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Tukey's Test (tukey + test)
Kinds of Tukey's Test Selected AbstractsBiocompatibility evaluation of alendronate paste in rat's subcutaneous tissueDENTAL TRAUMATOLOGY, Issue 2 2009Graziela Garrido Mori Therefore, this study aimed to investigate the biocompatibility of experimental alendronate paste in subcutaneous tissue of rats, for utilization in teeth susceptible to root resorption. The study was conducted on 15 male rats, weighing ,180,200 grams. The rats' dorsal regions were submitted to one incision on the median region and, laterally to the incision, the subcutaneous tissue was raised and gently dissected for introduction of two tubes, in each rat. The tubes were sealed at one end with gutta-percha and taken as control. The tubes were filled with experimental alendronate paste. The animals were killed at 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy. Scores were assigned to the inflammatory process and statistically compared by the Tukey test (P < 0.05). Alendronate paste promoted severe inflammation process at 7 days, with statistically significant difference compared to the control (P < 0.05%). However, at 15 days, there was a regression of inflammation and the presence of connective tissue with collagen fibers, fibroblasts and blood vessels was observed. After 45 days, it was observed the presence of well-organized connective tissue, with collagen fibers and fibroblasts, and few inflammatory cells. No statistical difference was observed between the control and experimental paste at 15 and 45 days. The experimental alendronate paste was considered biocompatible with subcutaneous tissue of rat. [source] Influence of intracoronal bleaching agents on the ultimate strength and ultrastructure morphology of dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2009V. Cavalli Abstract Objective, To evaluate the effects of intracoronal bleaching on ultimate tensile strength (UTS) of sound and etched dentine and its ultrastructure morphology. Methodology, Bovine dentine specimens with (e) or without previous etching with 37% phosphoric acid for 15 s were used for the intracoronal bleaching experiments. Teeth were randomly assigned to five treatments (n = 10): (C) control , no bleaching, (SP) sodium perborate, (CP) 35% carbamide peroxide, (25% HP) 25% hydrogen peroxide and (35% HP) 35% hydrogen peroxide. Bleaching was performed four times within a 72 h interval and afterwards, dentine pulp chamber blocks were obtained. The blocks were sectioned in 0.7 mm-thick slices and these were trimmed to reduce the inner dentine to a dumbbell shape with a cross-sectional area of 0.8 mm2. Specimens were tested with the microtensile method (0.5 mm min,1) and data were analysed (two-way anova -Tukey test, P < 0.05). Additional teeth were prepared for transmission electron microscopy (TEM) to evaluate dentine ultramorphology. Results, The mean values of the UTS (SD) in MPa for sound dentine were: C = 48.3(8.5)a, SP = 34.6 (8.2)b, CP = 32.9 (8.9)b, 25% HP = 28.0(4.6)b, 35% HP = 26.4(6.6)b, and pre-etched dentine: Ce = 38.9(13.8)a, SPe = 31.3 (9.3)ab, CPe = 28.4 (6.2)ab, 25% HPe = 30.0 (7.9)ab, 35% HPe = 19.9(4.6)b. Significant differences between the means are indicated by the letters. TEM observations exhibited demineralization areas for all bleaching treatments. Conclusion, Bleaching decreased dentine UTS after treatment. Pre-etched not-bleached dentine (Ce) presented UTS similar to pre-etched bleached dentine, except for 35% HPe. The decrease of UTS of bleached dentine could be attributed to ultrastructural alterations such as loss of inorganic components. [source] Evaluation of the monocyte counting by two automated haematology analysers compared with flow cytometryINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2005E. GRIMALDI Summary The aim is to determine the monocyte count performance of the Bayer Diagnostics ADVIA®120 and Coulter® LH 750 automated haematology analysers and the results obtained by these two instruments were compared with those provided by Becton Dickinson FACScan flow cytometer using the combination of CD45/CD14 MoAb. Linearity and imprecision were also evaluated. The linearity of both instruments was good. Coulter® LH 750 showed better precision (4.3%) than ADVIA 120 (9.0%) both within and between batch. A significant correlation (r = 0.973) was found between the LH 750 and the flow cytometry method, while a modest one was observed between the latter and the ADVIA 120 (r = 0.880). When comparing the percentage of monocytes by means of one-way anova and Tukey test, it was found that the LH 750 provided the closest results in comparison with flow cytometry, with no statistical difference between the means (mean difference MO% = 0.6); however the difference was statistically different between the ADVIA 120 and flow cytometry (mean difference MO% = ,4.06). These data were confirmed by Altman,Bland and Deming regression analyses. [source] Effect of curing mode on bond strength of self-adhesive resin luting cements to dentinJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2010T. R. Aguiar Abstract In this study, the in vitro bond strength of dual-curing resin cements to indirect composite restorations when the cement was either light polymerized or allowed to only autopolymerize was evaluated. Occlusal dentin surfaces of 56 extracted human third molars were flattened to expose coronal dentin. Teeth were assigned to eight groups (n = 7) according to resin cement products and polymerization modes: conventional cement (Panavia F 2.0; Kuraray Medical) and self-adhesive cements [RelyX Unicem (3M ESPE), BisCem (Bisco), and G-Cem (GC Corp.)]. Cements were applied to prepolymerized resin discs (2-mm-thick Sinfony; 3M ESPE), which were subsequently bonded to the prepared dentin surfaces. The restored teeth were either light-polymerized through the overlying composite according to manufacturers' instructions or were allowed to only self-cure. After 24 h, the teeth and restorations were sectioned to obtain multiple bonded beams (1.0 mm2) and tested in tension at a crosshead speed of 0.5 mm/min until failure. Data (MPa) were analyzed by two-way ANOVA and Tukey test (, = 0.05). Light activation of some cement systems (G-Cem and Panavia F 2.0) increased the bond strength, while the curing mode did not affect the bond strength for some (RelyX Unicem and BisCem). The bond strength in the autopolymerized mode varied among products. In general, the use of self-adhesive resin cements did not provide significantly higher bond strengths than that of a conventional material, and two self-adhesive cements yielded significantly lower bond values (regardless of cure mode) than the other products. