Uso efectivo de los adhesivos de octava generación / Effective use of eighth generation adhesives

Introducción: se realizó una revisión bibliográfica con el objetivo de conocer, analizar y comparar los diferentes tipos de adhesivos de octava generación que se encuentran en el mercado y la diferencia que existe entre cada uno. Los adhesivos universales han demostrado mejoras en su resistencia, sobre todo en las técnicas de aplicación y en las propiedades de estos materiales, al mejorar la fuerza adhesiva para que el odontólogo pueda brindar tratamientos restaurativos exitosos. Objetivo: conocer, analizar y comparar los diferentes tipos de adhe- sivos de la octava generación empleados en odontología. Material y métodos: se realizó una búsqueda en las bases de datos electrónicas PubMed, BVS, Redalyc y ScienceDirect. Se utilizaron 32 artículos que cumplieron con los criterios predeterminados y la especificidad reque- rida para la pregunta de investigación. Conclusiones: se demostró que la tecnología cada día avanza, sobre todo en el área de los adhesivos, ya que éstos son de mucha utilidad en el día a día del odontólogo; es importante conocer cada uno de éstos, puesto que es un poco complejo seleccionar el correcto, mas no el uso. En la actualidad, existen diversas opciones por las que el odontólogo puede optar, es por ello que el pro- fesional debe estar capacitado sobre cada una de las diferentes marcas existentes y, de acuerdo al tratamiento, debe elegir cuál es mejor utilizar en una rehabilitación. Es importante para el odontólogo conocer estos materiales, ya que esto lo beneficiará al momento de llevar un plan de tratamiento restaurador (AU)

Introduction: a bibliographic review was carried out to learn about, analyze, and compare the different types of eighth-generation adhesives on the market and the difference between each one. Universal adhesives have demonstrated improvements in their resistance, especially in the application techniques and properties of these materials, improving the adhesive strength so that the dentist can provide successful restorative treatments. Objective: to know, analyze and compare the different types of eighth-generation adhesives used in dentistry. Material and methods: a search was made of the following electronic databases: PubMed, BVS, Redalyc, ScienceDirect. Finally, 32 articles that met the predetermined criteria and the specificity required for the research question were used. Conclusions: it was demonstrated that technology is advancing every day, especially in the area of adhesives since these are very useful in the daily life of the dentist. It is important to know each one of these since it is a little complex at the moment of selecting the correct one, but not the use. Currently, there are several options that the dentist can choose, which is why the professional must be trained on each of the various existing brands and according to the treatment which is the best to use at the time of rehabilitation. The dentist needs to know these materials since they will benefit him/her when carrying out a restorative treatment plan (AU)

Adhesión a dentina part II: estrategias para optimizar la adhesión a dentina y protocolos adhesivos / Dentin bonding part II: strategies to optimize dentin bonding and adhesive protocols

La adhesión a dentina con sistemas adhesivos polimé-ricos representa un desafío que surge de la necesi-dad de vincular un sustrato dentario heterogéneo y variable con materiales que presentan todavía cier-tos aspectos a atender para poder conseguir el máxi-mo desempeño. El propósito del presente artículo es evaluar algunas de las estrategias propuestas para mejorar la adhesión a dentina, y sugerir un protocolo de trabajo con los diferentes tipos de sistemas adhesivos (AU)

Dentin bonding with polymeric adhesive systems represents a challenge that arises from the need to link a heterogeneous and variable dental substrate with materials that still have certain aspects to be addressed in order to achieve maximum performance. The aim of this article is to evaluate some of the proposed strategies to improve dentin bonding and to suggest a protocol for each different type of bonding systems (AU)

Biomateriales que inducen la remineralización del esmalte dental y dentina / Biomaterials that induce remineralization of the dentin and enamel surface

