Effect of liners on composite resin microleakage after selective carious lesion removal: an experimental study / Efecto de los recubrimiento en la microfiltración de resina compuesta después de la eliminación selectiva de lesiones cariosas: un estudio experimental

Objetive: To evaluate microleakage of composite resins (CR) placed over different cavitary liners after managing deep caries lesions through selective removal of soft carious tissue to soft dentin (SRCT-S). Material and Methods: Fifty four human teeth were collected for microleakage testing. Each assay comprised ICDAS 5 or ICDAS 6 carious lesions and sound teeth for controls. Sound teeth were prepared with cavities that mirrored the carious teeth cavities, which were prepared with SRCT-S. Sound and carious teeth were further randomly assigned to one of the three experimental groups: Group A: universal adhesive (UA) + CR, Group B: glass ionomer cement liner + UA + CR, and Group C: calcium hydroxide + UA+ CR. Occlusal microleakage (OM) and cervical microleakage (CM) was classified within one of 5 depth categories. ANOVA and Chi-square tests were computed (p<0.05). Results: OM and CM were similarly distributed across subgroups (p>0.05). All Group C samples with carious lesions presented some degree of microleakage. However, no statistically significant differences were observed between groups and within each group (p>0.05). Conclusion: Teeth restored with CR after SRCT-S using calcium hydroxide as a liner material seem to exhibit higher microleakage than those restored using glass ionomer or UA alone. Further clinical research is needed to deepen these findings. Clinical significance: The application of calcium hydroxide as a liner under a composite resin may reduce the longevity of a restoration after performing selective or partial removal of carious tissues. Clinicians should rethink the need of using calcium hydroxide for this application, albeit the lack of clinical evidence.

Objetivo: Evaluar la microfiltración de resinas compuestas (RC) colocadas sobre diferentes liners cavitarios después del manejo de lesiones de caries profundas mediante la remoción selectiva de tejido cariado blando hasta dentina blanda (SRCT-S). Material y Métodos: Se recolectaron 54 dientes humanos para pruebas de microfiltración. Cada ensayo comprendía lesiones cariosas ICDAS 5 o ICDAS 6 y dientes sanos para los controles. Se prepararon dientes sanos con cavidades que reflejaban las cavidades de los dientes cariados, que se prepararon con SRCT-S. Los dientes sanos y cariados se asignaron al azar a uno de los tres grupos experimentales: Grupo A: adhesivo universal (AU) + RC, Grupo B: revestimiento de cemento de ionómero de vidrio + AU + RC, y Grupo C: hidróxido de calcio + AU+ RC. La microfiltración oclusal (MO) y la microfiltración cervical (MC) se clasificaron dentro de una de las 5 categorías de profundidad. Se calcularon las pruebas ANOVA y Chi-cuadrado (p<0,05). Resultados: La MO y MC se distribuyeron de manera similar en los subgrupos (p> 0,05). Todas las muestras del Grupo C con lesiones cariosas presentaron algún grado de microfiltración. Sin embargo, no se observaron diferencias estadísticamente significativas entre grupos y dentro de cada grupo (p>0,05). Conclusión: Los dientes restaurados con RC después de SRCT-S usando hidróxido de calcio como material de revestimiento parecen exhibir una mayor microfiltración que aquellos restaurados usando ionómero de vidrio o AU solo. Se necesita más investigación clínica para profundizar estos hallazgos. Relevancia clínica: la aplicación de hidróxido de calcio como revestimiento debajo de una resina compuesta puede reducir la longevidad de una restauración después de realizar la eliminación selectiva o parcial de los tejidos cariados. Los médicos deberían reconsiderar la necesidad de usar hidróxido de calcio para esta aplicación, aunque no haya evidencia clínica.

