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1.
Braz. j. oral sci ; 20: e214073, jan.-dez. 2021. ilus
Artigo em Inglês | BBO, LILACS | ID: biblio-1282556

RESUMO

Aim: this study aimed to compare the sealing ability of two types of commercially available calcium silicate bioceramic based root canal sealers and a resin based root canal sealer. Methods: Twenty one single-rooted teeth were used, samples (n= 21) were randomly divided into three groups according to the sealer used (group A; ADSEAL, group B; Wellroot, group C; Ceraseal). Roots were then cleaved longitudinally in the labiolingual direction; all samples were then sectioned at three, six, and nine mm from the root tip. The penetration of sealers into the dentinal tubules was examined at 1000x with a scanning electron microscope. Data were tested for normality using Shapiro Wilk test. ANOVA test was used for analyzing normally distributed data followed by Bonferroni post hoc test for pair-wise comparison. Significance level p≤0.001. Results: groups B and C showed better sealing ability than group A in all the three sections. The coronal section showed higher sealing ability than the middle section followed by the apical section in the three tested groups. Conclusion: it can be concluded that both calcium silicate-based sealers had better sealing ability and higher bond strength than the resin epoxy- based sealer


Assuntos
Materiais Restauradores do Canal Radicular , Silicatos , Compostos de Cálcio , Resinas Epóxi , Tomografia com Microscopia Eletrônica
2.
Braz. j. oral sci ; 19: e206155, jan.-dez. 2020. ilus
Artigo em Inglês | BBO, LILACS | ID: biblio-1116428

RESUMO

Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey's post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values


Assuntos
Propriedades de Superfície , Cerâmica , Resinas Compostas , Resistência ao Cisalhamento , Tomografia com Microscopia Eletrônica
3.
Braz. dent. sci ; 22(3): 305-312, 2019. tab, ilus
Artigo em Inglês | LILACS, BBO | ID: biblio-1008364

RESUMO

Objective: The aim of the study was to evaluate the influence of different surface post-etching treatments in flexural strength, contact angle and surface roughness of a lithium disilicate ceramic. Material and Methods: 60 bars (16 x 2 x 4 mm) were divided in six groups (n=10): C, no treatment; HF, hydrofluoric acid for 20 s (HF) + washing (60 s), drying (30s); HFL, HF + washing (60 s), drying (30 s) and luting; HFNL, HF + washing (60 s) + neutralization with sodium bicarbonate (SB) for 40 s + washing (5s), drying (30 s) and luting; HFUL, HF + washing (60 s) + ultrasonic bath (UB) for 4 min, drying (30 s) and luting; HFNUL, HF + washing (60 s) + SB (40 s) + UB (4 min) and luting. The bars were submitted to three-points flexural strength test. 25 ceramic blocks (12 x 7 x 7 mm) were divided into five groups (n=5) to evaluate roughness and contact angle C - no treatment; HF - HF ; HFU - HF and UB for 5 min ; HFN - HF and SB; HFNU - HF, UB and SB. A scanning electron microscope (SEM) showed the surface of the samples. ANOVA one-way statistical analysis was done for comparison of results. Results: There was no statistical difference for flexural strength (p-value = 0.15) and for surface roughness (p-valor = 0.15). However, it was obtained statistically significant difference for contact angle (p-valor = 0.00). SEM images showed precipitates after the acid etching, which were removed by post-etching treatments. Conclusion: It can be concluded that the different post-etching surface treatments did not increase the flexural strength, surface roughness, but it influenced the ceramic wetting and SEM images (AU)


