RESUMO
AIMS: The protein alpha1-microglobulin (alpha1-microg) is filtered by the glomeruli and fully reabsorbed by the proximal tubules, and tubulointerstitial injury compromises its reabsorption. The aim of this study was to determine which functional, morphological and inflammatory renal disorders associated with tubulointerstitial damage interfere with urinary excretion of alpha1-microg in patients with glomerulopathies. PATIENTS AND METHODS: 38 patients (33.6 +/- 11.3 years) with primary or secondary glomerulopathies diagnosed by renal biopsies were studied. The urinary fractional excretion of alpha1-microg (FEalpha1-microg), the urinary monocyte chemoattractant protein-1/urinary creatinine (UMCP-1) index and 24-h proteinuria were determined. In the cortex of renal biopsies, the number of macrophages/104 microm2 of glomerular tuft (GT) and tubulointerstitial (TI) areas, the relative interstitial area (RCIA), and the relative interstitial fibrosis area (CIF) were measured. Results are reported as median and range and the Spearman non-parametric test was used to determine the correlations. RESULTS: FEalpha1-microg was 0.165% (0.008% - 14,790.0%) in patients with glomerulopathies and 0.065% (0.010% - 0.150%) in the control group (p < 0.05; Mann-Whitney U-Test). FEalpha1-microg was correlated with creatinine clearance (r = -0.4396; p = 0.0358), UMCP-1 index (r = 0.5978; p < 0.0001), number of macrophages/TI area (r = 0.5634; p = 0.0034) and RCIA (r = 0.7436; p < 0.0001). However, FEa1-microg was not correlated with proteinuria (r = 0.1465; p = 0.5153) or with CIF (r = 0.0039; p = 0.98). CONCLUSIONS: renal MCP-1 and the expansion and number of macrophages of the tubulointerstitial area participate in the increase of urinary excretion of alpha1-microg in patients with glomerulopathies. Although proteinuria and interstitial fibrosis have not been associated with this effect, the present study does not exclude some of these disorders in the pathophysiology of urinary excretion of alpha1-microg.
Assuntos
alfa-Globulinas/urina , Glomerulonefrite/urina , Túbulos Renais Proximais/metabolismo , Proteinúria/urina , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Biópsia , Quimiocina CCL2/urina , Creatinina/metabolismo , Progressão da Doença , Feminino , Glomerulonefrite/complicações , Glomerulonefrite/fisiopatologia , Humanos , Imuno-Histoquímica , Túbulos Renais Proximais/patologia , Masculino , Nefelometria e Turbidimetria , Prognóstico , Proteinúria/etiologia , Proteinúria/fisiopatologiaRESUMO
This study evaluated the surface roughness pattern of resin-based restorative materials during brushing preceded by a regimen that simulated a dynamic pH-cycling. Restoratives included two resin composites (Renamel Microfill and Charisma), two polyacid-modified composite resins (Compoglass-F and Dyract AP) and one resin-modified glass ionomer cement (Fuji II LC Improved). Twenty standardized cylindrical specimens of each material were prepared according to a randomized complete block design. After finishing and polishing, the average surface roughness (Ra) and profile-length ratio (LR) of the specimens were determined. The experimental units were subjected to a pH-cycling regimen, and then to 10,000 brushing strokes. New readings of both the Ra and LR parameters were obtained. The same protocol of pH-cycling, brushing simulation and surface roughness measurements were repeated 10 times. Data was analyzed using ANOVA according to split-plot design and Tukey's test. Results showed the pH-cycling followed by 10,000 brushing strokes provided a remarkable increase in Ra for all restorative materials except for Renamel. Throughout the brushing simulation, Renamel, Charisma, Compoglass-F and Dyract AP showed steady textures, whereas Fuji II LC Improved exhibited a progressive increase in surface roughness. Among the materials tested, Renamel presented the smoothest surface, followed by Charisma and Compoglass-F, which did not differ from each other except at the baseline. Dyract AP was different from both these materials except at the baseline. Fuji II LC Improved had the roughest surface texture.
