Uso de dientes bovinos como elección para trabajos de investigación en odontología / The use of bovine teeth as a choice for dental investigation papers

Los dientes animales de las diferentes especies (hu- mano, equino, cerdo, etc.) están constituidos histológi- camente por cuatro tejidos fundamentales. Ellos son: esmalte, dentina, cemento y pulpa dental. Su compo- sición, estructura, morfología y tamaño son disímiles para cada género. Según numerosas investigaciones, los dientes de bovino serían los de elección por ser de fácil obtención y por tener muy pocas, o ninguna, diferencias tanto a nivel macro como microscópico con respecto a los dientes humanos. El objetivo de la presente revisión es aportar información actualizada acerca de las características histológicas de los tejidos dentarios bovinos y profundizar el conocimiento de las similitudes y diferencias de los dientes bovinos y humanos dando soporte a otros estudios compa- rativos y promoviendo la utilización de las piezas dentarias bovinas en trabajos de investigación en odontología (AU)

The animal teeth of the different species (human, equine, pig, etc.) are histologically constituted by four fundamental tissues: enamel, dentin, cement and dental pulp. Their composition, structure, morphology and size are dissimilar for each gender. According to numerous investigations, bovine teeth would be the ones of choice because they are easy to obtain and have very few or no differences, both at the macro and microscopic levels, with respect to human teeth. The objective of this review is to provide updated information about the histological characteristics of bovine dental tissues and deepen the knowledge of the similarities and differences between bovine and human teeth, supporting other comparative studies and promoting the use of bovine dental pieces in research work in dentistry (AU)

El esmalte dental bovino como modelo experimental para la investigación en odontología: una revisión de la literatura / Bovine dental enamel as experimental model for research in dentistry. A literature review

El propósito de esta revisión bibliográfica es aportar información actualizada acerca de las características de los dientes bovinos en relación con su uso como sustitutos de dientes humanos en trabajos de investigación. De acuerdo con la información registrada, los dientes bovinos serían excelentes sustitutos de la dentición humana para la realización de ensayos de laboratorio con el esmalte dental como modelo experimental (AU)

The purpose of this bibliographic review is to provide updated information about the characteristics of bovine teeth to be used as substitutes for human teeth in dental research. According to the information recorded, bovine teeth appear to be excellent substitutes for human dentition for conducting laboratory tests, using dental enamel as an experimental model (AU)

Esmalte en terminología: concordancia y propuesta para terminologia anatomica, histologica y embryologica / Enamel in terminology: concordance and proposal for anatomical, histological and embryological terminology

El esmalte dental es una estructura considerada en Terminologia Anatomica, Histologica y Embryologica. Los términos incluidos relacionados a él presentan tres raíces asociadas: enamel, amelo y adamantino. El objetivo de este artículo es analizar la etimología de estas raíces y presentar propuestas en latín y español que unifiquen las denominaciones relacionadas al esmalte dentario. En la búsqueda fueron utilizaron diccionarios médicos, terminológicos y etimológicos. Los resultados obtenidos señalan tres orígenes diferentes para cada raíz: adamantino es un término grecolatino relacionado a la extrema dureza de una estructura; enamel tiene un origen anglo-normando y antiguo alto germánico relacionado a la acción de fundir, derretir, y el aspecto estético que esto produce en un material; y amelo, el cual en sí mismo está relacionado a la botánica mientras que el término completo ameloblasto, fue acuñado por un académico estadounidense. Si bien la etimología de adamantino y enamel señalan características de firmeza y estética, respectivamente, en el desarrollo de la propuesta se decidió mantener el término latinizado enamelum y su adjetivo enameleus, eliminando las otras dos raíces relacionadas al esmalte dentario. Se realizó la propuesta para los cambios en los términos del idioma latín y su traducción al español, acorde a los requerimientos de la FIPAT para Terminologia Anatomica, Histologica y Embryologica, con el fin de unificar la denominación de los términos asociados y derivados del esmalte dental, para fines académicos y de investigación.

Dental enamel is a structure considered in Anatomical, Histological and Embryological Terminology. The included terms related to it have three associated roots: enamel, amelo and adamantino. The objective of this article is to analyze the etymology of these roots and present proposals in Latin and Spanish that unify the denominations related to tooth enamel. In the search, medical, terminological and etymological dictionaries were used. The results obtained indicate three different origins for each root: adamantine is a Greco-Roman term related to the extreme hardness of a structure; enamel has an Anglo-Norman and ancient high Germanic origin related to the action of melting, melting, and the aesthetic appearance that this produces in a material; and amelo, which in itself is related to botany while the full term ameloblast, was coined by an American academic. Although the etymology of adamantine and enamel indicate characteristics of firmness and aesthetics, respectively, in the development of the proposal it was decided to maintain the Latinized term enamelum and its adjective enameleus, eliminating the other two roots related to dental enamel. The proposal was made for changes in the terms of the Latin language and its translation into Spanish, according to the requirements of the FIPAT for Anatomical, Histological and Embryological Terminology, in order to unify the denomination of the associated terms and derivatives of dental enamel, for academic and research purposes.

