scholarly journals Influence of chemical and mechanical polishing on water sorption and solubility of denture base acrylic resins

2004 ◽  
Vol 15 (3) ◽  
pp. 225-230 ◽  
Author(s):  
Juliana Saab Rahal ◽  
Marcelo Ferraz Mesquita ◽  
Guilherme Elias Pessanha Henriques ◽  
Mauro Antonio Arruda Nóbilo

Influence of polishing methods on water sorption and solubility of denture base acrylic resins was studied. Eighty samples were divided into groups: Clássico (CL), and QC 20 (QC) - hot water bath cured; Acron MC (AC), and Onda Cryl (ON) - microwave cured; and submitted to mechanical polishing (MP) - pumice slurry, chalk powder, soft brush and felt cone in a bench vise; or chemical polishing (CP) - heated monomer fluid in a chemical polisher. The first desiccation process was followed by storage in distilled water at 37 ± 1ºC for 1 h, 1 day, 1, 2, 3 and 4 weeks. Concluding each period, water sorption was measured. After the fourth week, a second desiccation process was done to calculate solubility. Data were submitted to analysis of variance, followed by Tukey test (p<0.05). Means of water sorption (%) and solubility (%), respectively, were: CL-MP: 1.92 and 0.02; CL-CP: 1.98 and 0.52; QC-MP: 2.31 and -0.05; QC-CP: 2.32 and 0.25; AC-MP: 2.45 and -0.07; AC-CP: 2.43 and 0.41; ON-MP: 2.32 and -0.06; ON-CP: 2.34 and 0.27. Mechanical polishing promoted significantly lower solubility of acrylic resins; initially, water sorption values were higher for chemically polished samples, however, after 4 weeks all groups were similar.

2018 ◽  
Vol 26 (0) ◽  
Author(s):  
Rosana Marques Silva Figuerôa ◽  
Bruna Conterno ◽  
César Augusto Galvão Arrais ◽  
Carolina Yoshi Campos Sugio ◽  
Vanessa Migliorini Urban ◽  
...  

Author(s):  
Cindy Yurike Aprilia, Liman, Muhtarudin dan Agung Kusuma Wijaya

This research aimed to investigate the effect of various scarification treatments on the germination of tree saga seeds (Adenanthera pavonina L.). This study used a completely randomized design (CRD) with 6 treatments and 3 replications. The treatments in this study were P0 (control), P1 (soaked using distilled water for 24 hours), P2 (soaked using hot water 60 °C for 15 minutes), P3 (sanded skin), P4 (soaked using 1% H2SO4 for 30 minutes), and P5 (soaked using goat urine for 30 minutes).  The data obtained were analyzed by Analysis of Variance and continued with the Least Significant Difference Test (LSD) level of 5%. The results showed that the treatment had a very significant effect (P <0.01) on germination rate. The best treatment that can increase the germination of a tree saga seeds (Adenanthera pavonina L.) was by eroding the seed skin using sandpaper. This treatment can produce an average germination of 78.89%, while the treatment that produce the highest abnormal seeds was found in the treatment by soaking using 1% H2SO4 for 30 minutes.  The treatment that produce normal seeds, dead seeds, and the highest fungus-stricken seeds were found in the treatment by eroding the seed skin using sandpaper. The treatment that produced the highest hard seed was control.   Keywords: Germination, Saga, Scarification.


2020 ◽  
Vol 33 (3) ◽  
pp. 720-727
Author(s):  
HOHANA LISSA DE SOUSA MEDEIROS ◽  
CLARISSE PEREIRA BENEDITO ◽  
NADJAMARA BANDEIRA DE LIMA DANTAS ◽  
JORGE RICARDO SILVA DO COUTO JÚNIOR ◽  
LUIRLA BENTO RAMALHO

