Smear layer removal efficacy of different irrigating solutions: A comparative scanning electron microscope evaluation.

Aims: Comparative evaluation of cleaning efficacy of smear layer removal by different irrigating solutions such as 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline Hydrochloride (HCl) with 2.5% NaOCl for smear layer removal in the apical third of root canal. Settings and Design: In vitro material science study. Materials and Methods: Seventy-five single rooted permanent maxillary central incisor teeth were subjected to standardized root canal instrumentation (crown down technique). The teeth were randomly divided into five groups with 15 teeth in each groups: (1) Normal saline (n = 15) (2) 2.5% NaOCl (n = 15) (3) 17% EDTA + 2.5% NaOCl (n = 15) (4) 10% citric acid + 2.5% NaOCl (n = 15) (5) 1.0% tetracycline HCL + 2.5% NaOCl (n = 15). After final irrigation, the teeth were prepared for scanning electron microscope analysis to evaluate the cleaning of apical third of radicular dentine to determine the presence or absence of smear layer. Statistical Analysis Used: The results were analyzed by nonparametric statistical analysis techniques. Kruskal-Wallis test, Mann-Whitney test and Chi-square tests were carried out. Results: There was no significant statistical difference in the efficacy of smear layer removal when 2.5% NaOCl was compared with 17% EDTA with 2.5% NaOCl, 10% citric acid with 2.5% NaOCl and 1% tetracycline HCl with 2.5% NaOCl in apical third of root canals. Conclusions: The present study suggests that irrigating agents, citric acid and tetracycline HCl can be used as an alternative to EDTA for the removal of smear layer in endodontics.

Evaluación radiográfica y microscópica de la acción de quelantes en la remoción del barro dentinario / Radiographic and microscopic evaluation of the action of chelating agents in dental smear layer removal

Introducción: el tratamiento endodóntico realiza la limpieza y conformación del sistema de conductos radiculares, ya que virutas de dentina y materiales orgánicos, como los microorganismos, creadas por la acción de la instrumentación, forman el llamado barro dentinario. Objetivo: evaluar in vitro la remoción del barro dentinario y la disminución de la densidad de túbulos dentinarios, con soluciones irrigadoras quelantes. Métodos: se trata de un estudio experimental para el cual fueron seleccionados 30 dientes unirradiculares de humanos después del examen radiográfico inicial, y en el que se constató la presencia de canal único, ausencia de calcificación, reabsorción interna y tratamiento endodóntico concluido o en proceso. Luego se procedió a la instrumentación con tres diferentes soluciones irrigadoras: ácido etilenodiaminetetracético 17 por ciento, ácido cítrico 10 por ciento e hipoclorito de sodio 5,25 por ciento (grupo control). Posteriormente se evaluó radiográficamente cada diente instrumentado con el uso de una escala de densidad que fue confeccionada de aluminio con diferentes marcadores de densidades. Para el análisis por microscopio electrónico de barrido se utilizaron tres dientes de cada grupo, tratados con diferentes soluciones irrigadoras. Siete dientes de cada grupo se infiltraron con azul de metileno para la lectura de la infiltración marginal en el microscopio estereoscópico. Los dientes fueron evaluados en sus tres tercios: cervical, medio y apical. Resultados: se encontró que radiográficamente no hubo diferencia estadísticamente significativa entre los promedios de las densidades de los grupos de dientes en todos los tercios. Por microscopio electrónico de barrido se encontró una diferencia estadísticamente significativa entre los tres grupos de sustancias irrigadoras (p < 0,001), en el tercio cervical la remoción del barro dentinario fue mayor. Y por microscopio óptico se observó una mayor infiltración en el grupo de ácido etilenodiaminetetracético seguido del grupo ácido cítrico y por último el grupo control. Conclusión: el análisis de la densidad radiográfica y microscópica mostró que las sustancias quelantes fueron eficientes en la remoción del barro dentinario, excepto en el grupo control. Ninguna de las sustancias demostró alteraciones de densidad radiográfica de los túbulos dentinarios(AU)

