Influencia de diferentes intensidades de luz en la resistencia de unión de un sistema adhesivo utilizando un colorante fluorescente para su observación

The purpose of this study was to use a fluorescent dye and CLSM microscope to observe the effect of different light intensities on dentin tensile bond strength. Flat dentin surfaces were created on 16 intact human third molars and divided in 4 groups: Group G1 - halogen - KM -200R®; Group G2 - LED - Ultraled®; Group G3 - LED - UltraLume LED5® and Group G4 - LED - Biolux Single V®. For all the groups, the restoration procedure used Single Bond® adhesive, mixed with rodamin B and InTen-S® composite resin. Then, they were cut on serial sections to obtain 1 mm2 area and submitted to micro tensile test and after words, the fractures were analyzed with a digital microscope and CLSM. The statistical analysis showed that all in all groups, except Group G2, which had a significant smaller tensile bond strength ratio. The fracture mode analysis showed that there were significant differences when comparing groups G1 / G2, and G2 / G4. There is no evidence of relevant differences among the other groups. With these results, we conclude that the use of fluorescent dye and CLSM demonstrated to be a simple and nondestructive technique, and that there are evidences that light intensities influenced the dentine tensile.El objetivo de este trabajo fue el de utilizar un colorante fluorescente y microscopio CLSM para observar la influencia de diferentes intensidades de luz en la resistencia de unión de un sistema adhesivo. Para tal fin, fueron creadas superficies planas en la dentina de 16 dientes terceros molares y divididos en 4 grupos: Grupo G1 - Foto-activador halógeno - KM-200R®; Grupo G2 - Foto-activador LED - Ultraled®; Grupo G3 - Foto-activador LED - UltraLume®LED5 y Grupo G4 - Foto-activador LED - Biolux Single V®. Para todos los grupos el procedimiento restaurador fue realizado utilizando el adhesivo Single Bond® pigmentado con rodamina B y la resina compuesta InTen-S®. Seguidamente, cada conjunto fue cortado, resultando en espécimen de aproximadamente 1 mm2 de sección transversal, que luego fue seleccionado y llevado al test de micro-tracción para finalmente ser examinado con un microscopio digital y de CLSM. Los resultados mostraron luego de la evaluación estadística que el grupo 2 obtuvo valores medios de resistencia adhesiva significativamente menores que los demás grupos, que fueron semejantes entre si. Con relación al tipo de fractura, hubo diferencia entre los grupos G1 / G2 y entre los grupos G2 / G4; entre los otros grupos no hubo evidencia de diferencias significativas. Con esos resultados concluimos que la utilización de pigmentos fluorescentes y CLSM demostró ser una técnica simple y no destructiva, así también como la existencia de evidencias de que la intensidad de la luz foto-activadora influenció en la resistencia de unión en dentina

Effect of Er:YAG laser and diamond drill on hybrid layer morphology obtained with self-etch adhesive: analysis by SEM and confocal laser scanning microscopy (CLSM)

This study aimed to evaluate the effect of Er:YAG (L) and diamond drills (DD) on: 1) the microshear bond strength (MPa); 2) the adhesive interface of two-step (TS) – Adper Scotchbond Multipurpose and one-step (OS) adhesives – Adper EasyOne, both from 3M ESPE. Material and methods: According to the preparation condition and adhesives, the samples were divided into four groups: DD_TS (control); DD_OS; L_TS and L_OS. 60 bovine incisors were randomly divided into experimental and groups: 40 for microshear bond strength (n = 10) and 20 for the adhesive interface morphology [6 to measure the thickness of the hybrid layer (HL) and length of tags (t) by CLSM (n = 3); 12 to the adhesive interface morphology by SEM (n = 3) and 2 to illustrate the effect of the instruments on dentine by SEM (n = 1)]. To conduct the microshear bond strength test, four cylinders (0.7 mm in diameter and 1 mm in height with area of adhesion of 0.38 mm) were constructed with resin composite (Filtek Z350 XT – 3M ESPE) on each dentin surface treated by either L or DD and after adhesives application. Microshear bond strength was performed in universal testing machine (EMIC 2000) with load cell of 500 kgf and a crosshead speed of 0.5 mm / min. Adhesive interface was characterized by thickness of hybrid layer (HL) and length of tags (t) in nm, with the aid of UTHSCSA ImageTool software. Results: Microshear bond strength values were: L_TS 34.10 ± 19.07, DD_TS 24.26 ± 9.35, L_OS 33.18 ± 12.46, DD_OS 21.24 ± 13.96. Two-way ANOVA resulted in statistically significant differences only for instruments (p = 0.047). Mann-Whitney identified the instruments which determined significant differences for HL thickness and tag length (t). Concerning to the adhesive types, these differences were only observed for (t). Conclusion: It can be concluded that 1) laser Er:YAG results in higher microshear bond strength values regardless of the adhesive system (TS and OS); 2) the tags did not significant affect the microshear bond strength; 3) the adhesive interface was affected by both the instruments for cavity preparation and the type of adhesive system used