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source] Effects of a peripheral enamel bond on the long-term effectiveness of dentin bonding agents exposed to water in vitroJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Andre F. Reis Abstract This study evaluated the effects of water exposure on the in vitro microtensile bond strength (,TBS) of etch-and-rinse and self-etching adhesives to human dentin over a 1-year storage period. Five adhesive systems used were as follows: a one-step self-etching adhesive (One-up Bond F-OB), two two-step self-etching primers (Clearfil SE Bond-SE and Clearfil Protect Bond-CP), and two etch-and-rinse adhesives (Single Bond-SB and Prime&Bond NT-PB). Dentin surfaces were bonded, restored, and assigned to four subgroups, according to the degree of water exposure: 24 h of peripheral water exposure (24 h-PE) (having circumferential enamel); and 1 year of peripheral exposure (1 yr-PE), direct exposure (1 yr-DE) (dentin directly water-exposed), or directly exposed to oil only (no water exposure) (1 yr-DOE). A composite-enamel bond adjacent to the restoration is determined if the water exposure was peripheral or direct. After storage periods, specimens were serially sectioned, trimmed to an hourglass shape with a cross-sectional area of 1 mm2 at the interface, and tested in tension. Results were analyzed by two-way ANOVA and Tukey test (, = 0.05). No difference was found between 24 h-PE and 1 yr-PE for OB, CP, SB, and PB. However, ,TBS values significantly dropped after 1 yr-DE for SE, CP, SB, and PB. A decreased ,TBS was seen in SE after 1 yr-PE, but no differences existed between 1 yr-PE and 1 yr-DE. Similar or increased ,TBS values were noted in 1 yr-DOE for all adhesives. Water-storage for 1 year significantly decreased ,TBS for all adhesives. However, except for SE, the presence of a peripheral composite-enamel bond seemed to reduce the degradation rate in resin-dentin interfaces for all materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Endothelial cell growth on silicon modified hydrogenated amorphous carbon thin filmsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008A. A. Ogwu Abstract The biological response of human microvascular endothelial cells (HMEC-1) seeded on Si-DLC films and on control surfaces was evaluated in terms of initial cell enhancement, growth, and cytotoxicity. The microstructure of the films was characterised by Raman spectroscopy and X-ray photoelectron spectroscopy. The effect of changes in microstructure, surface energy, surface electronic state, and electronic conduction, on the biological response of the films to endothelial cells was investigated. Endothelial cell adhesion and growth was found to be affected by changes in the microstructure of the films induced by silicon doping and thermal annealing. We observed a significant statistical difference in endothelial cell count between the as-deposited DLC and Si-DLC films using the one sample t -test at a p -value of 0.05. We also found a statistically significant difference between the adhesion of HMEC films on DLC and Si-DLC films at various annealing temperatures using the one-way ANOVA F statistic test at p < 0.05 and the post-hoc Tukey test. One sample t -test at p < 0.05 of MTT-assay results showed the endothelial cells to be viable when seeded on DLC/Si-DLC films. We suspect that the increased adhesion of endothelial cells induced by increasing the amount of silicon in the Si-DLC films is associated with the development of a suitable surface energy due to silicon addition, which neither favored cell denaturing nor preferential water spreading before cellular attachment on the film surface. The presence of an external positively charged dipole on the Si-DLC films confirmed by our Kelvin probe measurements is also expected to enhance the adhesion of endothelial cells that are well known to carry a negative charge. The Si-DLC films investigated hold potential promise as coatings for haemocompatible artificial implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Effects of a 10% Carbamide Peroxide Bleaching Agent on Roughness and Microhardness of Packable Composite ResinsJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2005ROBERTA TARKANY BASTING DDS ABSTRACT Purpose:: Bleaching agents containing 10% carbamide peroxide may be applied to the surface of preexisting packable resin-based composite restorations. The aim of this in vitro study was to evaluate the effect of a 10% carbamide peroxide bleaching agent (Review, SS White, Rio de Janeiro, Brazil) on surface roughness and microhardness of three packable resin-based composites (Fill Magic condensable, Vigodent, Rio de Janeiro, Brazil; Alert, Jeneric Pentron, Wallingford, CT, USA; Definite, Degussa, Hanau, Germany). Materials and Methods: For the control (no bleaching) and experimental (bleaching treatment) groups, 12 specimens of each material were prepared in cylindrical acrylic molds. The experimental specimens were exposed to the bleaching agent for 6 hours a day for 3 weeks. During the remaining time (18 h), they were stored in artificial saliva. The control specimens remained immersed in artificial saliva throughout the experiment. Surface roughness and microhardness measurements were performed on the top surface of each specimen. Results: Analysis of variance and the Tukey test showed no significant differences in roughness among the packable composites evaluated (p=.18), but those submitted to the treatment with a 10% carbamide peroxide bleaching agent displayed significantly higher mean surface roughness than did the corresponding control group for each material. For the microhardness tests, there were significant differences among materials (p < .0001). Alert showed the highest microhardness values followed by Definite and Fill Magic condensable. Conclusions: Ten percent carbamide peroxide bleaching agents may change the surface roughness of packable composites, but they do not alter their microhardness. [source] In vitro evaluation of the effect of core diameter for removing radicular post with ultrasoundJOURNAL OF ORAL REHABILITATION, Issue 6 2004E. Alfredo summary, The removal of radicular posts for endodontic reasons as well as their replacement is a common procedure in dental practice. The use of ultrasound is becoming a standard practice since it reduces the stress to displace the core from the canal minimizing the risks of root fractures, perforations and further wearing of dental structure. Thus, the