ABSTRACT Seeds of ‘sabiá’ (Mimosa caesalpiniifolia Benth.) have coat dormancy, which hampers the absorption of water and oxygen, thereby delaying germination. Thus, this study aimed to evaluate methods for overcoming dormancy associated with priming on germination and vigor of seeds of ‘sabiá’, considering the efficiency, practicality and cost of treatment. The experimental design was completely randomized, in a 4 x 5 factorial scheme (four methods for overcoming dormancy x five types of priming), constituting 20 treatments with four replicates of 25 seeds. The methods for overcoming dormancy used were tip removal, seed immersion in hot water at 100 °C for three minutes, immersion in sulfuric acid for 10 minutes and intact seeds. For the determination of physiological conditioning of seeds, the imbibition curve with the different priming agents was constructed. Priming was done on filter paper moistened with solutions of mannitol at the potentials of -0.2 MPa (16 hours), -0.4 MPa (24 hours) and -0.6 MPa (36 hours) and only with distilled water for the hydropriming (12 hours) and seeds without priming. The variables analyzed were first count of germination, germination, root length, shoot length and dry weight of seedlings. The data were subjected to analysis of variance by F test and Tukey test at 5% probability. The dormancy of M. caesalpiniifolia seeds should be overcome with the use of hot water (100 °C) for three minutes, without the need for priming.


2015 ◽  
Vol 26 (4) ◽  
pp. 357-362 ◽  
Author(s):  
Fernando Freitas Portella ◽  
Fabrício Mezzomo Collares ◽  
Paula Dapper Santos ◽  
Cláudia Sartori ◽  
Everton Wegner ◽  
...  

<p>The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59±0.06 and 12.54±0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.</p>


2019 ◽  
Vol 18 ◽  
pp. e191404
Author(s):  
Ísis Franco Pereira ◽  
Emilena Maria Castor Xisto Lima

Aim: To evaluate the marginal accuracy of provisional crowns made with acrylics resins and to identify the surface(s) with the highest marginal discrepancy. Methods: A direct technique was used to fabricate 96 provisional restorations with 8 materials: Dencrilay, Dencôrlay, Dencôr, Vipicor, Duralay, Resinlay Speed, Refine Bright and Alike (n=12). The provisional crowns were made on a prepared molar-shaped metal die with a vinyl polysiloxane impression as a matrix. Marginal discrepancy of provisional restorations was analyzed at buccal, lingual, mesial and distal surfaces of metal die finish line in a stereomicroscope lupe at 100X. The images obtained were transferred to the Corel Draw X7 program and the distances from the cervical margins of the specimen to the reference lines were measured vertically. Comparisons were made with 1-way analysis of variance and the Tukey test (p <0.05). Results: The Alike resin exhibited the lowest marginal discrepancy (0.018 mm) and was significantly different from the Dencôrlay (0.037 mm), Filter Bright (0.034 mm), Duralay (0.033 mm) and Vipicor (0.032) resins. The buccal surface showed the highest marginal discrepancy (0.040 mm) compared to those of other surfaces (distal 0.029mm, lingual 0.028mm and mesial 0.024mm). Conclusion: The marginal adaptation of all materials and surfaces tested in this study were within a clinical acceptable limit. The Alike resin showed the best performance compared to Dencôrlay, Refine Bright, Duralay, and Vipicor resins. The buccal surface showed the highest marginal discrepancy than those of the other tested surfaces.


2013 ◽  
Vol 39 (5) ◽  
pp. 545-549 ◽  
Author(s):  
Itamar Lopes-Júnior ◽  
Barbara de Lima Lucas ◽  
Henner Alberto Gomide ◽  
Vanderlei Luiz Gomes

Four commercial brands of chemically activated acrylic resin were compared through photoelastic analysis. Photoelastic resin blocks were made with 2 implants placed parallel to each other and 2 square transfer copings splinted. Both transfers were splinted with chemically activated acrylic resin: Dencrilay, Duralay I, Duralay II, and GC. Data were analyzed by 2-way analysis of variance and Tukey test (P &lt; .05). Statistically significant differences were found among the 3 brands of chemically activated acrylic resin. Dencrilay showed greater dimensional alteration. Duralay I and GC are recommended for the transfer of the position of the multi-implants.


2011 ◽  
Vol 22 (6) ◽  
pp. 490-496 ◽  
Author(s):  
Iara Augusta Orsi ◽  
Vanessa Gomes Andrade ◽  
Pierina Sueli Bonato ◽  
Lariça Barbosa Raimundo ◽  
Daniella Silva Herzog ◽  
...  