Desde los sesentas, con la invención del vidrio bioactivo, los tratamientos de remineralización se han popularizado entre los cirujanos dentistas y su utilización es cada vez mayor; la remineralización, en conjunto con las adecuadas medidas de higiene preventiva, representa uno de los mejores abordajes mínimamente invasivos y a un costo comparativamente bajo. Este estudio documental tiene por objetivo establecer una mejor comprensión del uso clínico de los biomateriales que inducen la remineralización de la superficie del esmalte dental y dentina. Se realizó una exploración utilizando motores de búsqueda (bases de datos en PubMed, Medigraphic, y Science Direct). El proceso de localización de los estudios relevantes se efectuó introduciendo palabras clave como: silicatos de calcio, fosfopéptidos de caseína-fosfato de calcio amorfo, remineralización, esmalte y dentina, incluyéndose en el procedimiento artículos de antigüedad no superior a siete años, en español e inglés, publicados en revistas científicas aprobadas por pares.Actualmente, no es posible remineralizar del todo la estructura dentaria, por lo cual, en un futuro cercano, los esfuerzos de la odontología de remineralización deben apuntar al desarrollo de agentes biomiméticos inteligentes que restauren al cien por ciento la estructura dental perdida (AU)

Since the sixties, with the invention of bioactive glass, remineralization treatments have become popular among dental surgeons. Their usage is increasing; remineralization, in conjunction with appropriate preventive hygiene measures, represents one of the best minimally invasive treatments at a relatively low cost. This documentary study aims to establish a better understanding of the clinical use of biomaterials that induce remineralization of the surface of teeth enamel and dentin. A search was conducted using search engines (PubMed and Medigraphic databases, and Science Direct). The search process for the relevant studies was carried out by introducing keywords such as calcium silicates, phosphopeptides of amorphous calcium casein-phosphate, remineralization, enamel and dentin, including in the search articles no older than seven years in Spanish and English published in scientific reviewed journals. Currently, it is not possible to completely remineralize the dentary structure so, in the near future, remineralization dentistry efforts should aim to develop (AU)

Uso do fluoreto de sódio como dessensibilizante no clareamento dental: uma revisão de literatura / Use of sodium fluoride as a desensibilizer in dental bleaching: a literature review

Objetivo: Verificar, por meio de uma revisão de literatura, a efetividade do uso do fluoreto de sódio como dessensibilizante para casos de sensibilidade induzida por clareamento dental. Resultados: O clareamento dentário tornou-se um dos procedimentos estéticos mais procurados na odontologia. Atualmente, existem duas técnicas supervisionadas por dentistas: o clareamento caseiro e o de consultório. Os materiais mais utilizados são o peróxido de carbamida e o de hidrogênio, respectivamente. O clareamento dental baseia-se na premissa de que o peróxido de hidrogênio penetra na estrutura dentária para interagir com os cromóforos orgânicos. Embora o protocolo de clareamento exija o uso de agentes oxidantes de baixa concentração, a sensibilidade dentária ainda está presente e pode ser considerado o principal efeito adverso da técnica de clareamento. Para minimizar este problema, a aplicação tópica de dessensibilizantes antes e após o clareamento dentário tem mostrado bons resultados na redução da intensidade de sensibilidade. Considerações finais: Mediante revisão apresentada, constatou-se que fluoreto de sódio quando utilizado após o protocolo clareador, como dessensibilizante, não elimina a sensibilidade, mas diminui a intensidade da dor. Quando utilizado antes do clareamento dental, não apresenta resultados positivos. Ademais, salienta-se que quando o fluoreto é incorporado no gel clareador, resulta em menor desmineralização do esmalte dentário.(AU)

Objective: To verify, through a literature review, the effectiveness of using sodium fluoride as a desensitizer for cases of sensitivity induced by tooth whitening. Literature review: Teeth whitening has become one of the most desired aesthetic procedures in dentistry. Currently, there are two techniques supervised by dentists: home whitening and office whitening. The most used materials are carbamide peroxide and hydrogen peroxide, respectively. Teeth whitening is based on the premise that hydrogen peroxide penetrates the tooth structure to interact with organic chromophores. Although the whitening protocol requires the use of low concentration oxidizing agents, tooth sensitivity is still present and can be considered the main adverse effect of the whitening technique. To minimize this problem, the topical application of desensitizers before and after tooth whitening has shown good results in reducing the intensity of sensitivity. Final considerations: Upon the review presented, it was found that sodium fluoride, when used after the whitening protocol, as a desensitizer, does not eliminate sensitivity, but reduces the intensity of pain. When used before tooth whitening, it has no positive results. Furthermore, it should be noted that when fluoride is incorporated into the whitening gel, less enamel demineralization is induced.(AU)

Evaluación semicuantitativa de los microelementos del esmalte en un modelo de obesidad inducido por glutamato monosódico en ratas / Semi-quantitative evaluation of enamel microelements in an obesity model induced by monosodium glutamate in rats

