Blue Covarine Toothpaste versus Office Whitening: Which is the Most Effective on Stained Teeth? / Creme Dental de Blue Covarine Versus Clareamento de Consultório: Qual é o Mais Efetivo em Dentes Pigmentados?

Alternative whitening strategies to hydrogen peroxide have been proposed, such as the inclusion of abrasive and/or pigmented particles in the toothpaste. This study compared the whitening effectiveness of a toothpaste containing Blue Covarine (BC) vs. an in-office whitening treatment using 35% hydrogen peroxide (HP) in teeth stained. Bovine incisors blocks (6.0x6.0x2.0 mm) were stained with green tea (GT), orange soda (OS), or red wine (RW). The samples were randomly assigned into 8 groups (n=15), according to the type of staining and whitening treatment: G1 ­ no staining, BC (Control); G2 ­ no staining, HP (Control); G3 ­ GT, BC; G4 ­ GT, HP; G5 ­ OS, BC; G6 ­ OS, HP; G7 ­ RW, BC; G8 ­ RW, HP. Color change (ΔE), luminosity (L*), green-red axis (a*), and blue-yellow axis (b*) were recorded with spectroscopy at T0 ­ baseline, T1 ­ immediately after toothbrushing or in office tooth whitening, and T2 ­ after the conclusion of the treatments. The whiteness index for dentistry (WID) was calculated. Data were analyzed by two-way repeated measured mixed ANOVA and Bonferroni test (α=0.05). HP showed a better whitening performance (ΔE) (p ≤ 0.042). Otherwise, no effects of the whitening agent were observed (p = 1.000). Data from ΔL, Δa, and Δb showed statistically significant differences for experimental groups (p < 0.001). In the WID analysis, BC and HP had similar effects within control and RW groups. In conclusion, blue covarine toothpaste may be a viable option for extrinsically stained teeth. However, for severe staining, HP-based whitening agents proved to be the most effective treatment strategy. (AU)

Estratégias de clareamento alternativas ao peróxido de hidrogênio têm sido propostas, como a inclusão de partículas abrasivas e/ou pigmentadas nos cremes dentais. Este estudo comparou a eficácia clareadora de um creme dental contendo Blue Covarine (BC) com um tratamento de clareamento em consultório com peróxido de hidrogênio a 35% (HP) em dentes pigmentados. Blocos de incisivos bovinos (6,0x6,0x2,0 mm) foram pigmentados com chá verde (GT), refrigerante de laranja (OS) ou vinho tinto (RW). As amostras foram distribuídas aleatoriamente em 8 grupos (n = 15), de acordo com o tipo de pigmento e tratamento clareador: G1 - sem coloração, CB (Controle); G2 - sem coloração, HP (Controle); G3 - GT, BC; G4 - GT, HP; G5 - OS, BC; G6 - SO, HP; G7 - RW, BC; G8 - RW, HP. Mudança de cor (ΔE), luminosidade (L *), eixo verde-vermelho (a*) e eixo azul-amarelo (b*) foram registrados com espectroscopia em T0 - baseline, T1 - imediatamente após a escovação ou clareamento dental em consultório, e T2 - após a conclusão dos tratamentos. O índice de brancura para odontologia (WID) foi calculado. Os dados foram analisados por ANOVA mista de duas vidas para medidas repetidas e teste de Bonferroni (α = 0,05). HP apresentou melhor desempenho de clareamento (ΔE) (p ≤ 0,042). Os dados de ΔL, Δa e Δb mostraram diferenças estatisticamente significativas para os grupos experimentais (p <0,001). Na análise WID, BC e HP tiveram efeitos semelhantes nos grupos controle e RW. Em conclusão, o creme dental covarine azul pode ser uma opção viável para dentes com coloração extrínseca. No entanto, para manchas graves, os agentes de clareamento à base de HP provaram ser a estratégia de tratamento mais eficaz. (AU)

Radiopacity and Chemical Assessment of New Commercial Calcium Silicate-Based Cements / Radiopacidad y Evaluación Química de Cementos Comerciales en Base a Silicato de Calcio

ABSTRACT: The aim of the study was to evaluate the chemical composition and radiopacity of new calcium-silicatebased cements. Discs of 10 mm x 1 ± 0.1mm were prepared of BiodentineTM, TheraCal, Dycal and GC Fuji IX (n=5). The samples were radiographed directly on an PSP occlusal plate adjacent to an aluminium step wedge. The radiopacity of each specimen was determined according to ISO 9917/2007. Statistical analyses were carried out using ANOVA and Tukey's test at a significance level of 5 %. The chemical constitution of materials was determined by scanning electron microscopy (SEM) and energy dispersive x-ray element mapping. The radiopacities of the materials in decreasing order were: GC Fuji IX (3.45 ± 0.16 mm), Dycal (3.18 ± 0.17), BiodentineTM (2.79 ± 0.22), and TheraCal (2.17 ± 0.17). TheraCal showed the lowest radiopacity compared to the other materials, followed by BiodentineTM. Dycal and GC Fuji IX radiopacity values did not present significant statistical differences. Scanning electron microscopy and energy dispersive X-ray analysis revealed the presence of zirconium in BiodentineTM; and strontium, barium and zirconium in TheraCal as radiopacifying elements. The new calcium silicate cements present distinctive chemical composition. BiodentineTM contains zirconium as a radiopacifying element and has higher radiopacity values than TheraCal, which contains barium and strontium as radiopacifiers.

