Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures / 北京大学学报(医学版)

OBJECTIVE@#To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).@*METHODS@#A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.@*RESULTS@#The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).@*CONCLUSION@#Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

Kinetic and toxicological effects of synthesized palladium(II) complex on snake venom (Bungarus sindanus) acetylcholinesterase

The venom of the krait (Bungarus sindanus), an Elapidae snake, is highly toxic to humans and contains a great amount of acetylcholinesterase (AChE). The enzyme AChE provokes the hydrolysis of substrate acetylcholine (ACh) in the nervous system and terminates nerve impulse. Different inhibitors inactivate AChE and lead to ACh accumulation and disrupted neurotransmission. Methods: The present study was designed to evaluate the effect of palladium(II) complex as antivenom against krait venom AChE using kinetics methods. Results: Statistical analysis showed that krait venom AChE inhibition decreases with the increase of Pd(II) complex (0.025-0.05 µM) and exerted 61% inhibition against the AChE at a fixed concentration (0.5 mM) of ACh. Kinetic analysis using the Lineweaver Burk plot showed that Pd(II) caused a competitive inhibition. The compound Pd(II) complex binds at the active site of the enzyme. It was observed that K m (Michaelis-Menten constant of AChE-ACh into AChE and product) increased from 0.108 to 0.310 mM (45.74 to 318.35%) and V max remained constant with an increase of Pd(II) complex concentrations. In AChE K Iapp was found to increase from 0.0912 to 0.025 µM (29.82-72.58%) and did not affect the V maxapp with an increase of ACh from (0.05-1 mM). K i (inhibitory constant) was estimated to be 0.029µM for snake venom; while the K m was estimated to be 0.4 mM. The calculated IC50 for Pd(II) complex was found to be 0.043 µM at constant ACh concentration (0.5 mM). Conclusions: The results show that the Pd(II) complex can be deliberated as an inhibitor of AChE.(AU)

Efecto citotóxico de los compuestos de inclusión de paladio (II) en la beta-ciclodextrina / Cytotoxic effect of palladium (II) inclusion compounds in beta-cyclodextrin

Resumen Introducción. Las tiosemicarbazonas y sus complejos de paladio (II) poseen actividad antineoplásica con pocos efectos secundarios, por lo cual se las considera como una nueva alternativa terapéutica. Sin embargo, existen diferencias en los rangos de la concentración inhibitoria media (CI50) asociada a la divergencia estructural y la solubilidad de los complejos, así como a la sensibilidad de los blancos celulares. La inclusión de fármacos en la beta-ciclodextrina con fines terapéuticos ha mejorado su solubilidad y estabilidad, pero los efectos de su combinación con los complejos de paladio (II) y las tiosemicarbazonas no se han comprobado aún. Objetivo. Estudiar el efecto citotóxico de los complejos de paladio en la beta-ciclodextrina. Materiales y métodos. La actividad citotóxica de los complejos de paladio en la beta-ciclodextrina se evaluó en la línea celular de cáncer de mama (MCF-7), empleando el método de la sulforodamina B. Resultados. Los ligandos MePhPzTSC y Ph2PzTSC, sus complejos de paladio (II) libres e incluidos en la beta-ciclodextrina y el cisplatino mostraron actividad citotóxica en la línea celular MCF-7; sin embargo, la citotoxicidad fue mayor con la inclusión en la beta-ciclodextrina ([Pd(MePhPzTSC)2]•ß-CD y [Pd(Ph2PzTSC)2]•ß-CD). La concentración inhibitoria media (CI50) para estos complejos se obtuvo en concentraciones de 0,14 y 0,49 μM, y con dosis hasta cinco veces inferiores comparadas con las concentraciones de los ligandos libres (1,4 y 2,9 μM), de los complejos de paladio (II) libres (0,57 y 1,24 μM) y del cisplatino (6,87 μM). Conclusiones. El uso de la beta-ciclodextrina mejoró significativamente la actividad citotóxica de las tiosemicarbazonas y sus complejos de paladio (II), lo cual probablemente está asociado al incremento de la solubilidad y biodisponibilidad del compuesto, estrategia que se puede sugerir para el diseño de futuros fármacos antineoplásicos.