Assuntos
Compômeros , Resinas Compostas , Análise de Variância , Resinas Compostas/química , Cimentos de Ionômeros de Vidro/química , Concentração de Íons de Hidrogênio , Teste de Materiais , Metacrilatos/química , Tamanho da Partícula , Ácidos Polimetacrílicos/química , Resinas Sintéticas/química , Silicatos/química , Estatísticas não Paramétricas , Propriedades de Superfície , Escovação DentáriaRESUMO
PURPOSE: To evaluate the microhardness of enamel treated with two different 10% carbamide peroxide bleaching materials at different time intervals. MATERIALS AND METHODS: Two bleaching agents were analyzed: Opalescence (OPA) and Rembrandt (REM). The control group (CON) consisted of dental fragments maintained in artificial saliva. Bleaching was accomplished for 8 hrs per day and stored during the remaining time in an individual recipient with artificial saliva. Enamel microhardness testing was performed before the initial exposure to the treatments and after 1, 7, 14, 21, 28, 35 and 42 days. RESULTS: The ANOVA, followed by the Bartlet and Tukey tests, showed significant differences for treatments (P < 0.00001) from day 7-day 42. From the 7th to the 14th day, OPA presented an increase of enamel microhardness over time while REM presented a decrease of microhardness. Statistical differences were not found between REM and the control group (OPA > CON = REM). From the 21st-35th day, enamel fragments bleached with OPA and REM presented a decrease of microhardness. Statistical differences of microhardness were verified among all the treatments (OPA > CON > REM). On the day 42, statistical differences were not found between OPA and the control group, but they were found between REM and the control group (OPA = CON > REM). The polynomial regression showed an increase of microhardness for OPA until the 21st day, followed by a decrease of microhardness up to the 42nd day. A decrease of microhardness for REM was verified. There were alterations in enamel microhardness as a function of bleaching time when using the two different 10% carbamide peroxide whiteners. Over a 42-day treatment time, bleaching with REM agent caused a decrease in enamel microhardness. The OPA agent initially increased the microhardness, then returned to the control level. Different bleaching materials with the same concentration of carbamide peroxide have different effects on the enamel.
Assuntos
Esmalte Dentário/efeitos dos fármacos , Peróxidos/efeitos adversos , Clareamento Dental/efeitos adversos , Ureia/efeitos adversos , Análise de Variância , Peróxido de Carbamida , Solubilidade do Esmalte Dentário/efeitos dos fármacos , Combinação de Medicamentos , Dureza/efeitos dos fármacos , Humanos , Distribuição Aleatória , Estatísticas não Paramétricas , Ureia/análogos & derivadosRESUMO
This study visually compared the radiopacity of seven restorative materials (3 resin-modified glass-ionomer cements, 3 polyacid-modified composite resins, and 1 conventional glass-ionomer cement) to a sound tooth structure sample, and an aluminium stepwedge. All hybrid materials were more radiopaque, except for one resin-modified glass-ionomer cement, than both the tooth structure and conventional glass-ionomer cement.
Assuntos
Compômeros , Meios de Contraste , Cimentos de Ionômeros de Vidro , Radiografia Dentária , Resinas Acrílicas , Alumínio , Compômeros/química , Resinas Compostas , Restauração Dentária Permanente , Cimentos de Ionômeros de Vidro/química , Humanos , Maleatos , Metacrilatos , Imagens de Fantasmas , Distribuição Aleatória , Resinas Sintéticas , Silicatos , Estatísticas não ParamétricasRESUMO
The purpose of this study was to evaluate the microleakage of six glass-ionomer composite resin hybrid materials compared with a glass-ionomer cement and a composite resin. Standardized class 5 dentin cavities were prepared on root surfaces of 240 extracted human teeth that were randomly assigned to eight groups and restored using the following restorative systems: (I) Vitremer, (II) Compoglass, (III) Photac-Fil Aplicap, (IV) Variglass, (V) Dyract, (VI) Fuji II LC, (VII) Ketac-Fil Aplicap, and (VIII) Z100. The teeth were thermocycled, placed in a 2% methylene blue solution, and sectioned with diamond disks. Dye penetration was scored on a scale of 0-3. Results showed no significant differences among groups VIII, IV, I, V, VI, III, and II. There were also no significant differences among groups VI, III, II, and VII.
