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1.
Braz. dent. j ; 32(3): 56-64, May-June 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1345501

ABSTRACT

Abstract It aims on evaluate the effect of the test environment on static fatigue behavior of lithium disilicate-based (LD), and yttrium oxide-stabilized zirconia (YSZ) ceramics. Specimens of LD (IPS e.max CAD, Ivoclar Vivadent) and YSZ (IPS e.max ZirCAD MO, 3 mol% Y2O3, Ivoclar Vivadent) were randomly allocated into three groups: tested in air, inert (paraffin oil, Sigma Aldrich) or distilled water. The static fatigue test (n=15) was performed using a piston-on-three ball assembly, adapted from ISO 6872, as follows: starting load 100 N for LD and 300 N for YSZ; loading application time set to 1 hour for each loading step; step size of 50 N for LD and 100 N for YSZ, applied successively until fracture. Data from static fatigue strength (MPa) and time to fracture (hours) were recorded. Fractographic analysis was executed. Survival analysis corroborates absence of influence of environment on static fatigue outcomes (fatigue strength, time to fracture and survival rates) for YSZ. For LD, specimens tested in air presented statistically superior survival rate and static fatigue strength (p= 0.025). In regards of time to fracture, LD tested in air were superior than when tested in distilled water (p=0.019) or inert (p=0.017) environments. No statistical differences for Weibull modulus were observed. Failures started on the tensile stress surface. Thus, the test environment did not affect slow crack growth (SCG) mechanisms during static fatigue test of YSZ ceramics, but it plays a significant role for the static fatigue behavior of lithium disilicate-based glass ceramics, indicating a high susceptibility to SCG.


Resumo O presente estudo objetivou investigar a influência do ambiente de teste no comportamento a fadiga estática (resistência à fratura e tempo para falha) de cerâmicas à base de dissilicato de lítio (LD) e zircônia estabilizada com ítria (YSZ). Espécimes de LD (IPS e.max CAD, Ivoclar Vivadent) e YSZ (IPS e.max ZirCAD MO, 3mol% Y2O3, Ivoclar Vivadent) foram obtidos e alocados aleatoriamente em três grupos: testado em ar, em líquido inerte (óleo de parafina) ou em água destilada. O teste de fadiga estática (n= 15) foi realizado usando o teste pistão sobre três esferas, ISO 6872, da seguinte forma: carga inicial 100 N para LD e 300 N para YSZ; tempo de aplicação de carregamento definido para 1 hora para cada etapa de carregamento; tamanho do passo de 50 N para LD e 100 N para YSZ, aplicados sucessivamente até a fratura. Dados de resistência à fadiga estática (MPa) e tempo até a fratura (horas) foram registrados. A análise fractográfica foi executada. A análise de sobrevivência corrobora a ausência de influência do ambiente de teste nos resultados de fadiga estática (resistência à fadiga, tempo de fratura e taxas de sobrevivência) para a YSZ. Para LD, os corpos de prova testados em ar apresentaram taxa de sobrevivência e resistência à fadiga estática estatisticamente superiores (p= 0,025). Em relação ao tempo de fratura, os espécimes LD testados em ar foram superiores aos testados em água destilada (p= 0,019) ou em ambiente inerte (p= 0,017). Não foram observadas diferenças estatísticas para o módulo de Weibull. Todas as falhas começaram no lado onde se concentra a tensão de tração (lado de baixo) durante o teste. Com base nisso, observa-se que o ambiente de teste não afetou os mecanismos de crescimento lento de trinca durante o teste de fadiga estática da cerâmica YSZ, mas desempenha um papel significativo na resistência à fadiga estática da cerâmica de vidro à base de dissilicato de lítio, indicando alta susceptibilidade ao crescimento lento e subcrítico de trincas.


Subject(s)
Ceramics , Dental Porcelain , Surface Properties , Zirconium , Materials Testing , Computer-Aided Design , Dental Stress Analysis , Glass
2.
Infectio ; 25(1): 59-62, ene.-mar. 2021. tab, graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1154404

ABSTRACT

Resumen La neumonía en el paciente inmunocomprometido es un reto diagnóstico al cual el clínico se enfrenta cada vez con más frecuencia , al momento de hablar de infiltrados en vidrio esmerilado es menester tener siempre en cuenta la posibilidad de neumonía por Pneumocystis Jirovecii, que por mucho tiempo se pensó como una enfermedad propia del huésped inmunosuprimido con VIH, a través del tiempo se ha manifestado en pacientes con trasplantes de órgano sólido y de precursores hematopoyéticos, asociado a autoinmunidad, al uso crónico de corticoesteroides y más recientemente al uso de terapia biológicas. La descripción de esta enfermedad y sus métodos diagnósticos en huéspedes inmunosuprimidos no VIH no es del todo claro, sabemos que el tratamiento de elección en estos casos es el trimetropin-sulfametoxazol (TMP-SMX) el cual no cuenta con evidencia de alta calidad al momento de plantear una dosis ni un tiempo de duración establecidos. Presentamos el caso de un paciente con diagnóstico de glomerulonefritis por enfermedad de cambios mínimos corticodependiente y quien desarrolló neumonía por Pneumocystis Jirovecii confirmada por histopatología quien recibió tratamiento y tuvo un desenlace positivo.