RESUMEN: En la actualidad, existen múltiples modelos experimentales de obesidad, unos de ellos es la utilización de glutamato monosódico (GMS), un potenciador del sabor ampliamente utilizado en industria alimentaria. Este GMS ha sido relacionado con obesidad, diabetes, insulino resistencia, así como en alteraciones en múltiples órganos, tales como testículos, riñón e hígado, entre otros. Ha sido reportado el efecto del GMS en estructuras orales, tales como las glándulas salivales, alterando su morfología y función. La relación del efecto del GMS frente a tejidos dentarios no ha sido reportada, siendo esto relevantes debido a la información que proporciona a disciplinas tales como arqueología científica, identificación forense, paleoecología y odontología. El objetivo del estudio fue observar la modificación de los elementos en la superficie dental, en un modelo de obesidad inducida por GMS, en ratas. Se utilizaron 12 ratas neonatas Sprague Dawley machos, divididas en dos grupos según exposición a GMS (Grupo Control y Grupo GMS 1: 4 mg/g peso de GMS, 5 dosis, mantenidas 16 semanas. Fue calculado el índice de masa corporal (IMC) e Índice de Lee, además de ser analizados el porcentaje de masa de los elementos C, O, Na, P, Ca, Fe y K en la superficie dental, mediante análisis semicuantitativo. Los resultados indican que GMS indujo obesidad en las ratas, así como alteraciones en los porcentajes de masa de los elementos en la superficie dental, evidenciándose disminución de Ca, P y O, además de aumentos en C y Fe. Según reportes previos, la obesidad inducida por GMS, causa alteraciones en secreción y composición salival, elemento íntimamente relacionado con la composición del esmalte, lo que vendría a explicar nuestros resultados. Entender la composición superficial del esmalte superficial podría ayudarnos a comprender de mejor manera la relación entre caries dentaria y obesidad.

SUMMARY: Monosodium glutamate (MSG) is a flavor enhancer widely used in the food industry. It has been associated with obesity, diabetes, insulin resistance, as well as alterations in multiple organs, such as testicles, kidney, liver, among others. While its effect on oral structures such as the salivary glands has been reported, the impact on dental tissues has not been described. Since this information is also relevant in fields such as forensic identification, palaeoecology and dentistry, the objective of the study was to observe alterations on the tooth surface in a model of obesity in rats induced by MSG. Twelve neonate male Sprague Dawley rats were used, divided into two groups according to MSG exposure (Control Group and MSG1 Group: 4 mg / g weight of MSG, 5 doses were maintained for 16 weeks. Body mass index (BMI) and Lee's index as well as mass percentage of elements C, O, Na, P, Ca, Fe and K on the tooth surface were evaluated by semi-quantitative analysis. In addition to increases in C and Fe, results indicate that MSG induced obesity and alterations in the percentages of mass on the tooth surface in rats, showing a decrease in Ca, P and O, According to previous reports, MSG induced obesity causes alterations in secretion and salivary composition, an aspect closely related to enamel composition, thus explaining our results. Enhanced knowledge of enamel surface composition may help improve our understanding of the relationship between dental caries and obesity.

Microabrasión del esmalte. Indicaciones, limitaciones y alcance clínico / Enamel micro-abrasion. Indications, limitations and clinical scope

Existen muchas patologías pigmentarias que alteran la estética del color dentario; algunas de ellas pueden circunscribirse a la superficie externa del esmalte y por ende ser tratadas con una técnica microabrasiva para su eliminación. La indicación de un tratamiento más agresivo en relación al blanqueamiento convencional, dependerá no solo de la ubicación de la lesión, sino también de la severidad de la misma, de la calidad de la estructura del tejido adamantino y de la anatomía dentaria entre muchas otras variables (AU)

ere are many pigment pathologies that alter the aesthetics of tooth color; Some of them can be confined to the outer surface of the enamel and therefore be treated with a microabrasive technique for their removal. e indication of a more aggressive treatment in relation to conventional whitening will depend not only on the location of the lesion, but also on its severity, the quality of the structure of the adamantine tissue and the dental anatomy among many other variables (AU)

Effect of hydrochloric acid commercial presentation for microabrasion technique on loss of enamel structure and surface / Efeito da apresentação comercial de ácido clorídrico para técnica de microabrasão na perda de estrutura e superfície do esmalte