objective of this study was to evaluate the effect of a reduction in the core diameter when removing radicular posts with ultrasound. Twenty-four teeth were divided in two groups. Group I received posts with the dowel and core of the same diameter (1·7 mm) and group II received posts with the dowel diameter 2 mm larger (3·7 mm) than the core diameter. Zinc phosphate cement was used to cement the posts in all groups. Half of the samples of each group received ultrasonic energy for 8, 2 min for each face. All samples were submitted to traction on an Instron machine (model 4444). Data were analysed statistically with anova and the Tukey test, revealing significant differences (P < 0·05) between groups. The authors concluded that the mean tension necessary to displace the posts from the roots was reduced by 26% when ultrasound was applied. The reduction of the post-diameter reduced the necessary tension to remove them by 24% compared with larger posts. [source] Influence of working side contacts on masticatory function for mandibular distal extension removable partial denturesJOURNAL OF ORAL REHABILITATION, Issue 3 2003S. Sueda summary The aim of this study was to clarify the influence of working side contacts for masticatory function for a distal extension removable partial denture. Five subjects who had edentulous arches from second premolar to second molar opposing natural teeth participated. Working side contacts were altered by using three types of artificial teeth attached to the denture base. A-form teeth made contact with opposite teeth while acting as the working side in a lateral excursion. The cusp angles of B- and C-form teeth were decreased by 10° and 20°, respectively compared with A-form teeth. B-and C-form teeth discluded with opposite teeth on the working side. Subjects were asked to perform two kinds of masticatory performance test. Obtained data were evaluated by the repeated-measures anova and the Tukey test for multiple comparisons. Results revealed that there was a significant difference (P=0·001) in the three types of teeth in the mixing ability test and the value of A-form teeth was statistically less value than those of the other teeth. However, there was no significant difference in the comminuting ability test. These results suggested that working side contacts between artificial teeth and opposite natural teeth influenced mixing ability, but not comminuting ability. [source] The Effect of Coating Patterns with Spinel-Based Investment on the Castability and Porosity of Titanium Cast into Three Phosphate-Bonded InvestmentsJOURNAL OF PROSTHODONTICS, Issue 7 2010Anelise R. F. Pieralini DDS Abstract Purpose: This study evaluated the effect of pattern coating with spinel-based investment Rematitan Ultra (RU) on the castability and internal porosity of commercially pure (CP) titanium invested into phosphate-bonded investments. The apparent porosity of the investment was also measured. Materials and Methods: Square patterns (15 × 15 × 0.3 mm3) were either coated with RU, or not and invested into the phosphate-bonded investments: Rematitan Plus (RP), Rema Exakt (RE), Castorit Super C (CA), and RU (control group). The castings were made in an Ar-arc vacuum-pressure machine. The castability area (mm2) was measured by an image-analysis system (n = 10). For internal porosity, the casting (12 × 12 × 2 mm3) was studied by the X-ray method, and the projected porous area percentage was measured by an image-analysis system (n = 10). The apparent porosity of the investment (n = 10) was measured in accordance with the ASTM C373-88 standard. Results: Analysis of variance (One-way ANOVA) of castability was significant, and the Tukey test indicated that RU had the highest mean but the investing technique with coating increased the castability for all phosphate-bonded investments. The analysis of the internal porosity of the cast by the nonparametric test demonstrated that the RP, RE, and CA with coating and RP without coating did not differ from the control group (RU), while the CA and RE casts without coating were more porous. The one-way ANOVA of apparent porosity of the investment was significant, and the Tukey test showed that the means of RU (36.10%) and CA (37.22%) were higher than those of RP (25.91%) and RE (26.02%). Conclusion: Pattern coating with spinel-based material prior to phosphate-bonded investments can influence the castability and the internal porosity of CP Ti. [source] Influence of Artificial Accelerated Aging on Dimensional Stability of Acrylic Resins Submitted to Different Storage ProtocolsJOURNAL OF PROSTHODONTICS, Issue 6 2010Lucas da Fonseca Roberti Garcia DDS Abstract Purpose: The aim of this study was to evaluate the influence of artificial accelerated aging on dimensional stability of two types of acrylic resins (thermally and chemically activated) submitted to different protocols of storage. Materials and Methods: One hundred specimens were made using a Teflon matrix (1.5 cm × 0.5 mm) with four imprint marks, following the lost-wax casting method. The specimens were divided into ten groups, according to the type of acrylic resin, aging procedure, and storage protocol (30 days). GI: acrylic resins thermally activated, aging, storage in artificial saliva for 16 hours, distilled water for 8 hours; GII: thermal, aging, artificial saliva for 16 hours, dry for 8 hours; GIII: thermal, no aging, artificial saliva for 16 hours, distilled water for 8 hours, GIV: thermal, no aging, artificial saliva for 16 hours, dry for 8 hours; GV: acrylic resins chemically activated, aging, artificial saliva for 16 hours, distilled water for 8 hours; GVI: chemical, aging, artificial saliva for 16 hours, dry for 8 hours; GVII: chemical, no aging, artificial saliva for 16 hours, distilled water for 8 hours; GVIII: chemical, no aging, artificial saliva for 16 hours, dry for 8 hours GIX: thermal, dry for 24 hours; and GX: chemical, dry for 24 hours. All specimens were photographed before and after treatment, and the images were evaluated by software (UTHSCSA , Image Tool) that made distance measurements between the marks in the specimens (mm), calculating the dimensional stability. Data were submitted to statistical analysis (two-way ANOVA, Tukey test, p= 0.05). Results: Statistical analysis showed that the specimens submitted to storage in water presented the largest distance between both axes (major and minor), statistically different (p < 0.05) from control groups. Conclusions: All acrylic resins presented dimensional changes, and the artificial accelerated aging and storage period influenced these