Abstract The pneumonia in the immunocompromised patient is a diagnostic challenge that the clinician faces more and more frequently, every time we talk about ground glass infiltrates it is necessary to always take into account the possibility of pneumonia due to Neumocystis Jirovecii, which for a long time was thought as a disease of the immunosuppressed host with HIV, but that across the time it has manifested itself in patients with solid organ transplants and hematopoietic precursors, associated with autoimmunity, the chronic use of corticosteroids and more recently the use of biological therapy. The description of this disease and the diagnostic methods in non-HIV immunosuppressed hosts is not entirely clear, we know that the treatment of choice in these cases is trimethropin-sulfamethoxazole (TMP-SMX), which does not have high-quality evidence at the time of a dose or a time of established duration. We present the case of a patient diagnosed with glomerulonephritis due to corticodependent minimal change disease and who suffers from pneumocystis Jirovecii pneumonia confirmed by histopathology, which received treatment and had a positive outcome


Subject(s)
Humans , Male , Adolescent , Pneumonia, Pneumocystis , Pneumonia , Autoimmunity , HIV , Immunocompromised Host , Adrenal Cortex Hormones , Glass
3.
Braz. oral res. (Online) ; 35: e012, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132751

ABSTRACT

Abstract The purpose of this study was to analyze the effect of the application of different concentrations of EDTA on the adhesion of fiber posts to root dentin using self-adhesive resin cements. After endodontic treatment, 78 single roots were randomly divided into six groups (n = 13) according to the combination of the following factors: surface dentin treatment - control (distilled water), 17% EDTA and 24% EDTA; and self-adhesive resin cement - RelyX U200 (RX); and Multilink Speed (ML). After fiber post cementation, six slices were obtained for each root. Ten roots of each group were used for bond strength (BS) and three for microhardness (MH) evaluations. Data obtained from BS and MH tests for each resin cement were subjected to two-way ANOVA (surface treatment vs. root region) and to a post-hoc Tukey's test (α = 0.05). The lowest BS value was observed in the 24% EDTA group for RX cement, whereas the highest values for ML cement were observed for the control group in the middle and apical regions. In the MH test, the lowest value for RX was observed for 24% EDTA in the cervical region, whereas and the highest value for the ML cement was observed in the control group. Regarding both self-adhesive resin cements tested, the application of 24% EDTA was not able to improve the adhesion of fiber posts to root canal.


Subject(s)
Resin Cements , Materials Testing , Post and Core Technique , Edetic Acid/pharmacology , Dental Pulp Cavity , Dentin , Glass
4.
Dent. press endod ; 10(3): 75-80, Sept-Dec.2020. Tab
Article in English | LILACS | ID: biblio-1348014

ABSTRACT

Introdução: Pinos de fibra de vidro são bastante utilizados quando dentes tratados endodonticamente apresentam grande perda estrutural e necessitam de suporte para a sua reconstrução coronária. A completa adesão do pino à parede do canal radicular é fundamental para o sucesso dessa restauração. Resíduos de cimento endodôntico que permanecem nas paredes dentinárias, mesmo após o preparo para a cimentação, podem interferir negativamente na sua adesão e contribuir para o seu deslocamento. Objetivo: O objetivo da presente revisão de literatura foi avaliar o efeito de diferentes cimentos endodônticos e o tempo decorrido entre a obturação e a cimentação do pino na resistência de união entre o pino e a parede do canal radicular. Métodos: Essa revisão de literatura incluiu 21 estudos que analisaram a influência de cimentos endodônticos na adesão de pinos de fibra de vidro, entre os quais 9 acrescentaram a variável tempo na sua análise, com pinos cimentados logo após a obturação do canal radicular e dias após a obturação. Resultados: Os dentes obturados com cimentos à base de resina demonstraram maior resistência ao deslocamento dos pinos durante os testes. Parece haver uma predominância de menores valores de adesão quando os pinos são cimentados imediatamente após a obturação com cimentos contendo eugenol. Conclusões: Os tipos de cimento endodôntico e o período entre a obturação e a cimentação do pino podem afetar a força de ligação entre a parede do canal radicular e o pino de fibra de vidro (AU).


ntroduction: Glass fiber posts are widely used when endodontically treated teeth present great structural loss and require support for coronal reconstruction. Complete adhesion of the post to the root canal wall is fundamental for the success of this restoration. Endodontic sealer residues that remain on the dentin walls, even after preparation for cementation, may negatively interfere with the adhesion and contribute for post displacement. This literature review evaluated the effect of different endodontic sealers and the time between obturation and post cementation on the bond strength. Methods: This literature review included 21 studies that analyzed the influence of endodontic sealers on the adhesion of glass fiber posts, among which 9 added the variable time in their analysis. Results: Teeth filled with resin-based sealers showed higher post push-out bond strength during testing. There seems to be predominance of lower adhesion values when the posts are cemented immediately after filling with eugenol-containing sealers. Conclusions: The type of endodontic sealer and period between obturation and post cementation can affect the bond strength between root canal wall and the glass fiber post(AU).


Subject(s)
Root Canal Obturation , Cementation , Glass , Literature
5.
J. oral res. (Impresa) ; 9(5): 405-413, oct. 31, 2020. ilus, graf, tab
Article in English | LILACS | ID: biblio-1179032

ABSTRACT

Introduction: This study evaluated the influence of sonic vibration and thermocycling on the bond strength of fiberglass posts using conventional dual-cured and self-adhesive resin cements. Material and Methods: Ninety-six single-rooted endodontically treated teeth were divided randomly into eight groups according to the cement used (dual-cured or self-adhesive resin cement), use of sonic vibration during post accommodation, and aging conditions (24h in distilled water or 5,000 thermal cycles). The fiberglass posts (White Post DC1, FGM) were cleaned with alcohol, treated with silane and cemented with dual-cured (Allcem Core, FGM) or with self-adhesive resin cement (seT, SDI). For groups in which sonic vibration was used, the posts were accommodated, and sonic vibration was applied for 10 s using a special tip placed on top of the post (Sonic Smart Device, FGM). Pull-out tests were performed after storage in distilled water for 24h at 37°C or after thermocycling (5000 cycles, at 5°C and 55°C). The results were evaluated using three-way ANOVA and Tukey's test (α=0.05). Results: Significant differences were not observed between the bond strengths of dual-cured (87.93±41.81 N) and self-adhesive cement (82.53±41.43 N). Bond strength for the sonic vibration groups (100.36±42.35 N) was significantly higher than for groups without sonic vibration (70.13±34.90 N). There were significant differences between specimens subjected to thermocycling (98.33±39.42 N) and those stored for 24h in distilled water (72.16±39.67 N). Conclusion: It can be concluded that both sonic vibration and thermocycling significantly improved bond strength of fiberglass posts with the two evaluated resin cements.