Introdução: A técnica de microabrasão pode ser realizada através de pasta pronta para uso, disponível comercialmente, ou o profissional pode manipulá-la no consultório. Objetivo: Verificar o efeito da apresentação comercial do ácido clorídrico a 10% na manipulação de pasta para microabrasão sobre a superfície do esmalte. Metodologia: Foram selecionados incisivos bovinos e divididos em dois grupos, de acordo com a apresentação comercial do ácido clorídrico (líquido ou em gel). O tratamento foi realizado através de dez aplicações com 10s de duração cada, intercaladas por lavagem de 10s. Vinte incisivos (n=10) foram utilizados para se determinar a perda de estrutura do esmalte. Cada amostra foi pesada, em balança analítica, antes e após submissão à microabrasão. Outras 20 amostras (n=10) foram utilizadas para determinação da rugosidade superficial média (Ra) utilizando-se um rugosímetro. Três amostras de cada grupo do experimento anterior foram selecionadas, aleatoriamente, e outras três amostras adicionais foram preparadas como controle (baseline) para análise em MEV. Resultados: Verificou-se diferença estatística significativa entre a massa final e a inicial e rugosidade superficial das amostras, independente da apresentação comercial do ácido. Nas imagens de MEV observou-se presença de superfície regular para o grupo controle (baseline). Nas demais imagens verificou-se superfície com considerável irregularidade e dissolução discreta do esmalte. Conclusões: O tratamento realizado causou perda significativa de estrutura e aumentou a rugosidade superficial dos espécimes, independente da apresentação comercial do ácido e sem apresentar diferença entre os grupos ao final. A apresentação comercial do ácido não parece ser um fator a interferir no tratamento. (AU)

Introduction: The microabrasion technique can be performed using a commercially available paste, or the dentist can prepare it in his office. Objective: To verify the effect of hydrochloric acid commercial presentation in the handling of microabrasion paste on the enamel surface. Methodology: Bovine incisors were divided into two groups, according to the commercial presentation of 10% hydrochloric acid (liquid or gel). The treatment was carried out through ten applications of 10 s duration each, intercalated with a 10s wash. Twenty teeth (n=10) were used to determine the loss of enamel structure. Each sample was weighed on an analytical balance before and after submission to microabrasion. Another 20 teeth (n=10) were used to determine the average surface roughness (Ra) using a rugosimeter. Three samples from each group of the previous experiment were selected, randomly, and another three additional samples were repared as a control (baseline) for SEM analysis. Results: There was a statistically significant difference between the final and initial mass and the surface roughness of the samples, regardless of the acid commercial presentation. In the SEM images, a regular surface was observed for the control group (baseline). In the other images, there was a surface with considerable irregularity and a slight dissolution of the enamel. Conclusions: The treatment carried out. (AU)

Use of Antibiotics in early Childhood and Dental Enamel Defects in 6- to 12-year-old Children in Primary Health Care / Uso de antibióticos na primeira infância e defeitos de esmalte dentário em crianças de 6 a 12 anos na Atenção Primária à Saúde

ABSTRACT Dental enamel defects (DED) are lesions that occur due several factors. Proper care is needed to promote their treatment and prevention. The aim of this study was to evaluate the occurrence of DED in permanent teeth of children who used antimicrobial drugs in the first four years of life. This is a crosssectional study carried out in a Primary Health Care (PHC) service, which included children from six to 12 years of age. DED were evaluated by oral examination, and data on the use of antimicrobials in early childhood were collected based on medical records. Data were analyzed with the chisquare test and Fisher's exact test. The sample included 144 children. In relation to DED, 50% (72) and 20.1% (29) presented opacity and hypoplasia, respectively. Amoxicillin was the most frequently prescribed drug, followed by sulfamethoxazole + trimethoprim. Among the children, 78.5% (113) were prescribed antimicrobial drugs at least once during the first 4 years of life, and 55% (79) of them presented some type of DED. There was no statistically significant association between the variables analyzed. In conclusion, there was high prevalence of children with DED, and amoxicillin was the most commonly prescribed antibiotic.