alterations. [source] Investigation of a New Approach to Measuring Contact Angles for Hydrophilic Impression MaterialsJOURNAL OF PROSTHODONTICS, Issue 2 2007Gerard Kugel DMD Purpose: The purpose of this investigation was to examine the initial water contact angles of seven unset impression materials using commercially available equipment, in an effort to determine whether polyether impression materials (Impregum) have lower contact angles and are, therefore, more hydrophilic than VPS impression materials. Materials and Methods: The hydrophilic properties of unset polyether and VPS impression materials were analyzed with respect to their water contact angle measurements using the commercially available Drop Shape Analysis System DSA 10. Twenty-five data points per second were collected via video analysis. There was no delay from start of measurement and data collection. Data was collected for approximately 12 s. Droplet size was determined on the thickness of canula. If the droplets became too small in volume, the water that evaporated during the measurement was large in comparison to the volume of the droplet. Therefore, 5 ,l was chosen as the lowest volume. Five trials were conducted per series for each featured material. Contact angles were calculated using the circle fitting method. Three tests using this technique were designed to control the variables of contact angle measurement with regard to time, the varying amount of fluid in contact with impression material during clinical use, and material thickness. Sample thickness of impression material was controlled by stripping the paste flat on a glass plate using a marking template to ensure a constant film thickness. Tests were conducted in a climatized room at 24°C ± 1°C. Deionized water was used as the fluid. The device was calibrated according to manufacturer's instruction for Young,Laplace fitting prior to the measurements. Results were analyzed using One-Way ANOVA, Tukey test, and t -test, as appropriate. Results: Comparing the fast setting impression materials by One-Way ANOVA and Tukey tests (p < .05) revealed the initial contact angles to range from 66.2 ± 1.5° to 127.5 ± 4.4°, of which the polyether material was the lowest after 45 s (66.2 ± 1.5°), 120 s (70.3 ± 2.8°), and 24 h (80.3 ± 1.0°) after start of the mix. The selected times represent the different stages of unset material, ranging from 45 s as the earliest practical data collection time to 24 h, at which a stone model would be poured. The polyether materials tested exhibited lower contact angles and, thus, significantly higher initial hydrophilicity than all measured VPS materials. Additionally, Impregum impression materials are more hydrophilic in the unset stage than in the set stage. VPS may show a stepwise development of hydrophilicity in the set stage that was not observed in the unset stage. Conclusions: The polyether impression materials tested were significantly more hydrophilic before, during, and after setting than that of VPS impression materials. Regardless of the amount of water in contact with the impression material, the polyether impression materials showed a significantly higher hydrophilicity in the unset stage than the VPS materials. The initial contact angle was not dependent on the thickness of the material. All parameters, including variation of time, volume of water droplet, and thickness of material, resulted in different absolute contact angles, but did not lead to a dramatic change in the ranking of the materials with regard to their hydrophilic behavior. [source] Performance of Five Commercially Available Tooth Color-Measuring DevicesJOURNAL OF PROSTHODONTICS, Issue 2 2007Alma Dozi Purpose: Visual tooth color assessment is neither accurate nor precise due to various subjective and objective factors. As newly developed tooth color-measuring devices for dental application provide the possibility of a more objective means of color determination, their performances in vitro and in vivo must be evaluated. The objective of this study was to evaluate the accuracy and precision of five commercially available tooth color-measuring devices in standardized and in clinical environments. Materials and Methods: In an in vitro study, standards (A1, A2, A3, A3.5, and A4 shade tabs of Vita Lumin) were measured five times with five electronic devices (ShadeScan, Easyshade, Ikam, IdentaColor II, and ShadeEye) by two operators. In an in vivo study, the right upper central incisors of 25 dental students were measured with the same electronic devices by a single operator. Vita shade tab codes were expressed as CIE (International Commission on Illumination) L*a*b* values and in terms of the precision and accuracy of ,E color differences. The Mann-Whitney statistical test was used to analyze the differences between the two operators in the in vitro study, and the Kruskal-Wallis one-way analysis of variance on ranks with the post-hoc Tukey test was used to analyze the accuracy and precision of electronic devices. Results: No statistically significant difference was found between the different operators in the in vitro study. The obtained precision was Easyshade > ShadeScan , Ikam > IdentaColor II > ShadeEye. The obtained accuracy was Easyshade > ShadeScan , Ikam > ShadeEye > IdentaColor II. In the in vivo study, the Easyshade and the Ikam were the most precise, and the ShadeEye and the IdentaColor II were more precise than the ShadeScan. With respect to accuracy, there was no statistical difference between the ShadeScan, Ikam, and the Easyshade. The IdentaColor II was considered inaccurate (,Ea= 3.4). Conclusions: In the clinical setting, the Easyshade and Ikam systems were the most reliable. The other devices tested were more reliable in vitro than in vivo. [source] Preventive effect of iron gel with or without fluoride on bovine enamel erosion in vitroAUSTRALIAN DENTAL JOURNAL, Issue 2 2010MG Bueno Abstract Background:, The aim of this study was to evaluate the preventive effect in vitro of experimental gel containing iron and/or fluoride on the erosion of bovine enamel. Methods:, To standardize the blocks (n = 80), specimens (4 × 4 mm) were previously selected to measure the initial microhardness. The blocks were randomly allocated into four groups of 20 samples each: C (control, placebo gel); F (fluoride gel, 1.23% NaF); Fe (iron gel, 10 mmol/L FeSO4) and F + Fe (fluoride + iron gel). The gels were applied and removed after 1 minute. The blocks were then submitted to six alternating remineralization and demineralization cycles. The beverage Coca-Cola® (10 minutes, 30 mL) was used for demineralization, and