This study evaluated the release of glutaraldehyde from heat-polymerized acrylic resins subjected to disinfection followed by chemical and mechanical polishing. Ninety disc-shaped specimens (15 x 4 mm), 30 per resin (Lucitone 550, QC-20 and Classico), were made and assigned to 2 groups according to the type of polishing. One side of each specimen was not polished and the other was either mechanically (n=45) or chemically (n=45) polished, and immersed in water at 50°C for 1 h to allow the release of intrinsic substances and then kept in distilled water for 7 days. The specimens were disinfected by immersion in 2% glutaraldehyde for 10 min. After this period, 3 specimens from each group were immersed in water for 15, 30, 60, 120 and 240 min. For the 15-, 30-, 60-min immersions, 4 water exchanges were done at the end of period. High performance liquid chromatography (HPLC) was used to detect and quantify the glutaraldehyde released after each period. Data were analyzed statistically by two-way ANOVA and multiple comparisons were done by Tukey’s and Scheffé’s tests (α=0.05). No glutaraldehyde release was observed from the specimens with chemical polishing at any of the immersion periods, while the mechanically polished specimens released glutaraldehyde. In the groups with water exchanges, Lucitone released more disinfectant in the 15-min period (0.040 μg/mL), Classico in the 30-min (0.021 μg/mL) and 60-min (0.018 μg/mL) periods, and QC-20 the same amount (-1.760 μg/mL) in all periods. In the groups without water exchanges, Lucitone released the highest amount of disinfectant (-1.370 μg/mL), differing significantly from QC-20 (0022 g/mL) and Classico (0019 g/mL), which were similar. The findings of this showed that chemically polished specimens from the 3 resin brands did not release glutaraldehyde after different periods of immersion, while glutaraldehyde release was observed from the mechanically polished specimens, especially from those made of Lucitone resin.


2019 ◽  
Vol 44 (6) ◽  
pp. 609-614 ◽  
Author(s):  
NC Ramos ◽  
JN Luz ◽  
MC Valera ◽  
RM Melo ◽  
GSFA Saavedra ◽  
...  

SUMMARY The aim of this study was to evaluate the color stability of light-cured and dual-cured resin cements after artificial accelerated aging. Ten specimens (6-mm diameter and 2-mm thickness) for each of five resin cements were prepared: GC (dual-cured cement, GCem), Vb (light-cured cement, Variolink II only the base), Vbc (dual-cured cement, Variolink II base with catalyst), VV (light-cured cement, Variolink Veneer), and FR (flowable resin composite, light cured). The samples were polished and stored in an accelerated artificial aging machine for 308 hours (160 klx), with cycles of 120 minutes under light and 60 minutes in the dark. All aging was carried out in distilled water at 37°C and light irradiation at 765 W/m2. The samples were evaluated in a spectrophotometer before and after aging, and results were calculated according to CIEDE2000. The data were statistically analyzed (one-way analysis of variance and Tukey test, 95% confidence). The results of ΔE00 were statistically significant for the type of cement (p&lt;0.001), with differences among tested groups. Variolink II (base only and base + catalyst) and the flowable resin were the cements with the lowest color variations after the artificial accelerated aging. Considering the values ΔE00 of acceptability and perceptibility, none of the tested cements showed acceptable values.


1986 ◽  
Vol 66 (2) ◽  
pp. 377-381 ◽  
Author(s):  
P. A. SCHUPPLI

Soils were extracted by hot water, dilute CaCl2, and by mannitol-CaCl2 solutions and boron was determined by either azomethine-H or the curcumin method. Results were strongly method dependent; in particular results by the simplest method, mannitol-CaCl2, were generally lower and not highly correlated (r = 0.64) with those by the recommended procedure. This procedure involves extraction with hot distilled H2O (2:1 solution:soil), centrifugation, filtration, color development with azomethine-H and correction for background color. Extractable boron values by this procedure ranged from 0.1 to 1.4 mg kg−1. Background color can be further reduced by the substitution of 0.02 M CaCl2 for distilled water. Key words: CSSC reference soil samples, hot-water-soluble boron


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