Objetivo: O objetivo do estudo foi avaliar a influência de diferentes tratamentos pós-condicionamento na resistência à flexão, ângulo de contato e rugosidade superficial de uma cerâmica de dissilicato de lítio. Material e Métodos: 60 barras (16 x 2 x 4 mm) foram divididas em seis grupos (n = 10): C, sem tratamento; HF, ácido fluorídrico durante 20 s (HF) + lavagem (60 s), secagem (30 s); HFL, lavagem com HF + (60 s), secagem (30 s) e cimentação; HFNL, HF + lavagem (60 s) + neutralização com bicarbonato de sódio (SB) por 40 s + lavagem (5s), secagem (30 s) e cimentação; HFUL, HF + lavagem (60 s) + banho ultrassônico (UB) por 4 min, secagem (30 s) e cimentação; HFNUL, HF + lavagem (60 s) + SB (40 s) + UB (4 min) e cimentação. As barras foram submetidas ao teste de resistência à flexão de três pontos. 25 blocos cerâmicos (12 x 7 x 7 mm) foram divididos em cinco grupos (n = 5) para avaliação da rugosidade superficial e ângulo de contato C - sem tratamento; HF - HF; HFU - HF e UB por 5 min; HFN - HF e SB; HFNU - HF, UB e SB. Um microscópio eletrônico de varredura (MEV) foi utilizado para análise da superfície das amostras. A análise estatística unidirecional ANOVA-um fator foi realizada para comparação dos resultados. Resultados: Não houve diferença estatística para a resistência à flexão (p-valor = 0,15) e para a rugosidade superficial (p-valor = 0,15). No entanto, obteve-se diferença estatisticamente significante para o ângulo de contato (p-valor = 0,00). Imagens de microscopia eletrônica de varredura mostraram a formação de precipitados após o ataque ácido, que foram removidos pelos tratamentos pós-condicionamento. Conclusão: Pode-se concluir que os diferentes tratamentos de superfície pós-condicionamento não aumentaram a resistência à flexão, rugosidade da superfície, mas influenciaram na molhabilidade da cerâmica e nas imagens em MEV.(AU)


Assuntos
Tomografia com Microscopia Eletrônica , Resistência à Flexão , Ácido Fluorídrico
4.
Rev. odontopediatr. latinoam ; 8(1): 49-65, 2018. ilus, tab, graf
Artigo em Espanhol | COLNAL, LILACS | ID: biblio-1005870

RESUMO

Objetivo: Evaluar el efecto de diferentes marcas de selladores de fosas y fisuras hidrófobos e hidrófilos en Microscopio electrónico de barrido de emisión de campo (MEB-EC) expuestos a humedad relativa. Materiales y Métodos: Se utilizaron 40 premolares extraídos con fines ortodóncicos, se dividieron al azar en 8 grupos: Grupo 1: sellador Clinpro® (ambiente seco), Grupo 2: sellador Clinpro® (ambiente húmedo), Grupo 3: sellador Embrace WetBond® (ambiente seco), Grupo 4: sellador Embrace Wet-Bond® (ambiente húmedo), Grupo 5: sellador UltraSeal XT Hydro® (ambiente seco), Grupo 6: sellador UltraSeal XT Hydro® (ambiente húmedo), Grupo 7: sellador UltraSeal XT Plus® (ambiente seco) y el Grupo 8 sellador UltraSeal XT Plus® (ambiente húmedo). Resultados: El Grupo 1 (Clinpro®/ambiente seco) Mostró valores de adhesión al esmalte superiores, de forma estadísticamente significativa, en relación a los demás grupos y mejor calidad en la formación de "tags" en comparación con los otros grupos, independientemente si el ambiente era seco o húmedo. Conclusiones: Los selladores Clinpro 3M®, utilizados en condiciones secas o de relativa humedad demostró tener buenos resultados. La resina fluida UltraSeal XT Plus® utilizada en condiciones húmedas no proporcionó buenos resultados observándose poca formación de tags; los selladores hidrófilos (Embrace Wetbond ® y UltraSeal XT Hydro®) utilizados en un ambiente húmedo tenían una capacidad de adaptación, observándose buena formación de tags; Los selladores hidrófilos usados en ambientes secos no se adaptan a la superficie y tienen una tendencia a fallar en lo que respecta a la adhesión.