Effects of bleaching using 10% carbamide peroxide with calcium or amorphous calcium phosphate on enamel mineral content and hardness / Asociación entre la severidad de Hipomineralización Incisivo-Molar (HIM) y lesiones cavitadas de caries en escolares

ABSTRACT This study evaluated enamel mineral content and surface microhardness before and after bleaching treatment using 10% carbamide peroxide (CP) containing calcium (Ca) or amorphous calcium phosphate (ACP). Thirty-six bovine slabs were randomly allocated into 3 groups (n = 12) according to bleaching treatment: G1 - Opalescence PF 10% (CP), G2 -NiteWhite ACP (CP+ACP), and G3 - Opalescence PF (10%) with calcium (CP+CA). The bleaching agent was applied on enamel surface for 6 h/day over a period of 21 days. Enamel surface was evaluated by Knoop microhardness (KNH) and micro energy-dispersive X-ray fluorescence spectrometry (p-EDXRF) at baseline and at after bleaching treatment. Data were statistically analyzed by repeated measures ANOVA and Tukey's test (a = 0.05). There was a significant decrease in microhardness after bleaching treatments for all study groups, but no difference between bleaching gels. There was no difference in the Ca/P ratio measured by p-EDXRF for all groups at the study times, but the mean value was lower in group CP+CA than in group CP+ACP. Group CP was similar to both CP+ACP and CP+CA. It can be concluded that enamel microhardness decreased after the bleaching process, regardless of the presence of calcium or ACP, but there was no significant change in the Ca/P ratio of enamel after bleaching for each tested gel. This indicates that the bleaching gels have erosive potential, causing softening of enamel without promoting surface loss, regardless of the presence of calcium of ACP ions.

RESUMO Este estudo avaliou o conteúdo mineral do esmalte e a microdureza superficial antes e após o tratamento clareador, utilizando peróxido de carbamida 10% (PC) contendo cálcio (Ca) ou fosfato de cálcio amorfo (ACP) em sua composigao. Trinta e seis espécimes de esmalte bovino foram alocados aleatoriamente em 3 grupos (n = 12) de acordo com os tratamentos clareadores: G1 - Opalescence PF 10% (CP), G2 -NiteWhite (CP+ACP); e G3 - Opalescence PF (10%) com cálcio (CP + CA). O agente clareador foi aplicado na superficie do esmalte por 6 h/dia por um periodo de 21 dias. A superficie do esmalte foi avaliada por microdureza Knoop (KNH) e espectrometria de fluorescencia de raios X micro-dispersiva (p-EDXRF) no inicio e após o tratamento clareador. Os dados foram analisados estatisticamente pelo teste ANOVA de medidas repetidas e Tukey (a = 0,05). Houve uma diminuigao significativa da microdureza após os tratamentos clareadores para todos os grupos estudados, mas nao houve diferenga entre os diferentes géis. Nao houve diferenga da relagao Ca/P mensurada por p-EDXRF para todos os grupos nos tempos estudados; no entanto, o grupo CP+CA apresentou menor valor comparado ao grupo CP+ACP. O grupo CP foi similar aos grupos CP+ACP e CP+CA. Portanto, pode-se concluir que houve redugao significativa da microdureza do esmalte após o clareamento, independente da presenga de cálcio ou APC na composigao dos géis, embora nao tenha havido alteragao significando na relagao Ca/P do esmalte após o clareamento. Isto indica um potencial erosivo dos géis clareadores, causando o amolecimento sem perda da estrutura do esmalte, independente da presenga dos íons cálcio e ACP.

Bandas de Hunter-Schreger: propuesta terminológica / Hunter-Schreger bands: terminological propose

Las Bandas de Hunter-Schreger (BHS), son bandas claras y oscuras, que se aprecian en el esmalte debido a la distínta curvatura de los prismas del esmalte, resultan ser ampliamente mencionadas en estudios, tanto odontológicos como antropológicos, mas no se ven reflejadas en Terminologia Histologica. El objetivo del presente trabajo fue realizar un análisis del término BHS, con el fin de proponerlo como nuevo término histológico, y así poder ser incluido en Terminologia Histologica por la Federative International Programme for Anatomical Terminology (FIPAT). Luego del análisis en textos de estudio y publicaciones científicas, proponemos en reemplazo del término BHS, por dos términos: diazone prismatica (diá del griego δι á 'a través de' y del griego zon(e) ζωνη 'faja', 'zona de la tierra') y parazone prismatica (pará gr. 'a lo largo de' y del griego zon(e) ζωνη 'faja', 'zona de la tierra'), definiendo así términos más descriptivos y que no utilizan epónimos, tal como lo establece la Terminología Internacional. Proponer nuevos términos que estén más acorde con los señalado por la International Federation of Associations of Anatomists (IFAA) y la propia terminología, presenta grandes desafíos; un término no sólo es una palabra que hace referencia a una estructura morfológica, sino que también es una unidad del lenguaje, que une a la comunidad morfológica en un solo lenguaje. Por lo cual proponemos que el término sea incluido por la FIPAT en próximas discusiones.