RESUMO Os defeitos do esmalte dentário (DED) são lesões que ocorrem devido a vários fatores e é necessária atenção para promover seu tratamento e prevenção. O objetivo foi avaliar a ocorrência de DED em dentes permanentes de crianças que usaram antimicrobianos nos primeiros quatro anos de vida. Tratase de um estudo transversal realizado em um serviço de Atenção Primária à Saúde (APS), que incluiu crianças de seis a 12 anos de idade. A DED foi avaliada por dados de exames bucais, e os dados sobre o uso de antimicrobiano na primeira infância foram coletados com base em prontuários médicos. A análise foi realizada com o teste do quiquadrado e o teste exato de Fisher. A amostra foi composta por 144 crianças. Em relação ao DED, 50%(72) e 20,1%(29) apresentaram opacidade e hipoplasia, respectivamente. A amoxicilina foi o medicamento prescrito com mais freqüência, seguido pelo sulfametoxazol+ trimetoprim. Entre as crianças, 78,5%(113) receberam medica mentos antimicrobianos pelo menos uma vez nos primeiros 4 anos de vida e 55%(79) deles apresentaram algum tipo de DED. Não houve associação estatisticamente significante entre as variáveis analisadas. Em conclusão, houve uma alta prevalência de crianças com DED e a amoxicilina foi o antibiótico mais comumente prescrito.

Evaluación de la adhesión de sistemas adhesivos de grabado total en esmalte dental bovino usando un agente desproteinizante: un estudio in vitro / Evaluation of adhesion of total etch adhesive systems on bovine dental enamel using a deproteinizing agent: an in vitro study

Introducción: Hoy en día, la mayoría de los pacientes requieren tratamiento de ortodoncia fija convencional, la cual utiliza procedimientos adhesivos afines con la superficie amelodentinaria. Aunque existen diferentes técnicas adhesivas que pueden ofrecer adecuados niveles de resistencia al desalojo, el uso del hipoclorito de sodio (NaClO) como agente desproteinizante no ha sido bien definido en materiales de cementación en aparatología ortodóncica convencional. Objetivo: El objetivo de este estudio fue determinar los niveles de resistencia al desalojo con pruebas de microtensión y análisis topográfico con microscopia electrónica de barrido. Material y métodos: 20 bloques de esmalte bovino fueron expuestos superficialmente a soluciones acondicionadoras (ácido ortofosfórico al 37%) con y sin agente desproteinizante (NaClO al 5.25%); finalmente, brackets individuales de ortodoncia fueron cementados con sistemas adhesivos y resinas compuestas de casas comerciales (Ormco y 3M). Las pruebas de resistencia al desalojo fueron realizadas con una máquina de fuerzas universales y el análisis topográfico con microscopia electrónica de barrido. Resultados: El uso del NaClO al 5.25% y la marca Ormco tuvieron estadísticamente los mejores niveles de adhesión que el grupo sin desproteinización y la casa comercial 3M, respectivamente. La topografía adamantina expuesta al agente desproteinizante mostró características de superficie relacionadas con el patrón de grabado tipo I. Conclusión: El uso de un agente desproteinizante (NaClO 5.25%) así como una marca comercial (Ormco) en particular podrían definir el aumento en los niveles de adhesión en superficies adamantinas con aparatología ortodóncica convencional (AU)

Introduction: Nowadays, patients require conventional fixed orthodontic treatment, which uses adhesive procedures related to the dentinal denture surface. Although there are different adhesive techniques that can offer adequate levels of bonding resistance, the use of NaClO as a deproteinizing agent has not been well defined in cementing materials in conventional orthodontic appliances. Objective: The objective of this study was to determine the levels of bond resistance using micro tension tests and topographic analysis with scanning electron microscopy. Material and methods: Twenty-blocks of bovine enamel were exposed superficially to conditioning solutions (37% orthophosphoric acid) with and without deproteinizing agent (5.25% NaClO); finally, individual orthodontic brackets were cemented with adhesive systems and resin composites of different trademarks (Ormco and 3M). Bonding resistance tests were performed with a universal force machine and topographic analysis was made with scanning electron microscopy. Results: The use of 5.25% NaClO and the Ormco brand had statistically better levels of adhesion than the group without deproteinization and the 3M brand, respectively. Adamantine topography exposed to the deproteinizing agent showed surface characteristics related to the type I etching pattern. Conclusion: The use of a deproteinizing agent (NaClO 5.25%) as well as a trademark (Ormco) in particular conditions could define the increase in adhesion levels on adamantine surfaces with conventional orthodontic appliances (AU)

Effect of violet LED light on in-office bleaching protocols: a randomized controlled clinical trial

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.