Introduction: as part of endodontic treatment, root canals are cleaned and shaped, since shavings of dentin and organic materials, such as microorganisms, resulting from the action of instrumentation, create the so-called dental smear. Objective: carry out an in vitro evaluation of smear layer removal and dentinal tubule density reduction using chelating irrigation solutions. Methods: an experimental study was conducted for which 30 single-rooted human teeth were selected after initial radiographic examination to verify the presence of a single canal, absence of calcification, internal resorption and endodontic treatment either completed or underway. Next, instrumentation was performed with three different irrigation solutions: 17 percent ethylenediaminetetraacetic acid, 10 percent citric acid and 5.25 percent sodium hypochlorite (control group). Each instrumented tooth was then evaluated radiographically using a density scale made of aluminum with different density markers. Scanning electron microscope analysis was performed on three teeth from each group, which were treated with different irrigation solutions. Seven teeth from each group were infiltrated with methylene blue to determine marginal infiltration under the stereomicroscope. The teeth were evaluated on their three thirds: cervical, middle and apical. Results: radiographs did not reveal any statistically significant difference between the mean densities of the different groups of teeth in all thirds. Scanning electron microscopy showed a statistically significant difference between the three groups of irrigation substances (p < 0,001), with greater smear layer removal from the cervical third. Optical microscopy showed that infiltration was greatest in the ethylenediaminetetraacetic acid group, followed by the citric acid group, and lowest in the control group. Conclusion: analysis of radiographic and microscopic density revealed that except for the control group, chelating agents were efficient in removing dental smear. None of the substances showed any alteration in the radiographic density of dentinal tubules(AU)

Possible protective effect of dietary extra-virgin olive oil on experimentally induced acute colitis in adult male albino rats: a histological and immunohistochemical study

Many therapies are used nowadays to control colitis, but side effects limit long-term effectiveness. There is growing interest in the use of dietary supplements to avoid undesirable effects that accompany the classical treatment. Considerable attention has been focused on the use of extra-virgin olive oil [EVOO] in colitis. The aim of the study was to investigate the effect of pretreatment with dietary EVOO on modulating the extent and severity of experimentally induced acute colitis in adult male albino rats. Thirty-five adult male albino rats were divided randomly into three groups: group I, which served as the control group; group II [the colitis group], in which colitis was induced by intracolonic injection of 1 ml of 2% acetic acid daily for 3 days; and group III [the protection group], in which animals received 1 ml of EVOO /100 gm body weight daily by oral gavage for 10 days starting 7 days before the induction of colitis as in the previous group. At the end of the experiment, the distal part of the colon was removed and prepared for light and scanning electron microscopic study. Statistical and morphometric studies were also performed. Induction of colitis in group II showed massive mucosal ulceration, hemorrhage, and mononuclear cellular infiltration. Moreover, submucosal exudate and vacuolation in the muscularis externa were also detected. Immunohistochemical examination showed intense infiltration by tumor necrosis factor-alpha immunoreactive cells. Pretreatment with EVOO in group III protected the colon from acetic acid-induced colitis, which was manifested by preservation of crypts and their lining epithelium and by decrease in mononuclear cellular infiltration. Administration of EVOO to adult male albino rats had an ameliorating effect on experimentally induced acute colitis, and therefore it could be used as a protective dietary measure to attenuate colitis in high-risk people

Histological study on the effect of nicotine administration on the bone of adult male albino rat and the possible protective role of vitamin E

Cigarette smoking is one of the major problems affecting the health of humans. Many studies have been conducted on different organs of the body, but only a few have been conducted on the effect of cigarette smoking on bone. Vitamin E is a potent antioxidant supplement that might alleviate these hazardous effects on bone. The aim of our study was to evaluate the effect of nicotine on bone and whether the addition of vitamin E could protect the bone against nicotine-induced effects. Forty-five animals were used and divided into three groups comprising 15 animals each. Group I served as the control group. Animals in group II received nicotine. Animals in group III received nicotine in addition to vitamin E. At the end of the experiment the animals were sacrificed and the femur bone specimens were dissected and processed. The specimens were subjected to histological study: H and E and scanning electron microscopy. Evaluation of bone mineral density using energy dispersive X-ray was also carried out. Statistical analysis was carried out for all data recorded. Animals of group II showed thinning out of compact bone and trabeculae of cancellous bone of the proximal end of the femur. An increase in adipocytes in adjacent bone marrow was also detected. Cracking and microfracture of bone were apparent, as well as irregular endosteal pores. There was decrease in calcium content in the bone. Group III showed improvement in the morphology of bone and mineral content. Statistical analysis confirmed these results. We concluded that nicotine has hazardous effects on bone, and vitamin E has a protective role against nicotine