Hunter-Schreger Bands (HSB), are light and dark bands, which can be seen in the enamel due to the different curvature of the enamel prisms, they are widely mentioned in studies, both dental and anthropological, but are not reflected in Terminologia Histologica. The aim of the present work was to carry out an analysis of the HSB term, in order to propose it as a new histological term, and thus be able to be included in Terminologia Histologica by the Federative International Program for Anatomical Terminology (FIPAT). After the analysis in study texts and scientific publications, we propose in replacement of the term HSB, for two terms: diazone prismatica (diá of Greek δι á 'through' and of Greek zon(e) ζωνη 'strip', 'zone of the earth') and parazone prismatica (pará gr. 'along' and from the Greek zon(e) ζωνη 'strip', 'zone of the earth'), thus defining the most descriptive and noneponymous terms, as the International Terminology says. Propose new terms that are more in agreement with those indicated by the International Federation of Associations of Anatomists (IFAA) and the own terminology, presents great answers; A term is not only a word that refers to a morphological structure, but also a unit of language, which unites the morphological community in a single language. So we propose that the term sea included by the FIPAT in the next discussions.

Smile makeover by veneers ­ case report / Sonrisa mejorada por carillas dentales - reporte de un caso

Ceramic veneers have evolved in the last few years as an aesthetic restoration in the field of aesthetic dentistry. It is a conservative option as compared to full coverage crowns for improving the patients smile. Ceramic veneers are widely used for smile designing in patients with fluorosis, midline diastema, hypoplastic teeth, and peg shape laterals. Clinical relevance: This article highlights the smile designing of a young patient with fluorosis using ceramic veneers, which not only improves the smile of the patient but has positive psychological benefits.

Las carillas de cerámica han evolucionado en los últimos años como una restauración estética en el campo de la odontología estética. Es una opción conservadora para mejorar la sonrisa de los pacientes en comparación con las coronas de cobertura total. Las carillas de cerámica se usan ampliamente para el diseño de sonrisas en pacientes con f luorosis, diastema de la línea media, dientes hipoplásicos, o laterales en forma de clavija. Relevancia clínica: este artículo destaca el diseño de la sonrisa en un paciente joven con f luorosis utilizando carillas de cerámica, que no solo mejora la sonrisa del paciente sino que entrega beneficios psicológicos.

Uso de terminologia histologica en textos de histología oral: capítulo esmalte / Use of terminologia histologica in oral histology texts: enamel chapter

Para la enseñanza y aprendizaje de cualquier disciplina es clave el uso de una terminología clara y definida. Particularmente en el caso de Morfología, el rol de Programa Federativo Internacional de Terminología Anatómica (FIPAT) ha permitido avanzar a lograr la máxima unificación de la terminología asociada a esta disciplina, que considera múltiples variaciones lingüísticas en sus términos, dificultando su comprensión y difusión. Para que esta labor tenga un impacto más profundo en el uso correcto de la terminología internacional se debe articular un trabajo con los procesos de formación profesional que incorporan esta disciplina. El objetivo principal del presente estudio fue analizar la correcta utilización de Terminologia Histologica en los textos de estudios de Histología Oral, disponibles en Chile. Para este trabajo, se realizó un análisis de 4 textos de Histología Oral, dentro de los cuales se encontraban los 2 más utilizados por los estudiantes según las bases de datos de biblioteca de tres Universidades chilenas tanto públicas como privadas, además de 2 textos del área en idioma distinto al español (inglés y portugués). El análisis consistió, comparar el uso de los términos histológicos del capítulo "Esmalte" con los términos incluidos en Terminologia Histologica. Además de registrar errores en la denominación de términos tales como, eponimias, sinonimias y comparar con dos idiomas distintos al español, con el fin de descartar la traducción como problema principal. De los textos analizados el 100 % presentaba una mayor cantidad de términos histológicos en comparación con los 14 descritos por Terminologia Histologica, de los cuales solo 7 son nombrados en la totalidad de los textos. Se encontraron 59 términos para las distintas estructuras del esmalte entre todos los textos, de éstos, solo 15 son nombrados conjuntamente en los cuatro textos y 7 poseen un término asignado en FIPAT. Además son descritas múltiples estructuras que no están construidas bajo las consideraciones de la FIPAT, presentando eponímias y sinonimias. Llama la atención que la mayoría de los términos extraídos no poseen representación en Terminologia Histologica además del uso predominante de epónimos y sinónimos tanto entre los textos de estudio como dentro de los mismos encontrándose veinte términos con más de un nombre. A partir de estos resultados se sugiere realizar las modificaciones pertinentes además de proponer focos para mejorar el uso de Terminologia Histologica en la formación de los futuros profesionales.