Abstract Introduction: Thiosemicarbazones and palladium (II) complexes have antineoplastic activities with mild side effects, for which they are considered new alternative antineoplastic drugs. However, the IC50 ranges of these complexes vary due to differences in their structure and solubility and their sensitivities for various cellular targets. Beta-cyclodextrin is an additive used to improve the solubility and stability of various drugs for therapeutic use, but the combination of beta-cyclodextrin with palladium (II) complexes and thiosemicarbazones has not been tested yet. Objective: To study the cytotoxic effect of palladium (II) inclusion complexes in beta-cyclodextrin. Materials and methods: We tested the cytotoxic activity of palladium complexes combined with betacyclodextrin in the breast cancer cell line MCF-7 using a sulforhodamine B assay. Results: We tested the antiproliferative activity of palladium (II) complexes with and without the ligands MePhPzTSC and Ph2PzTSC and with and without beta-cyclodextrin in MCF-7 cells and compared them to that of cisplatin. All combinations showed antiproliferative activity; however, the activity was greater for the combinations that included beta-cyclodextrin: ([Pd (MePhPzTSC) 2] • ß-CD and [Pd (Ph2PzTSC) 2] • ß-CD), at concentrations of 0.14 and 0.49 μM, respectively. The IC50 for this complex was 5-fold lower than that of the ligand-free combinations (1.4 and 2.9 μM, respectively). The IC50 for free palladium (II) complex was 0.571.24 μM and that for cisplatin was 6.87 μM. Conclusions: Beta-cyclodextrin significantly enhanced the cytotoxic activities of palladium (II) complexes and thiosemicarbazones probably by improving their solubility and bioavailability. The addition of betacyclodextrin is a possible strategy for designing new anticancer drugs.

Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures

ABSTRACT Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm) was used. Six groups were formed according to the alloy’s framework (CoCr or PdAg) and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm). A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05) between the groups. Pearson correlation test (p<0.05) was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm.

Influence of shape and finishing on the corrosion of palladium-based dental alloys

PURPOSE: The purpose of this study was to evaluate the effects of the surface treatment and shape of the dental alloy on the composition of the prosthetic work and its metallic ion release in a corrosive medium after casting. MATERIALS AND METHODS: Orion Argos (Pd-Ag) and Orion Vesta (Pd-Cu) were used to cast two crowns and two disks. One of each was polished while the other was not. Two as-received alloys were also studied making a total of 5 specimens per alloy type. The specimens were submersed for 7 days in a lactic acid/sodium chloride solution (ISO standard 10271) and evaluated for surface structure characterization using SEM/EDAX. The solutions were quantitatively analysed for the presence of metal ions using ICP-MS and the results were statistically analysed with one-way ANOVA and a Tukey post-hoc test. RESULTS: Palladium is released from all specimens studied (range 0.06-7.08 microg.cm(-2).week(-1)), with the Pd-Cu alloy releasing the highest amounts. For both types of alloys, ion release of both disk and crown pairs were statistically different from the as-received alloy except for the Pd-Ag polished crown (P>.05). For both alloy type, disk-shaped pairs and unpolished specimens released the highest amounts of Pd ions (range 0.34-7.08 microg.cm(-2).week(-1)). Interestingly, in solutions submerged with cast alloys trace amounts of unexpected elements were measured. CONCLUSION: Shape and surface treatment influence ion release from dental alloys; polishing is a determinant factor. The release rate of cast and polished Pd alloys is between 0.06-0.69 microg.cm(-2).week(-1), which is close to or exceeding the EU Nickel Directive 94/27/EC compensated for the molecular mass of Pd (0.4 microg.cm(-2).week(-1)). The composition of the alloy does not represent the element release, therefore we recommend manufacturers to report element release after ISO standard corrosion tests beside the original composition.