Introducción: Este estudio evaluó la influencia de la vibración sónica y el termociclado en la fuerza de unión de los postes de fibra de vidrio utilizando cementos de resina autoadhesivos y de curado dual convencionales Material y Métodos: Se dividieron aleatoriamente noventa y seis dientes tratados endodónticamente de raíz única en ocho grupos según el cemento utilizado (cemento de resina de curado dual o autoadhesivo), el uso de vibración sónica durante la acomodación posterior y las condiciones de envejecimiento (24 horas agua destilada o 5.000 ciclos térmicos). Los postes de fibra de vidrio (White Post DC1, FGM) se limpiaron con alcohol, se trataron con silano y se cementaron con cemento de curado dual (Allcem Core, FGM) o con cemento de resina autoadhesivo (seT, SDI). Para los grupos en los que se utilizó vibración sónica, se acomodaron los postes y se aplicó la vibración sónica durante 10 s utilizando una punta especial colocada en la parte superior del poste (Sonic Smart Device, FGM). Las pruebas de extracción se realizaron después del almacenamiento en agua destilada durante 24 horas a 37ºC o después del termociclado (5000 ciclos, a 5ºC y 55ºC). Los resultados se evaluaron mediante ANOVA de tres vías y la prueba de Tukey (α = 0.05). Resultados: No se observaron diferencias significativas entre las resistencias de adhesión del cemento de curado dual (87,93 ± 41,81 N) y el cemento autoadhesivo (82,53 ± 41,43 N). La fuerza de unión para los grupos de vibración sónica (100,36 ± 42,35 N) fue significativamente mayor que para los grupos sin vibración sónica (70,13 ± 34,90 N). Hubo diferencias significativas entre los especímenes sometidos a termociclado (98,33 ± 39,42 N) y los almacenados durante 24 h en agua destilada (72,16 ± 39,67 N). Conclusión: Se puede concluir que tanto la vibración sónica como el termociclado mejoraron significativamente la fuerza de unión de los postes de fibra de vidrio con los dos cementos de resina evaluados.


Subject(s)
Humans , Vibration , Post and Core Technique/instrumentation , Resin Cements/chemistry , Flexural Strength , Glass , Sonication/methods , Tooth Root , Dental Bonding , Dentin-Bonding Agents , Dentin/chemistry , Ultrasonic Waves
6.
Rev. Ateneo Argent. Odontol ; 62(1): 31-38, jun. 2020. ilus
Article in Spanish | LILACS | ID: biblio-1148166

ABSTRACT

Se analizan aspectos fármaco-tecnológicos y clínicos de biocerámicos bioabsorbibles compuestos por biovidrios con capacidad osteogénica y microbicida, para ser utilizados como relleno bioactivo en el conducto radicular y como tratamiento terapéutico en el sitio de a lesión apicoperirradicular de origen endodóntico. Mediante un diagrama ternario se consideraron las diversas variables cuyos valores determinan las diferentes fases de los vidrios bioactivos, hasta alcanzar la formación de hidroxiapatita, cuando se someten a un medio biológico. Se analizaron composición y mecanismo de acción en la reparación posendodóntica, que parte de la integración del biomaterial al tejido duro sano, sin formación de fibrosis o proceso inflamatorio inmune (AU)


Pharmacotechnological and clinical aspects of bioabsorbable bioceramics composed of bioglasses with osteogenic and microbicidal capacity are analyzed, to be used as a bioactive filler in the root canal and as a therapeutic treatment at the site of an apicoperiradicular lesion of endodontic origin. By means of a ternary diagram, the various variables whose values determine the different phases of the bioactive glasses were considered, until reaching the formation of hydroxyapatite, when subjected to a biological medium. Composition and mechanism of action were analyzed in post-endodontic repair, which starts from the integration of the biomaterial into healthy hard tissue, without the formation of fibrosis or an immune inflammatory process (AU)


Subject(s)
Biocompatible Materials , Ceramics , Durapatite , Absorbable Implants , Glass , Osteogenesis/physiology , Periapical Diseases/therapy , Wound Healing , Calcarea Silicata , Bone Substitutes , Physical and Chemical Properties
7.
J. appl. oral sci ; 28: e20190384, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1134801

ABSTRACT

Abstract Objectives This study evaluated if the use of a bioactive glass-ceramic-based gel, named Biosilicate (BS), before, after or mixed with bleaching gel, could influence the inflammation of the dental pulp tissue of rats' molars undergoing dental bleaching with hydrogen peroxide (H2O2). Methodology The upper molars of Wistar rats (Rattus norvegicus, albinus) were divided into Ble: bleached (35% H2O2, 30-min); Ble-BS: bleached and followed by BS-based gel application (20 min); BS-Ble: BS-based gel application and then bleaching; BS/7d-Ble: BS-based gel applications for 7 days and then bleaching; Ble+BS: blend of H2O2 with BS-based gel (1:1, 30-min); and control: placebo gel. After 2 and 30 days (n=10), the rats were euthanized for histological evaluation. The Kruskal-Wallis and Dunn statistical tests were performed (P<0.05). Results At 2 days, the Ble and Ble-BS groups had significant alterations in the pulp tissue, with an area of necrosis. The groups with the application of BS-based gel before H2O2 had moderate inflammation and partial disorganization in the occlusal third of the coronary pulp and were significantly different from the Ble in the middle and cervical thirds (P<0.05). The most favorable results were observed in the Ble+BS, which was similar to the control in all thirds of the coronary pulp (P>0.05). At 30 days, the pulp tissue was organized and the bleached groups presented tertiary dentin deposition. The Ble group had the highest deposition of tertiary dentin, followed by the Ble-BS, and both were different from control (P<0.05). Conclusion A single BS-based gel application beforehand or BS-based gel blended with a bleaching gel minimize the pulp damage induced by dental bleaching.