For the teaching and learning of any discipline the use of a clear and defined terminology is key. Particularly in the case of Morphology, the role of the International Federative Program of Anatomical Terminology (FIPAT) has made it possible to advance towards the maximum unification of the terminology associated with this discipline, which considers multiple linguistic variations in its terms, hindering its understanding and dissemination. For this work to have a more profound impact on the correct use of international terminology, work must be articulated with the vocational training processes that incorporate this discipline. The main objective of the present study was to analyze the correct use of Terminologia Histologica in the texts of Oral Histology studies, available in Chile. For this work, an analysis of 4 texts of Oral Histology was carried out, among which were the 2 most used by students according to the library databases of three Chilean universities, both public and private, as well as 2 texts from the area. in a language other than Spanish (English and Portuguese). The analysis consisted in comparing the use of the histological terms of the "Enamel" chapter with the terms included in Terminologia Histologica. In addition to registering errors in the denomination of terms such as, eponymias, synonimies and compare with two languages ??other than Spanish, in order to rule out translation as the main problem. Of the texts analyzed, 100 % had a greater number of histological terms compared to the 14 described by Terminologia Histologica, of which only 7 are named in all the texts. 59 terms were found for the different enamel structures among all the texts, of these, only 15 are named together in the four texts and 7 have a term assigned in FIPAT. In addition, multiple structures are described that are not constructed under the considerations of the FIPAT, presenting eponyms and synonyms. It is noteworthy that most of the extracted terms do not have representation in Terminologia Histologica besides the predominant use of eponyms and synonyms either, between the various texts or within them, and twenty terms can be found with more than one name. From these results it is suggested that pertinent modifications be made, in addition to proposing foci to improve the use of Terminologia Histologica in the training of future professionals.

Perikymata: a non-existent term: a scientific literature invention? Terminology analysis and proposal / Periquematíe: un término inexistente. ¿una invención de la literatura? Análisis de la terminología y propuesta

SUMMARY: The constant and gradual apposition of the enamel during odontogenesis forms different histological structures on the tooth, including the perikymata, which appear on the crown surface as ridges between two imbrication lines. Although they are enameldependent structures described in various scientific texts and publications, they are not included in the enamel-dependent histological terms published in the Terminologia Histologica. The aim of this study was to analyze the term perikymata from a linguistic point of view and propose it as a new histological term. The word perikymata is derived from the Greek words perí 'around'+ kyma, 'wave', introduced by Preiswerk in 1895. Although the term is descriptive in itself, concentrating only information about the structure in a single word, as the terminology establishes, this does not indicate its location. We propose the term perikymata enamelis (perikymata of the enamel) be added. Although proposing new terms that are more in line with the International Federation of Associations of Anatomists (IFAA) and its terminology poses great challenges, a term is not just a word that makes reference to a morphological structure, it is also a unit of language, a means of communication, which in this case unites the morphological community in a single language.

RESUMEN: La aposición constante y paulatina del esmalte, durante la odontogénesis, forman en el diente distintas estructuras histológicas, uno de ellas son los perikymatas; los cuales se presentan en la superficie coronaria, como rodetes o crestas bajas, entre dos líneas de imbricación. Si bien son estructuras dependientes del esmalte, descritas en múltiples textos y publicaciones científicas, estas no se encuentran dentro de los términos histológicos dependientes del esmalte, publicados en Terminologia Histologica. El objetivo del estudio fue realizar un análisis del término perikymata desde un punto de vista lingüístico y proponerlo como nuevo término histológico. El término perikymata deriva de las palabras griegas perí 'alrededor de' + kyma, 'onda', introducido por Preiswerk en 1895, si bien el término es descriptivo por si solo concentrando la información de la estructura en una sola palabra, tal como lo establece la terminología, este no indica su ubicación. Debido a lo anterior proponemos agregar el término perikymata enamelis (periquematíe del esmalte). Aunque proponer nuevos términos que estén más acorde con los señalado por la International Federation of Associations of Anatomists (IFAA) y la propia terminología, presenta grandes desafíos; un término no sólo es una palabra que hace referencia a una estructura morfológica, sino que también es una unidad del lenguaje, un vehículo de comunicación, que en este caso une a la comunidad morfológica en un solo lenguaje.