Color stability of conventional and bulk fill composite resins

Objective: This study compared the color stability of different dental composite resins after prolonged exposure to a coffee solution. Methods: Sixty-four cylindrical discs (10 mm diameter x 2 mm thickness) were prepared using 8 different dental composite resins (n=8, per group). The specimens were first immersed in artificial saliva for 24 h followed by immersion in a coffee solution for 14 days. The assessment of chromatic variation (ΔE) was performed with the aid of a Vita Easyshade Advanced spectrophotometer (VITA Zahnfabrik, Bad Sackingen, Germany). The color of each specimen was calculated based on the L*, a* and b* coordinates of the CIELab system. Results: Grandio SO had the lowest average chromatic variation (ΔE=7.77) after immersion in coffee solution. Durafill VS, Grandio and Z350 XT (ΔE=8.58; ΔE=9.52; ΔE=10.39, respectively) showed similar chromatic variation, with no statistical difference in relation to Grandio SO. However, the other dental composite resins evaluated showed statistically higher values of ΔE compared to Grandio SO, and Enamel HRi (ΔE=20.56) demonstrated the highest chromatic variation. Conclusion: The Bulk Fill and hybrid composite resins from the same manufacturer (Micerium, Avegno, Italy) showed greater chromatic variation than the other composite resins tested. Grandio SO (Voco, Cuxaven, Germany) had the lowest ΔE variation

Clareamento interno em dentes despolpados como alternativa a procedimentos invasivos: relato de caso

The increasing interest of patients for a better aesthetic appearance of their smile, associated with the development of new materials and techniques, encouraged by media couverage of this concept of beauty, provided an important evolution of cosmetic dentistry. As the darkness of a single anterior tooth or a group of teeth, in most cases, impairs the appearance of the smile and there is growing appreciation of the less invasive procedures, the technique of tooth bleaching is an important option for aesthetic treatment. To have success in the bleaching treatment, it is important to have knowledge of the origin, nature and composition of the stain. Among the causes of color changes acquired post-eruptive, dental trauma, with or without pulp necrosis, is one of the most commonly encountered etiologies, characterized by a reddish-brown color. Current techniques of bleaching for teeth treated endodontically employ oxidative agent hydrogen peroxide. The objective of this paper is to describe the immediate technique of bleaching non-vital tooth by presenting a clinical case.O crescente interesse dos pacientes por uma melhor aparência estética do sorriso, associado ao desenvolvimento de novos materiais e técnicas, incentivados por uma divulgação na mídia desse conceito de beleza, propiciou uma evolução importante da odontologia estética. Como o escurecimento de um único dente anterior ou de um grupo de dentes, na maioria das vezes, interfere negativamente na aparência do sorriso e há cada vez mais uma valorização dos procedimentos menos invasivos, a técnica de clareamento dental representa uma opção importante de tratamento estético. Para que se tenha sucesso no tratamento clareador, é importante ter o conhecimento da origem, da natureza e da composição da mancha. Entre as causas das alterações de cor adquiridas pós-eruptivas, o traumatismo dental, associado ou não à necrose pulpar, é uma das etiologias mais comumente encontradas, caracterizando-se por uma coloração marrom-avermelhada. As atuais técnicas de clareamento para dentes tratados endodonticamente empregam como agente oxidativo o peróxido de hidrogênio. O objetivo deste artigo é descrever a técnica imediata de clareamento de dente não vital por meio da apresentação de um caso clínico

Efeitos da aplicação de resina hidrofóbica sobre a resistência de união de adesivos autocondicionantes de frasco único

