981 resultados para Self-adhesive resin cement
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Introduction: Parkinson`s disease (PD) is a neurodegenerative disorder with prominent motor manifestations and many other non-motor symptoms that significantly decrease quality-of-life and are frequently under-recognized, for example depression. Objective: To study the validity of a Brazilian version of the Zung Self-rating Depression Scale (SDS) for the diagnosis of depression in patients with PD. Methods: We evaluated 78 consecutive non demented patients over the age of 40 with diagnosis of PD at a Movement Disorders Outpatient Clinic, who could read and understand questionnaires. They completed the SIDS and the Geriatric Depression Scale with 15 items (GDS-15). The diagnosis of depression was made after a structured clinical interview based on DSM-IV criteria for the diagnosis of major depression (SCID-CV). Results: The prevalence of major depression was 23.1%. Cronbach`s alpha was 0.73 and the area under the ROC curve was 0.93 for the SDS. The score index of 55 had a sensitivity of 88.9% and a specificity of 83.3% for the diagnosis of depression. The total scores of the SDS and GDS-15 were highly correlated (0.652, p < 0.0001) and correlated weakly with the scores of a motor scale. Discussion: The SIDS is a valid too] for screening depression in patients with PD since the specific SDS index of 55 is adopted. Two shortened versions could be used with good results. (C) 2009 Published by Elsevier Ltd.
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Aminoglycoside antibiotics cause considerable toxicity to the inner ear. A progressive hearing loss at high frequencies resulted from the loss of hair cells in the base of the cochlea and a constant preoccupation with finding a treatment that protects against their toxic effects. A self-protection phenomenon to high ototoxic doses of gentamicin is proposed in this paper. Thirty-eight adult guinea pigs with normal hearing were tested using Preyer`s reflex and the distortion product otoacoustic emission (DPOAE) test, and their cochleae were analyzed by scanning electron microscopy. To the four groups investigated, group I (control) and group II (low dose, 10 mg/kg/day for 30 days) showed a normal DPOEA and normal outer hair cells; group III (high dose, 160 mg/kg/day for 10 days) showed the absence of DPOEA and damage to the outer hair cells; and group IV (low dose, 10 mg/kg/day for 30 days followed by a high dose of 160 mg/kg/day for 10 days) showed a normal DPOEA and normal outer hair cells. These results demonstrate that there was a considerable self-protection phenomenon by gentamicin.
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Purpose: To investigate the effects of intrapulpal temperature changes induced by a quartz tungsten halogen (QTH) and a light emitting diode (LED) curing units on the metabolism of odontoblast-like cells. Methods: Thirty-six 0.5 mm-thick dentin discs obtained from sound human teeth were randomly assigned into three groups: QTH, LED and no light (control). After placement of the dentin discs in pulp chamber devices, a thermistor was attached to the pulpal surface of each disc and the light sources were applied on the occlusal surface. After registering the temperature change, odontoblast-like cells MDPC-23 were seeded on the pulpal side of the discs and the curing lights were again applied. Cell metabolism was evaluated by the MTT assay and cell morphology was assessed by SEM. Results: In groups QTH and LED the intrapulpal temperature increased by 6.4 degrees C and 3.4 degrees C, respectively. The difference between both groups was statistically significant (Mann-Whitney; P< 0.05). QTH and LED reduced the cell metabolism by 36.4% and 33.4%, respectively. Regarding the cell metabolism, no statistically significant difference was observed between both groups (Mann-Whitney; P> 0.05). However, when compared to the control, only QTH significantly reduced the cell metabolism (Mann-Whitney; P< 0.05). It was concluded that the irradiance of 0.5 mm-thick human dentin discs with a QTH in comparison to a LED curing unit promoted a higher temperature rise, which propagates through the dentin negatively affecting the metabolism of the underlying cultured pulp cells. (Am J Dent 2009;22:151-156).
Resumo:
The tissue microarray (TMA) technique allows multiple tissue samples in a single block. Commercial adhesive tape is used to avoid the loss of tissue samples during the immunostaining process. Few reports exist in the literature comparing the use of these adhesive tapes to other adhesive techniques. The objective of this study was to compare loss of sections adhered to slides using commercial adhesive tapes versus using silanized only slides. TMA was constructed with varying tissues using a fixed-base device (Beecher Instruments), placing 108 cylinders of 1 mm diameter in duplicate, spaced 1.2 mm apart. Section of 4 mu m were cut from the TMA block and adhered to 30 silanized slides and 30 commercial glass slides using adhesive tape, according to manufacturer`s recommendations. Vimentin immunoexpression was evaluated by immunohistochemistry. Antigenic recovery was realized in citrate buffer using a microwave oven. Cylinder loss in the immunohistochemical process was quantified and expressed as: total (>80%), almost complete (75-79%), or partial (50-74%). The commercial adhesive tape group presented lesser total loss (1.1 versus 6.4%), almost complete loss (2.2 versus 3.5%), and partial loss (2.1 versus 3.8%) than the silanized slide group (ANOVA, P < 0.05). The sum of total and almost complete losses in the silanized slide group was 9.9%, greater than the losses in slides using commercial adhesive tapes (3.3%) and less than reported and considered acceptable in the literature (10-30%). In conclusion, the use of silanized only slides presents very satisfactory results, requires less training, and reduces costs significantly, thus justifying their use in research.