Subject(s)
Animals , Male , Pulpitis/prevention & control , Tooth Bleaching/methods , Dental Pulp/drug effects , Tooth Bleaching Agents/chemistry , Glass/chemistry , Hydrogen Peroxide/chemistry , Pulpitis/chemically induced , Pulpitis/pathology , Time Factors , Tooth Bleaching/adverse effects , Random Allocation , Reproducibility of Results , Treatment Outcome , Rats, Wistar , Dental Pulp/pathology , Tooth Bleaching Agents/adverse effects , Hydrogen Peroxide/adverse effects , Molar
8.
Medwave ; 20(1): e7772, 2020.
Article in English, Spanish | LILACS | ID: biblio-1087876

ABSTRACT

ANTECEDENTES La ubicación precisa de un cuerpo extraño intraocular es crucial para el manejo de pacientes con trauma ocular abierto. La tomografía computarizada se usa habitualmente para detectar su ubicación en el segmento posterior. Reportamos tres casos con diferentes cuerpos extraños intraoculares en el segmento posterior, que fueron localizados con precisión mediante la tomografía computarizada y ecografía modo B. PRESENTACIÖN DEL CASO Presentamos tres casos con diferentes mecanismos de trauma, tipos de cuerpo extraño intraocular, síntomas clínicos y pronóstico visual. La tomografía computarizada determinó la ubicación exacta de todos los cuerpos extraños intraoculares en el segmento posterior. El ultrasonido modo B se realizó en un paciente con un cuerpo extraño intraocular no metálico. El primer caso tuvo una lesión ocular perforante con un cuerpo extraño intraorbitario; el caso dos y el caso tres presentaron diferentes tipos de cuerpos extraños intraoculares con pronóstico diferente. El manejo y el pronóstico fue distinto en todos los casos; todos se manejaron con éxito. La ubicación exacta de los cuerpos extraños intraoculares utilizando las diferentes modalidades de diagnóstico es importante en estos pacientes. Estos casos sirven como recordatorio de que el uso adecuado de las pruebas de imagen es indispensable en el contexto de un cuerpo extraño intraocular relacionado con trauma ocular abierto. CONCLUSIÓN Las diferentes técnicas de imágenes son muy importantes para la detección de un cuerpo extraño intraocular. La tomografía computarizada es una de las modalidades de imagen más simple y efectiva para la localización de cuerpos extraños intraoculares relacionadas con trauma ocular abierto.


BACKGROUND: Determining the precise location of intraocular foreign bodies is crucial for the management of patients with open-globe injury. Computed tomography is the most common method for detecting intraocular foreign bodies in the posterior segment. In this article, we describe three cases of open-globe injury with different types of intraocular foreign bodies in the posterior segment that were accurately located using computed tomography scans and B-scan ultrasonography. CASE PRESENTATION: Each of the three cases of open-globe injury described in this report had different types of ocular trauma, clinical symptoms, and intraocular foreign bodies. Computed tomography scans showed the exact location of the intraocular foreign bodies in the posterior segment in two of the three cases. A B-scan ultrasound was used to determine the location of a non-metallic intraocular foreign body in the third case. All three patients had intraocular foreign bodies, and one of them had an additional orbital foreign body. Case 1 had a perforating eye injury with the additional intraorbital foreign body; Cases 2 and Case 3 had different types of intraocular foreign bodies and prognoses. Various treatment approaches were used, ranging from observation to surgery, depending on the location of the intraocular foreign bodies, and all cases were successfully managed. These three cases show that proper use of various types of imaging tests is indispensable in the context of an intraocular foreign body related to open-globe injury. CONCLUSION: Imaging techniques are crucial for the detection of an intraocular foreign body, and computed tomography is one of the simplest and most useful, especially in cases of open-globe injury.


Subject(s)
Humans , Male , Adolescent , Adult , Tomography, X-Ray Computed , Eye Injuries, Penetrating/diagnostic imaging , Eye Foreign Bodies/diagnostic imaging , Ultrasonography , Plastics , Wounds, Gunshot/complications , Wounds, Gunshot/diagnostic imaging , Blast Injuries/complications , Blast Injuries/diagnostic imaging , Magnetic Resonance Imaging , Radiography , Eye Injuries, Penetrating/complications , Eye Foreign Bodies/etiology , Glass , Metals
9.
Braz. oral res. (Online) ; 34: e004, 2020. tab, graf
Article in English | LILACS | ID: biblio-1055523

ABSTRACT

Abstract The aim of this study was to analyze the structural, morphological and mechanical properties of two different lithium disilicate glass-reinforced ceramics for CAD-CAM systems (IPS e.max CAD and Rosetta SM). Five methodologies were used for both ceramics: microstructure (n = 2) was analyzed using x-ray diffraction (XRD); morphological properties (n = 2) were analyzed by scanning electron microscopy (SEM), with and without hydrofluoric etching; porosity (n = 3) was assessed using 3D micro-computed tomography (micro-CT); flexural strength was measured (n =1 0) using the three-point bending test; and bond strength was determined with self-adhesive resin cement (n = 10), using a microshear bond test. After performing all the tests, the data were analyzed using t-Student test and two-way ANOVA. All the tests used a significance level of α = 0.05. High peak positions corresponding to standard lithium metasilicate and lithium disilicate with similar intensities were observed for both ceramics in the XRD analysis. Morphological analysis showed that the crystalline structure of the two ceramics studied showed no statistical difference after acid etching. Additionally, no significant differences were recorded in the number or size of the pores for the ceramics evaluated. Moreover, no differences in flexural strength were found for the ceramic materials tested, or in the bond strength to ceramic substrates for the resin cements. Based on the study results, no significant differences were found between the two CAD-CAM lithium disilicate glass-reinforced ceramics tested, since they presented similar crystalline structures with comparable intensities, and similar total porosity, flexural strength and bond strength.