artificial saliva (1 hour) for remineralization. The effect of erosion was measured by wear analysis (profilometry). Data were analysed by ANOVA and the Tukey test for individual comparisons (p <0.05). Results:, The mean wear (± SD, ,m) was C: 0.94 ± 0.22; F: 0.55 ± 0.12; Fe: 0.49 ± 0.11 and F + Fe: 0.55 ± 0.13. When the experimental gels were used, there was statistically significant reduction in enamel wear in comparison with the control (p <0.001). However, the experimental gels did not differ significantly among them. Conclusions:, The gels containing iron with or without fluoride are capable of interfering with the dissolution dental enamel in the presence of erosive challenge. [source] The effects of chronic administration of sumatriptan and dipyrone on serotonergic system in the rat brain: an immunohistochemical studyACTA NEUROLOGICA SCANDINAVICA, Issue 4 2009E. Genç Objective,,, To investigate the effects of chronic high dose sumatriptan and dipyrone treatment on central serotonergic system in rats. Materials and methods,,, Male Sprague,Dawley rats (seven per group) were daily injected with sumatriptan (3 mg/kg), dipyrone (400 mg/kg) or saline for 30 days. The brains of animals were surgically removed and immunohistochemically stained for serotonin. Serotonin-positive stained cells were counted automatically by using a computerized image analysis program. Statistical analysis carried out using one-way ANOVA followed by post hoc Tukey test. Results,,, A significant decrease in serotonin-positive cells in the brainstem was observed after chronic sumatriptan administration while chronic use of dipyrone induced a significant increase in serotonin-positive cells both in the cortex and midbrain. Conclusion,,, Our data suggest that central serotonergic system might be modified by chronic use of sumatriptan and dipyrone. [source] Investigation of a New Approach to Measuring Contact Angles for Hydrophilic Impression MaterialsJOURNAL OF PROSTHODONTICS, Issue 2 2007Gerard Kugel DMD Purpose: The purpose of this investigation was to examine the initial water contact angles of seven unset impression materials using commercially available equipment, in an effort to determine whether polyether impression materials (Impregum) have lower contact angles and are, therefore, more hydrophilic than VPS impression materials. Materials and Methods: The hydrophilic properties of unset polyether and VPS impression materials were analyzed with respect to their water contact angle measurements using the commercially available Drop Shape Analysis System DSA 10. Twenty-five data points per second were collected via video analysis. There was no delay from start of measurement and data collection. Data was collected for approximately 12 s. Droplet size was determined on the thickness of canula. If the droplets became too small in volume, the water that evaporated during the measurement was large in comparison to the volume of the droplet. Therefore, 5 ,l was chosen as the lowest volume. Five trials were conducted per series for each featured material. Contact angles were calculated using the circle fitting method. Three tests using this technique were designed to control the variables of contact angle measurement with regard to time, the varying amount of fluid in contact with impression material during clinical use, and material thickness. Sample thickness of impression material was controlled by stripping the paste flat on a glass plate using a marking template to ensure a constant film thickness. Tests were conducted in a climatized room at 24°C ± 1°C. Deionized water was used as the fluid. The device was calibrated according to manufacturer's instruction for Young,Laplace fitting prior to the measurements. Results were analyzed using One-Way ANOVA, Tukey test, and t -test, as appropriate. Results: Comparing the fast setting impression materials by One-Way ANOVA and Tukey tests (p < .05) revealed the initial contact angles to range from 66.2 ± 1.5° to 127.5 ± 4.4°, of which the polyether material was the lowest after 45 s (66.2 ± 1.5°), 120 s (70.3 ± 2.8°), and 24 h (80.3 ± 1.0°) after start of the mix. The selected times represent the different stages of unset material, ranging from 45 s as the earliest practical data collection time to 24 h, at which a stone model would be poured. The polyether materials tested exhibited lower contact angles and, thus, significantly higher initial hydrophilicity than all measured VPS materials. Additionally, Impregum impression materials are more hydrophilic in the unset stage than in the set stage. VPS may show a stepwise development of hydrophilicity in the set stage that was not observed in the unset stage. Conclusions: The polyether impression materials tested were significantly more hydrophilic before, during, and after setting than that of VPS impression materials. Regardless of the amount of water in contact with the impression material, the polyether impression materials showed a significantly higher hydrophilicity in the unset stage than the VPS materials. The initial contact angle was not dependent on the thickness of the material. All parameters, including variation of time, volume of water droplet, and thickness of material, resulted in different absolute contact angles, but did not lead to a dramatic change in the ranking of the materials with regard to their hydrophilic behavior. [source] MULTIPLE TIME-INTENSITY ANALYSIS AND ACCEPTANCE OF RASPBERRY-FLAVORED GELATINJOURNAL OF SENSORY STUDIES, Issue 5 2009ALESSANDRA B. PALAZZO ABSTRACT Face to face with the scenario of current human nutrition, there is an ever-growing preoccupation with the provision of healthy and rapidly prepared diets, gelatin being an important product, taking into consideration its properties, such as muscular regeneration and bone strengthening. The objective of this work is to evaluate different brands of raspberry-flavored gelatin, both traditional and diet, by multiple time-intensity analysis for sweet, acid and raspberry flavor, as well as an acceptance test with 120 consumers. The statistical analysis included variance analysis, Tukey tests and Internal Preference Map. The results showed that there was no significant difference between all the samples to the time in which the maximum intensity of sweetness and acidity occurs. The results indicated a greater acceptance of the traditional samples, which were preferred by the majority (85% regarding intention to purchase). The aspartame/acessulfame-potassium edulcorants were those that recorded behavior most distant from sucrose, compared with sodium saccharine and sodium