Assuntos
Compômeros , Resinas Compostas , Infiltração Dentária , Cimentos de Ionômeros de Vidro , Cimentos de Resina , Resinas Acrílicas , Corantes , Resinas Compostas/química , Infiltração Dentária/diagnóstico , Adesivos Dentinários , Cimentos de Ionômeros de Vidro/química , Humanos , Maleatos , Metacrilatos , Azul de Metileno , Distribuição Aleatória , Cimentos de Resina/química , Resinas Sintéticas , Silicatos , Dióxido de Silício , Estatísticas não Paramétricas , ZircônioRESUMO
OBJECTIVE: This study was intended to quantify the marginal leakage of three glass-ionomer-resin composite hybrid materials and compare it with the leakage exhibited by a glass-ionomer cement and a bonded resin composite system. METHOD AND MATERIALS: Standardized Class V cavities were prepared on root surfaces of 105 extracted human teeth, randomly assigned to five groups of 21 each, and restored with either Ketac-Fil Aplicap, Z100/Scotchbond Multi-Purpose Plus, Vitremer, Photac-Fil Aplicap, or Dyract. The teeth were thermally stressed for 500 cycles and stained with methylene blue. The microleakage was quantified spectrophotometrically, and the data were statistically analyzed with Friedman's test. RESULTS: There were no significant differences in microleakage among the five groups. Restorations of all tested materials showed some marginal leakage in Class V cavities. CONCLUSION: The microleakage performance of glass-ionomer-resin composite hybrid materials was similar to those of a conventional glass-ionomer and a bonded resin composite system.
Assuntos
Compômeros , Resinas Compostas , Infiltração Dentária , Restauração Dentária Permanente/métodos , Cimentos de Ionômeros de Vidro , Cimentos de Resina , Distribuição de Qui-Quadrado , Infiltração Dentária/diagnóstico , Adesivos Dentinários , Estudos de Avaliação como Assunto , Humanos , Modelos Lineares , Maleatos , Metacrilatos , Resinas Sintéticas , Silicatos , Dióxido de Silício , Espectrofotometria , Estatísticas não Paramétricas , ZircônioRESUMO
OBJECTIVE: The purpose of this study was to evaluate the effectiveness of various surface treatments for resin-modified glass-ionomer restorative materials by determining dye uptake spectrophotometrically. METHOD AND MATERIALS: Two hundred twenty-four specimens, 4.1 mm in diameter and 2.0 mm thick, were made of 3 materials: Vitremer, Fuji II LC, and Photac-Fil Aplicap. Specimens were divided into 15 groups. The positive and negative control specimens remained unprotected, while the experimental specimens were protected with Heliobond light-activated bonding resin, Colorama nail varnish, or surface coatings indicated by the manufacturers of the glass-ionomer materials: Finishing Gloss for Vitremer, Fuji Varnish for Fuji II LC, and Ketac Glaze for Photac-Fil. The disks were immersed in 0.05% methylene blue for 24 hours except for the negative control group, which was immersed in deionized water. After 24 hours, the disks were removed, washed, and individually placed in 1 mL of 65% nitric acid for 24 hours. The solutions were centrifuged and the spectrophotometric absorbance was determined at 606 nm. The dye uptake was expressed in micrograms of dye per milliliter, and the results were analyzed with the Kruskal-Wallis test. RESULTS: There were no differences in dye uptake among the 3 resin-modified glass-ionomer restorative materials; however, all of them required surface protection. CONCLUSION: The best surface protection for the 3 evaluated materials was obtained with Heliobond light-activated bonding resin.
Assuntos
Restauração Dentária Permanente/métodos , Cimentos de Ionômeros de Vidro/química , Corantes , Resinas Compostas , Infiltração Dentária/prevenção & controle , Adaptação Marginal Dentária , Laca , Modelos Lineares , Resinas Sintéticas , Estatísticas não Paramétricas , Propriedades de SuperfícieRESUMO
The purpose of this in vitro study was to evaluate the dye penetration around amalgam restorations in dentin cavities by a quantitative test. Standardized circular cavities were prepared on the facial surface of 75 extracted human single-rooted teeth, and restored with dental amalgam. Different bonding/sealing treatments were used on the cavity walls before the restorations were placed. The specimens were thermo-cycled between 5 +/- 2 degrees C and 55 +/- 2 degrees C for 500 cycles with 1-minute dwell times, followed by immersion in a 2% methylene blue solution for 12 hours at 37 degrees C. The quantitative microleakage was evaluated by spectrophotometry and was expressed by microgram dye per tooth structure. The results showed that the use of bonded amalgam restorations was more effective in reducing microleakage.