Introduction: It is known that self-etching adhesive systems can act as semi-permeable membranes. Objective: Evaluate the effects of additional layer of hydrophobic resin on the microtensile bond strength of self-etching one-bottle adhesives. Material and method: Sixty bovine incisors were used in this study. The facial enamel surfaces of the crowns were abraded with silicon carbide paper to expose flat, mid-coronal dentin surfaces. The following adhesives were used: Clearfil Tri S Bond (CTSB), AdheSE One (ADH) and One Coat  7.0 (OC). Each material was tested with and without applying an additional layer of hydrophobic material from the same manufacturer. Z-350 composite resin was inserted in three 1 mm increments. All adhesive restorative procedure was performed under simulated pulpal pressure and the microtensile test was performed immediately after curing the composite resin. Data were submitted to ANOVA and Tukey test (p < 0.05). Result: For all adhesives tested, the worst results were observed in groups which the additional layer of hydrophobic resin was not applied. Conclusion: The application of additional layer of hydrophobic material can improve the adhesion of self-etching all-in-one adhesive systems.Introdução: Sabe-se que sistemas adesivos autocondicionantes podem atuar como membranas semipermeáveis, o que pode comprometer a adesão. Objetivo: Buscou-se avaliar os efeitos da aplicação adicional de resina hidrofóbica sobre a resistência de união à microtração de sistemas adesivos autocondicionantes de frasco único sobre dentina bovina. Material e método: Sessenta incisivos bovinos tiveram a face vestibular desgastada até se obter superfície dentinária plana. Foram utilizados os seguintes sistemas adesivos: Clearfil Tri S Bond (CTSB), AdheSE One (ADO) e One Coat  7.0 (OC). Os sistemas adesivos foram testados com (G4, G5, G6) e sem (G1,  G2,  G3) a aplicação de camada adicional de material hidrofóbico do mesmo fabricante (Clearfil SE Bond, AdheSE e One Coat SE, respectivamente), resultando em seis grupos experimentais (n  =  10). Após o procedimento adesivo, resina composta Z-350 foi inserida em três incrementos de 1 mm. Todo o procedimento adesivo restaurador foi executado sob pressão pulpar simulada e o teste de microtração foi executado imediatamente após a polimerização da resina composta. Os dados obtidos foram submetidos à ANOVA e ao teste de Tukey (p < 0,05). Resultado: Para todos os adesivos testados, os piores resultados foram observados nos grupos em que a camada adicional de resina hidrofóbica não foi aplicada. Conclusão: A aplicação de camada adicional de material hidrofóbico pode melhorar a resistência de união de sistemas adesivos autocondicionantes de passo único

Sistemas cerámicos puros parte 2: materiales, propiedades ópticas y consideraciones clínicas

While dentistry continues to advance, the aesthetic techniques have evolved in proceedings more effective, functional and biocompatible. Meanwhile, cosmetic dentistry has become a bit more complex and technically difficult. With improvement of the properties (physical and optical) of the ceramics and the establishment of a working protocol, ceramic restorations have become increasingly popular. Currently there are several ceramic systems have excellent optical properties such as opalescence, fluorescence, translucency, chromaticity, which allow the restoration to mimic the tooth structure. From the physical point of view has restored biomechanical integrity and strengthening the remaining tooth structure. All this has led the profession to experience the use of new ceramic systems ranging from conventional feldspathic ceramics to modem ceramic reinforced, injected or computer-aid made. The material selection should be based on clinical need, aesthetic and functional requirements, restoration site, prosthetic design and laboratory techniques. In this article we will deal with the characteristics of the materials, their optical properties and clinical considerations for proper selection.Mientras la odontología continúa avanzando, las técnicas estéticas han evolucionado en procedimientos más efectivos, funcionales y biocompatibles. Al mismo tiempo, la odontología estética se ha tornado un poco más compleja y técnicamente dificultosa. Con la mejoría de las propiedades (físicas y ópticas) de las cerámicas y el establecimiento de un protocolo de trabajo, las restauraciones cerámicas se han tornado cada día más populares. Actualmente existen diversos sistemas cerámicos que poseen excelentes propiedades ópticas como opalescencia, fluorescencia, translucidez, cromaticidad, que permiten mimetizar la restauración a la estructura dentaria. Desde el punto de vista físico se ha logrado devolver integridad biomecánica y estructural reforzando al remanente dentario. Todo esto ha llevado a la profesión a experimentar el uso de nuevos sistemas cerámicos que van desde las convencionales cerámicas feldespáticas hasta las modernas cerámicas reforzadas, inyectadas o confeccionadas con auxilio de computadoras. Su selección debe estar basada en la necesidad clínica, exigencias estéticas y funcionales, localización de la restauración, diseño protético y técnicas de laboratorio. Durante este artículo estarán abordadas las características de los materiales, sus propiedades ópticas y consideraciones clínicas para una correcta selección