RESUMEN: El objetivo de este estudio fue evaluar la composición química y la radiopacidad de nuevos cementos en base a silicato de calcio. Discos de 10 mm x 1 ± 0,1 mm fueron preparados con BiodentineTM, TheraCal, Dycal y GC Fuji IX (n=5). Las muestras fueron radiografiadas directamente en una película PSP oclusal adyacente a una cuña escalonada de aluminio. La radiopacidad de cada espécimen fue determinada de acuerdo a la norma ISO 9917/ 2007. Se realizaron los análisis estadísticos con las pruebas ANOVA y test de Tukey con un nivel de significancia de 5 %. La constitución química de los materiales fue determinada con microscopía electrónica de barrido y con mapeo por análisis con dispersión de energía de rayos X. La radiopacidad de los materiales en orden decreciente fue: GC Fuji IX (3,45 ± 0,16 mm), Dycal (3,18 ± 0,7 mm), BiodentineTM (2,79 ± 0,22 mm), y TheraCal (2,17 ± 0,17 mm). TheraCal mostró la menor radiopacidad comparada con los otros materiales, seguido de BiodentineTM. Los valores de radiopacidad de Dycal y GC Fuji IX no presentaron diferencias estadísticas significativas. Los análisis de microscopía electrónica de barrido y mapeo por análisis con dispersión de energía de rayos X revelaron la presencia de zirconio en BiodentineTM; y de estroncio, bario y zirconio en TheraCal, como elementos radiopacos. Los nuevos cementos en base a silicato de calcio presentan una composición química distintiva. BiodentineTM contienen zirconio como elemento que provee radiopacidad y tiene mayor valor de radiopacidad que TheraCal, el cual contiene bario y estroncio como agente radiopaco.

Color stability of conventional and bulk fill composite resins / Estabilidade cromática de resinas convencionais e resinas bulk fill

ABSTRACT 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.

RESUMO Objetivo: Comparar diferentes resinas compostas em relação á estabilidade de cor após exposição prolongada em solução de café. Métodos: Sessenta e quatro discos cilíndricos (10mm x 2mm) foram confeccionados a partir de 8 diferentes marcas comerciais de compósitos (n= 8 por grupo); os espécimes foram imersos em saliva artificial, e posteriormente em café, sendo por conseguinte feita a avaliação da variação cromática (ΔE), utilizando espectrofotômetro Vita Easyshade Advanced (VITA Zahnfabrik, Bad Sackingen, Germany). O padrão de cada espécime foi medido examinando as coordenadas L*, a* e b* do sistema CIELab. Resultados: A resina composta Grandio SO apresentou a menor média de variação cromática (ΔE= 7,77) após a imersão em solução de café. Semelhantemente, a variação cromática das resinas compostas Durafill VS, Grandio e Z350 XT (ΔE=8,58; ΔE=9,52; ΔE=10.39) que não apresentaram diferença estatística. Todavia, as demais resinas compostas avaliadas apresentaram valores estatisticamente maiores de ΔE em relação a resina Grandio SO, sendo que a resina Enamel HRi (ΔE= 20,56) apresentou a maior variação cromática registrada. Conclusão: As resinas da categoria bulk fill e as resinas híbridas produzidas pelo mesmo fabricante (Micerium, Avegno, Itália) tiveram alterações cromáticas superiores às demais resinas testadas sendo que a resina GrandioSO (Voco, Cuxaven, Alemanha) foi a que apresentou menor alteração de ∆E.

Forensic dentistry methods to estimate the chronological age of individuals: a topic review / Métodos de odontología forense para estimar la edad cronológica de los individuos: revisión de tema

ABSTRACT. Introduction: global mobilization has created new needs. From sporting events to criminal matters, determining the chronological age of individuals is being used by forensic surgeons worldwide. The objective of the present study was to analyze the forensic methods to estimate the age of individuals, including the advantages and limitations of these methods. Method: a search was conducted in the Sistema de Bibliotecas de la Universidad Mayor (SIBUM): Dentistry & Oral Sciences Source, ClinicalKey, and Science Direct Freedom Collection, selecting papers published from 1980 to 2014. A manual search was also conducted, including specific journals and texts in this field, with no limitation as to the year of publication. The inclusion criteria were research projects aimed at determining the chronological age of individuals through forensic analysis of oral tissues. All published texts in a language other than English were excluded. In total, 70 publications were analyzed. Technological advances have paved the way for the study of new parameters; however, the original ones identified by Gustafson in 1950 are still studied. Conclusions: most studied methods are invasive in some degree. In addition, none of these techniques is accurate in its own; therefore, the combination of different measurement techniques is recommended, opening a field of research on techniques that are less invasive and can be a complement to the existing ones. Finally, the available information lead to conclude that research on populations of African and Asian descent is lacking, which is a current challenge because of globalization, migration, and the heterogeneity of current populations.

RESUMEN. Introducción: la movilización global ha generado nuevas necesidades; desde eventos deportivos hasta asuntos criminales, determinar la edad cronológica de los individuos está siendo utilizado por forenses en todo el mundo. El objetivo del presente estudio consistió en analizar los métodos forenses para la estimación de la edad de los individuos, incluyendo las ventajas y limitaciones de dichos métodos. Método: se realizó una búsqueda en el Sistema de Bibliotecas de la Universidad Mayor (SIBUM): Dentistry & Oral Sciences Source; ClinicalKey y Science Direct Freedom Collection, y se seleccionaron artículos publicados entre los años 1980 y 2014. Se hizo además una búsqueda manual, incluyendo revistas específicas y textos de la materia, sin limitación en cuanto al año de publicación. Como criterio de inclusión, se tuvieron en cuenta las investigaciones cuyo objetivo era determinar la edad cronológica de los individuos mediante el análisis forense de tejidos orales. Se excluyeron todos los textos publicados en otro idioma que no fuera inglés. En total, se analizaron 70 publicaciones. Los avances tecnológicos han permitido el estudio de nuevos parámetros; sin embargo, se siguen estudiando los originales identificados por Gustafson en 1950. Conclusiones: la mayoría de los métodos estudiados representan algún grado de invasión. Además, ninguna de estas técnicas es exacta por sí sola, por lo que se recomienda combinar distintas técnicas de medición, abriendo un campo de investigación a técnicas menos invasivas que puedan ser un complemento de las ya existentes. Finalmente, con la información disponible podemos determinar que faltan investigaciones sobre poblaciones de origen africano y asiático, lo que representa un desafío en la actualidad debido a la globalización, las migraciones y la heterogeneidad de las poblaciones actuales.

