737 resultados para finishing
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Objective: The objective of this paper was to verify if the final irrigation at 17% EDTA, separately or followed by chlorhexidine digluconate at 2% interferes on the apical marginal leakage in root canal overfilling, due to the use of two root canal filling materials (Sealer 26TM or SealapexTM). Methods: Forty lower incisors extracted, with a single root canal, were biomechanically prepared, at 2.0mm beyond the radicular apex, with ProTaper SystemTM, finishing it with the F3 instrument. Irrigation was accomplished with 1.0 mL NaOCl at 2.5% at each change of equipment caliper and, in the end, with 5.0 mL normal saline solution. After achieving this procedure, the foraminal channels was standardized with a file K 25 until its DO appears in the foraminal opening. From this moment, the teeth were subdivided into two groups of 20 specimens each, because of the final irrigation method used: I – irrigation with EDTA at 17% for 3min and II – identical protocol, thus, after EDTA aspiration at17%, it was again irrigated with chlorhexidine digluconate at 2%, also kept intra-canal for 3min. Each group was again sub-divided into two sub-groups (ten teeth each), according to the cement used (Sealer 26TM or SealapexTM), and filled by using a single gutta-percha F1 (ProTaperTM, Universal Filling), in such a manner that it goes 2.0 mm beyond the radicular apex. Soon after that, the teeth were immersed in Rhodamine BTM for 72h, vacuum and after the roots have been bucolingually grooved, the leakages marked were measured with program Image ToolTM. Results and Conclusions: The leakage magnitude was similar among themselves (p > 0.05), except for group Sealapex®, thus the final use with chlorhexidine reduced apical leakage (p < 0.05).
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The success achieved by the use of composite resins in anterior teeth precipitately leads their use in posterior teeth. However, the indiscriminate application of these materials in cavities with several diverse sizes rapidly pointed out their lack of resistance to oclusal and proximal wear. OBJECTIVE: To evaluate the surface roughness of composite resin in relation to finishing and polishing technique. MATERIAL AND METHODS: Eight experimental groups (n = 15) were divided according to finishing and polishing technique: G1 – Z250TM composite resin without surface finishing and polishing; G2 – Z250TM composite resin plus surface finishing and polishing; G3 – P60TM composite resin without surface finishing and polishing; G4 – P60TM composite resin plus surface finishing and polishing; G5 – Prodigy CondensableTM composite resin without surface finishing and polishing; G6 – Prodigy CondensableTM composite resin plus surface finishing and polishing; G7 – SurefillTM composite resin without surface finishing and polishing; G8 – SurefillTM composite resin plus surface finishing and polishing. Three packable and one microhybrid (control group) composite resin was used. The surface roughness was measured using a profilometer at three points in each sample. The results were evaluated by ANOVA and Tukey test (p < 0.05). RESULTS: Prodigy CondensableTM composite resin showed the lowest surface roughness, while SurefillTM showed the highest surface roughness. Comparing the resins used, only between P60TM and SurefillTM there were no statistically significant differences (p > 0,05). CONCLUSION: Surface roughness was lower in all types of resin composites surfaces in contact with Mylar matrix strip than in areas submitted to finishing and polishing procedure.
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The aim of this study was evaluate the dental enamel after whitening treatment with Opalescence Boost PF® 38%, correlating the structural alterations in the surface of the enamel with its respective pH and verify if whitened teeth submitted to different finishing and polishing techniques show similar surface texture to healthy teeth (control group). Sixty premolars were divided in 6 groups (n = 10), which had been immersed in artificial saliva during all the experiment. Protocol whitening was performed according to the manufacturer recommendations, and then the specimens were submitted to different polishing technique with Sof-Lex Pop On® disks, Flex Diamond® felt disks using two different micrometric polishing pastes (Enamelize® and Diamond Polish®) and two nanometric polishing pastes (Lummina-E Diamond and Lummina-E Alumina), according to the groups. Representative specimens were analyzed in scanning electronic microscopy (SEM). Whitening gel used in this experiment had modified the morphologic aspect of the enamel surface. It was found that two nanometric polishing pastes (G5 and G6) promoted a less rough surface compared to control group even after the whitening process.
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This report shows the resolution of a case study whose aim was promote the aesthetic and functional rehabilitation of upper left hemi-arch over endosseous and needle implant prostheses. To improve the position of the needle implants, we performed the bucco-palatal bending of needles splinting them with composite resin; we removed the screwed implant prosthesis in the regions of the premolars (24 and 25) and molar (26). The mini-abutments of the last two implants were replaced, and in the first premolar and canine, we used cemented abutments due to implant angulation having planned soldering because of implant size and contact with one needle implant that could interfere with intimate contact bone/implant damaging biomechanics. Pick-up impressions were performed with an open tray, using a retractor cord in the needle implants and respective transfer copings. Therefore, models were related on semi-adjustable articulator after a face-bow recording and interocclusal indexes. After working cast fabrication and try-in of infra-structures, these were adjusted and related into the articulator again. Then, after ceramic build-up, adjustments, finishing, and torque, chemically-activated resin cement was applied on units 21 to 24. At the end of the case, we concluded that a good aesthetic and functional rehabilitation depends on thorough knowledge of techniques for each clinical situation.