Subject(s)
Ceramics/chemistry , Computer-Aided Design , Dental Porcelain/chemistry , Glass/chemistry , Reference Values , Surface Properties , X-Ray Diffraction , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Analysis of Variance , Porosity , Dental Bonding/methods , Resin Cements/chemistry , Shear Strength , Flexural Strength
10.
Braz. oral res. (Online) ; 34: e020, 2020. tab, graf
Article in English | LILACS | ID: biblio-1089398

ABSTRACT

Abstract: This in vitro study aimed to assess the effects of different pretreatments used to adapt glass-fiber posts cemented to root canals with different resin cements, regarding porosity percentage and bond strength. Twelve bovine incisor roots were prepared with Largo drills. After post space preparation, the specimens were randomized into two types of pretreatment groups (n = 3): water-wet bonding and ethanol-wet bonding. After the post were cemented, the roots were stored in 100% humidity at room temperature for 7 days. The samples were scanned by microcomputed tomography (micro-CT). Images were reconstructed by NRecon software, and CTAn software was used to analyze the porosity percentage (%) at the luting interface. Evaluation of the push-out bond strength was performed by serially cutting the roots, and submitting the slices to testing. Additionally, the resin cement post-gel shrinkage values (%) were measured using the strain-gauge method (n = 10). Data were analyzed by two-way ANOVA, Tukey's test and Student's t test (a = 0.05). The roots prepared with ethanol-wet bonding using RelyX™ U200 had significantly lower porosity in the coronal and apical thirds (p < 0.05). The group prepared with ethanol-wet bonding using RelyX™ ARC presented better bond strength results in the coronal and apical thirds (p < 0.05). RelyX™ ARC (0.97%) produced a higher post-gel shrinkage value than RelyX™ U200 (0.77%). Canals pretreated with ethanol-wet bonding presented better outcomes in regard to porosity percentage and push-out bond strength.


Subject(s)
Animals , Cattle , Tooth Root/drug effects , Post and Core Technique , Dentin-Bonding Agents/pharmacology , Resin Cements/chemistry , Ethanol/pharmacology , Root Canal Irrigants/chemistry , Materials Testing , Cattle , Porosity , Dental Bonding , Dental Materials/chemistry , Dental Pulp Cavity , X-Ray Microtomography , Glass
11.
Article in Korean | WPRIM | ID: wpr-811325

ABSTRACT

PURPOSE: We developed a novel method for measurement of hyperacuity and verified the utility thereof.METHODS: We developed a three-dimensional (3D) hyperacuity test using a 3D liquid crystal flat screen, a left- and right-image polarized display, and liquid crystal shutter glasses. We tested the technique in three groups: normal (n = 48), with cataracts (n = 14), and with macular disease (n = 35). We used a chart consisting of five dots and a reference line. Of the five dots, one was variably shifted from the other dots. A chart was presented to one eye and the reference line or blank image to the other eye; a subject scored positive when the dot in the unusual position was recognized.RESULTS: Hyperacuity was measured in terms of the reference line seen by the reference eye (RR), a blank image seen by the reference eye (RB), the reference line seen by the contralateral eye (CR), and a blank image seen by the contralateral eye (CB). All test scores were significantly lower when the reference line was seen than not (RR vs. RB and CR vs. CB; p < 0.01, respectively). For the RR and CR tests, no significant difference was apparent between the normal and cataracts group (p = 0.553, p = 0.494) but such differences were evident between the normal and macular disease groups (p = 0.028, p = 0.002). Also, visualization of the reference line by the reference and contralateral eyes did not differ (p > 0.05).CONCLUSIONS: Measurement of hyperacuity using our new method was not affected by media opacity but was significantly affected by macular disease. Presentation of a reference line facilitated hyperacuity assessment.


Subject(s)
Cataract , Eyeglasses , Glass , Liquid Crystals , Methods
12.
Article in Korean | WPRIM | ID: wpr-811323

ABSTRACT

PURPOSE: We used a questionnaire to explore perceptions and clinical practice patterns of Korean pediatric ophthalmologists in terms of amblyopia.METHODS: From September to November 2018, we conducted a web-based questionnaire survey of 99 specialists of the Korean Association for Pediatric Ophthalmology and Strabismus who operated ophthalmology clinics in Korea. We received 56 responses (56.57%) and retrospectively analyzed the data.RESULTS: The average specialist age was 44.0 ± 9.7 years. The mean age of treated amblyopia patients was 3 to 5 years (69.6%); the most common amblyopia was refractive anisometropic amblyopia (75.0%). On average, treatment commenced at 4 years of age (53.6%); child and parent co-operation most significantly influenced treatment success (46.4%). The preferred test was cycloplegic refraction (96.4%) and the preferred treatment occlusion therapy (100%) with glasses correction (98.2%). Occlusion therapy was most commonly performed for 2 hours/day (69.6%); the minimum age for eyeglasses prescription was 2.10 ± 1.18 years. Only three respondents (5.36%) prescribed contact lenses and only one (1.79%) performed refractive surgery.CONCLUSIONS: In Korea, amblyopia treatment is based on occlusion therapy and glasses correction. However, the time of treatment commencement, the duration of occlusion therapy, and the glasses used for correction varied. It is necessary to develop guidelines for amblyopia treatment; these should reflect current medical conditions.