Effect of Clinical Experience on Accuracy and Reliability of Radiographic Caries Detection / Efecto de la Experiencia Clínica en la Precisión y Concordancia de Detección de Caries en Radiografías

ABSTRACT: The purpose of this study was to investigate the accuracy and interobserver reliability of examiners with different levels of clinical experience, when diagnosing radiographic proximal caries lesions. Bitewing radiographs were selected from a patient attending Operative Dentistry Clinic, Universidad de Chile. Radiographic examination was performed by three different groups: A: third year dentistry students, B: fourth year dentistry students, and C: dentist recently graduated. Thirty-two proximal surfaces were scored as: 0, sound; 1: enamel caries; and 2: dentinal caries. The data were analysed and accuracy and interexaminer reliability were calculated. Accuracy values for enamel caries were: A (0.54), B (0.55) and C (0.58), and dentinal caries were: A (0.55), B (0.61) and C (0.63). Interexaminer reliability denoted marginal agreement for all groups, A (0.249), B (0.213) and C (0.282) for enamel caries and A (0.058), B (0.102), and C (0.344) for dentinal caries. The results of this study indicate that the accuracy and interexaminer reliability of bitewing radiographic examination were influenced by the clinical experience when detecting radiographic proximal caries, however low values of accuracy and interexaminer reliability were noted, reinforcing the necessity of improving education and training in radiographic caries detection.

RESUMEN:El objetivo de este trabajo fue evaluar la precisión y concordancia entre examinadores con distinto nivel de experiencia clínica, al diagnosticar lesiones de caries proximales en radiografías. Un set de radiografías bitewing fue seleccionado de un paciente que acudió a la Clínica de Operatoria de la Facultad de Odontología, Universidad de Chile. El examen radiográfico fue realizado por tres grupos distintos: A: estudiantes de Odontología de tercer año, B: estudiantes de Odontología de cuarto año, y C: dentistas recientemente graduados. Treinta y dos superficies proximales fueron analizadas y evaluadas como: 0, sana; 1: lesión de caries de esmalte, 2: lesión de caries dentinaria. Los datos obtenidos fueron analizados y la precisión y concordancia entre examinadores fueron calculadas. Los valores de precisión en lesiones de esmalte fueron: A (0,54), B (0,55) y C (0,58), y para lesiones dentinarias fueron: A (0,55), B (0,61) y C (0,63). La concordancia entre examinadores denotó ser marginal para todos los grupos, A (0,249), B (0,213) y C (0,282) en lesiones de esmalte y A (0,058), B (0,102), y C (0,344) en lesiones dentinarias. Los resultados de este estudio indican que la precisión y la concordancia entre examinadores está influenciada por la experiencia clínica, sin embargo los valores encontrados fueron bajos, lo que refuerza la necesidad de mejorar la educación y entrenamiento en detección de lesiones de caries en radiografías

Clinical effectiveness of fluorescence, digital images and ICDAS for detecting occlusal caries / Efetividade clínica da fluorescência, imagens digitais e ICDAS na detecção de cárie oclusal

Introduction: The detection of small caries lesions is still a challenge for dental professionals who in their clinical practice have a wide variety of methods to detect caries on occlusal surfaces. Objective: To clinically assess the effectiveness of the Vista Proof fluorescence camera, the Vista Cam digital intraoral micro camera and the International Caries Detection and Assessment System (ICDAS) visual criterion for detecting caries lesions on occlusal surfaces of permanent teeth. Material and method: One hundred and seven posterior teeth from adult patients were examined visually and by means of digital radiographs by an examiner who rated them according to the presence or absence of occlusal caries. The teeth were then assessed by the other examiner using ICDAS, fluorescence and magnified digital images. The effectiveness of the methods was measured based on sensitivity, specificity, positive and negative likelihood ratio. For each method, the Receiver Operating Characteristic (ROC) curve and the Area Under the ROC curve (AUROC) were estimated. Result: There was exceptional discrimination capacity for the intraoral images (AUROC=.93) and the ICDAS (AUROC=.91), with no significant statistical difference between them (z=.35, p=.73). The fluorescence exhibited an acceptable discrimination capacity (AUROC=0.78), although it was lower than the others. The positive likelihood ratio for the fluorescence was only 2.32, compared to 20.58 for the intraoral image and 58.11 for the ICDAS. Conclusion: Both methods and the ICDAS exhibited an adequate clinical performance, although the ICDAS and intraoral image were more effective than the fluorescence.