Effect of vitamin E supplementation on the colon diabetic rats with special emphasis on the myenteric plexus: an immunohistochemical and scanning electron microscopic study

Diabetes mellitus is a metabolic disorder characterized by the development of microvascular pathologies, of which neuropathy is the most common. There are many reports on upper gastrointestinal symptoms; however, few studies on the mechanism underlying colonic symptoms were conducted. The aim of the study was to evaluate the effect of vitamin E supplementation on the colon of diabetic rats with special emphasis on the myenteric plexus. A total of 30 male albino rats were divided into two groups: group I [control] and group II [experimental]. Diabetes was induced in group II rats using streptozotocin [35 mg/kg]. After 2 days, rats in group II were randomly classified into two subgroups: subgroup IIa [diabetic rats] and subgroup IIb [diabetic rats treated with vitamin E supplementation [2%] added to rodent chow]. Twelve weeks after induction of diabetes, specimens from the proximal colon were collected and processed for light and scanning electron microscopic examination. Specimens for light microscopy were stained with H and E and antiglial fibrillar acidic protein [anti-GFAP] immunostain and then studied morphometrically. Subgroup IIa showed ulceration of the mucosa, disturbed shape and depth of crypts, reduction in thickness of the musculosa and surface area of the myenteric plexus as well as a highly significant decrease in the mean number of myenteric nerve cells and enteric glial cells. Vitamin E supplementation [group IIb] showed significant improvement in these changes. Vitamin E supplementation in rats with chronic diabetes mellitus has a protective effect on myenteric nerve cells and enteric glial cells and could improve the abnormal histological and morphometric changes in the colon wall of diabetic rats

Effect of excess iodide on the structure of the thyroid gland of prepubertal male albino rats: a histological and immunohistochemical study

Excessive iodine intake is emerging as a new healthcare-related concern. Excess iodine is associated with a spectrum of effects on the thyroid. The aim of this study was to assess the effects of excess potassium iodide [KI] on the histological and immunohistochemical structure of the thyroid gland and evaluate the biochemical changes in thyroid hormones. Forty prepubertal male albino rats aged between 4 and 6 weeks were classified into two equal groups: group 1 [the control group], which was given distilled water, and group 2 [the KI-treated group], which was further subdivided into two equal subgroups. Subgroup 1a was given 0.1 mg KI/kg/day for 4 successive weeks and subgroup 1b was given 0.1 mg KI/kg/day for 8 successive weeks. At the end of the period, the animals were anesthetized and blood samples were collected for measurement of serum T3, T4, and thyroid-stimulating hormone. Thyroid glands were dissected out and processed for examination using light and electron microscopes. For light microscopic examination, the sections were stained with H and E and immunohistochemical analysis was carried out for localization of Fas. H and E-stained sections of the KI-treated subgroups showed highly significantly enlarged follicular cavities that were distended with vacuolated colloid. Most of the follicles were lined with flattened follicular cells with flattened nuclei. Follicular epithelial height was highly significantly decreased. Ultrastructurally, follicular cells showed dilatation of the cisternae of the endoplasmic reticulum, mitochondrial swelling, many electron-lucent zones, and collagen fibers in the interstitial spaces. Also, most of the nuclei were heterochromatic. Immunohistochemically, there was a highly significant increase in staining for Fas in the follicular cells of the treated subgroups. Biochemical assessment detected a nonsignificant decrease in T3 and T4 and a highly significant increase in the thyroid-stimulating hormone levels of the treated group. Excessive iodine intake affects thyroid structure and function. Hence, public iodine intake should be regulated to make sure that it is within optimal levels. Proper monitoring of the salt iodization program is essential. Also, drugs with high iodine content should be administered with caution