Subject(s)
Amblyopia , Child , Contact Lenses , Eyeglasses , Glass , Humans , Korea , Ophthalmology , Parents , Practice Patterns, Physicians' , Prescriptions , Refractive Surgical Procedures , Retrospective Studies , Specialization , Strabismus , Surveys and Questionnaires
13.
Article in Korean | WPRIM | ID: wpr-785352

ABSTRACT

PURPOSE: Allergic rhinitis is the most common atopic disease and the most common chronic disease of children. Eosinophil count and percentage in nasal smear are useful for differential diagnosis of allergic rhinitis. The aim of this study is to investigate the correlation between nasal eosinophil count and percentage.METHODS: Between January 2017 and August 2018, 221 children patients with a clinical history of rhinitis were tested at the outpatient respiratory and allergy unit of the Department of Pediatrics, School of Medicine, The Catholic University of Korea. Nasal secretion was collected by swabbing a children's nasal inferior turbinate 3–4 times with a cotton swab and then placed on to a glass slide. Later, the smear was stained by Giemsa stain.RESULTS: This is the first study to assess the comparison of nasal eosinophil count and percent. There is a positive correlation between nasal eosinophil count and percent Y=1.02 X+2.82 (Y=Eosinophil count, X=Eosinophil percentage). To determine the usefulness of nasal eosinophil count and percentage in the diagnosis of allergic rhinitis, we analyzed receiver operating characteristic curves. The cutoff value of the nasal eosinophil count was 6.5/high-power field, and that of the nasal eosinophil ratio was 3% for the diagnosis of allergic rhinitis.CONCLUSION: In patients with suspected rhinitis, one of the values of nasal eosinophil count or percentage can be used in clinical practice.


Subject(s)
Azure Stains , Child , Chronic Disease , Diagnosis , Diagnosis, Differential , Eosinophils , Glass , Humans , Hypersensitivity , Korea , Outpatients , Pediatrics , Rhinitis , Rhinitis, Allergic , ROC Curve , Turbinates
14.
Article in English | WPRIM | ID: wpr-820822

ABSTRACT

OBJECTIVES: Galla chinensis inhibited the adherence of planktonic oral bacteria and acid production by cariogenic bacteria. However, little is known about the relevant conditions of Galla Chinensis extract (GCE) exposure time and concentration and the effect of GCE on the structural and functional activity of cariogenic bacteria. The antibacterial effects of natural G. Chinensis extract on S. mutans , S. sanguinis, and S. oralis biofilms were evaluated in vitro.METHODS: Biofilms formed on glass surfaces were treated with different concentrations of GCE at different exposure times. The effects were assessed by examining the bactericidal activity, acidogenesis, minimum inhibitory concentration, and morphology.RESULTS: There was a statistically significant difference in the bacterial growth inhibition depending on the concentration of the GCE, with bacterial growth being inhibited as the concentration of GCE increased. A concentration of 1.0 mg/ml GCE had similar bactericidal effects against S. mutans and S. oralis biofilms to those produced by 2.0 mg/ml CHX. In the 1.0 mg/ml GCE group, incomplete septa were also observed in the outline of the cell wall, together with disruption of the cell membrane. In addition, there was also a slight exudation of the intracellular content from the bacteria in the 1.0 mg/ml GCE and 2 mg/ml CHX groups.CONCLUSIONS: These results indicate that GCE inhibits the growth of S. mutans, S. sanguinis, and S. oralis with increasing concentrations. It alters the microstructure of S. mutans biofilms. These results suggest that GCE might be a useful anti-bacterial agent for preventing dental caries.


Subject(s)
Bacteria , Biofilms , Cell Membrane , Cell Wall , Dental Caries , Glass , In Vitro Techniques , Microbial Sensitivity Tests , Plankton , Streptococcus mutans
15.
Chinese Journal of Stomatology ; (12): 461-465, 2020.
Article in Chinese | WPRIM | ID: wpr-827012

ABSTRACT

Fiber-reinforced resin composite posts (fiber posts) are used extensively for the restoration of root-treated teeth with excessive loss of coronal structure. However, the longevity of a fiber post restoration still needs to be improved because of the various confounding factors that affect bonding procedures. Operational specification for clinical use of dental intraradicular fiber post was established based on the in-depth discussions by a panel of experts from Society of Prosthodontics, Chinese Stomatological Association. This specification should be helpful in standardizing the clinical technique of fiber post placement and improving the clinical longevity of a fiber post restoration.


Subject(s)
Cementation , Composite Resins , Dental Bonding , Dental Stress Analysis , Glass , Materials Testing , Post and Core Technique , Resin Cements , Tooth Root
16.
Odontoestomatol ; 21(34): 33-43, Jul-Dic. 2019.
Article in Spanish | LILACS, BNUY, BNUY-Odon | ID: biblio-1024977

ABSTRACT

Los vidrios bioactivos (vb) son materiales cerámicos con una composición química tal que poseen la propiedad de inducir y conducir la mineralización de los tejidos. La obtención de estos vidrios por medio del método sol-gel y la posibilidad de obtener tamaño nanométrico de partícula, han ampliado y potenciado las indicaciones de estos materiales. Las propiedades antibacterianas de los vb son una característica sobresaliente; es debida a la liberación de iones que alcaliniza el medio, actuando sobre las colonias bacterianas. Las aplicaciones médicas y odontológicas de estos materiales son muy amplias, destacándose la regeneración ósea, la remineralización de los tejidos duros dentarios y el tratamiento de la hipersensibilidad. Sin embargo, por tratarse de materiales con estructura química amorfa, sus propiedades mecánicas no son buenas, siendo esta característica su principal limitación para la aplicación clínica en el área de la odontología restauradora. En este sentido las investigaciones científicas se han enfocado en determinar la posibilidad de incorporar vb a diversos materiales dentales como forma de combinar su bioactividad con propiedades mecánicas apropiadas. Hasta el momento no se ha logrado determinar la proporción y la metodología para incorporar vb en los materiales dentales sin alterar su comportamiento clínico, por lo que son necesarias más investigaciones.


