fasciolosis, the present study was undertaken to evaluate the maximum validity of coated plates at different temperatures and different times during one year of evaluation. Serum samples of patients infected with fasciolosis [n=10], hydatidosis [n=5], toxocariasis [n=5], and negative control sera [n=5] were examined. Two series of plates were considered. The first series were coated with Fasciola homogenate Ag 12 micro g/ml, and after some steps were blocked with gelatin and preserved at different temperatures as -80 °C, -20 °C, -4 °C and +4°C. The 2[nd] series were treated under the same criteria but were not blocked with gelatin. Each series were examined by ELISA test from 1[st] month to 12[th] month. Sera with 1:125 dilution, and peroxidase-conjugated goat anti-human IgG diluted 1:10000 were considered optimum. To ease reporting the results and due to many similarities only results related to 1[st], 6[th] and 12[th] months were analyzed and sensitivity, specificity plus cut-off were determined for each series separately. Preserving the coated plates, while unblocked at -80°C for 6-8 months is pertinent and functional and in that case, we can be sure the best out put would be applicable

18S ribosomal DNA sequence of Strongyloides stercoralis in Iran

Vahlkampfiids contains wide variety of genuses with some known as human pathogens such as Naegleria, Vahlkampfia and non pathogens such as Willaertia. Since there was no evidence of presence of Vahlkampfiids in different sources in Iran, we have analyzed soil samples to clarify the presence of these amebas. Seven soil samples collected in Tehran were analyzed to clarify the presence of Vahlkampfiids in soil sources, using microscopic examination of non nutrient agar cultures and specific Vahlkampfiids primer pair. Vahlkampfiids were detected in 2 out of 7 soil samples by direct examination of cultures. Sequence analysis confirmed that Willaertia magna [W. magna] was present in 2 samples. Additionally, Thecamoeba were detected in all of soil samples. To the best of our knowledge, this is the first report of existing W. magna and Thecamoeba in Iran. Over all, more research should be implicated in Iran for identification of Vahlkampfiids within different environmental sources as well as their pathogenic capability relevant for human beings

[Invitro evaluation of cytotoxicity and elemental release of three types of nickel-chromium basemetal alloys and comparison with one type of high noble [gold-palladium-silver] alloy]

Dental alloys following corrosion cause changes in oral tissues. As base metal alloys are used for fabrication of dental prostheses and are manufactured in Iran, the aim of this study was to investigate the cytotoxicity of three types of nickel-chromium base metal alloys with one type of high noble alloy on mouse fibroblast cell [L 929] by MTT test. In this experimental study, 12 disks of each alloy with 5mm diameter and 2.5 mm thickness were prepared and placed in RPMI culture medium for 48 hours and 72 hours [extract medium]. Then the extract mediums were diluted in two different dilutions of 200 micro 1 and 40 micro 1 and their cytotoxicity were evaluated by MTT assay and compared with two control groups consist of only culture media and culture media with teflon. The amount of Nickel, chromium, copper, zinc and silver released from each alloys were measured by flame atomic absorption device. The data were analyzed by Graph Instat software, one way ANOVA and Tukey tests. After 48 hours, no significant difference in cytotoxicity was found between samples and control groups. After 72 hours there was a significant difference between samples and control groups [Minalux vs. Control: P<0.01, Degubond vs. Control: P<0.001, Wiron 99 vs. Control: P<0.001, Supercast vs. Control: P<0.05] There was no significant difference in cytotoxicity with two dilutions of 200 micro 1 and 40 micro 1 between samples. Maximum release of nickel and chromium were observed from Minalux, silver from Degubond and zinc Supercast. The cytotoxicity of three Nickel-Chromium alloys and one high noble which were used in this study was not different. Cytotoxicity increased with time

Evaluation of enzyme-linked immunosorbent assay for the serodiagnosis of strongyloidosis

To evaluate an enzyme- linked immunosorbaent assay using filariform larvae of Strongyloides stercoralis to detect specific antibodies in patients with strongytoidosis. Design: Serum samples obtained from individuals infected with strongytoidosis and other parasitic diseases as well as normal people were analyzed by IgG-ELISA using crude antigen of filariform larvae. Setting: School of Public Health Serum Blood Bank, Tehran University of Medical Sciences, volunteers people and selected patients. Subjects: Serum samples were obtained from 46 individuals infected with strongytoidosis, 37 from normal individuals and 379 cases from others with different parasitic infections. Main outcome measures: The sensitivity, specificity, positive and negative predictive values of the test. Result: The cut-off point was 0.537. The sensitivity of the test was 93.47%, whereas the specificity was 96.15%. The positive and negative predictive values were 72.88% and 99.25% respectively. Three individuals with hydatidosis, one with ascariasis and 12 with toxocariasis had antibodies that were reactive against larval antigen. ELISA method using filariform larval antigen provides a sensitive and specific diagnostic assay