Objetivo: Avaliar o efeito de diferentes marcas de selantes hidrofóbicos e hidrofílicos em microscopia eletrônica de varredura expostos à umidade relativa. Materiais e Métodos: 40 prémolares extraídos para fins ortodônticos foram divididos aleatoriamente em 8 grupos: Grupo 1: Selante Clinpro® (ambiente seco), Grupo 2: Selante Clinpro® (ambiente úmido), Grupo 3: Selante WetBond® de Embrace (ambiente seco) Grupo 4: Selante Embrace WetBond ® (ambiente úmido), Grupo 5: Selante Ultra-Seal XT Hydro® (ambiente seco), Grupo 6: Selante UltraSeal XT Hydro® (ambiente úmido), Grupo 7: selante UltraSeal XT Plus (ambiente seco) ) e selante UltraSeal XT Plus® do Grupo 8 (ambiente úmido). Resultados: O Grupo 1 (Clinpro® / ambiente seco) mostrou valores mais elevados de adesão ao esmalte estatisticamente significativo, em relação aos demais grupos. Também apresentou melhor qualidade na formação de "tags" em comparação com os outros grupos, independentemente se o meio estava seco ou úmido. Conclusões: O selante Clinpro 3M®, utilizado em condições secas ou de umidade relativa, demonstraram bons resultados. A resina fluida UltraSeal XT Plus®, utilizada em condições úmidas, não proporcionou bons resultados com pouca formação de tags. Os selantes hidrofílicos (Embrace Wetbond® e UltraSeal XT Hydro®), utilizados em um ambiente úmido, tiveram capacidade de adaptação, observando boa formação de tags; Os selantes hidrófilos, utilizados em ambientes secos, não se adaptam à superfície e tendem a falhar em relação à adesão.


Objective: Evaluates the effectiveness of different brands of hydrophobic and hydrophilic pit and fissure sealants in scanning electron microscopy (SEM) exposed to relative humidity. Materials and Methods: 40 premolars extracted for orthodontic purposes were randomly divided into 8 groups: Group 1: Clinpro® sealant (dry environment), Group 2: Clinpro® sealant (wet environment), Group 3: Embrace WetBond® sealant (dry environment), Group 4: Embrace WetBond® sealant (wet environment), Group 5: UltraSeal XT Hydro® sealant (dry environment), Group 6: UltraSeal XT Hydro® (wet environment) sealant, Group 7: UltraSeal XT Plus sealant® (dry environment) and Group 8 UltraSeal XT Plus® sealant (wet environment). Results: Group 1 (Clinpro® / dry environment) showed higher values of adhesion to the enamel statistically significant, in relation to the other groups. It also showed better quality in the formation of "tags" in comparison with the other groups, independently if the atmosphere was dry or damp. Conclusions: Clinpro 3M® sealants, used in dry or relative humid conditions, proved to have good results. The UltraSeal XT Plus® fluid resin used in wet conditions did not provide good results with little tag formation; the hydrophilic sealants (Embrace Wetbond® and UltraSeal XT Hydro®) used in a humid environment had a capacity of adaptation, observing good formation of tags; Hydrophilic sealants used in dry environments do not adapt to the surface and have a tendency to fail with regard to adhesion.