Bioactive glasses (bg) are ceramic materials whose chemical composition allows them to induce and conduct tissue mineralization. As these glasses can be obtained with the sol-gel method and in nanometric particle sizes, their indication has been extended and enhanced. The antibacterial properties of bg are outstanding: they are possible given the release of ions, which alkalinizes the medium, acting on the bacterial colonies. The medical and dental applications of these materials are wide, with an emphasis on bone regeneration, remineralization of hard dental tissues and treatment of hypersensitivity. However, as they are materials with an amorphous chemical structure, their mechanical properties are not good, this being their main limitation for clinical application in restorative dentistry. In this sense, scientificresearch has focused on determining the possibility of including bg in various dental materials as a way to combine bioactivity with appropriate mechanical properties. So far, it has not been possible to determine the proportion and methodology necessary to include bg in dental materials without altering their clinical behavior, which is why further research isnecessary


Os vidros bioativos (vb) são materiais cerâmicos com uma composição química tal que eles possuem a propriedade de induzir e conduzir a mineralização dos tecidos. A obtenção desses vidros por meio do método sol-gel e a possibilidade de obtenção de partículas nanométricas ampliaram e reforçaram as indicações desses materiais. As propriedades antibacterianas dovb são uma característica marcante; é devido à liberação de íons que alcaliniza o meio, atuando nas colônias bacterianas. As aplicações médicas e odontológicas desses materiais são muito amplas, destacando-se a regeneração óssea, a remineralização dos tecidos duros e o tratamento da hipersensibilidade. No entanto, por serem materiais com estrutura química amorfa, suas propriedades mecânicas não são boas, sendo essa a sua principal limitação para aplicação clínica na área de odontologia restauradora. Nesse sentido, a pesquisa científica tem se concentrado em determinar a possibilidade de incorporar vb em vários materiais odontológicos, como forma de combinar sua bioatividade com propriedades mecânicas apropriadas. Até agora, não foi possível determinar a proporção e metodologia para incorporar vb em materiais odontológicos sem alterar seu comportamento clínico, razão pela qual mais pesquisas são necessárias


Subject(s)
Humans , Tooth Remineralization , Hypersensitivity , Dental Materials , Glass
17.
Braz. dent. j ; 30(4): 350-355, July-Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1011562

ABSTRACT

Abstract The aim of this study was to evaluate the effect of different glass fiber posts (GFPs) diameters on the push-out bond strength to dentin. Forty unirradicular human teeth were endodontically treated and used for cementation of GFPs (White Post DC, FGM) with different diameters (n=10): P1 - ø 1.6 mm coronal x 0.85 mm apical; P2 - ø 1.8 mm coronal x 1.05 mm apical; P5 - ø 1.4 mm coronal x 0.65 mm apical; and PC - customized post number 0.5 with composite resin (Tetric Ceram A2, Ivoclair Vivadent). All GFPs were cemented into the root canal using a dual-curing luting composite (Variolink II, Ivoclar Vivadent). One slice (1.7 mm) of each root third of cemented GFP (cervical, middle, and apical) was submitted to push-out testing. Failure modes of all specimens were classified as: adhesive failure between resin cement and post; adhesive failure between dentin and resin cement; cohesive failure within resin cement, post or dentin; and mixed failure. The data were analyzed with two-way ANOVA and Tukey's test (a=0.05). The highest bond strength values were presented for the P2 and PC groups. There was no statistically significant difference between the GFP thirds in each group. The groups P2, P5, and PC showed predominantly adhesive failure. For P1, the most prevalent type of failure was adhesive between resin cement and post. It may be concluded that a glass fiber post that is well adapted to the root canal presents higher bond strength values, regardless of GFP third.


Resumo O objetivo neste estudo foi avaliar o impacto de diferentes diâmetros de pinos de fibra de vidro (PFVs) na resistência de união à dentina. Quarenta dentes humanos unirradiculares foram tratados endodonticamente e utilizados para cimentação de PFVs (White Post DC, FGM) com diferentes diâmetros (n=10): P1 - ø 1,6 mm coronal x 0,85 mm apical; P2 - ø 1,8 mm coronal x 1,05 mm apical; P5 - ø 1,4 mm coronal x 0,65 mm apical; e PC - pino número 0,5 individualizado com resina composta (Tetric Ceram A2, Ivoclair Vivadent). Todos os PFVs foram cimentados no canal radicular usando cimento resinoso dual (Variolink II, Ivoclar Vivadent). As raízes foram seccionadas em três secções (cervical, média e apical) e submetidas ao teste push-out. Os modos de falha de todos os espécimes foram classificados em falha adesiva entre o cimento resinoso e pino, falha adesiva entre dentina e cimento resinoso, falha coesiva no cimento resinoso, pino ou dentina e falha mista. Os dados foram analisados ​​com ANOVA two-way e teste de Tukey (a=0,05). Os maiores valores de resistência da união foram apresentados para os grupos P2 e PC. Não houve diferença estatisticamente significante entre os terços dos PFVs cimentados na raiz para cada grupo. Os grupos P2, P5 e PC apresentaram predominantemente falha adesiva entre a dentina e o cimento resinoso. Para o grupo P1, o tipo de falha mais prevalente foi a adesiva entre cimento resinoso e pino. Pode-se concluir que o pino de fibra de vidro bem adaptado ao canal radicular apresentou os maiores valores de resistência da união, independentemente do terço dos PFVs.


Subject(s)
Humans , Post and Core Technique , Dental Bonding , Materials Testing , Resin Cements , Dental Pulp Cavity , Dentin , Glass
18.
Rev. ADM ; 76(3): 146-155, mayo-jun. 2019. ilus, tab
Article in Spanish | LILACS | ID: biblio-1021703

ABSTRACT

Introducción: El uso de postes de fibra de vidrio es el método actual más utilizado para la reconstrucción postendodóncica. Sin embargo, su adhesión sigue siendo impredecible debido al control limitado de su técnica de cementación. Las resinas bulk-fill revelan valores de fuerza flexural similares a la dentina y su empleo en la reconstrucción postendodóncica podría ser una alternativa viable y conservadora. Objetivo: Comparar tres técnicas de reconstrucción postendodóncica al medir su resistencia a fuerzas de desalojo, clasificar el tipo de fractura y falla adhesiva, evaluar su costo y tiempo de trabajo. Material y métodos: Se realizan 18 muestras divididas en tres grupos: grupo 1: poste más cemento de un paso, grupo 2: poste más cemento de tres pasos y grupo 3: reconstrucción postendodóncica con resina bulk-fill. Resultados: En la evaluación de la fuerza al desalojo no se encontró diferencia estadísticamente significativa en los tres grupos. Respecto al comportamiento y falla adhesiva, se encontró una diferencia significativa p < 0.001, favoreciendo a los grupos 2 y 3, por su adhesión en la porción radicular. El tipo de fractura fue restaurable para los tres grupos. Respecto al tiempo y costo, fueron significativamente menores para el grupo 3. Conclusión: En nuestro estudio no existió diferencia significativa en la fuerza al desalojo en los tres grupos; sin embargo, la hubo en el comportamiento, falla adhesiva, costo y tiempo, favoreciendo mayormente al grupo 3. La técnica de reconstrucción con resina puede ser una técnica predecible, suficientemente resistente, conservadora, rápida y de menor costo