cyclamate edulcorants. PRACTICAL APPLICATIONS The time-intensity analysis is important to provide how the flavor behavior is for the consumers during the food ingestion and is used in order to obtain the temporal profile of an attribute in a certain product. This analysis is different from the conventional descriptive analysis because it allows the verification of changes in the perception of a product's attribute over time. The sensory results showed in this study should be useful to researchers and product developers who are working with different edulcorants in food, especially in gelatin products. Observing both multiple time-intensity curves and affective data at the same time, it is possible to determine which intensity and duration of sensory characteristics have influenced the consumer's preference. [source] Growth and survival of the Calafia mother-of-pearl oyster Pinctada mazatlanica (Hanley 1856) under different sequences of nursery culture,late culture at Bahía de La Paz, Baja California Sur, MéxicoAQUACULTURE RESEARCH, Issue 12 2000Mario Monteforte The Calafia mother-of-pearl oyster, Pinctada mazatlanica (Hanley), and the Rainbow nacre shell, Pteria sterna (Gould), represent an important resource for México because of their potential in pearl production. The present work deals with the effect of different sequences of nursery culture-late culture on growth and survival of P. mazatlanica, from September 1993 to October 1994. The collected spat presented two main size groups: small (mean shell height of 7 mm), and large (13 mm). They were arranged into four experimental batches for each size group at a constant stocking density of 40,45 juvenile pearl oysters per Nestier cage. Three batches remained in nursery culture for 2, 4 and 6 months respectively, after which they were transferred to late culture in rail cages. A control group remained in nursery culture for 12 months. Growth was evaluated monthly and compared through anova and HSD Tukey tests. In addition to the shell height, width, depth (mm) and weight (g), data of shell volume (height × width × depth, in mm3) was also introduced to estimate and compare growth among the experimental groups. Mortality was estimated by counting the dead specimens every month and obtaining the percentage from a 100% initial survival at the start of the experiment. The juveniles showed different responses to the change from nursery culture to late culture; the level of each response varied significantly among the experimental groups at the end of the study. It seemed that a 6-month period for nursery culture was propitious for P. mazatlanica. [source] Original article: Effect of flask closure method and post-pressing time on the upper denture base adaptationGERODONTOLOGY, Issue 3 2010Andréa F. Lira doi:10.1111/j.1741-2358.2009.00307.x Effect of flask closure method and post-pressing time on the upper denture base adaptation Objectives:, The purpose of this study was to evaluate the effect of flask-closure methods, post-pressing times and acrylic resins on denture base adaptation. Materials and methods:, The resins were flasked using a hydraulic press and closed with the traditional clamp or RS system. Conventional heat-cure resin was polymerised immediately or at 6 h post-pressing at 74°C for 9 h. Rapid cycle heat-cure resin was polymerised in boiling water for 20 min. After cooling, the bases were deflasked and the sets of cast-base transversally sectioned in the regions distal to the canine, mesial to the first molar and in the posterior palatal zone. The adaptation was measured with an optical microscope (0.0005 mm) at five reference points for each section. Data were analysed using anova and Tukey's test (, = 0.05). Results:, Traditional clamp and immediate post-pressing time improved base adaptation for conventional heat-cure resin. Both post-pressing times showed most accurate base adaptation for conventional heat-cure resin when the traditional clamp was used. Immediate post-pressing time improved base adaptation for conventional heat-cure resin and the 6-h delay in time was significant for the rapid cycle heat-cure resin. Conclusions:, Traditional clamp and immediate post-pressing time improved base adaptation for conventional heat-cure resin. [source] Original article: Glass transition temperature of hard chairside reline materials after post-polymerisation treatmentsGERODONTOLOGY, Issue 3 2010Vanessa M. Urban doi:10.1111/j.1741-2358.2009.00312.x Glass transition temperature of hard chairside reline materials after post-polymerisation treatments Objective:, This study evaluated the effect of post-polymerisation treatments on the glass transition temperature (Tg) of five hard chairside reline materials (Duraliner II-D, Kooliner-K, New Truliner-N, Ufi Gel hard-U and Tokuso Rebase Fast-T). Materials and methods:, Specimens (10 × 10 × 1 mm) were made following the manufacturers' instructions and divided into three groups (n = 5). Control group specimens were left untreated. Specimens from the microwave group were irradiated with pre-determined power/time combinations, and specimens from the water-bath group were immersed in hot water at 55°C for 10 min. Glass transition (°C) was performed by differential scanning calorimetry. Data were analysed using anova, followed by post hoc Tukey's test (, = 0.05). Results:, Both post-polymerisation treatments promoted a significant (p < 0.05) increase in the Tg of reline material K. Materials K, D and N showed the lowest Tg (p < 0.05). No significant difference between T and U specimens was observed. Conclusion:, Post-polymerisation treatments improved the glass transition of material Kooliner, with the effect being more pronounced for microwave irradiation. [source] Dimensional accuracy of upper complete denture bases: the effect of metallic flask closure methodsGERODONTOLOGY, Issue 1 2009Rafael Leonardo Xediek Consani Objectives:, To verify the dimensional accuracy of upper complete denture bases under the effect of different methods of metallic flask closure. Materials and methods:, Wax record bases were assigned to six groups: 1,2: traditional clamp; 3,4: RS system; and 5,6: flask with screws. Flasks were immediately polymerised or bench stored for 6 h prior to polymerisation. Resin base-cast sets were sectioned at regions corresponding to the canines, first molars and posterior palatal zone. Gap discrepancies were measured at five points: right and left ridge crests, palatal midline, and right and left marginal limits of the flanges. An optical micrometer was used for measurement purposes. Results:, Data were submitted to