Assuntos
Humanos , Selantes de Fossas e Fissuras , Dente Pré-Molar , Tomografia com Microscopia Eletrônica
5.
Journal of Periodontal & Implant Science ; : 219-230, 2017.
Artigo em Inglês | WPRIM | ID: wpr-31824

RESUMO

PURPOSE: The purpose of this study was to compare the characteristics of single- and dual-species in vitro oral biofilms made by static and dynamic methods. METHODS: Hydroxyapatite (HA) disks, 12.7 mm in diameter and 3 mm thick, were coated with processed saliva for 4 hours. The disks were divided into a static method group and a dynamic method group. The disks treated with a static method were cultured in 12-well plates, and the disks in the dynamic method group were cultured in a Center for Disease Control and Prevention (CDC) biofilm reactor for 72 hours. In the single- and dual-species biofilms, Fusobacterium nucleatum and Porphyromonas gingivalis were used, and the amount of adhering bacteria, proportions of species, and bacterial reduction of chlorhexidine were examined. Bacterial adhesion was examined with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). RESULTS: Compared with the biofilms made using the static method, the biofilms made using the dynamic method had significantly lower amounts of adhering and looser bacterial accumulation in SEM and CLSM images. The proportion of P. gingivalis was higher in the dynamic method group than in the static method group; however, the difference was not statistically significant. Furthermore, the biofilm thickness and bacterial reduction by chlorhexidine showed no significant differences between the 2 methods. CONCLUSIONS: When used to reproduce periodontal biofilms composed of F. nucleatum and P. gingivalis, the dynamic method (CDC biofilm reactor) formed looser biofilms containing fewer bacteria than the well plate. However, this difference did not influence the thickness of the biofilms or the activity of chlorhexidine. Therefore, both methods are useful for mimicking periodontitis-associated oral biofilms.


Assuntos
Bactérias , Aderência Bacteriana , Biofilmes , Clorexidina , Durapatita , Tomografia com Microscopia Eletrônica , Fusobacterium nucleatum , Técnicas In Vitro , Métodos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Periodontite , Porphyromonas gingivalis , Saliva
6.
Journal of Lasers in Medical Sciences. 2016; 7 (1): 37-39
em Inglês | IMEMR | ID: emr-178968

RESUMO

Introduction: This study aimed to assess the Scanning Electron Microscope [SEM] analysis of tooth surface irradiated by erbium:yttrium-aluminum-garnet [EnYAG] laser with various parameters


Methods: Number of 25 extracted human third molars free of caries were used in this study.


The teeth were put into 5 groups for laser irradiation as follows: group 1 [power: 0.5 W, Energy: 50 mj]; group 2 [power: 1 W, Energy: 100 mj]; group 3 [power: 1.5 W, Energy: 150 mj]; group 4 [power: 2 W, Energy: 200 mj]; group 5 [power: 2.5 W, Energy: 250 mj]. All samples were prepared by repetition rate of 10 Hz and duration of 230 us, using a non-contact handpiece at a distance of 4 mm. Then, the samples were prepared for SEM examination


Results: SEM evaluation of every 25 samples, treated by EnYAG, showed that all groups had exposed dentinal tubules without any melted area or cracks


Conclusion: In this study we used SEM to investigate ablated dentine with different parameters of EnYAG laser energy. Our findings support these conclusions. All powers of laser below 3 W are proper for ablation, and make no cracks


Assuntos
Humanos , Tomografia com Microscopia Eletrônica , Dente , Dentina
7.
Artigo em Inglês | IMSEAR | ID: sea-156557