Patch Testing with Dental Screening Series in Oral Disease

BACKGROUND: The oral mucosa is constantly exposed to several irritants and allergens including dental materials, but the role of contact allergy in oral disease is obscure. OBJECTIVE: To analyze positive patch test results in patients with oral diseases and evaluate the clinical relevance of oral diseases with contact allergy to dental materials. METHODS: We retrospectively analyzed patch test results with dental screening series in 44 patients with oral disease from 2004~2011. RESULTS: Oral diseases included oral lichen planus (54.5%), cheilitis (27.3%), burning mouth syndrome (9.1%), and others (9.1%). Thirty-one of 44 patients (70.5%) had positive reactions to one or more allergens. The most commonly detected allergens were gold sodium thiosulfate (25.0%) and nickel sulfate (25.0%), followed by potassium dichromate (22.7%), cobalt (15.9%), palladium (6.8%), mercury (4.5%), copper (4.5%), and methylhydroquinone (4.5%). Six of 24 patients with oral lichen planus had a symptom in areas adjacent to dental materials and positive patch test reactions to allergens contained in the suspected dental materials. CONCLUSION: Patch tests with dental screening series are worth considering for oral diseases, especially for oral lichen planus.

Antifungal effect of electrolyzed hydrogen water on Candida albicans biofilm

PURPOSE: Candida albicans can cause mucosal disease in many vulnerable patients. Also they are associated with denture-related stomatitis. Electrolyzed water is generated by electric current passed via water using various metal electrodes and has antimicrobial activity. The aim of this study was to investigate antifungal activity of electrolyzed water on C. albicans biofilm. MATERIALS AND METHODS: C. albicans was cultured by sabouraud dextrose broth and F-12 nutrient medium in aerobic and 5% CO2 condition to form blastoconidia (yeast) and hyphae type, respectively. For formation of C. albicans biofilm, C. albicans was cultivated on rough surface 6-well plate by using F-12 nutrient medium in CO2 incubator for 48 hr. After electrolyzing tap water using various metal electrodes, the blastoconidia and hyphal type of C. albicans were treated with electrolyzed water. C. albicans formed blastoconidia and hyphae type when they were cultured by sabouraud dextrose broth and F-12 nutrient medium, respectively. RESULTS: The electrolyzed water using palladium electrode (EWP) exhibited antifungal effect on blastoconidia of C. albicans. Also, the EWP significantly has antifungal activity against C. albicans biofilm and hyphae. In the electrolyzed water using various metal electrodes, only the EWP have antifungal activity. CONCLUSION: The EWP may use a gargle solution and a soaking solution for prevention of oral candidiasis and denture-related stomatitis due to antifungal activity. (

Complexation of beta-sitosterol with tris [dibenzylideneacetone] dipalladium and its anti-microbial activity

Beta-sitosterol is a naturally occurring plant sterol [phytosterol] present in many fruits and vegetables. Scientific research has proven that beta-sitosterol is helpful in maintaining the proper functioning of our body. Previously we described the complexation of beta-sitosterol with trace metals [Mahmood et al., 2013]. Trace metals after the formation of complex unable to absorb in the body and hence eliminated out from the body thus reducing metal toxicity [Marsha, 1996]. The present article describes the complexation of beta-sitosterol with Palladium [Pd] metal. Palladium is a toxic metal and due to polluted and hazardous environment traces of this metal can be transferred into the body, which is harmful for human health. Our aim is to make Pd-sterol complex so that this toxic metal [Pd] does not absorb in the body and hence excreted out from the body in the complex form. In order to form this complex beta-sitosterol [Ib] is reacted with Tris [dibenzylideneacetone] dipalladium or [Pd[2] [DBA][3]] [Ia] in 2:1 ratio in an inert atmosphere and dimethylformamid [DMF] added as a solvent. The resulting complex [Pd[2] [DBA][3].[beta-sitosterol] [Ic] was identified by various spectroscopic techniques such as IR, Mass and [1]H-NMR. This new organo metallic complex [Ic] also showed significant antibacterial and antifungal activity. The present work revealed that Pd-sterol complex does not only reduce metal toxicity but also helpful in minimizing bacterial and fungal infections present in the body. Our research also concluded that we must take plenty of fruits and vegetables in our diet so that natural plant sterol such as beta-sitosterol can enhance our defense mechanism and maintain other functions of our body