Do commercial whitening dentifrices increase enamel erosive tooth wear?

Abstract Objective This in vitro study evaluated the effect of commercial whitening dentifrices on erosive tooth wear (ETW) of bovine enamel samples, in comparison with commercial regular dentifrices. Methodology Sixty bovine crowns were embedded in acrylic resin, polished and then had their baseline profile determined. They were randomly assigned to 5 groups (n=12/group), according to the type of commercial dentifrice to be tested: GI - Crest Anti-cavity Regular; GII - Crest 3D White; GIII - Colgate Total 12 Clean Mint; GIV - Colgate Optic White; GV - Placebo (negative control, fluoride-free dentifrice). The samples were submitted to daily erosive and abrasive challenges for 3 days. The erosive challenges were performed 3 times a day by immersing the specimens in 0.1% citric acid solution (pH 2.5) for 90 s. Each day after the first and last erosive challenges, the specimens were subjected to the abrasive challenge for 15 s, using a toothbrushing machine (Biopdi, São Carlos, SP, Brazil), soft toothbrushes and slurry (1:3 g/ml) of the tested toothpastes (1.5 N). The specimens were kept in artificial saliva between the challenges. The final profile was obtained and the ETW (µm) was calculated. Data were analyzed by Kruskal-Wallis and Dunn's tests (p<0.05). Results All dentifrices tested significantly reduced the enamel wear in comparison with the Placebo, except GIII. The median (95% CI) ETW was 1.35 (1.25-1.46)bc for GI, 1.17 (1.01-1.34)cd for GII, 1.36 (1.28-1.45)ab for GIII, 1.08 (1.04-1.14)d for GIV and 2.28 (2.18-2.39)a for GV. Conclusion When dentifrices from the same manufacturer were compared, the whitening dentifrices led to similar or less wear than the regular ones.

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.

Efectividad de un gel remineralizante / Efectiveness of a remineralizing gel

Este es un estudio ex vivo donde se evalúa la variación en peso de veintiún piezas dentarias sometidas a un ácido dental de uso dental y, posteriormente, a la acción del gel remineralizante, objeto de este estudio, obteniéndose por diferencia de peso la cantidad de material mineral, que queda retenida en la pieza. La acción del ácido ortofosfórico ha producido una disminución del peso entre 28-30% de la pieza dentaria. Luego de la aplicación del gel remineralizante, ésta aumentó entre 15-18% del peso, considerando este aumento como significativo (p menor 0.05). Este aumento demuesta la acción remineralizante, ya que después del lavado este aumento se mantiene (AU)

This is an in vitro study where the variation in weight of twenty-one dental pieces subjected to a dental acid and subsequently to the action of the remineralizing gel is evaluated, obtaining by weight difference the amount of hydroxyapatite that is retained in the piece. The action of orthophosphoric acid causes a decrease in weight between 28-30% of the tooth. After the application of the remineralizing gel, it increases between 15-18% by weight considering this significant increase (p less 0.05) (AU)

Remineralizing effect of commercial fluoride varnishes on artificial enamel lesions

Abstract: The aim of this study was to evaluate soluble and insoluble fluoride concentrations in commercial varnishes, and their remineralization effect on artificial caries enamel lesions using surface and cross-sectional microhardness evaluations. Forty bovine enamel blocks were separated into four groups (n=10): control (no treatment), Enamelast (Ultradent Products), Duraphat (Colgate-Palmolive) and Clinpro White Varnish (3M ESPE). Surface enamel microhardness evaluations were obtained, artificial enamel caries lesions were developed by dynamic pH-cycling, and the varnishes were then applied every 6 days, after which the enamel blocks were submitted to dynamic remineralization by pH cycles. After removal of the varnishes, the enamel surfaces were reassessed for microhardness. The blocks were sectioned longitudinally, and cross-sectional microhardness measurements were performed at different surface depths (up to 300 μm depth). Polarized light microscopy images (PLMI) were made to analyze subsurface caries lesions. The fluoride concentration in whole (soluble and insoluble fluoride) and centrifuged (soluble fluoride) varnishes was determined using an extraction method with acetone. The data were analyzed to evaluate the surface microhardness, making adjustments for generalized linear models. There was a significant decrease in enamel surface microhardness after performing all the treatments (p<0.0001). Enamelast and Duraphat showed significantly higher enamel microhardness values than the control and the Clinpro groups (p = 0.0002). Microhardness loss percentage was significantly lower for Enamelast (p = 0.071; One-way ANOVA). PLMI showed that subsurface caries lesions were not remineralized with the varnish treatments. No significant differences in the in-depth microhardness levels (p = 0.7536; ANOVA) were observed among the treatments. Enamelast presented higher soluble and insoluble fluoride concentrations than the other varnishes (p < 0.0001; Kruskal-Wallis and Dunn tests). Enamelast and Duraphat varnishes promoted enamel surface remineralization, but no varnish remineralized the subsurface lesion body. Although insoluble and soluble fluoride concentration values did not correspond to those declared by the manufacturer, Enamelast presented higher fluoride concentration than the others.