RESUMO

Context: Remineralization is defined as the process whereby calcium and phosphate ions are supplied from a source external to tooth to promote ion deposition into crystal voids in demineralized enamel to produce net mineral gain. The remineralization produced by saliva is less and also a slow process, therefore remineralizing agents are required. Aims: The study was planned to evaluate the effectiveness of homeopathic Calcarea Fluorica (calc‑f) tablets as remineralizing agents on artificial carious lesions using scanning electron microscope (SEM) and surface microhardness (SMH) testing. Subjects and Methods: A total of 24 patients needing removable orthodontic treatment were included in the study. They were divided into two groups of 12 patients each. The Group I consisted of patients in whom no tablets were given while Group II consisted of patients in whom calc‑f tablets were given in a dosage of 4 tablets twice a day. Four enamel samples with the artificial carious lesions were then embedded in the removable appliance for a period of 6 weeks. After 6 weeks, the enamel samples were retrieved and evaluated by SEM and SMH. Statistical Analysis Used: One‑sample Kolmogorov–Smirnov test and Student’s t‑test were applied to analyze the difference in the Vickers microhardness number (VHN) values of remineralized enamel obtained from control and experimental group. Results: The signs of remineralization such as reduction in depth prismatic holes or decrease in porosity, variable sized uneven distribution of deposits and amorphous deposits were seen in enamel samples of both the groups. The mean SMH of remineralized enamel sample of Group I and Group II were 270.48 and 302.06, respectively, and the difference was statistically significant. Conclusions: (1) Remineralization occurred in both the groups as indicated by SEM and the increase in surface hardness values in both the groups. (2) Remineralization of enamel samples in the control group as indicated by SEM and also by increase in VHN values indicated that the saliva has a tendency of remineralizing the early carious lesions. Conclusions drawn from the study are that the calc‑f tablets can be used as safe and cost effective remineralizing agent.


Assuntos
Cárie Dentária/tratamento farmacológico , Cárie Dentária/terapia , Esmalte Dentário/terapia , Tomografia com Microscopia Eletrônica , Fluoretos/uso terapêutico , Plantas Medicinais/uso terapêutico , Remineralização Dentária/métodos
8.
Protein & Cell ; (12): 521-525, 2012.
Artigo em Inglês | WPRIM | ID: wpr-757243

RESUMO

Insulin granule trafficking is a key step in the secretion of glucose-stimulated insulin from pancreatic β-cells. The main feature of type 2 diabetes (T2D) is the failure of pancreatic β-cells to secrete sufficient amounts of insulin to maintain normal blood glucose levels. In this work, we developed and applied tomography based on scanning transmission electron microscopy (STEM) to image intact insulin granules in the β-cells of mouse pancreatic islets. Using three-dimensional (3D) reconstruction, we found decreases in both the number and the grey level of insulin granules in db/db mouse pancreatic β-cells. Moreover, insulin granules were closer to the plasma membrane in diabetic β-cells than in control cells. Thus, 3D ultra-structural tomography may provide new insights into the pathology of insulin secretion in T2D.


Assuntos
Animais , Masculino , Camundongos , Diabetes Mellitus Tipo 2 , Patologia , Tomografia com Microscopia Eletrônica , Insulina , Metabolismo , Células Secretoras de Insulina , Metabolismo , Patologia , Camundongos Endogâmicos C57BL , Camundongos Obesos , Vesículas Secretórias , Metabolismo , Patologia
9.
Journal of Dental Medicine-Tehran University of Medical Sciences. 2011; 24 (3): 139-147
em Persa | IMEMR | ID: emr-122986

RESUMO

Marginal seal in class V cavities and determining the best restorative material to decrease microleakage is of great importance in operative dentistry. The aim of this study was to evaluate the effect of polishing time on the microleakage of three types of tooth-colored restorative materials in class V cavity preparations and to assess the marginal integrity of these materials using scanning electron microscope [SEM]. In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 30 bovine incisors [60 cavities]. The specimens were divided into three groups each containing 10 teeth [20 cavities]: group 1, Filtek Z 350 [nanocomposite]; group 2, Fjui IX/G Coat Plus [CGIC]; and group 3, Fuji II LC [RMGI]. In each group, half of the specimens [n=20] were finished/polished immediately and the rest of them were finished/polished after 24 hours. All the specimens were thermocycled for 2000 cycles [5-50 [degree sign] C]. epoxy resin replicas of 12 specimens [2 restorations in each subgroup] were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at room temperature, sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between incisal and cervical microleakage was made with Wilcoxon test. Incisal and cervical microleakage were not affected by polishing time in none of the three restorative materials [P>0.05]. Cervical microleakage only in Fuji IX with immediate polishing was significantly higher than incisal microleakage [P<0.05]. Incisal and cervical microleakage with immediate or delayed polishing were not significantly different in Fuji IX, Fuji II LC, and Z350 [P>0.05]. Immediate polishing is recommended in tooth-colored class V restorations