Histomorfología de la atrición en dientes temporarios / Histomorphology of attrition in temporary teeth

En la Facultad de Odontología de la Universidad Nacional del Nordeste, provincia de Corrientes, Argentina, se desarrolló un trabajo de investigación en el cual se estudiaron las características histológicas que presentaban el esmalte y la dentina de piezas dentarias temporarias bajo el proceso fisiológico de la atrición. Para dicho estudio, se obtuvieron 25 piezas dentarias temporarias de pacientes que concurrieron a la Cátedra de Odontopediatría para su atención. Las muestras fueron protocolizadas y clasificadas según la escala de desgaste dentario de Gerasimov modificada. Las piezas dentarias se procesaron mediante la técnica de desgaste para su observación al microscopio óptico, determinándose que el 48% de los casos el desgaste correspondía a grado I, el 36% al grado II y el resto al grado III. En los casos que afectó al esmalte únicamente se observó la sección de los prismas del esmalte. Cuando afectó esmalte y dentina en los grados II y III de la escala se observan tanto casos de dentina esclerótica como de trayectos muertos.

A research project was conducted at the School of Dentistry of the National University of the Northeast, Corrientes, Argentina. The histologic features of the enamel and dentin of temporary teeth under the physiological process of attrition were studied. For this study 25 temporary teeth were obtained from patients attending the Pediatric Dentistry Department for dental care. Samples were categorized and classified according to a modified version of Gerasimov’s tooth wear scale. The teeth were processed using the technical wear approach for observation through a microscope. It was determined that 48% of cases showed grade I wear, 36% grade II wear, and 16% grade III wear. In cases where only the dentin was affected, the section of the enamel prisms was observed. When both the enamel and the dentin were affected, reaching grade II and grade III wear levels, cases of both sclerotic dentin and dead tracts were observed.

Dental bleaching agents with calcium and their effects on enamel microhardness and morphology

Aim: To evaluate enamel microhardness and morphology after bleaching with hydrogen peroxide containing calcium in different concentrations. Methods: One hundred specimens of human teeth were ground and polished and had the initial microhardness evaluated. The specimens were randomly assigned into five groups (n=20): Group 1 - Control group (no treatment); Group 2 - Home Peroxide 6% (without calcium); Group 3 - Home Peroxide 7.5% (without calcium); Group 4 - White Class 6% (with calcium); Group 5 - White Class 7.5% (with calcium). For each group, the bleaching was performed according to the manufacturer's specifications. The specimens were bleached once a day for 5 days and subjected to pH cycling. Microhardness and scanning electron microscopy (SEM) analysis were performed before and after bleaching. Results: The results showed that groups submitted to bleaching treatment presented hardness loss compared to the control group. The group of 7.5% hydrogen peroxide with calcium showed a lower percentage of hardness loss in relation to other groups. Conclusion: Calcium in association with a higher hydrogen peroxide concentration may decrease microhardness changes on enamel.

Effect of adhesive remnant removal on enamel topography after bracket debonding

INTRODUCTION: At orthodontic treatment completion, knowledge about the effects of adhesive remnant removal on enamel is paramount. OBJECTIVE: This study aimed at assessing the effect of different adhesive remnant removal methods on enamel topography (ESI) and surface roughness (Ra) after bracket debonding and polishing. METHODS: A total of 50 human premolars were selected and divided into five groups according to the method used for adhesive remnant removal: high speed tungsten carbide bur (TCB), Sof-Lex discs (SL), adhesive removing plier (PL), ultrasound (US) and Fiberglass burs (FB). Metal brackets were bonded with Transbond XT, stored at 37oC for 24 hours before debonding with adhesive removing plier. Subsequently, removal methods were carried out followed by polishing with pumice paste. Qualitative and quantitative analyses were conducted with pre-bonding, post-debonding and post-polishing analyses. Results were submitted to statistical analysis with F test (ANOVA) and Tukey's (Ra) as well as with Kruskal-Wallis and Bonferroni tests (ESI) (P < 0.05). RESULTS: US Ra and ESI were significantly greater than TCB, SL, PL and FB. Polishing minimized Ra and ESI in the SL and FB groups. CONCLUSION: Adhesive remnant removal with SL and FB associated with polishing are recommended due to causing little damage to the enamel. .

INTRODUÇÃO: na finalização do tratamento ortodôntico, torna-se relevante o conhecimento da ação dos métodos de remoção do remanescente resinoso sobre o esmalte. OBJETIVO: o objetivo do estudo foi avaliar o efeito de métodos de remoção do remanescente de resina após a descolagem do braquete e do polimento na rugosidade (Ra) e topografia (ESI) do esmalte. MÉTODOS: foram selecionados 50 pré-molares humanos, divididos em cinco grupos, de acordo com o método empregado para a remoção da resina residual: broca carbide tungstênio em alta rotação (BCT), discos Sof-Lex (SL), alicate removedor de resina (AL), ultrassom (US) e pontas Fiberglass (PF). Braquetes metálicos foram colados com Transbond XT, armazenados a 37° por 24 horas antes da descolagem com alicate removedor de braquete, sendo aplicados posteriormente os meios de remoção e executado o polimento com pasta de pedra-pomes. Realizou-se análises qualiquantitativas, com avaliações antes da colagem dos braquetes, após a descolagem e após o polimento, sendo os valores obtidos submetidos à análise estatística com teste F (ANOVA), de Tukey (Ra) e testes de Kruskal-Wallis e Bonferroni (ESI) (p < 0,05). RESULTADOS: a Ra e o ESI do US foram significativamente maiores do que BCT, SL, AL e PF. O polimento reduziu a Ra e ESI dos grupos SL e PF. CONCLUSÃO: a remoção do adesivo resinoso com SL e PF associados ao polimento são os métodos mais indicados por ocasionarem as menores alterações do esmalte. .