Effect of hydroalcoholic extract of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves on the viability and activity of microcosm biofilm and on enamel demineralization

Abstract Objectives: The aim of this study was to assess the effect of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves hydroalcoholic extracts on viability and metabolism of a microcosm biofilm and on enamel demineralization prevention. Methodology: Microcosm biofilm was produced on bovine enamel using inoculum from pooled human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. The biofilm was daily-treated with the extracts for 1 min. At the end, it was analyzed with respect to viability by fluorescence, CFU counting and extracellular polysaccharides (phenol-sulphuric acid colorimetric assay) and lactic acid (enzymatic assay) production. The demineralization was measured by TMR. The data were compared using ANOVA or Kruskal-Wallis (p<0.05). Results: M. urundeuva All. at 100, 10 and 0.1 μg/mL and Q. grandiflora Mart. at 100 and 0.1 μg/mL reduced biofilm viability similarly to positive control (chlorhexidine) and significantly more than the negative-vehicle control (35% ethanol). M. urundeuva at 1000, 100 and 0.1 μg/mL were able to reduce both lactobacilli and mutans streptococci CFU counting, while Q. grandiflora (1000 and 1.0 μg/mL) significantly reduced mutans streptococci CFU counting. On the other hand, the natural extracts were unable to significantly reduce extracellular polysaccharides and lactic acid productions neither the development of enamel carious lesions. Conclusions: The extracts showed antimicrobial properties on microcosm biofilm, however, they had no effect on biofilm metabolism and caries protection.

Effect of iontophoresis on fluoride uptake in enamel with artificial caries lesion

Abstract: Iontophoresis is a noninvasive technique, based on the application of a constant low-intensity electric current to facilitate the release of a variety of drugs, whether ionized or not, through biological membranes. The objective of this research was to evaluate the effect of iontophoresis using different electric current intensities on the uptake of fluoride in dental enamel with artificial caries lesions. In this in vitro operator-blind experiment, bovine enamel blocks (n = 10/group) with caries-like lesions and predetermined surface hardness were randomized into 6 groups: placebo gel without fluoride applied with a current of 0.8 mA (negative control), 2% NaF gel without application of any current, and 2% NaF gel applied with currents of 0.1, 0.2, 0.4 and 0.8 mA. Cathodic iontophoresis was applied for 4 min. The concentration of loosely bound fluoride (calcium fluoride) and firmly bound fluoride (fluorapatite) was determined. The results were analyzed by the nonparametric Kruskal-Wallis and Dunn tests. Iontophoresis at 0.8 mA, combined with the application of fluoridated gel (2% NaF), increased fluoride uptake in enamel with caries-like lesions, as either calcium fluoride or fluorapatite.

Bonding of universal adhesive system to enamel surrounding real-life carious cavities