Histological study of hysteroscopy guided endometrial biopsy from secondary infertile patients after removal of a copper intrauterine contraceptive device

The intrauterine device [IUD] is a long-acting reversible method of contraception. Copper T380 IUD is a copper-wrapped T-shaped IUD containing no hormones. Although the IUD has been a contraceptive method for about 50 years, the possibility of causing subsequent secondary infertility remains controversial. This work was conducted to study the endometrial structure in patients suffering from secondary infertility after copper IUD removal. Thirty secondary infertile patients aged between 20 and 35 years were classified into two groups: the control group [10 patients], with no past history of IUD insertion, and the IUD group [20 patients], with a history of copper IUD insertion for 6 months to 3 years [subgroup B1] or for more than 3 years [subgroup B2]. Preovulatory hysteroscopy-guided endometrial biopsies were obtained and processed for light microscopy and transmission and scanning electron microscopy. Specimens from subgroup B1 showed focal loss of surface epithelium, cytoplasmic vacuolation, and small dark nuclei in surface epithelial cells. The stroma showed extravasated red blood cells, wide empty spaces, and cellular infiltration. In addition, the uterine glands of subgroup B2 appeared irregular and dilated with accumulated secretion and cellular debris as well as epithelial stratification. Ultrastructurally, focal loss, distortion and swelling of microvilli, indented nuclei, dilated rough endoplasmic reticulum, swollen mitochondria, and secondary lysosomes were observed in the surface epithelial cells. Scanning electron microscopy showed focal loss of microvilli, irregular surface, and mushroom-like protrusions in subgroup B1. These changes were more prominent in subgroup B2 with the appearance of fissures and corrugation of the surface. Copper IUD could induce different degrees of structural changes in the endometrium, which were directly proportional to the duration of IUD insertion. These changes could explain the secondary infertility that may occur in some cases after IUD removal

Surface evaluation of soft contact lens by scanning electron microscopy

A contact lens is a corrective, cosmetic or

comparative study between enterobius vermicularis and two uncommon forms of pinworms: First record of acanthoxyurus as a human parasite

Number of the order oxyurida is called pinworms. Pinworms infection has been to be the most common intestinal parasitosis. In the present work pinworm infection has been observed in 29 out of 100 examined children complaining anal itch, abdominal pain or sleeping disorders. The worms were remover, transferred to the decretory of parasitology. They were identified as female pinworms based on their general morphology. The light and scanning electron microscopic examination started with photographic documentation revealed the presence of three different types of oxyurid females that were differentiated from each other by specific characteristics of the worms as the shape of cephalic and caudal portions, mouth meaning, and cuticular surface of the body. Two genera were studied, the genus enterobius [E. vermicularis and E. gragorii] and genus Acanthoxyurus. It could be included that the [1] the use of scanning electron microscopy [SEM] allowed to report additional morophological features of the worms, including the cuticular surface, cervical cephalic end and caudal extremity. [2] In the present work uncommon forms of pinworms [Enterobius gregorii and Acanthoxyurus] were observed in three examined cases. A new species of Acanthoxyurus was recovered from one patient and its occurrence in human beings is reported for the first time. [3] It is the first locality record of Acanthoxyurus and Enterobius gregorii pinworms. [4] The present work presents the first comparative study between the classic pinworm [E.vermicularis] and the other two species of family Oxyuride obtained from children with pinworm infection

Equivalente esférico e valores da espessura da camada de fibras narvosas obtidas com o GDX tm Scanning Laser System / Spherical equivalent and nerve fiber layer thickness assessed with GDX tm Scanning Laser System

