Leakage studies have been performed frequently, since a fluid-tight seal provided by various dental filling materials has been considered clinically important. The leakage of the various root-end filling materials has been widely investigated mostly dye penetration method. These dye studies cannot offer any information about the quality of the seal of a test material over a long period of time The purpose of this study was to evaluate the microleakage of root end cavities in blood contamination filled amalgam, intermediate restorative material(IRM), light cured glass ionomer cement(GI) and mineral trioxide aggregate(MTA) by means of a modified fluid transport model. Fifty standard human root sections, each 5mm high and with a central pulp lumen of 3mm in diameter, were and filled with our commonly used or potential root end filling materials after they were contaminated with blood. At 24h, 72h, 1, 2, 4, 8, and 12 weeks after filling, leakage along these filling materials was determined under a low pressure of 10KPa(0.1atm) using a fluid transport model. The results were as follows: 1. MTA group showed a tendency of decreasing percent of gross leakage (20ml/day) in process of time, whereas the other materials showed a tendency of increasing in the process time. 2. At the all time interval, GI group leaked significantly less than amalgam group and IRM group (p<0.05). 3. At the 4 weeks, the percentage of gross leakage in MTA group decreased to 0% thereafter, the low percentage of gross leakage was maintained in MTA group until the end of the experiment, whereas the percentage in IRM group increased to 100%. 4. At the 12 weeks, percentage of gross leakage was significantly low in MTA group(0%), comparison with GI group(40%), amalgam group(90%) and IRM group(100%), but there was no significant difference between latter two materials.
Acrylic Resins ; Glass ; Glutamates ; Guanine ; Humans ; Light ; Silicon Dioxide ; Pemetrexed

OBJECTIVES: The aim of this study was to compare apical sealing ability and physical properties of MTA, MTA - AH-plus mixture (AMTA) and experimental Portland cement - Epoxy resin mixture (EPPC) for a development of a novel retro-filling material. MATERIALS AND METHODS: Forty-nine extracted roots were instrumented and filled with gutta-percha. Apical root was resected at 3 mm and the retro-filling cavity was prepared for 3 mm depth. Roots were randomly divided into 3 groups of 15 roots each. The retro-filling was done using MTA, AMTA, and EPPC as the groups divided. Four roots were used as control groups. After setting in humid condition for 24 hours, the roots were immersed in 1% methylene blue dye solution for 72 hours to test the apical leakage. After immersion, the roots were vertically sectioned and photos were taken to evaluate microleakage. Setting times were measured with Vicat apparatus and digital radiographs were taken to evaluate aluminum equivalent thickness using aluminum step wedge. The results of microleakage and setting time were compared between groups using one-way ANOVA and Scheffe's post-hoc comparison at the significance level of 95%. RESULTS: AMTA and EPPC showed less microleakage than MTA group (p < 0.05). AMTA showed the highest radio-opacity than other groups and the novel EPPC showed 5 mm aluminum thickness radio-opacity. EPPC showed the shortest initial and final setting times than other groups while the MTA showed the longest (p < 0.05). CONCLUSIONS: Under the condition of this study, the novel composite using Portland cement-Epoxy resin mixture may useful for retro-filling with the properties of favorable leakage resistance, radio-opacity and short setting time.
Aluminum ; Glutamates ; Guanine ; Gutta-Percha ; Immersion ; Methylene Blue ; Pemetrexed

Since its introduction in 1993, Mineral Trioxide Aggregate (MTA) has been shown to be superior to others in sealing, biocompatibility, and many other aspects of clinical endodontics. MTA is primarily Portland cement with bismuth oxide as a radiopacitifier. Although some studies suggested that the reasonable-priced Portland cement could be used instead of MTA, but MTAs are different from Portland cement in its composition, especially in heavy metal contents. Therefore, clinicians should be meticulous adapting the Portland cement as a MTA substitute.
Aluminum Compounds ; Bismuth ; Calcium Compounds ; Drug Combinations ; Endodontics ; Glutamates ; Guanine ; Oxides ; Silicates ; Pemetrexed