Sistemas cerámicos puros parte 1: una evolución basada en la composicíon

The continuing advances in technology, dental materials and equipment have contributed significantly to improve the level of esthetic dentistry today. Among these innovations, development of pure ceramic restorations has evolved to give different alternatives. Dental ceramics have presented a rapidly technological changing to improve mechanical and optical properties. Currently there are several systems of metal free ceramics with excellent mechanical and optical properties, for making crowns and plurals. These modern systems are presented with various compositions and different preparation techniques, making these more versatile. Within this perspective, the dental market offers a huge range of new indirect and metal-free materials for prostheses, providing new options, plus also new questions to decide among the available alternatives. The aim of this review is take a view of the different ceramic systems in terms of its composition and different techniques of production.Los continuos avances en la tecnología, materiales dentales y equipamientos han contribuido significativamente con el nivel que la Odontología estética está logrando hoy. Entre estas innovaciones, el desarrollo de restauraciones de cerámica pura ha evolucionado aportando diferentes alternativas. Las cerámicas han presentado una rápida evolución desde el punto de vista tecnológico con el objetivo de mejorar las propiedades mecánicas y ópticas. En la actualidad existen varios sistemas de cerámicas libres de metal con propiedades mecánicas y ópticas excelentes, para la confección de coronas unitarias y plurales. Estos sistemas modernos se presentan con variadas composiciones y diferentes técnicas de confección, haciendo de estos más versátiles. Dentro de esta perspectiva, el mercado odontológico ofrece una gama enorme de nuevos materiales indirectos y sistemas libres de metal para la confección de prótesis, lo que proporciona nuevas opciones, más también nuevas interrogantes para decidir entre las alternativas disponibles. En este contexto esta revisión de la literatura tiene como objetivo abordar los diferentes sistemas cerámicos del punto de vista de su composición y sus diferentes técnicas de obtención

Hidden caries: a critical review

Hidden caries is a type of lesion visualized in dentin, mainly by means of bitewing radiographs, in which, clinically, the occlusal enamel appears healthy or minimally demineralized and radiographically presents progressive demineralization in dentin, which may progress and compromise the pulp-dentin complex. Although the etiology of hidden caries is unknown, many theories have been studied, including structural and anatomical defects of enamel, their specific microbiota and the use of fluoride, which is most accepted theory. Considering the clinical concern, since these lesions have a silent progression and often are not detected on routine clinical examinations, this study aims to conduct a critical discussion of the etiology, prevalence, diagnostic methods and treatment decision for lesions of hidden caries, alerting professionals about the importance of routine use of bitewing radiographs even in patients considered “cariesfree” or low risk of caries, for more effective diagnosis

In-Office dental bleaching efficacy assessment in function of the light exposure regime by digital colometric reflectance spectroscopy

In-office dental bleaching has been subject of several studies. Generally those studies quantify through visual analysis, the shade reduction of the teeth submitted to different bleaching protocols (light sources, bleaching agent concentrations and irradiation time). The objective of this work is the determination of the influence of four irradiation protocols on the obtainment of better aesthetic results using a colorimetric spectrophotometer that quantifies color changes in each situation imposed. Forty bovine incisors were selected in function of similar anatomic characteristics; a concentrated coffee solution was used to stain the teeth. A commercial spectrophotometer was used to measure the color changes during evolution of the experiment (stain and bleaching phases) and the obtained data was analyzed by the ANOVA test. The obtained data showed the evolution of teeth color during the staining period, as well as, the color reduction that each bleaching protocol achieved. Based on our findings it is possible to conclude that bleaching protocols with larger irradiation periods did not showed significant differences when compared with shorter irradiation protocols, in that way the use of protocols with 30 min or more of consecutive irradiation are not clinically justified and also can cause several side effects