Introduction: The use of fiberglass posts is the current method most used for post-endodontic reconstruction. However, its adhesion remains unpredictable due to the limited control of its cementing technique. Bulkfill resins reveal values of flexural strength similar to dentin and their use in post-endodontic reconstruction could be a viable and conservative alternative. Objective: Compare three post-endodontic reconstruction techniques by measuring their resistance to eviction forces, classifying the type of fracture and adhesive failure, evaluating their cost and time of work. Material and methods: 18 samples are divided into 3 groups: group 1: post plus cement of 1 step, group 2: post plus cement of 3 steps and group 3: post-endodontic reconstruction with bulk-fill resin. Results: In the evaluation of the force to the eviction, no statistically significant difference was found in the 3 groups. Regarding the behavior and adhesive failure, a significant difference was found p < 0.001, favoring groups 2 and 3, due to its adhesion in the root portion. The type of fracture was restorable for the 3 groups. Regarding time and cost, they were significantly lower for group 3. Conclusion: In our study there was no significant difference in the force to the eviction in the three groups, however there was in the behavior, adhesive failure, cost and time, favoring mainly the group 3. The technique of reconstruction with resin can be a predictable technique, Sufficiently resistant, conservative, fast and of lower cost (AU)


Subject(s)
Post and Core Technique , Composite Resins , Dental Restoration, Permanent , Statistical Analysis , Dental Bonding , Glass , Mexico
19.
Braz. dent. j ; 30(2): 106-116, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-1001439

ABSTRACT

Abstract The aim of this study was to evaluate the push-out bond strength and interface permeability of glass-fiber posts in different regions of post space (cervical, middle, and apical) submitted to different irrigation solutions. Ninety single-rooted human teeth were submitted to endodontic treatment and divided into five groups, according to irrigation solutions: distilled water, 5.25% NaOCl, 25% polyacrylic acid, 2% chlorhexidine, and 23 ppm Ag NP dispersion. Each group was divided in 3 subgroups (n=6) according to cementation: SBU: Adper Scotchbond Universal + RelyX ARC; U200: RelyX U200; MCE: MaxCem Elite. Bond strength and sealing ability were measured in different areas of post space. The data was subjected to ANOVA and Fisher's test (a=0,05). The silver nanoparticle solution showed highest bond strength values and lowest interface permeability in all thirds analyzed for SBU group. In the U200 group, the highest bond strength values were found for sodium hypochlorite solution, with significant difference between this solution and polyacrylic acid. A decrease in bond strength values in cervical to apical direction was found for MCE group and the same behavior were found for others groups. Regarding interface permeability, use of silver nanoparticle solution resulted in lower values in cervical and apical thirds. There was a decrease in bond strength in cervical to apical direction. Different irrigation solutions and intraradicular depth influenced the bond strength and interface permeability of adhesive material to dentin substrate. Silver nanoparticle solution can effectively be used as an irrigation agent in post space prior to fiber post cementation process.


Resumo O objetivo deste trabalho foi avaliar a resistência de união e permeabilidade da interface de pinos de fibra de vidro nos diferentes terços da dentina intrarradicular (cervical, médio e apical) submetidos a diferentes agentes irrigantes. Noventa dentes unirradiculares humanos foram submetidos ao tratamento endodôntico e foram divididos em cinco grupos de acordo com os agentes irrigantes: água destilada, hipoclorito de sódio 5,25%, ácido poliacrílico 25%, clorexidina 2% e dispersão de nanopartícula de prata à 23 ppm. Os grupos foram divididos em 3 subgrupos (n=6) de acordo com a técnica adotada para cimentação adesiva dos pinos de fibra de vidro: Grupo SBU: sistema adesivo ScotchbondTM Universal + cimento resinoso RelyX ARC; Grupo U200: cimento resinoso autoadesivo RelyX U200; Grupo MCE: cimento resinoso autoadesivo Maxcem Elite. A resistência de união e a permeabilidade da interface foram mensurados em diferentes áreas da dentina intrarradicular. Os dados foram submetidos a ANOVA e teste de Fisher (a=0,05). Amostras representativas foram levadas à microscopia eletrônica de varredura. A solução de nanopartícula de prata apresentou os maiores valores de resistência de união em todos os terços analisados para o grupo SBU. No grupo U200, os maiores valores foram encontrados para a solução de hipoclorito de sódio, com diferença para o ácido poliacrílico. Observou-se uma diminuição nos valores de resistência de união na direção cérvico-apical para o grupo MCE e o mesmo comportamento foram encontrados para os demais grupos. Com relação a permeabilidade da interface, o uso da solução de nanopartícula de prata resultou em menores valores nos terços cervical e apical. Houve diminuição dos valores de resistência de união no sentido cérvico-apical. As diferentes soluções irrigantes, bem como a profundidade intrarradicular influenciaram a resistência de união e permeabilidade da interface dos materiais adesivos ao substrato dentinário. A nanopartícula de prata pode ser utilizada como agente irrigador do conduto radicular previamente à cimentação de pinos de fibra de vidro.


Subject(s)
Humans , Post and Core Technique , Dental Bonding , Metal Nanoparticles , Silver , Materials Testing , Resin Cements , Dentin , Glass
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