BACKGROUND: Pemetrexed, a multi-targeted antifolate has been used as a second line treatment against non-small cell lung cancer (NSCLC). We aimed to clarify the efficacy and survival according to line of treatment, histologic type, and expression of thymidylate synthase (TS). METHODS: Ninety-eight patients were treated with pemetrexed as a second line treatment (n=43) or as an additional course of treatment (n=55). TS expression was studied with immunohistochemistry and graded as 0 to 3 based on the extent of expression. RESULTS: The response rate (RR) in 98 subjects was 10.2% and the disease control rate (DCR=PR+SD) was 30.6%. RR and DCR were 12.7% and 32.7% in non-squamous cell carcinoma (NSQC) compared to 7.0% and 27.9% in squamous cell carcinoma (SQC) (p>.05). No significant differences in RR and DCR were observed between a second line group (4.7%, 20.9%) and a further line group (14.5%, 38.2%). A similar trend was observed in the 88 response evaluable subjects. TS was expressed in 28.6% (grade 1), 24.5% (grade 2) and 7.1% (grade 3), respectively, and it was not expressed in 39.8% of subjects. TS expression rate was significantly higher in the SQC (72.1%) compared to NSQC (50.9%, p=0.033). However, the efficacy of pemetrexed was not significantly different by the extent of TS expression. CONCLUSION: Pemetrexed showed efficacy, not only in a second-line setting, but also in further lines of treatment for NSCLC. The efficacy of pemetrexed tended to be higher in patients with NSQC compared to SQC. TS expression rate was significantly higher in SQC compared to NSQC.
Carcinoma, Non-Small-Cell Lung ; Carcinoma, Squamous Cell ; Glutamates ; Guanine ; Humans ; Immunohistochemistry ; Thymidylate Synthase ; Pemetrexed

Mineral trioxide aggregate (MTA), which was originally developed for repair of root perforations, is a biocompatible material with numerous clinical applications in endodontics. MTA must be allowed to set in the presence of moisture to optimize the material's physical and chemical properties. In the clinic, occasionally unset MTA has been detected after application of MTA on the tooth, and the reason has been unclear. This case report presents MTA washed-out for several years after placement at the root apex as an apical plug, and discusses the reason and things to consider in clinics.
Aluminum Compounds ; Calcium Compounds ; Drug Combinations ; Endodontics ; Glutamates ; Guanine ; Oxides ; Silicates ; Tooth ; Pemetrexed

OBJECTIVES: This study was performed to evaluate the effect of blood contamination on the compressive strength (CS) of Root MTA (RMTA) modified with Calcium chloride (CaCl2) and Disodium hydrogen phosphate (Na2HPO4) as setting accelerators over time. MATERIALS AND METHODS: A total of 110 cylindrical specimens of RMTA were divided into 6 experimental groups as follows: Group1, RMTA; Group 2, RMTA modified with CaCl2 (RMTA-C); Group 3, RMTA modified with Na2HPO4 (RMTA-N); Group 4, RMTA contaminated with blood; Group 5, RMTA-C contaminated with blood; Group 6, RMTA-N contaminated with blood. The CS of specimens in all groups was evaluated after 3 hr, 24 hr, and 1 wk. In the modified groups (groups 2, 3, 5, and 6) the CS of five specimens per group was also evaluated after 1 hr. RESULTS: Blood contamination significantly reduced the CS of all materials at all time intervals (p < 0.05). After 3 hr, the CS of specimens in the RMTA groups (with and without blood contamination) was significantly lower than those in the RMTA-C and RMTA-N groups (p < 0.05). The CS values were not significantly different at the other time intervals. In all groups, the CS of specimens significantly increased over time (p < 0.05). CONCLUSIONS: Blood contamination decreased the CS of both original and accelerated RMTA.
Aluminum Compounds ; Calcium Chloride ; Calcium Compounds ; Compressive Strength ; Drug Combinations ; Glutamates ; Guanine ; Hydrogen ; Oxides ; Silicates ; Pemetrexed