Assuntos
Animais , Tomografia com Microscopia Eletrônica , Polimento Dentário , Infiltração Dentária
10.
Neurosciences. 2009; 14 (4): 338-342
em Inglês | IMEMR | ID: emr-136913

RESUMO

To investigate the effects of oral cinnamon supplementation on the nervus ischiadicus at the electron microscopical level in rats. This study was performed between 2004-2006 in Dicle University School of Medicine, Diyarbakir, Turkey in 15 adult Sprague-Dawley rats. Rats were divided into 3 groups: control [C] [n=5], diabetic without cinnamon [D] [n=5], and diabetic with cinnamon [D-C] [n=5]. Diabetes was induced with intraperitoneal alloxan administration. All diabetic rats were treated with human insulin. All rats were fed with standard pellet chow. The D-C group rats were fed with standard pellet chow plus Cinnamomum cassia at the dose of 400 mg/kg. All rats were sacrificed after 3 months and we obtained the nervus ischiadicus of all rats. Contrast stained thin sections evaluated by Jeol-TEM-1010 electron microscope, were not statistically different in both groups and photo samples were obtained. Mean blood glucose, hemoglobin A1C, and lipid profile were not statistically different in both groups. Marked detachment of myelin lamellae at Schmidt-Lanterman clefts, lysis in cristae mitochondrialis and degenerative changes, severe dispersion of organelles in neurolemma, mesoaxon region, and remarkable edema at the endoneurium were found in diabetic rats. On the contrary, mesoaxon, nucleus, nucleolus and myelin sheet were almost of normal appearance at the ultra-structural level in the D-C group. Cinnamon extracts may have beneficial effects on the development of diabetic neuropathy in alloxan induced diabetic rats


Assuntos
Feminino , Animais de Laboratório , Cinnamomum zeylanicum , Nervo Isquiático/ultraestrutura , Diabetes Mellitus Experimental , Tomografia com Microscopia Eletrônica , Fitoterapia , Plantas Medicinais
11.
Iranian Journal of Environmental Health Science and Engineering. 2009; 6 (4): 253-260
em Inglês | IMEMR | ID: emr-93648

RESUMO

Tellurium compounds can be found in high concentrations in land and water near sites of waste discharge of industrial manufacturing processes and anodic sludge of copper mine. Potassium tellurite [K2TeO3] is toxic to many microorganisms at concentrations >1mg/mL. In this research, some species of facultative anaerobic bacteria [Bacillus sp.] were isolated from Sarcheshme copper mine[Kerman, Iran] which demonstrated high-level-resistance to tellurite and accumulation of metallic tellurium crystals. High-level-resistance was observed for Bacilli and cocci grown with certain organic carbon sources, implying that tellurite reduction is not essential to confer tellurite resistance. Level of adsorption was determined by inductively coupled plasma and spectrophotometer [Diethyldithiocarbamate method]. The level of tellurite concentration in the bacteria cell and the formation of tellurium nanocrystals were illuminated by transmission electron microscope and scanning electron microscope. The Te[0] crystals occur internally and each microorganism forms a distinctly different structure [for example Bacillus selenitreducens make tellurium nano rod]. In this study it was found that microorganism can grow 3.in 1500mg/L-2000mg/L and higher tellurite concentrations. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. This study is important because native bacteria from Sarcheshme [Kerman, Iran] that may show high-level-resistance to tellurite, were isolated


Assuntos
Mineração , Bactérias Anaeróbias/isolamento & purificação , Microscopia Eletrônica de Varredura , Nanotubos , Tomografia com Microscopia Eletrônica , Bactérias Aeróbias/crescimento & desenvolvimento , Nanoestruturas , Cobre
12.
Journal of Mashhad Dental School. 2007; 31 (1-2): 117-124
em Persa | IMEMR | ID: emr-102354