Morphology of the cement-enamel junction (CEJ), clinical correlations / Morfología de la unión amelo-cementaria (UAC), correlaciones clínicas

The following study describes the mineralized tissue distribution which composes the cement-enamel junction, in a simple of Chilean people, comparing several teeth surfaces. Cervical area was observed (M-V, D-V, M-L/P, D-L/P sites) from 136 (n=68) longitudinal sections on premolars and incisors, with orthodontic or prosthetic reasons for exodontia, which were analyzed by optical microscope in order to identify the type of cement-enamel junction. For that measurement it was Choquet's criteria, founding four types: 1) cement over enamel, 2) enamel over cement, 3) vis a vis, 4) Gap presence between enamel, cement and exposed dentin. The objective of this study was to determine the prevalence of these. As result, it was observed that there was no association between tooth surface and Choquet's classification; however that association was observed while comparing the type of tooth and the relationship with mineralized tissues at the CEJ. So, incisors were associated with class 1 and premolars with class 3 of Choquet. Class 3 prevalence is the most frequently observed in the sample size (51.9 percent), following class 1 (42.4 percent), class 4 (4.4 percent), and class 2 with the lower prevalence on the sample (1.5 percent). Because this region is fragile and highly susceptible to pathological changes and from the external environment, it must be carefully handled during clinical procedures such as teeth whitening, orthodontics, restorations, root scaling and clamp placement.

Se describe la distribución de los tejidos mineralizados que componen la unión amelocementaria de una muestra de la población chilena, con respecto a distintos dientes y distintas caras de éste. Se observó la región cervical (zona M-V, D-V, M-L/P, D- L/P) de 136 (n=68) secciones longitudinales de premolares e incisivos, con indicación de extracción por razones ortodónticas o protésica, los cuales fueron analizadas mediante lupa estereoscópica para identificar el tipo de relación cemento-esmalte. Fue utilizada para dicha observación los criterios de Choquet; así se observaron cuatro tipos: 1) Cemento sobre esmalte; 2) Esmalte sobre cemento; 3) Bis a bis y 4) Presencia de brecha entre el esmalte y cemento con la dentina expuesta. Se observó que no existía asociación entre caras del diente y la clasificación de Choquet, en cambio sí existió dicha asociación entre el tipo de diente y la relación de los tejidos mineralizados en la UAC. De esta manera, los incisivos se asocian con la clase 1 y los premolares con la clase 3 de Choquet. En cuanto a la prevalencia, la clase 3 era la más frecuente en el total de la muestra (51,9 por ciento) seguido de la clase 1 (42,2 por ciento), de la clase 4 (4,4 por ciento) y la clase 2 fue observada en una pequeña proporción de la muestra (1,5 por ciento). Debido a que esta región es frágil y altamente susceptible a cambios patológicos y del medio externo debe ser manejada cuidadosamente durante procedimientos clínicos como el blanqueamiento dental, tratamiento de ortodoncia, restauración, destartraje o colocación de clamps.

Clinical strategies for esthetic excellence in anterior tooth restorations: understanding color and composite resin selection

Direct composite resin restorations have become a viable alternative for patients that require anterior restorative procedures to be integrated to the other teeth that compose the smile, especially for presenting satisfactory esthetic results and minimum wear of the dental structure. Technological evolution along with a better understanding of the behavior of dental tissues to light incidence has allowed the development of new composite resins with better mechanical and optical properties, making possible a more artistic approach for anterior restorations. The combination of the increasing demand of patients for esthetics and the capacity to preserve the dental structure resulted in the development of different incremental techniques for restoring fractured anterior teeth in a natural way. In order to achieve esthetic excellence, dentists should understand and apply artistic and scientific principles when choosing color of restorative materials, as well as during the insertion of the composite resin. The discussion of these strategies will be divided into two papers. In this paper, the criteria for color and material selection to obtain a natural reproduction of the lost dental structures and an imperceptible restoration will be addressed.

In vitro study of microleakage of different techniques of surface preparation used in pits and fissures.