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Advanced Layering composite resins can be facilitated by a technique called "Lingual Matrix", where a guide is made of elastomer by molding a previously waxed tooth or sculped in an intraoral test drive restoration. This technique has many advantages to sophisticated layering, facilitation stratification, anatomic construcrion and the stages of finishing and polishing. However, in some clinical situations, the unfolding of the steps to obtains this matrix can be time consuming or even infeasible. To facilitate the achievement of this apparatus, a technique was idealized allowing significant reducrion in clinical time. This matrix, called the "BRB Matrix" is widly discussed in a didactic and clinical manner in this article, presenting its advantages in clinical cases where it is imperative to use a guide for conduction a controlled layering. The simplicity of this approach, as well as reduced clinical time and finacial costs turn it feasible in an everyday clinical practice.
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Pós-graduação em Zootecnia - FCAV
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Pós-graduação em Ciência e Tecnologia de Materiais - FC
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Pós-graduação em Genética e Melhoramento Animal - FCAV
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Pós-graduação em Genética e Melhoramento Animal - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The objective of this study was to evaluate the fatty acid profile and qualitative characteristics of meat from feedlot young bulls fed ground soybean or ground cottonseed, with or without supplementation of vitamin E. A total of 40 Red Norte young bulls, with an initial average age of 20 months, and an initial average BW of 339 +/- 15 kg, were allotted in a completely randomized design using a 2 x 2 factorial arrangement, with two oilseeds, and daily supplementation or not of 2500 IU of vitamin E. The experimental period was for 84 days, which was preceded by an adaptation period of 28 days. The treatments were ground soybean (SB), ground soybean plus vitamin E (SBE), ground cottonseed (CS) and ground cottonseed plus vitamin E (CSE). The percentage of cottonseed and soybean in the diets (dry matter basis) was 24% and 20%, respectively. Diets were isonitrogenous (13% CP) and presented similar amount of ether extract (6.5%). The animals were slaughtered at average live weight of 464 +/- 15 kg, and samples were taken from the longissimus dorsi muscle for the measurement of fatty acid concentration and the evaluation of lipid oxidation and color of the beef. Before fatty acid extraction, muscle tissue and subcutaneous fat of the longissimus dorsi were separated to analyze fatty acid profile in both tissues. Supplementation of vitamin E did not affect fatty acid concentration, lipid oxidation and color (P > 0.05). Subcutaneous fat from animals fed CS diet had greater C12: 0, C16: 0 and C18: 0 contents (P < 0.03). In addition, CS diets reduced the C18: 1 and C18: 2 cis-9, trans-11 contents in subcutaneous fat (P < 0.05). The muscle from animals fed CS tended to higher C16: 0 and C18: 0 contents (P < 0.11), and decreased C18: 1, C18: 2 cis-9, trans-11 and C18: 3 contents (P < 0.05) compared with SB. The Delta(9)-desaturase index was greater in muscle from animals fed SB (P < 0.01). At 42 days of age, meat from cattle fed SB had a greater lipid oxidation rate (P < 0.05). Meat from animals fed SB diets had less lightness and redness indices than meat from animals fed CS diets after 14 days of age. In conclusion, the addition of ground cottonseed in the finishing diets did increase the saturated fatty acid content of the longissimus dorsi. However, animals fed cottonseed exhibited greater lightness and redness of beef. In this study, the addition of vitamin E did not affect qualitative characteristics of meat.
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The objective of this work was to evaluate the effect of immunocastration and supplementation with ractopamine in the quality of pork loin enhanced with salt and sodium tripolyphosphate. Treatments consisted of the sexual condition of the swine (females, physically castrated and immunocastrated males) and supplementation or not with ractopamine in finishing diet. The loins subjected to the enhancement with sodium tripolyphosphate and salt were evaluated as to physical-chemical, microbiological, and sensory parameters. There was no interaction between sexual condition and ractopamine on fresh pork loin characteristics. The addition of ractopamine in the diet increased the shear force in fresh loins. There was also no effect of sexual condition nor of ractopamine in purge loss and loin protein content. Loins of immunocastrated animals had less weight loss by cooking, whereas loins of animals non-supplemented with ractopamine showed higher moisture than those supplemented. Enhancement decreases the shear force of the cuts, which was lower in the immunocastrated animals without ractopamine supplementation. Immunocastration provided pork loins with high a* and L* values. Differences in the appearance and texture of pork loins, regardless of sexual condition and ractopamine, are not perceived by consumers, showing that enhancement standardizes the cuts.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In experimental conditions, cutting forces were studied during turning of green alumina billets, including their correlation with surface aspects of the workpiece. The correlation between cutting power and the removal rate are important parameters for defining the design of ceramic products, since inadequate parameters can produce excessive surface damage to the workpiece. This study examined the forces obtained during turning of alumina workpieces with 99.8% purity in their green state, by means of a three-point dynamometer, evaluating the cutting, feed and depth forces, using a cermet tool under constant machining conditions. Variables were compared with the forces, including surface finish, tool wear and temperature during machining. In the study, it was found that the depth of cut had no significant effect on the surface quality, and the cutting speed and feed influencing the finish. However, preliminary tests for selecting the cutting conditions showed that unsuitables cutting speeds and feeds generate severe damage to the workpiece surface. The best condition was 1.00 mm depth of cut, and the forces increasedfor with each pass performed, with the feed force the variable with greatest increases in relation to the cutting and depth forces, and wear of the cutting tool directly influenced the surface finish, generated by the highly abrasive nature of the alumina particles of the green compact. It is emphasized that the alumina in its green state showed high abrasive effect on the cutting tool during the turning process and the surface finishing of the green workpiece had a direct influence on the sintered workpiece.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)