External beam radiation therapy and a low-dose-rate brachytherapy boost without or with androgen deprivation therapy for prostate cancer

Purpose To assess outcomes with external beam radiation therapy (EBRT) and a low-dose-rate (LDR) brachytherapy boost without or with androgen deprivation therapy (ADT) for prostate cancer. Materials and Methods From January 2001 through August 2011, 120 intermediate-risk or high-risk prostate cancer patients were treated with EBRT to a total dose of 4,500 cGy in 25 daily fractions and a palladium-103 LDR brachytherapy boost of 10,000 cGy (n = 90) or an iodine-125 LDR brachytherapy boost of 11,000 cGy (n = 30). ADT, consisting of a gonadotropin-releasing hormone agonist ± an anti-androgen, was administered to 29/92 (32%) intermediate-risk patients for a median duration of 4 months and 26/28 (93%) high-risk patients for a median duration of 28 months. Results Median follow-up was 5.2 years (range, 1.1-12.8 years). There was no statistically-significant difference in biochemical disease-free survival (bDFS), distant metastasis-free survival (DMFS), or overall survival (OS) without or with ADT. Also, there was no statistically-significant difference in bDFS, DMFS, or OS with a palladium-103 vs. an iodine-125 LDR brachytherapy boost. Conclusions There was no statistically-significant difference in outcomes with the addition of ADT, though the power of the current study was limited. The Radiation Therapy Oncology Group 0815 and 0924 phase III trials, which have accrual targets of more than 1,500 men, will help to clarify the role ADT in locally-advanced prostate cancer patients treated with EBRT and a brachytherapy boost. Palladium-103 and iodine-125 provide similar bDFS, DMFS, and OS. .

Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application). Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension). Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant. .

Influence of cryogenic treatment and age-hardening heat treatment on the corrosion behavior of a dental casting Ag-Pd alloy / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study is to investigate the influence of cryogenic treatment and age-hardening heat treatment on the corrosion behavior of a dental casting Ag-Pd alloy.</p><p><b>METHODS</b>A low gold content dental casting alloy composed of Ag-Pd-Cu-Au was prepared for this study. Corrosion test was performed according to ISO 10271:2001 dental metallie-corrosion test methods. Experimental specimens were casted according to a standard dental lost-wax casting procedure, treated with solution by heating the specimens to 900 degrees C, and immediately quenched in ice water. The specimens were then divided into four groups and subjected to heat treatment, cryogenic treatment, and heat treatment combined with cryogenic treatment. The specimens after the solution treatment were taken as control. The metallographic structures of the specimens were observed. The electrochemical parameters and the quantity of non-precious metallic ions released were evaluated via electrochemical and static immersion tests.</p><p><b>RESULTS</b>Metallographic observation revealed that all the treatments resulted in a change in the microstructure of the alloy. The treatments were effective in improving the electrochemical parameters, such as an increase in Eocp and Ecorr and a decrease in Icorr (P < 0.05). The amount of non-noble metal ions released showed no difference compared with the control group (P > 0.05).</p><p><b>CONCLUSION</b>After different treatments, the antierosion properties of the alloy satisfied the ISO requirements. Age-hardening heat treatment and cryogenic treatment improved the corrosion resistance of the alloy.</p>

Potentiation of a novel palladium (II) complex lethality with bee venom on the human T-cell acute lymphoblastic leukemia cell line (MOLT-4)