Objective : The purpose of this in vitro study was to evaluate the effect of different techniques of surface preparation on the microleakage of a sealant applied with traditional acid etching and self-etched bonding agent. Study Design : A total of 60 extracted third molars were randomly assigned into six groups (n = 10/each). The occlusal surfaces were sealed with a sealant (Clinpro) after one of the following pretreatments: (1) phosphoric acid etching; (2) Prompt L-Pop; (3) laser + etching; (4) laser + Prompt L-Pop; (5) air abrasion + etching; (6) air abrasion + Prompt L-Pop. The specimens were immersed in a 0.5% basic fuchsin solution. Buccolingual cuts parallel to the long axis of the tooth were made. The surfaces were scored 0--2 for extent of microleakage using a microscope and the data were analyzed statistically. Results : The poorest results were obtained with laser + Prompt L-Pop which showed a greater number of specimens with microleakage (80%). Air abrasion surface preparation + phosphoric acid etching showed less microleakage than the other groups (40%). Kruskal--Wallis and t-tests revealed no significant difference in microleakage between six groups. Conclusion : The self-etching adhesive studied seems an attractive alternative to the acid-etch technique for sealant application in young children where simplifications in the clinical procedure are warranted. No significant difference was noted between the different types of enamel preparation before fissure sealant.

Apical stress distribution on maxillary central incisor during various orthodontic tooth movements by varying cemental and two different periodontal ligament thicknesses: A FEM study.

Context: During fixed orthodontic therapy, when the stress levels in the periodontal ligament (PDL) exceedsan optimum level, it could lead to root resorption. Aims: To determine an apical stress incident on the maxillary central incisor during tooth movement with varying cemental and periodontal ligament thickness by Finite Element Method (FEM) modeling. Settings and Design: A three dimensional finite element model of a maxillary central incisor along with enamel, dentin, cementum, PDL and alveolar bone was recreated using EZIDCOM and AUTOCAD software. ALTAIR Hyper mesh 7.0 version was used to create the Finite Element meshwork of the tooth. This virtual model was transferred to Finite Element Analysis software, ANSYS where different tooth movements were performed. Materials and Methods: Cemental thickness at the root apex was varied from 200 μm to 1000 μm in increments of 200 μm. PDL thickness was varied as 0.24 mm and 0.15 mm. Intrusive, Extrusive, Rotation and Tipping forces were delivered to determine an apical stress for each set of parameters. Results: Results indicated that an apical stress induced in the cementum and PDL, increased with an increase in cementum and PDL thickness respectively. Apical stress induced in the cementum remained the same or decreased with an increase in the PDL thickness. Apical stress induced in the PDL decreased with an increase in the cementum thickness. Conclusion: The study concluded that the clinical delivery of an orthodontic forces will cause stress in the cementum and PDL. Hence, it is necessary to limit the orthodontic force to prevent root resorption.

Avaliação da eficácia dos tratamentos de superfície do esmalte na prevenção do manchamento dentário pós clareamento / Efficacy evaluation of enamel surface treatments on the prevention of staining after tooth bleaching

Este trabalho estudou a eficácia de alguns tratamentos de superfície do esmalte dental na prevenção do manchamento pós clareamento exógeno com peróxido de hidrogênio a 35%. Cinquenta e cinco incisivos bovinos hígidos foram despolpados e seccionados na junção cemento-esmalte. Procedeu-se a profilaxia e o exame da área experimental com microscopia óptica para assegurar a ausência de defeitos de superfície. O terço incisal da vestibular foi planificado...

Crown dimensions and proximal enamel thickness of mandibular second bicuspids

To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5 percent). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70) on the right and 8.65 mm (± 0.54) on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22) to 1.40 mm (± 0.17), on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21) and 1.46 mm (± 0.12). No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

Effect of occlusal restoration on stresses around class V restoration interface: A finite-element study.

Background: Causes of failures in class V restorations have always been controversial until now, since the biomechanical aspects of these restorations have been understood. Aims and Objective: This study was aimed to verify the hypothesis that eccentric forces are the cause of cuspal flexure, which lead to excessive stresses at the periphery of a class V restoration, further it identifies the amount of the stress and the flexure increase in the presence of an occlusal restoration using different restorative materials to restore (both cervical and occlusal) along with their comparison with respect to amount of stresses around the cervical restorations. Materials and Methods : The study was done by modeling a mandibular first premolar which was sectioned bucco-lingually, in the NISA, EMRC II finite element software. A 100N eccentric load was applied on the tooth structure and stresses were observed at the peripheries of the class V restoration when it was restored with composite and with glass ionomer cement. The stresses were further analyzed in the presence of occlusal restorations with different materials and configurations. Results: It was seen that the stresses at the gingival wall interface in case of class V glass ionomer cement was more than that for composite. In the presence of an occlusal amalgam restoration, the cuspal flexure was more than that of occlusal composite and the stresses at the class V peripheries were also statistically significant. Conclusion: It was suggested that lower modulus composites can flex with the tooth structure decreasing the bond failure and that the stresses are much lesser when there is absence of an occlusal restoration. Occlusal composite restorations reinforce the tooth structure and reduce the cuspal flexure as compared to silver amalgam.