Introdução: A detecção de pequenas lesões de cárie ainda é um desafio para profissionais da Odontologia, que em sua prática clínica dispõem de uma grande variedade de métodos para detectar cáries nas superfícies oclusais. Objetivo: Avaliar clinicamente a efetividade da câmera de fluorescência Vista Proof, da microcâmera intraoral digital Vista Cam e do critério visual ICDAS (International Caries Detection and Assessment System) para detecção de lesões de cárie nas superfícies oclusais. Material e método: Cento e sete dentes posteriores de pacientes adultos foram examinados visualmente e por meio de radiografias digitais por um examinador que os classificou de acordo com a presença ou ausência de cárie. Os dentes foram então avaliados por outro examinador que utilizou o ICDAS, fluorescência e imagens digitais ampliadas. A efetividade dos métodos foi mensurada por meio da sensibilidade, especificidade, razão de verossimilhança positiva e negativa. Para cada método, a curva ROC (Receiver Operating Characteristic) e a área sob a mesma - AUROC (Area Under the ROC curve) foram estimadas. Resultado: Houve excepcional capacidade discriminante para as imagens intraorais (AUROC=0,93) e para o ICDAS (AUROC=0,91), com diferença estatística não significativa entre eles (z=0,35, p=0,73). A fluorescência apresentou capacidade discriminante aceitável (AUROC=0,78), embora tenha sido menor que os outros. A razão de verossimilhança positiva para a fluorescência foi 2,32, comparado a 20,58 para a imagem intraoral e 58,11 para o ICDAS. Conclusão: Ambos os métodos e o ICDAS exibiram um adequado desempenho clínico, sendo que o ICDAS e a imagem intraoral foram mais efetivos que a fluorescência.

Enhanced bioactive properties of BiodentineTM modified with bioactive glass nanoparticles

Abstract Objective To prepare nanocomposite cements based on the incorporation of bioactive glass nanoparticles (nBGs) into BiodentineTM (BD, Septodent, Saint-Maur-des-Fosses Cedex, France) and to assess their bioactive properties. Material and Methods nBGs were synthesised by the sol-gel method. BD nanocomposites (nBG/BD) were prepared with 1 and 2% nBGs by weight; unmodified BD and GC Fuji IX (GIC, GC Corporation, Tokyo, Japan) were used as references. The in vitro ability of the materials to induce apatite formation was assessed in SBF by X-ray diffraction (XRD), attenuated total reflectance with Fourier transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. BD and nBG/BD were also applied to dentine discs for seven days; the morphology and elemental composition of the dentine-cement interface were analysed using SEM-EDX. Results One and two percent nBG/BD composites accelerated apatite formation on the disc surface after short-term immersion in SBF. Apatite was detected on the nBG/BD nanocomposites after three days, compared with seven days for unmodified BD. No apatite formation was detected on the GIC surface. nBG/BD formed a wider interfacial area with dentine than BD, showing blockage of dentine tubules and Si incorporation, suggesting intratubular precipitation. Conclusions The incorporation of nBGs into BD improves its in vitro bioactivity, accelerating the formation of a crystalline apatite layer on its surface after immersion in SBF. Compared with unmodified BD, nBG/BD showed a wider interfacial area with greater Si incorporation and intratubular precipitation of deposits when immersed in SBF.

Real-time quantitative polymerase chain reaction (QPCR) for the identification and quantification of streptococcus mutans in saliva and dental biofilm in children / Técnica de reacción de polimerasa en cadena (QPCR) en tiempo real para la identificación y cuantificación de streptococcus mutans en saliva y biopelícula dentaria de niños

ABSTRACT Introduction: the objective of this study was to use real-time qPCR to identify and quantify the Streptococcus mutans species in samples of saliva and dental biofilm. Methods: 27 children were randomly chosen with the following criteria: 8 years of age, low socio-economic levels, residing in the northern metropolitan area of Santiago de Chile; they were asked to attend an appointment while fasting with no teeth brushing for at least 12 hours, in order to collect non-stimulated saliva and a pool of supragingival dental biofilm of all the mesio-vestibular sides of anterior and posterior teeth. The amount of S. mutans in the samples was quantified by qPCR using primers that amplify a fragment of the gtfB gene of S. mutans. Results: the amplification showed 98% efficiency with a fluorescence of 3.36 cycles. The melting curve presented a single maximum at the same temperature for all samples. Conclusion: the methodology allows the specific identification and quantification of gene gtfB of S. mutans in saliva and dental biofilm in a quick and reliable manner, contributing to the identification of individual cariogenic risk.

RESUMEN. Introducción: el objetivo del presente estudio consistió en implementar la técnica de qPCR en tiempo real para identificar y cuantificar la especie Streptococcus mutans en muestras de saliva y biopelícula dentaria. Métodos: se seleccionaron al azar 27 niños de 8 años de edad, de nivel socio-económico bajo del área norte de la región metropolitana de Santiago de Chile, que se citaron en ayunas y sin cepillado durante al menos 12 horas, para colectar saliva no estimulada y un pool de biopelícula dentaria supragingival de todas las caras mesio-vestibulares de dientes anteriores y posteriores. Se cuantificó la cantidad de S. mutans en las muestras mediante qPCR empleando partidores que amplifican un fragmento del gen gtfB de S. mutans. Resultados: la amplificación presentó 98% de eficiencia con delta de fluorescencia de 3,36 ciclos. La curva de fusión (melting) presentó un solo máximo a una misma temperatura para todas las muestras. Conclusión: la metodología permite la identificación y cuantificación específica del gen gtfB de S. mutans en muestras de saliva y biopelícula dentaria, de forma rápida y exacta, aportando a la determinación del riesgo cariogénico individual.