Background : Although honeybee venom (BV) has been reported to induce apoptosis in different types of cancerous cells, its synergistic effects with customary anti-cancer drugs remain largely unknown. In the present study, we evaluated the cytotoxic effect of BV alone (as a natural product) and the synergistic cytological effects of this component in combination with [Pd (bpy) (Pi-Pydtc)]NO3 - a novel palladium complex on human T-cell lymphoblastic leukemia cells. To investigate the cytotoxic effect of the BV alone and in combination with palladium complex on MOLT-4 cells MTT assay was performed. In order to determine the apoptotic effects of BV separately and in combination with Pd (II) complex on these cells and its ability to induce apoptosis, morphological examination, flowcytometric analysis and caspase-3 colorimetric assay were done. Results : We found that BV induced morphological changes, namely nuclear shrinkage, and inhibited MOLT-4 cell proliferation; both effects were dose- and time-dependent. Flow cytometry by Annexin-V antibody demonstrated that BV induced apoptosis in MOLT-4 cells. Furthermore, BV induced apoptosis independently of caspase-3 in these cells. In addition, we proved a clear synergistic effect of BV on [Pd (bpy) (Pi-Pydtc)]NO3. The apoptotic pathway activated by BV in combination with Pd complex was caspase-3-dependent. Conclusions : These observations provide an explanation for the anti-proliferative properties of BV, and suggest that this agent may be useful for treating lymphoblastic leukemia alone or in combination with chemotherapy drugs pending further investigations on animal models as preclinical tests.(AU)

Influence of cryogenic treatment and age-hardening heat treatment on the microhardness of palladium-silver dental alloys / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the influence of cryogenic treatment and age-hardening heat treatment on the micro-Vicker's hardness of palladium-silver dental alloys.</p><p><b>METHODS</b>A low-gold content dental casting alloy composed of Ag-Pd-Cu-Au was prepared for this study. Experimental specimens according to standard requirements were prepared following a standard dental laboratory casting procedure, cast specimens were heated to 900 degrees C and quenched in ice water. The specimens were then divided into 4 groups. They were subsequently subjected to different treatments, including age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment. The non-treated group was used as control. The micro-Vicker's hardness value was examined. The significance of correlation was analyzed.</p><p><b>RESULTS</b>The micro-Vicker's hardness of specimens after age-hardening heat treatment, cryogenic treatment, heat treatment combined with cryogenic treatment increased by 129%, 13% and 141%, respectively, compared with that of the non-treated control group. Conclusion Age-hardening heat treatment and cryogenic treatment were effective in elevating the hardness of Ag-Pd-Cu-Au alloy.</p>

Change in metabolic status of glutathione by palladium nitrate in blood components

This piece of research work present the toxicological impact of varied concentrations of Palladium Nitrate [Pd [NO[3][2] by changing the chemical status of glutathione and the way how glutathione plays its role in detoxification and conjugation processes of [Pd [NO[3][2] in whole blood components [plasma and Cytosolic fraction]. The impact of different concentration of [Pd [N03]2] on reduced glutathione level in whole blood component [Plasma and Cytosolic fraction] were measured spectrophotometrically following Standard Ellman's method. Compared with control sample, significant decrease in the GSH content in whole blood components [plasma and Cytosolic fraction] was obtained with various concentrations [100microM-1000microM] of Palladium Nitrate. Depleted GSH level was more pronounced with time incubation period [0-90] minutes. These finding shows that changes in the GSH status produced by palladium nitrate could either be due to palladium nitrate and glutathione [Pd-SG] complex formation or by conversion of reduce glutathione [2GSH + Pd[+2] -> GSSG]. This change in the GSH metabolic status provides information regarding the mechanism of palladium, in blood components

Does the casting mode influence microstructure, fracture and properties of different metal ceramic alloys?