Evaluation of different LED light-curing devices for bonding metallic orthodontic brackets

The aim of this study was to assess the influence of different light-emitting diodes (LED) light-curing devices for bonding orthodontic brackets, using the shear bond strength and analysis of adhesive remnant index (ARI). Crowns from 60 bovine incisors received brackets bonded with Transbond XT. Specimens were divided into 4 groups (n=15) according to the light-curing procedures: HL = control, halogen light; OR = Ortholux LED; UL = Ultraled XP, and RD = Radii LED. All light-curing procedures were performed for 40 s. Shear bond strength test was evaluated using an universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test. The ARI scores were evaluated with a stereoscopic magnifying glass and analyzed statistically by Kruskal-Wallis test. A significance level of 5 percent was set for all analyses. Shear bond strength means in MPa and standard deviations were 9.82 (3.28), 12.70 (3.35), 9.04 (2.80) and 11.22 (2.36) for HL, OR, UL and RD, respectively. OR presented the highest shear bond strength mean value. HL differed significantly (p<0.05) from Groups OR and RD. However, these groups did not differ significantly from each other (p>0.05). Regarding the ARI scores, no statistically significant difference was observed (p>0.05) among the groups. In conclusion, Ortholux LED and Radii LED units provided the highest values of bracket adhesive strength.

O objetivo deste estudo foi avaliar a influência de diferentes aparelhos de luz tipo LED na colagem de bráquetes ortodônticos, através do teste de resistência ao cisalhamento e do Índice de Remanescente do Adesivo (IRA). Coroas de 60 incisivos bovinos receberam a colagem de bráquetes com compósito Transbond XT. A amostra foi dividida em 4 grupos (n=15) de acordo com os seguintes tipos de fotoativação: HL: controle, luz halógena; OR= Ortholux LED; UL= Ultraled XP e RD= Radii LED. Todas as fotoativações foram realizadas por 40 s. O teste de resistência ao cisalhamento foi realizado em máquina universal de ensaios mecânicos à velocidade de 0,5 mm/min. Os dados foram analisados estatisticamente pelo ANOVA e teste de Tukey. Os escores do IRA foram avaliados em lupa estereoscópica e analisados estatisticamente pelo teste de Kruskal-Wallis. O nível de significância de 5 por cento foi adotado para todas as análises. Os valores médios (MPa) e o desvio-padrão do teste de resistência ao cisalhamento foram 9,82 (3,28), 12,70 (3,35), 9,04 (2,80) e 11,22 (2,36) para o grupo HL, OR, UL e RD, respectivamente. O grupo OR apresentou os maiores valores médios de resistência ao cisalhamento. O grupo HL diferiu significativamente (p<0,05) dos grupos OR e RD. Entretanto, este dois grupos não diferiram estatisticamente entre si (p>0,05). Quanto ao escores do IRA, nenhuma diferença estatística significante foi observada (p>0,05) entre os grupos. Concluiu-se que as unidades de luz Ortholux LED e Radii LED proporcionaram maiores valores de resistência adesiva aos bráquetes.

Clareamento de dentes vitais com a utilização da luz / In-affice dental bleaching oi vital teeth with the use af light

A crescente demanda por um sorriso branco e saudável associada à introdução de novos materiais e técnicas, resultou em uma evolução significativa na Odontologia estética. Dentre os tratamentos mais procurados pelos pacientes, o clareamento de dentes vitais realizado em consultório - também chamado de clareamento assistido - tem sido amplamente utilizado e consiste na utilização de géis de peróxido de carbamida ou hidrogênio em alta concentração. A principal vantagem dessa técnica são os significativos resultados estéticos alcançados em poucas sessões, com curta duração. No entanto, a técnica requer do Cirurgião-Dentista conhecimento técnico-científico e cuidados especiais, não apenas com as estruturas de esmalte e dentina, como também com os tecidos moles da cavidade bucal. Este artigo tem como objetivo abordar aspectos importantes da técnica que auxiliarão o profissional na sua realização em consultório. Serão abordados estudos que descrevem as indicações da técnica, bem como os que discutem os seus benefícios e limitações, apresentando aspectos científicos importantes para a prática clínica.

Within the most requested treatments, in-office dental bleaching has been widely in- dicated and consists on the use of high concentrated carbamide and hydrogen peroxides (25-38%). The main advantage of the technique is the significant esthetic results that can be achieved in few clinical sessions with a short period of exposure of the bleaching agent to the dental surface. However, the in-office bleaching requires from the professional some technical and scientific skills and specific care not only with enamel and dentin structures but also with the surrounding soft tissues. This manuscript aims to address important topics that will help professionals in their day-by-day clinic. Studies related to the in-office technique, its benefits and limitations will be discussed and important scientific information will be highlighted in order to guide the clinical practice.