Personality Style in Patients Looking for Tooth Bleaching and Its Correlation with Treatment Satisfaction

Abstract In the last years the focus in dentistry has shifted to an "esthetic dentistry" approach, where patients are concerned about reaching a better look of their teeth. Vital tooth bleaching is a technique with immediate results, which improves the appearance and patient's self-esteem. The aim of this study was to recognize personality characteristics determined by the Millon Index of Personality Styles of participants looking for tooth bleaching and to correlate them to satisfaction with the treatment. Forty participants were included and filled out the Millon Index of Personality Styles form before treatment. Expectation about tooth bleaching was quantified from 1 to 5. Patients were treated with bleaching agent according to manufacturer's directions. One week after treatment, the patient's satisfaction was quantified from 1 to 5. Prevailing personality characteristics were determined. Expectations and satisfaction values of all patients were correlated with each of the presented personality scales by Spearman Rho test. Ten scales prevailed over their counterpart. Median of patient's expectation was 2 and satisfaction 4. Only the score of a single characteristic (extraversing) showed statistically significant correlation with patient satisfaction. Patients looking for tooth bleaching treatment seem to have common personality characteristics. Almost all of them wanted to achieve a moderate change in teeth color and the result of the treatment was usually satisfactory.

Resumo Ultimamente, o foco da Odontologia deslocou-se para uma "odontologia estética", em que os pacientes se preocupam em conseguir uma aparência melhor para seus dentes. O branqueamento vital é uma técnica com resultados imediatos que melhora aparência e auto-estima do paciente. O objetivo deste estudo foi detectar características de personalidade definidas pelo Índice Millon de Estilos de Personalidade de pessoas que buscaram branqueamento dental e correlacioná-las com a satisfação com o tratamento. Foram incluídos 40 participantes que preencheram o formulário do Índice Millon de Estilos de Personalidade antes do tratamento. A expectative sobre o branqueamento dental foi quantificada com valores de 1 a 5. Os pacientes foram tratados com agente branqueador de acordo com as instruções do fabricante. Uma semana depois o tratamento, a satisfação do paciente foi quantificada com valores de 1 a 5. Foram determinados as características predominantes. Os valores da expectativa e da satisfação foram correlacionados com cada escala de personalidade apresentada através do teste de Spearman Rho. Dez escalas prevaleceram sobre a sua contrapartida. A mediana das expectativas foi 2 e das satisfações foi 4. O valor de uma característica apenas (extraversão) apresentou correlação estatisticamente significante com a satisfação do paciente. Os pacientes que buscam o branqueamento dental parecem ter características comuns de personalidade. Quase todos queriam conseguir uma mudança moderada na cor dos dentes e o resultado do tratamento foi geralmente satisfatório.

The current state of calcium silicate cements in restorative dentistry: a review / Revisión del estado actual de cementos de silicato de calcio en odontología restauradora

ABSTRACT Calcium silicate cements have been used as dental materials for more than twenty years; however, their use in restorative dentistry is more recent. Better mechanical properties and shorter curing times make them suitable for a variety of applications in which they are used as a substitute of dentin, including direct/indirect pulp capping and as cavity base/liner. These materials may also be used to restore enamel temporarily. This article seeks to review the available scientific evidence with a focus on their applications in restorative dentistry. The information was gathered by reviewing original scientific research articles and literature reviews published in journals available in databases such as Medline/Pubmed and Scielo, along with technical information provided by the manufacturers of these cements. This article describes the composition, instructions for use, and curing reaction of calcium silicate cements, as well as the scientific evidence on their applications in restorative dentistry.

RESUMEN Los cementos de silicato de calcio se han aplicado como materiales dentales desde hace más de veinte años; sin embargo, su uso en el área de la odontología restauradora es más reciente. Mejores propiedades mecánicas y menores tiempos de endurecimiento le permiten ser indicados para una variedad de aplicaciones en las que este material se utiliza como sustituto dentinario, entre ellas el recubrimiento pulpar directo/indirecto y como base/liner cavitario. A su vez, también se podría utilizar como material para restaurar esmalte de manera temporal. El presente artículo busca revisar la evidencia científica disponible, enfocándola a sus aplicaciones en odontología restauradora. La información se obtuvo a partir de artículos originales de investigación científica y revisiones de literatura, publicados en revistas disponibles en bases de datos como Medline/Pubmed y Scielo, junto a la información técnica otorgada por los fabricantes de estos cementos. El presente trabajo describe la composición, el modo de empleo, la reacción de fraguado y la evidencia científica sobre las aplicaciones de los cementos de silicato de calcio en odontología restauradora.

Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study

Abstract The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) - after in-office or at-home bleaching treatment; T1 - immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001). Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

Avances en el Estudio de la Diversidad Bacteriana Oral Asociada a Caries Dental Mediante el Estudio Genómico / Advances in the Study of Oral Bacterial Diversity Associated with Dental Caries by Genomic Study

La caries es una enfermedad infecciosa, transmisible y multifactorial, que conduce a la pérdida de minerales reversible o irreversible de los tejidos duros susceptibles del diente, por acción de productos ácidos provenientes de la fermentación de los hidratos de carbono de la dieta por la actividad metabólica del biofilm adherido a la superficie dentaria. Aunque tradicionalmente se ha considerado al Streptococcus mutans como el responsable de la enfermedad, actualmente otras bacterias, denominadas no mutans, se han asociado con el inicio, progresión y actividad de la enfermedad en esmalte, dentina y cemento radicular. Para profundizar el estudio de la diversidad bacteriana oral asociada a caries dental se han aplicado diversas metodologías, dentro de las cuales destaca el estudio del metagenoma oral. Este nos permite estudiar comunidades bacterianas completas mediante el análisis del DNA, en un determinado ambiente sin necesidad de aislar y cultivar las especies, entregando información sobre la diversidad taxonómica y filogenética de estas comunidades. Existen diferentes métodos de análisis de la diversidad bactariana, entre los que tenemos el análisis del ARNr 16S mediante electroforésis, PCR, microarreglos, secuenciamiento de última generación, entre otros. El estudio del metagenoma oral ha permitido identificar especies que no han podido ser aisladas por métodos convencionales, además de identificar su presencia o ausencia en las distintas etapas del desarrollo de la enfermedad de caries dental, permitiendo un mejor conocimiento del desarrollo de esta patología. El estudio basado en el metagenoma ha dado a conocer una diversidad microbiana oral inesperada, dando información relevante para la actualización de los conocimientos y así identificar nuevos objetivos terapéuticos. El propósito de esta revisión bibliográfica es exponer los principales resultados que ha aportado el estudio del metagenoma sobre la diversidad microbiana, aplicado específicamente a la comunidad bacteriana oral.