The aim of the present study was to evaluate the tensile strength, elongation, microhardness, microstructure and fracture pattern of various metal ceramic alloys cast under different casting conditions. Two Ni-Cr alloys, Co-Cr and Pd-Ag were used. The casting conditions were as follows: electromagnetic induction under argon atmosphere, vacuum, using blowtorch without atmosphere control. For each condition, 16 specimens, each measuring 25 mm long and 2.5 mm in diameter, were obtained. Ultimate tensile strength (UTS) and elongation (EL) tests were performed using a Kratos machine. Vickers Microhardness (VM), fracture mode and microstructure were analyzed by SEM. UTS, EL and VM data were statistically analyzed using ANOVA. For UTS, alloy composition had a direct influence on casting condition of alloys (Wiron 99 and Remanium CD), with higher values shown when cast with Flame/Air (p < 0.05). The factors 'alloy" and 'casting condition" influenced the EL and VM results, generally presenting opposite results, i.e., alloy with high elongation value had lower hardness (Wiron 99), and casting condition with the lowest EL values had the highest VM values (blowtorch). Both factors had significant influence on the properties evaluated, and prosthetic laboratories should select the appropriate casting method for each alloy composition to obtain the desired property.

In in-vitro evaluation of effect of different finish lines on marginal adaptation in metal-ceramic restorations under thermo-mechanical loading.

The aim of this study was to evaluate the marginal gap in terms of cement film thickness associated with shoulder, shoulder with 45° bevel, shoulder with 30° bevel and chamfer, under thermo-mechanical loading. Forty human mandibular molars were prepared and restored with ceramo-metal crowns. Teeth were thermo-mechanically loaded and vertically sectioned to evaluate the cement film thickness. Shoulder with 45° bevel provided the least marginal gap as compared with all the tested finish lines.

Development and Evaluation of the Quick Anaero-system-A New Disposable Anaerobic Culture System / 대한진단검사의학회지

BACKGROUND: We developed a new disposable anaerobic culture system, namely, the Quick anaero-system, for easy culturing of obligate anaerobes. METHODS: Our system consists of 3 components: 1) new disposable anaerobic gas pack, 2) disposable culture-envelope and sealer, and 3) reusable stainless plate rack with mesh containing 10 g of palladium catalyst pellets. To evaluate the efficiency of our system, we used 12 anaerobic bacteria. We prepared 2 sets of ten-fold serial dilutions of the 12 anaerobes, and inoculated these samples on Luria-Bertani (LB) broth and LB blood agar plate (LB-BAP) (BD Diagnostic Systems, USA). Each set was incubated in the Quick anaero-system (DAS Tech, Korea) and BBL GasPak jar with BD GasPak EZ Anaerobe Container System (BD Diagnostic Systems) at 35-37degrees C for 48 hr. The minimal inoculum size showing visible growth of 12 anaerobes when incubated in both the systems was compared. RESULTS: The minimal inoculum size showing visible growth for 2 out of the 12 anaerobes in the LB broth and 9 out of the 12 anaerobes on LB-BAP was lower for the Quick anaero-system than in the BD GasPak EZ Anaerobe Container System. The mean time (+/-SD) required to achieve absolute anaerobic conditions of the Quick anaero-system was 17 min and 56 sec (+/-3 min and 25 sec). CONCLUSIONS: The Quick anaero-system is a simple and effective method of culturing obligate anaerobes, and its performance is superior to that of the BD GasPak EZ Anaerobe Container System.

The electrochemical properties of four dental casting suprastructure alloys coupled with titanium implants