Objetivo: Estudar a influência do equivalente esférico nos valores obtidos pelo GDX tm Scanning Laser System.Métodos: Foram avaliados 41 voluntários sem doenças oculares e com campo visual sem alteraçöes.Foi realizada a polarimetria de varredura a laser como GDX tm Scanning Laser System de acordo com as instruçöes contidas no manual do aparelho.Foram comparados os valores obtidos nesse axame em um grupo de pacientes com equivalente esférico positivo e em um outro com este valor nulo ou negativo, pelo teste de Mann-Whitney.Resultados: Näo se verificou diferença estatística entre os valores obtidos nos olhos de pacientes do grupo I e os do grupo II.Näo foi encontrada correlaçäo entre o equivalente esférico e os valores obtidos com o GDX tm Scanning Laser System.Conclusöes: Na amostra estudada näo houve diferença estatística entre os valores obtidos em um grupo de olhos com equivalente esférico positivo e outro com este valor negativo ou nulo, usando-se o GDX tm Scanning Laser System.

Referencia comprensiva de una nueva aleación para amalgama dental / Comprensive strength of the new alloys for dental amalgam

El presente trabajo de investigación tuvo como objetivo deteminar la resistencia comprensiva de una nueva aleación para amalgama dental y comparar los resultados de esta propiedad mecánica con otras tres amalgamas de su mismo género. Así mismo se realizó una evaluación del tamaño y forma de las partículas de cada uno de los sistemas de aleaciones a través de la observación del microscopio electrónico de barrido. Para el logro del objetivo principal, se utilizó la Norma Venezolana 773-89 de Control de Calidad para Productos Odontológicos, aleaciones para amalgamas dentales que permitió evaluar la resistencia comprensiva. La presente investigación concluyó que esta nueva aleación para amalgama dental producida en la República del Perú supera el valor mínimo aceptable que la Norma de Control de Calidad exige

Fine structure and histometry of the enamel prismless layer of unerupted third molar teeth

Se examina la capa aprismática de 20 terceros molares humanos no erupcionados, usando microscopía electrónica de barrido. Los dientes se conservaron en alcohol al 70 por ciento y luego fracturados en dirección buco-lingual. Las caras bucal y lingual se subdividieron en tres regiones: cervical, media y oclusal. Nuestros resultados demostraron que la capa aprismática se encuentra en tres regiones, en ambas caras, bucal y lingual, de los terceros molares no erupcionados, presentando valores de 5,01µm en la superior y 5,58µm en la inferior. En las caras bucal y lingual y en las tres regiones; oclusal, media y cervical, el grosor de la capa de esmalte aprismático presenta un valor que aumenta desde oclusal hacia cervical 3,36µm; 5,28µm y 8,11µm. La capa aprismática esta compuesta por cristales de hidroxiapatita dispuestos en forma paralela entre sí, y perpendicularmente a la superficie de la capa externa del esmalte

Aplicación de la microscopia electrónica al estudio de la sangre periférica en el síndrome de inmunodeficiencia adquirida (SIDA) / Aplication of the electronic microscopy to peripheral blood study in the acquired immunodeficiency syndrome (AIDS)

El síndrome de inmunodeficiencia adquirida (SIDA), es producido por los virus de la inmunodeficiencia humana (VIH 1 y VIH 2), los cuales inducen en los pacientes trastornos progresivos de la inmunidad celular. A los fines de detectar si ocurren alteraciones a nivel ultraestructural de los leucocitos, que ayuden a clarificar la patogenia del SIDA, se procesó sangre periférica de 10 pacientes seropositivos sintomáticos, 15 seropositivos asintomáticos y 9 personas sanas, según los métodos de Watanabe y Donahue modificado por Pirela y col. para su estudio con el microscopio electrónico de transmisión (MET), y de Boyum y col. y Nakstad y col. para ser estudiados con el microscopio electrónico de barrido (MEB). Se detectaron en linfocitos y monocitos estructuras tubuloreticulares (TRS) en el interior del retículo endoplasmático rugoso en el 72,7% de los pacientes seropositivos sintomáticos y en 20% de los asintomáticos, y cisternas cilíndricas confrontadas (CCC) en un paciente seropositivo sintomático y en uno asintomático. Estas estructuras estan relacionadas con interferon tipo I y nuestros hallazgos coinciden con los reportados por la mayoría de otros autores. La presencia de estas inclusiones ha sido asociada con la evolución y pronóstico de los pacientes con SIDA