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The objective of this study was to evaluate in vitro light activation of the nano-filled resin composite Vita shade A1 and A3 with a halogen lamp (QTH) and argon ion laser by Knoop microhardness profile. Materials and methods: Specimens of nanofilled composite resin (Z350-3 M-ESPE) Vita shade A1 and A3 were prepared with a single increment inserted in 2.0-mm-thick and 3-mm diameter disc-shaped Teflon mold. The light activation was performed with QTH for 20 s (with an intensity of approximately 1,000 mW/cm(2) and 700 mW/cm(2)) and argon ion laser for 10 s (with a power of 150 mW and 200 mW). Knoop microhardness test was performed after 24 h and 6 months. The specimens were divided into the 16 experimental groups (n = 10), according to the factors under study: photoactivation form, resin shade, and storage time. Knoop microhardness data was analyzed by a factorial ANOVA and TukeyA ` s tests at the 0.05 level of significance. Results: Argon ion laser was not able to photo-activate the darker shade of the nanofilled resin composite evaluated but when used with 200 mW it can be as effective as QTH to photo-activate the lighter shade with only 50% of the time exposure. After 6 months storage, an increase in the means of Knoop microhardness values were observed. Conclusions: Light-activation significantly influenced the Knoop microhardness values for the darker nanofilled resin composite.
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The purpose of this in vitro study was to evaluate the effect of etching time on the tensile bond strength (TBS) of a conventional adhesive bonded to dentin previously irradiated with erbium:yttrium-aluminum-garnet (Er:YAG) and erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers. Buccal and lingual surfaces of 45 third molars were flattened until the dentin was exposed and randomly assigned to three groups (n = 30) according to the dentin treatment: control (not irradiated), irradiated with Er:YAG (1 W; 250 mJ; 4 Hz; 80.6 J/cm(2)) laser or Er,Cr:YSGG (4 W; 200 mJ; 20 Hz; 71.4 J/cm(2)) laser, and into three subgroups (n = 10) according to acid etching time (15 s, 30 s or 60 s) for each experimental group. After acid etching, the adhesive was applied, followed by the construction of an inverted cone of composite resin. The samples were immersed in distilled water (37A degrees C for 24 h) and subjected to TBS test [50 kilogram-force (kgf), 0.5 mm/min]. Data were analyzed by analysis of variance (ANOVA) and Tukey statistical tests (P a parts per thousand currency signaEuro parts per thousand 0.05). Control group samples presented significant higher TBS values than those of all lased groups. Both irradiated groups exhibited similar TBS values. Samples subjected to the different etching times in each experimental group presented similar TBS. Based on the conditions of this in vitro study we concluded that Er:YAG and Er,Cr:YSGG laser irradiation of the dentin weakens the bond strength of the adhesive. Moreover, increased etching time is not able to modify the bonding strength of the adhesive to irradiated dentin.
Resumo:
Background: This study evaluated mechanical properties of glass ionomer cements (GICs) used for atraumatic restorative treatment. Wear resistance, Knoop hardness (Kh), flexural (F(s)) and compressive strength (C(s)) were evaluated. The GICs used were Riva Self Cure (RVA), Fuji IX (FIX), Hi Dense (HD), Vitro Molar (VM), Maxxion R (MXR) and Ketac Molar Easymix (KME). Methods: Wear was evaluated after 1, 4, 63 and 365 days. Two-way ANOVA and Tukey post hoc tests (P = 0.05) analysed differences in wear of the GICs and the time effect. F(s), C(s), and Kh were analysed with one-way ANOVA. Results: The type of cement (p < 0.001) and the time (p < 0.001) had a significant effect on wear. In early-term wear and Kh, KME and FIX presented the best performance. In long-term wear, F(s) and C(s), KME, FIX and HD had the best performance. Strong explanatory power between F(s) and the Kh (r(2) = 0.85), C(s) and the Kh (r(2) = 0.82), long-term wear and F(s) of 24 h (r(2) = 0.79) were observed. Conclusions: The data suggested that KME and FIX presented the best in vitro performance. HD showed good results except for early-term wear.