Abstract: This study aimed to evaluate the bond strength of a universal adhesive system to enamel surrounding real-life carious cavities. Twenty-eight permanent molars (n = 7) with carious lesions in dentin were subjected to selective carious tissue removal to firm dentin and had their crowns sectioned longitudinally. A universal adhesive system (Single Bond Universal [SBU] used in either etch-and-rinse and self-etch strategies) was compared with an etch-and-rinse Adper Single Bond 2 (ASB) and a self-etch Clearfil SE Bond (CSE) adhesive systems (control systems). Adhesives were applied on the enamel, assumed demineralized, surrounding the cavity margins and on sound enamel (control substrate). Composite cylinders were built (0.72 mm2) and microshear bond strength (µSBS) test was performed after 24 h of water storage. The µSBS values (MPa) were analyzed using two-way ANOVA and Tukey's post hoc tests (α = 0.05). Bond strength values obtained in demineralized enamel surrounding carious cavity margins were significantly lower than that obtained in sound enamel (distant from carious cavity margins) (p = 0.035). The bonding strategy of the SBU did not influenced the bond strength values, which were higher than that obtained with ASB. CSE showed similar µSBS values to ASB and SBU in the self-etch mode. In conclusion, the bond strength to enamel assumed demineralized is lower than to sound enamel. The enamel surrounding carious cavities jeopardize the bonding of universal adhesive system. The bond strength of universal adhesive is similar, regardless to bonding strategy.

Effect of grape seed extract-containing phosphoric acid formulations on bonding to enamel and dentin

Abstract The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

Quantitative image of fluorescence of ceramic and resin-cement veneers

Abstract The main of the study was quantify the effect of two ceramics with two underlying resin cements on apparent fluorescence levels. Buccal surfaces of two bovine incisors were ground flat producing one enamel and one dentin substrate. The veneers were fabricated (0.5 and 1.0 mm thickness) using two ceramics (IPSe.max Press and IPSe.max Zirpress, Ivoclar Vivadent). Veneers were cemented using either light-cured (Variolink II, Ivoclar Vivadent) or self-adhesive dual (Rely X U200, 3M ESPE) cement. The layered Control group materials had no cement application. Semi-quantitative fluorescence image analysis (Matlabs software, Matworks) involved processing the images as captured under each daylight (DL, Gretagmacbeth) and ultraviolet illuminants (UVA, Sylvania) within a neutral-gray lightbox (Macbeth Spectral Light). Statistical analysis of the quantitative fluorescence values was performed using two-way ANOVA and Tukey's test (p < 0.05). The e.max Zirpress on the dentin substrate produced greater fluorescence (p < 0.05) when subjected to UV illumination and more fluorescence (p < 0.05) than e.max Press in both cement groups. Light-cured cement produced higher (p < 0.05) fluorescence than the dual-cement with e.max Press on enamel under UV illumination. The fluorescence for e.max Press on the dentin substrate was greater (p < 0.05) than for e.max Zirpress using dual self-adhesive cement subjected to daylight illumination. Thus, it is possible to conclude that the combination of ceramic and cement produce definite, significant effects on the apparent fluorescence, vital quality for restorative dentistry.

Deproteinization of primary enamel with sodium hypochlorite before phosphoric acid etching

The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group AAcid Etching with 37% H3PO4 gel for 15 s; Group B5% NaOCl for 60 s + Acid Etching with 37% H3PO4for 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by KolgomorvSmirnov test and the nonparametric unpaired MannWhitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern (AU)

El objetivo del estudio fue evaluar la desproteinización del esmalte primario a través de los tipos de patrones de grabado, con y sin NaOCl 5% utilizado antes del grabado ácido con H3PO4 37%. Quince dientes primarios humanos extraídos se seleccionaron al azar para el presente estudio in vitro, se prepararon bloques de 1mm x 1 mm y se dividieron en dos grupos (n = 21). Estos grupos se trataron de la siguiente manera: Grupo A: Grabado ácido con H3PO4 37% en gel durante 15 segundos; Grupo B: NaOCl 5% durante 60 segundos + Grabado ácido con H3PO4 37% durante 15 segundos. Las muestras se prepararon para el análisis de microscopía electrónica de barrido. Las imágenes obtenidas se evaluaron principalmente por la calidad de los grabados tipo I y II de la superficie del esmalte primario, utilizando el software Image J. Los datos se analizaron en cuanto a su normalidad mediante la prueba de KolgomorvSmirnov, se utilizó pruebas no paramétricas: Prueba de MannWhitney no pareada. Como resultado, se encontró que el área de superficie media de los valores de patrón de grabado de tipo I y II para el Grupo A era 1922,314 µm2 y el Grupo B era 3840,473 µm2. Finalmente, llegamos a la conclusión de que se puede usar la desproteinización con NaOCl 5% antes del grabado ácido para aumentar el área de adhesión y la calidad del patrón de grabado (AU)