OBJECTIVES: As the choice of suprastructure alloy to be combined with titanium for the oral cavity is still a much debated issue, the aim of this study was to investigate the electrochemical interaction of the suprastructure/implant couples under the determined experiment conditions. MATERIAL AND METHODS: The potentiodynamic polarization curves and open-circuit potentials (OCP) of four UCLA type suprastructures coupled with straight Swiss Plus implant fixtures were taken in Afnor type artificial saliva solution at 37°C. The concentration of ions leached into artificial saliva solutions was estimated with ICP-MS. SEM images of the margins of suprastructure/implant couples were obtained before and after the electrochemical tests. RESULTS: The OCP value of titanium became passive at the most negative potential. The lowest difference between the initial and constant OCP value was exhibited by the Au based suprastructure. Suprastructures made greater contributions to the potentiodynamic polarization curves of the implant/suprastructure couples. According to the ICP-MS results, Pd based and Au based couples dissolved less than Co-Ni based and Co-Cr based couples. CONCLUSIONS: Within the conditions this study, it may be concluded that the titanium implant forms a stable passive oxide layer in artificial saliva exposed to open air and does not affect the corrosion properties of the suprastructures. Pd based and Au based couples have been found to be more corrosion-resistant than base alloy couples.

Determination of malathion in blood and urine using thin-layer chromatography.

Malathion is a broad-spectrum Organophosphorus insecticide generally used to control a variety of insects. Routinely it is analysed by Gas Liquid Chromatography & High Performance Liquid Chromatography. Now an attempt has been made to develop a new method for analysis of Malathion in biological samples using Thin Layer Chromatography (TLC) technique, which is inexpensive, accurate and non-destructive. Malathion was extracted from blood and urine using solvent extraction methods and then identified on the TLC plates. For chromatographic separation, various binary and tertiary solvent systems were used to demonstrate in the laboratory. For detection on developed plates, palladium chloride reagent was used which successfully increased the sensitivity without dispensing with the simplicity of the method. For the analysis, a total of 20 solvent systems were chosen. Out of these 20 solvent systems, the three best solvent systems namely Cyclohexane: Chloroform (60:40), Hexane: Acetone (80:20) and Acetone: Hexane: Toluene (40:40:20) were chosen for statistical analysis which included the calculation of mean Rf value, value of standard deviation and coefficient of variance. The method developed is simple, inexpensive, accurate and non-destructive that allows for sensitive and reproducible analysis of Malathion.

Induction of biliary cholangiocarcinoma cell apoptosis by 103Pd cholangial radioactive stent gamma-rays / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>In recent years, interventional tumor therapy, involving implantation of intra-cholangial metal stents through percutaneous trans-hepatic punctures, has provided a new method for treating cholangiocarcinoma. (103)Pd cholangial radioactive stents can concentrate high radioactive dosages into the malignant tumors and kill tumor cells effectively, in order to prevent re-stenosis of the lumen caused by a relapsed tumor. The aim of the present study was to investigate the efficacy of gamma-rays released by the (103)Pd biliary duct radioactive stent in treating cholangiocarcinoma via induction of biliary cholangiocarcinoma cell apoptosis.</p><p><b>METHODS</b>A group of biliary duct cancer cells was collectively treated with a dose of gamma-rays. Cells were then examined by the 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl terazolium-bromide (MTT) technique for determining the inhibition rate of the biliary duct cancer cells, as well as with other methods including electron microscopy, DNA agarose gel electrophoresis, and flow cytometry were applied for the evaluation of their morphological and biochemical characteristics. The growth curve and the growth inhibition rate of the cells were determined, and the changes in the ultrastructure of the cholangiocarcinoma cells and the DNA electrophoresis bands were examined under a UV-lamp.</p><p><b>RESULTS</b>The gamma-ray released by (103)Pd inhibited cholangiocarcinoma cell growth, as demonstrated when the growth rate of the cells was stunned by a gamma-ray with a dosage larger than 197.321 MBq. Typical features of cholangiocarcinoma cell apoptosis were observed in the 197.321 MBq dosage group, while cell necrosis was observed when irradiated by a dosage above 245.865 MBq. DNA agarose gel electrophoresis results were different between the 197.321 MBq irradiation dosage group, the 245.865 MBq irradiation dosage group, and the control group.</p><p><b>CONCLUSIONS</b>(103)Pd radioactive stents which provide a radioactive dosage of 197.321 MBq are effective in the treatment of cholangiocarcinoma; (103)Pd radioactive stents should be useful for the clinical treatment of cholangiocarcinoma.</p>