anova, and the means compared by Tukey's test (, = 0.05). Results revealed significant differences in the flask closure technique, polymerisation time, section, and their interactions. Discrepancy values for the RS system and flask with screws were significantly lower than those related to the traditional clamp, regardless of whether resin polymerisation was immediate or delayed for 6 h. Conclusions:, Flask closure methods should be considered when the denture base stability and comfort of the patient are being assessed during clinical use of the dentures. [source] Bond strength of AH Plus and Epiphany sealers on root dentine irradiated with 980 nm diode laserINTERNATIONAL ENDODONTIC JOURNAL, Issue 9 2008E. Alfredo Abstract Aim, To evaluate the bond strength of AH Plus and Epiphany sealers to human root canal dentine irradiated with a 980 nm diode laser at different power and frequency parameters, using the push-out test. Methodology, Sixty canine roots were sectioned below the cementoenamel junction to provide 4-mm-thick dentine discs that had their root canals prepared with a tapered bur and irrigated with sodium hypochlorite, ethylenediaminetetraacetic acid and distilled water. The specimens were assigned to five groups (n = 12): one control (no laser) and four experimental groups that were submitted to 980 nm diode laser irradiation at different power (1.5 and 3.0 W) and frequency (continuous wave and 100 Hz) parameters. Half of specimens in each group had their canals filled with AH Plus sealer and half with Epiphany. The push-out test was performed and data (MPa) were analysed statistically by anova and Tukey's test (P < 0.05). The specimens were split longitudinally and examined under SEM to assess the failure modes after sealer displacement. Results, The specimens irradiated with the diode laser and filled with AH Plus had significantly higher bond strength values (8.69 ± 2.44) than those irradiated and filled with Epiphany (3.28 ± 1.58) and the nonirradiated controls (3.86 ± 0.60). The specimens filled with Epiphany did not differ significantly to each other or to the control (1.75 ± 0.69). There was a predominance of adhesive failures at Epiphany,dentine interface (77%) and mixed failures at AH Plus,dentine interface (67%). Conclusions, The 980 nm diode laser irradiation of root canal dentine increased the bond strength of AH Plus sealer, but did not affect the adhesion of Epiphany sealer. [source] The effect of pH on surface hardness and microstructure of mineral trioxide aggregateINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2008M. S. Namazikhah Abstract Aim, To evaluate the surface microhardness of mineral trioxide aggregate (MTA) specimens following exposure of their surface to a range of acidic environments during hydration. In addition, the morphological microstructure features of samples were studied by scanning electron microscopy (SEM). Methodology, White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Four groups, each of 10 specimens, were formed using a pressure of 3.22 MPa and exposed to pH 4.4, 5.4, 6.4 and 7.4, respectively, for 4 days. Vickers microhardness of the surface of each specimen was measured after exposure. Four groups of two specimens were prepared and treated in the same way prior to qualitative examination by SEM. Data were subjected to one-way anova and post hoc Tukey's test. Result, The greatest mean surface hardness values (53.19 ± 4.124) were observed following exposure to pH 7.4 with the values decreasing to 14.34 ± 6.477 following exposure to pH 4.4. The difference between these values at the 95% CI (33.39,44.30) was statistically significant (P < 0.0001). There were no distinct morphological differences between groups in terms of the internal microstructure. However, a trend was observed that the more acidic the solution, the more extensive the porosity of the specimens. Conclusion, Under the conditions of this study, surface hardness of MTA was impaired in an acidic environment. [source] Histological evaluation of MTA as a root-end filling materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2007P. F. E. Bernabé Abstract Aim, To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored. Methodology, Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using anova analysis and Tukey's test. Results, A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls. Conclusions, GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present. [source] Cytotoxicity analysis of EDTA and citric acid applied on murine resident macrophages cultureINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2007K. F. Amaral Abstract Aim, To assess the ex vivo cytotoxicity of EDTA and citric acid solutions on macrophages. Methodology, The cytotoxicity of 17% EDTA and 15% citric acid was evaluated on murine macrophage cultures using MTT-Tetrazolium method [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide]. A total of 5 × 105 cells were plated in medium culture with 17% EDTA or 15% citric acid. Fresh medium was used as a control. Toxicity values were analysed statistically by anova and Tukey's test (P < 0.05) at short (0, 6, 12, 24 h) and medium periods (1, 3, 5, 7 days), using ELISA absorbance. Results, On the short term, both EDTA (0.253 nm) and citric acid (0.260 nm) exhibited cytotoxic effects on macrophage cultures (P < 0.05). On the medium term, statistical differences were observed (P < 0.05) between the groups. EDTA (0.158 nm) and citric acid (0.219 nm) were cytotoxic when compared with the control group; EDTA-reduced macrophage viability significantly more than citric acid (P < 0.05). Conclusions, Both EDTA and citric acid had effects on macrophages cells ex vivo, but citric acid was less toxic in periods from 1 to 7 days of use. [source] Cytotoxicity of substances leached or dissolved from pulp capping materialsINTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2005B. N. Cavalcanti Abstract Aim, To evaluate the cytotoxic effects of substances leached or dissolved from pulp capping materials on human pulp fibroblasts. Methodology, The substances were applied to cell cultures in conditioned media. The experimental groups were: GI (control; n = 24) , cultures treated with fresh medium; GII (n = 24) , cultures treated with calcium hydroxide cement; GIII (n = 24) , cultures treated with adhesive resin and GIV (n = 24) , cultures treated with 37% orthophosphoric acid. The media were conditioned by placing the crude materials in contact with fresh culture medium for 1 h. The cytotoxicity analysis was performed using the Trypan blue dye exclusion assay at times of 0, 6, 12 and 