RESUMO

One of the most important disadvantages of using of tooth colored restorations is microleakage. This is more noticeable when there is a cavity with dentinal walls. Despite all improvements in dentin bonding agents, thusfar, no adhesive has been able to overcome microleakage between resin-dentin. The purpose of this survey is investigating the effect of filler on microleakage of self-etch adhesives with dentin and SEM interfacial morphology evaluation. Class V cavities were made on extracted human premolars [n=60]. Then the teeth were randomly divided into 6 groups based on type of adhesives used. Next teeth were grouped as filled adhesive [Xeno III, Clearfil SE Bond, Excite] and three grouped as unfilled adhesive [iBond, Bistite II, Single Bond]. After restoration, specimens were treated by thermocycling and a dye penetration test was done. Then longitudinal sections were made toward the direction of the buccal lingual and were observed carefully under a stereomicroscope for any leakage. From each group, 2 samples were prepared for investigating micromorphology of resin under an SEM electronic mircroscope. Data was analyzed by the Kruskal-Wallis test and Mann-Whitney test with an accuracy level of 0.05%. Using the Mann-Whitney test, it was clear that in the one-step self-etch adhesive, the filled type [Xeno III] had reduction in microleakage compared to the unfilled type [i Bond]. On the two-step self-etch and total etch adhesives, there was no significant difference between filled and unfilled adhesive in reduction of microleakage. In SEM investigations self-etch adhesives make thinner hybrid layers, but there are more resin tags with more regularity in this system and resin is well penetrated in the spaces due to demineralization and was polymerized. The filled type of one-step self-etch adhesive [Xeno III] had more reduction in microleakage than other groups. There was no significant difference between the two types [filled and unfilled] two-step self-etch and total etch adhesives in reduction of microleakage. It was clear that if self-etch adhesive is used carefully give better sealing compared to total etch adhesive. Because they can infiltrate the spaces made due to demineralization and get polymerized


Assuntos
Adesivos Dentinários , Infiltração Dentária , Tomografia com Microscopia Eletrônica , Descoloração de Dente
13.
Egyptian Journal of Hospital Medicine [The]. 2007; 29 (December): 492-510
em Inglês | IMEMR | ID: emr-162080

RESUMO

This study was carried out to evaluate the protective effect of ginger Zingeber officinale extract [ZOE] against the acrylamide [AC] which is an industrial chemical used in water treatment and it is synthesized during cooking of starch food at high temperature. Thirty adult male albino mice, each weighs 20-25 g were divided into three groups [10 mice/group]: [I]control group. II]acrylamide treated group. [III] acrylamide and ginger group. Acrylamide was given to experimental animals in the drinking water at a non-lethal dose of 200 p.p.m for 10 weeks [3 days/week]. Ginger extract was orally administrated at 50 mg/L [tilde 5 ml/day] for 10 weeks [3 days/week]. The ileum samples were collected for light microscope study and for scanning and transmission electron microscope examination. This study revealed that acrylamide induces pathological changes of the ileum of the treated mice specially the absorptive epithelial cells. The scanning electron microscopic study revealed damage of the ileal villi, some red blood corpuscles appeared at the site of damage. The transmission electron microscopic examination clearly demonstrated degeneration of most cell organelles as mitochondria, deterioration and degranulation of the rough endoplasmic reticulum, dilatation of Golgi apparatus. The administration of ginger extract decreased the histological alterations and ensuring the anti-inflammatory, and antitoxic effects of ZOE at its chosen dosage level


Assuntos
Animais de Laboratório , Acrilamida/efeitos adversos , Camundongos , Mitocôndrias , Retículo Endoplasmático Rugoso , Amido , Extratos Vegetais , Tomografia com Microscopia Eletrônica , Substâncias Protetoras , Intestinos/efeitos dos fármacos
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