The purpose of this study was to compare the dye leakage of MTA (mineral trioxide aggregate) apical plug produced by two orthograde placement techniques (hand condensation technique and ultrasonically assisted hand condensation technique). To simulate straight canal, 60 transparent acrylic blocks with straight canal were fabricated. These transparent acrylic blocks were divided into 2 groups (Group C; hand condensation technique (HC) and Group U; ultrasonically assisted hand condensation technique (UAHC)) of 30 blocks with each MTA application method. Each group was divided into 2 subgroups (n = 15) with different canal size of #70 (subgroup C70 and subgroup U70) and #120 (subgroup C120 and subgroup U120). After apical plug was created, a wet paper point was placed over the MTA plug and specimen was kept in a humid condition at room temperature to allow MTA to set. After 24 hours, remaining canal space was backfilled using Obtura II. All specimens were transferred to floral form socked by 0.2% rhodamine B solution and stored in 100% humidity at room temperature. After 48 hours, resin block specimens were washed and scanned using a scanner. The maximum length of microleakage was measured from the scanned images of four surfaces of each resin block using Photoshop 6.0. Statistical analysis was performed with Mann-Whitney U test. Group U of UAHC had significantly lower leakage than Group C of HC in #70-size canal (subgroup U70) (p < 0.05).
Glutamates ; Guanine ; Hand ; Humidity ; Rhodamines ; Root Canal Filling Materials ; Ultrasonics ; Pemetrexed

MTA is rarely applied in the repair of root fractured section. A case of maxillary second premolar which fractured ten years ago had been connected with MTA in this article and the cone beam CT was used to evaluate the treatment effect.
Bicuspid ; Cone-Beam Computed Tomography ; Glutamates ; Guanine ; analogs & derivatives ; Humans ; Pemetrexed ; Tooth Root

AIMTo study the thermal stability, decomposition process and kinetics of such purine pharmaceuticals as aciclovir (Acv), penciclovir (Pcv), and their parent substance, guanine.

METHODSUsing infrared technique, accelerating test method and thermogravimetry to investigate the thermal decomposition processes and using Coast-Redfern method, MKN method and Ozawa method to deal with the data to get kinetic functions.

RESULTSThe decomposition process and the formed products were derived, the kinetic model function was suggested by comparison of the kinetic parameters.

CONCLUSIONPcv and Acv's degrading product for the first step is guanine. The sequences of their thermal stabilities is: Pcv > Acv. The two drugs' kinetic equation of thermal decomposition is expressed as: da/dt = Ae-Ea/RT2(1-alpha)3/2.

Acyclovir ; analogs & derivatives ; chemistry ; Drug Stability ; Guanine ; chemistry ; Hot Temperature ; Kinetics ; Thermodynamics ; Thermogravimetry

OBJECTIVES: The current review aimed to describe the major findings of the NIMH Collaborative Multisite Multimodal Treatment Study of Children with Attention-Deficit Hyperactivity Disorder (MTA) with regard to the treatment of children with attention-deficit hyperactivity disorder (ADHD). METHODS: We performed a general review of the literature regarding the efficacy of the MTA's proposed treatments. RESULTS: There is a large and still increasing body of evidence regarding the MTA's treatment outcomes. We present and discuss details of the findings at each follow-up point. CONCLUSION: Currently, findings regarding the MTA's treatments suggest children with combined-type ADHD exhibit significant impairment in adolescence, despite their initial symptom improvement. Further studies, using innovative treatment approaches and targeting specific areas of adolescent impairment, are needed in order to enhance ADHD treatment outcomes.
Adolescent ; Child ; Combined Modality Therapy ; Follow-Up Studies ; Glutamates ; Guanine ; Humans ; National Institute of Mental Health (U.S.) ; Pemetrexed