Dental caries is an infectious, transmissible and multifactorial disease, which leads towards a reversible and irreversible loss of minerals found in hard tissues of a tooth, caused by acids from carbohydrates fermentation due to metabolic activity of the biofilm attached to the tooth surface. Although Streptococcus mutans has been thought to be responsible for tooth decay, another bacterium named no mutans has been linked to the beginning, progression and activity of the disease in the enamel, dentine and cement. One of the methodologies put into practice to deepen the study of oral bacteria diversity related to carious cavities is oral metagenome. This methodology allows the study of whole bacterial groups by the analysis of DNA in a particular environment without the need of isolating and cultivating species, providing information about the taxonomical and phylogenetic diversity of these groups. There are different methods to study the bacterial diversity, including 16 S rRNA analysis through electrophoresis, PCR, microarrays, next generation sequence (NGS). The metagenome tool permits to recognize species that have not been able to be isolated by conventional methods. As well as identify its presence or absence in the different stages of the dental caries development, which allows a better understanding of development of the disease. The metagenome-based study has revealed an unexpected oral microbial diversity, giving information relevant to the updating of knowledge and identifies new therapeutic targets. The purpose of this review is to present the main results has brought the study of the metagenome on microbial diversity, applied specifically to the oral bacterial community in health and caries disease.

Can a bleaching toothpaste containing Blue Covarine demonstrate the same bleaching as conventional techniques? An in vitro, randomized and blinded study

ABSTRACT Objective The purpose of this in vitro study was to compare the efficacy of a bleaching toothpaste containing Blue Covarine vs. conventional tooth bleaching techniques using peroxides (both in-office and at-home). Material and Methods Samples were randomly distributed into five experimental groups (n=15): C - Control; BC – Bleaching toothpaste containing Blue Covarine; WBC – Bleaching toothpaste without Blue Covarine; HP35 - In-office bleaching using 35% hydrogen peroxide; and CP10 – At-home bleaching with 10% carbamide peroxide. The dental bleaching efficacy was determined by the color difference (ΔE), luminosity (ΔL), green-red axis (Δa), and blue-yellow axis (Δb). The CIELab coordinates were recorded with reflectance spectroscopy at different times: T0 - baseline, T1 – immediately after bleaching, T2 - 7 days, T3 - 14 days, and T4 - 21 days after the end of treatments. Data were analyzed by a repeated measures mixed ANOVA and post hoc Bonferroni test, with a significance level of 5%. Results No significant differences were found between the treatment groups C, BC, and WBC. The groups HP35 and CP10 showed significantly higher whitening efficacy than groups C, BC, and WBC. Conclusions There were no significant differences in the whitening efficacy between a Blue Covarine containing toothpaste, a standard whitening toothpaste, and a control. Neither of the whitening toothpastes tested were as effective as in-office or at-home bleaching treatments.

Increased longevity of resins based composite restorations and their adhesive bond: a literature review / Aumento de longevidad de restauraciones de resinas compuestas y de su unión adhesiva: revisión de tema

ABSTRACT. Introduction: the goal of this literature review is to analyze the findings included in the literature concerning different alternatives to increase longevity of resin-based composite restorations and their adhesive bond. Methods: bibliographies in the EBSCO database (Elton B Stephens Company) were reviewed using the following key words: "composite repair bond strength"; "restorations sealing"; composite restorations longevity"; "restorations refurbishment"; "composite bond strategy"; "dental adhesive collagen cross linking"; "proanthocyanidin dentin bond strength"; "multiple layer dentin bond strength", and "dentin adhesive evaporation bond strength". Clinical and laboratory results were analyzed in terms of repairing, sealing, and refurbishing defective restorations, in addition to improvements in impregnation of adhesive surfaces, resistance of adhesive polymers, and the progress recently made concerning resistance to hydrolytic collagen degradation. Results: repairing, sealing, or refurbishing defective restorations allow keeping tooth structure healthy, reducing potential damage to dental pulp, as well as operatory pain, often caused without anesthetics. New bonding management techniques provide adhesive procedures with increased longevity. Conclusions: repairing, refurbishing, or sealing defective composite resins increase the longevity of restorations and restored teeth by using minimally invasive dental techniques. Other methods, such as improving impregnation of adhesive surfaces, increasing adhesive polymers strength, and hydrolytic degradation of collagen are promising advances that modify the management of bonding techniques, providing patients with restorative treatments of increased longevity.