24 h for cell viability assay, and at 1, 3, 5 and 7 days for survival assay. Data were treated by anova (P < 0.05) and Tukey's test (P < 0.05). Results, GI and II presented similar cell viability and cell growth. GIII and IV exhibited statistically significant lower percentages of cell viability: GIV only at the 0 h experimental time, whereas in GIII this viability markedly diminished reaching values of 10% by 12 h. Cell growth was impaired only in cultures of GIII. Conclusions, Substances dissolved from the adhesive system tested were cytotoxic for human dental pulp fibroblasts in culture, whilst substances leached from calcium hydroxide were biocompatible. [source] Effect of bleaching agents on bonding to pulp chamber dentineINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2005S. Timpawat Abstract Aim, To determine the effect of intracoronal bleaching agents on adhesion of bonding agents to pulp chamber dentine. Methodology, Forty extracted human maxillary anterior teeth were randomly divided into four groups of 10 teeth each. Bleaching agents were sealed in pulp chambers for 7 days, as in clinical use. Group 1 (control): distilled water, group 2: 35% hydrogen peroxide, group 3: sodium perborate mixed with water, and group 4: sodium perborate mixed with 35% hydrogen peroxide. Teeth were stored in saline at 37 °C for 7 days. After the bleaching agent was removed, teeth were leached in water for a further 7 days prior to bonding. The crown was cut vertically from mesial to distal and the labial pulp chamber dentine was prepared for bonding with Clearfil SE-Bond and filled with resin composite (Clearfil AP-X). The bonded specimens were kept moist at 37 °C for 24 h. Microtensile bond strengths were determined using a universal testing machine. Additional teeth were prepared using the same bleaching procedures to investigate the scanning electron microscopic appearance of the dentine surface. Results, Mean values (±SD) of microtensile bond strength for the experimental groups were: group 1: 5.29 ± 2.21 MPa, group 2: 5.99 ± 1.51 MPa, group 3: 9.17 ± 1.65 MPa and group 4: 3.99 ± 1.31 MPa. Dentine treated with sodium perborate in water (group 3) had significantly higher mean bond strength when compared with the other three groups (P < 0.05, Tukey's test). Mean bond strength was lowest when dentine was treated with sodium perborate plus hydrogen peroxide (group 4). Conclusions, In terms of subsequent bond strength during restoration, sodium perborate mixed with distilled water appears to be the best intracoronal bleaching agent. [source] Cell Proliferation of Human Fibroblasts on Alumina and Hydroxyapatite-Based Ceramics with Different Surface Treatments,INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2010Juliana Marchi Biocompatibility is an important characteristic of dental implant material, and in vitro tests are required to elucidate the interaction between these materials and human tissues. Cell proliferation assays were done with fibroblasts plated on the surface of alumina and hydroxyapatite sintered samples, each with a different surface treatment (sintered, rectified, or polished). After 1, 2, and three days, the samples were prepared for scanning electron microscopy observations. The data were compared by analysis of variance followed by Tukey's test. It was concluded that neither the hydroxyapatite or alumina substrate is cytotoxic, and hydroxyapatite is more biocompatible than alumina. [source] Development and evaluation of a laboratory scale conch for chocolate productionINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2009Andrea Bordin Schumacher Summary In this study a laboratory scale conch was developed with the purpose of testing new formulations using small amounts of chocolate mass. The equipment was built with working parts of others machines and the chocolate manufactured with the conch was evaluated in relation to the viscosity, moisture, acidity and polyphenol concentration. The resulting chocolate was tempered and then evaluated by a sensory panel. The results were always compared with an industrial conching process. The material used in the assays was dark chocolate (40% cocoa). Data were submitted to variance analysis (anova) and when there was significant difference among the averages, the Tukey's test was applied. It was verified that the reduction of moisture and viscosity of the mass in the laboratory scale was similar to industrial scale. The parameters acidity and polyphenols showed no significant alterations when comparing both process scales. However, in the sensory analysis a flavour difference between the processing scales was perceptible. [source] Adhesion of a self-etching system to dental substrate prepared by Er:YAG laser or air abrasionJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008Wanessa C. Souza-Zaroni Abstract The purpose of this study was to assess the microtensile bond strength of a self-etching adhesive system to enamel and dentin prepared by Er:YAG laser irradiation or air abrasion, as well as to evaluate the adhesive interfaces by scanning electron microscopy (SEM). For microtensile bond strength test, 80 third molars were randomly assigned to five groups: Group I, carbide bur, control (CB); II, air abrasion with standard tip (ST); III, air abrasion with supersonic tip (SP); IV, Er:YAG laser 250 mJ/4 Hz (L250); V, Er:YAG laser 300 mJ/4 Hz (L300). Each group was divided into two subgroups (n = 8) (enamel, E and dentin, D). E and D surfaces were treated with the self-etching system Adper Prompt L-Pop and composite buildups were done with Filtek Z-250. Sticks with a cross-sectional area of 0.8 mm2 (±0.2 mm2) were obtained and the bond strength tests were performed. Data were submitted to ANOVA and Tukey's test. For morphological analysis, disks of 30 third molars were restored, sectioned and prepared for SEM. Dentin presented the highest values of adhesion, differing from enamel. Laser and air-abrasion preparations were similar to enamel. Dentin air-abrasion with standard tip group showed higher bond strength results than Er:YAG-laser groups, however, air-abrasion and Er:YAG laser groups were similar to control group. SEM micrographs revealed that, for both enamel and dentin, the air-abrasion and laser preparations presented irregular adhesive interfaces, different from the ones prepared by rotary instrument. It was concluded that cavity preparations accomplished by both Er:YAG laser energies and air abrasion tips did not positively influence the adhesion to enamel and dentin. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] | ||||||||||||||||||||||