RESUMEN. Introducción: el objetivo de esta revisión es analizar los resultados de las diferentes alternativas que presenta la literatura para incrementar la longevidad de las restauraciones con base a resinas compuestas. Métodos: fueron revisadas las bibliografías en la base de datos EBSCO (Elton B Stephens Company), en idioma inglés bajo los siguientes acrónimos " composite repair bond strengh"; "restorations sealing"; composite restorations longevity; "restorations refurbishment"; "composite bond estrategy"; "dental adhesive collagen cross linking"; "proanthocyanidin dentin bond strength";" multiple layer dentin bond strength"; and "dentin adhesive evaporation bond strength". Se examinan los resultados clínicos y de laboratorio de reparación, sellado y remodelado de restauraciones defectuosas, además de las mejoras en la impregnación de las superficies adhesivas, la resistencia de los polímeros adhesivos y los avances en el aumento de la resistencia a la degradación hidrolítica del colágeno. Resultados: la reparación, sellado y remodelado de restauraciones defectuosas permite la preservación de estructura dentaria sana, reducción del potencial daño a la pulpa dental y reducción del dolor operatorio, la mayoría de las veces efectuado sin uso de anestésicos. Nuevas técnicas para el manejo de la adhesión proporcionan incremento en la longevidad de los procedimientos adhesivos. Conclusiones: la reparación, remodelado y sellado de resinas compuestas defectuosas, incrementa la longevidad de las restauraciones y de los dientes restaurados con la aplicación de técnicas de odontología mínimamente invasiva. Adicionalmente otras metodologías, tales como mejoras en la impregnación de las superficies adhesivas, aumento de la resistencia de los polímeros adhesivos e incremento de la resistencia a la degradación hidrolítica del colágeno constituyen promisorios avances que modifican el manejo de las técnicas adhesivas, que permitirá ofrecer tratamientos restauradores de mayor longevidad a la población.

Comparación de la fuerza adhesiva de 2 sistemas de cementos de resina en diferentes regiones radiculares en la cementación de postes de fibra / Comparison of bond strength of two resin cement systems in different roots region on the cementation of fiber posts

La causa de fracaso más común de los postes de fibra es su desalojo, principalmente debido a la compleja adhesión dentro del conducto radicular. El principal objetivo de este estudio fue determinar si existe diferencia significativa en la resistencia adhesiva mediante el test push-out en la cementación de postes de fibra con RelyX U-200® (U200) y Core Paste XP® (CPX) en diferentes regiones radiculares. MATERIALES Y MÉTODOS Se seleccionaron 40 premolares, se seccionaron a 15 mm del ápice, fueron tratados endodóncicamente y fueron divididos aleatoriamente en 2 grupos de 20, a los cuales se les cementó un poste de fibra translúcido Exacto® con U200 y CPX. Después de 24 h cada muestra fue seccionada transversalmente a nivel cervical, medio y apical. Fueron sometidas al test de push-out mediante la máquina Tinius Olsen HK5-S para cuantificar la resistencia adhesiva en megapascales. Se utilizó el test Shapiro-Wilk, test de ANOVA de 2 factores y Tukey con un nivel de significación del 95%. RESULTADOS No hubo diferencia significativa de ambos cementos (p = 0,457), pero sí hubo diferencia cuando se comparó el tipo de cemento y la región; CPX presentó valor significativamente mayor en el tercio cervical (p < 0,05), mientras que U200 presentó un valor significativamente mayor en el tercio apical (p < 0,05). CONCLUSIONES No hubo diferencia significativa en el valor de adhesión cuando se comparó solo el factor cemento entre U200 y CXP, sin embargo hubo un mayor valor de CXP a nivel cervical y de U200 a nivel apical.

Loosening is the most common failure of fiber posts, mainly due to complex adhesion within the root canal. The main objective of this study was to determine if significant differences in adhesive resistance, using the push-out test, in the cementation of fiber posts with RelyX U-200® (U200) and Core Paste XP® (CPX) in different root regions. MATERIALS AND METHODS A selection of 40 premolars were sectioned 15 mm from the apex, treated endodontically and then randomly divided in two groups of 20, using an Exacto translucent fiber post with U200 and CPX, respectively. After 24 hours, each sample was sectioned into cervical, middle and apical. The test push-out test was performed using a Tinius Olsen HK5-S machine to quantify the adhesive strength in Mega Pascals. The test Shapiro-Wilk, two-factor Anova and Tukey tests were used with a significance level of 95% RESULTS There were no significant differences between the cements (P = .457) but if there was difference when comparing the type of cement and region. CPX showed a value significantly higher in the cervical third (P < .05), while U200 presented a value significantly higher in the apical third (P < .05). CONCLUSIONS There was no significant difference in the value of the adhesive strength in the comparison between U200 and CXP, however there was a higher value of CXP at cervical and U200 at apical level.

Fracture resistance of endodontically-treated teeth submitted to bleaching treatment with hydrogen peroxide and titanium dioxide nanoparticles photoactivated by LED-laser / Resistência à fratura de dentes tratados endodonticamente submetidos a tratamento clareador com peróxido de hidrogênio e nanopartículas de dióxido de titânio fotoativado por LED-laser

Objective: The aim of this study was evaluate the fracture resistance of endodontically-treated teeth after bleaching treatment using 15% hydrogen peroxide plus titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser, in comparison with protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP) or sodium perborate (SP). Material and method: After endodontic treatment, fifty bovine extracted incisors were divided into five groups (n = 10): G1- without bleaching; G2- 35HP; G3- 37CP; G4- 15HPTiO2 photoactivated by LED-laser and G5- SP. In G2 and G4, the bleaching protocol was applied in 4 sessions, with a 7 day interval between each session. In G3 and G5, the materials were kept in the pulp chamber for 21 days, but replaced every 7 days. After 21 days, the crowns were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until fracture. The data were submitted to ANOVA and Tukey tests (p = 0.05). Result: The bleaching treatment in endodontically-treated teeth with 15HP plus TiO2 nanoparticles and photoactivated by LED-laser caused reduction of the fracture resistance similarly provided by 35HP, 37CP or SP (p>0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p<0.05). Conclusion: All bleaching protocols reduced the fracture resistance of endodontically-treated teeth, but there were no differences between each other. .

Objetivo: Avaliar a resistência à fratura de dentes tratados endodonticamente após tratamento clareador usando peroxido de hidrogênio a 15% com nanopartículas de dióxido de titânio (15HPTiO2) fotoativado por LED-laser, em comparação aos protocolos usando peróxido de hidrogênio 35% (35HP), peróxido de carbamida 37% (37CP) ou perborato de sódio (SP). Material e método: Após tratamento endodôntico, 50 incisivos bovinos extraídos foram divididos em 5 grupos (n = 10): G1- sem clareamento; G2- 35HP; G3- 37CP; G4- 15HPTiO2 fotoativado por LED-laser e G5- SP. Nos grupos G2 e G4, o protocolo de clareamento foi aplicado em 4 sessões, com 7 dias de intervalo entre cada sessão. Nos grupos G3 e G5, os materiais foram inseridos na câmara pulpar por 21 dias e trocados a cada 7 dias. Após 21 dias, as coroas foram submetidas à força de compressão com velocidade de 0,5 mm/min, aplicada a 135º em relação ao longo eixo da raiz. empregando máquina de ensaios mecânicos, até a fratura. Os dados foram submetidos aos testes de ANOVA e Tukey (p = 0.05). Resultado: O tratamento clareador em dentes tratados endodonticamente com 15HP e nanopartículas de TiO2 fotoativado por LED-laser proporcionou redução da resistência à fratura semelhante ao 35HP, 37CP ou SP (p>0,05). Todos os tratamentos clareadores reduziram a resistência coronária à fratura quando comparados aos dentes sem tratamento (p<0,05). Conclusão: Todos os protocolos de clareamento reduziram a resistência à fratura dos dentes tratados endodonticamente, sem diferenças estatisticamente significantes entre os grupos. .

Indicators of the risk mechanics for Class-I and Class-II amalgam and composite resin restorations

AIM: To determine indicators of prognosis for mechanical risks of amalgam and composite resin restorations in permanent teeth. METHODS: Thirty-nine adult patients with direct clinical, photographic, radiographic and model examinations. A total of 256 restorations were classified as "not satisfactory," with Bravo or Charlie values according to the modified Ryge /USPHS criteria. The total "n" was divided into Bravo and Charlie groups according to the value obtained in the "marginal adaptation" parameter. Each of the groups was sub-divided by the type of material (amalgam and composite resins) and the class: occlusal (O) and proximal (MOD). RESULTS : Comparing the Bravo and Charlie groups, the statistically significant indicators were: the mesiodistal dimension (p=0.037), the distal isthmus (p<0.05), the average of the isthmuses (p<0.05), the distal (p<0.05) cavity depth, and the average depth of the MOD (p<0.05) cavities. It was concluded that the type and the class of the restoration are not indicators for sampling. CONCLUSIONS: With regard to the design of the cavity preparation, the valid mechanical risk indicators include the mesiodistal dimension, the distal isthmus, the average of the isthmuses, the depth of the distal cavity and the average depth of the MOD cavities. A simple clinical assessment does not provide sufficient information to establish the indicators for mechanical failure risk of restorations...

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)

ABSTRACT Introduction and Objective: 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.

Interação multidisciplinar para reabilitação de um dente posterior com sistema IPS E. MAX / Multidisciplinary approach to restore a posterior teeth with IPS e. max system

A Odontologia atual está constantemente aprimorando os tratamentos odontológicos com terapias conservadoras que restabelecem a função, preservando a saúde dos tecidos bucais e a estética. No entanto, as novas terapias também exigem a realização de planos de tratamentos multidisciplinares para obtenção de sucesso clinico e satisfação do paciente. A Periodontia tem ampliado sua abordagem terapêutica para facilitar/possibilitar a realização de tratamentos restauradores, visando à manutenção da integridade dos dentes após o procedimento restaurador. O caso clinico relata um tratamento multidisciplinar envolvendo Dentística, Endodontia e Periodontia, para reabilitação de um elemento unitário posterior afetado por uma lesão de cárie extensa com invasão do espaço biológico. Realizou-se aumento de coroa com osteotomia no dente 36 para recuperar este espaço biológico. Além disso, foi necessária a realização do tratamento endodôntico seguido do procedimento restaurador. Indicou-se realização de uma onlay cerâmica do sistema IPS e.max Press (Ivoclar), devido às exigências mecânicas do caso. O tratamento planejado garantiu função e resistência adequada, preservando os tecidos bucais. Concluiu-se que a abordagem multidisciplinar possibilitou a realização de um tratamento conservador que ofereceu satisfação ao paciente, preservando sua saúde bucal.

Influence of type of bur and acid etching on dentin hydraulic conductance

El objetivo de este estudio fue comparar la tasa de filtración ex vivo (conductancia hidráulica) en discos de dentina humana tratados mecánicamente con fresas de diamante de diferente granulometría y carbide con o sin grabado ácido. Método: 60terceros molares sanos recientemente extraídos de pacientes entre 18-30 años, fueron limpiados, desinfectados (0.1% timol) e incluidos en bloques de resina epóxica. Los discos de dentinase obtuvieron mediante la reducción de la superficie oclusal con instrumentos rotativos cilíndricos, formando los siguientes nueve grupos de 12 muestras c/u: 1: grano fino (FG); 2: granomedio (MG); 3: grano grueso (CG); 4: fresas de carburotungsteno (C); 5: FG con grabado ácido (AO); 6: GM con AO;7: GG con AO; 8: C con AO; 9: sólo grabado ácido. Se determinó la conductancia hidráulica en el modelo experimental bajo presión constante de 200 mm de altura de H2O. No seobservaron diferencias entre la conductancia hidráulica entre los diferentes tipos de fresas (p = 0,5).Se encontraron diferencias en la conductancia hidráulica de discos de dentina con y sin grabado ácido (p < 0,001). El tipo de fresa no afecta la conductacia hidráulica dentinaria.El grabado ácido aumenta significativamente la conductanciahidráulica dentinaria