In vitro dentin permeability and tubule occlusion of in-office desensitizing materials / Permeabilidade da dentina e oclusão tubular in vitro de materiais dessensibilizantes de consultório

Objetivo: O objetivo desse estudo foi investigar a permeabilidade dentinária e a oclusão tubular de materiais dessensibilizantes de uso em consultório. Métodos: Blocos de dentina bovina foram obtidos e imersos em EDTA 0,5 M para promover a abertura dos túbulos dentinários. Os materiais testados foram: verniz placebo (PLA); verniz fluoretado (FLU); verniz de NaF 5% + 5% trimetafosfato de sódio nanoparticulado (TMP); sistema adesivo universal (SBU); verniz contendo partículas S-PRG (SPRG); solução de Biosilicato (BIOS) e solução de amelotina (AMTN). Os materiais foram aplicados e os espécimes submetidos ao desafio erosivo-abrasivo. A permeabilidade dentinária foi avaliada em T0 (inicial), T1 (após a aplicação dos materiais) e T2 (após o desafio erosivo-abrasivo). As imagens confocais foram usadas para avaliar o comprimento e o número dos túbulos ocluídos e as imagens de microscopia eletrônica de varredura (MEV) para avaliar o número de tubulos abertos. Os dados de permeabilidade e MEV foram analisadas pelo teste ANOVA duas medidas repetidas e pós teste de Tukey. O comprimento e número de túbulos dentinários ocluídos foram analisadas pelo teste ANOVA um critério e pós teste de Tukey, Kruskal-Wallis e pós teste de Dunn's, respectivamente. Os testes de correlação de Spearman e Pearson também foram realizados. O nível de significância foi de 5%. Resultados: O grupo AMTN mostrou os menores valores de permeabilidade em T1 e a seguinte ordem decrescente ocorreu em T2: AMTN=SBU>BIOS=SPRG>TMP>FLU>PLA. O grupo SBU teve o maior comprimento médio de túbulos dentinários ocluídos. O grupo AMTN teve maior número de túbulos dentinários ocluídos do que PLA e FLU e os menores valores de túbulos dentinários abertos foram observados para os grupos AMTN e SBU. Uma correlação significativa foi encontrada entre as análises realizadas. Significância: O sistema adesivo universal e a proteína amelotina foram mais efetivos em reduzir a permeabilidade dentinária através da oclusão dos túbulos dentinários(AU)

Objectives: The aim of this study was to investigate the dentin permeability and tubule occlusion of in-office desensitizing materials. Methods: Bovine dentin blocks were obtained and immersed in 0.5 M EDTA to open dentinal tubules. The materials tested were: placebo varnish (PLA); fluoride varnish (FLU); NaF 5% + 5% nanoparticulate sodium trimetaphosphate varnish (TMP); universal adhesive system (SBU); S-PRG filler-containing varnish (SPRG); Biosilicate solution (BIOS) and amelotin solution (AMTN). The materials were applied, and specimens were submitted to an erosive-abrasive challenge. Dentin permeability was evaluated at T0 (initial), T1 (after application of materials) and T2 (after erosive-abrasive challenge). Confocal images were used to evaluate length and number of dentinal tubules occluded and images from scanning electron microscopy (SEM) to evaluate opened dentinal tubules. Permeability and SEM data were evaluated by two-way repeated measures ANOVA and Tukey tests. The length and number of dentinal tubules occluded were evaluated by one-way ANOVA and Tukey, Kruskal-Wallis and Dunn's tests, respectively. Spearman and Pearson correlation tests were also used. The significance level was 5%. Results: AMTN group showed the lowest permeability value in T1 and the following decreasing order occurred in T2: AMTN=SBU>BIOS=SPRG>TMP>FLU>PLA. SBU group had the highest mean value of dentinal tubules occluded lengths. AMTN group had greater number of dentinal tubules occluded than PLA and FLU and the lowest values of opened dentin tubules were observed for AMTN and SBU groups. A significant negative correlation was found between the analysis. Significance: Universal adhesive system and the AMTN solution were more effective to reduce dentin permeability by occluding dentin tubules(AU)

Proteção da vitalidade dentino-pulpar em odontopediatria: uma revisão de literatura / Dentin-pulp protection in pediatric dentistry: a review

Dentin and pulp are considered interdependent substrates, known as the dentin-pulp complex. In front of injuries such as caries and trauma, this complex should be protected with restorative materials considered to be protective agents. An ideal material should have properties such as biocompatibility, be antimicrobial, be insoluble in the oral environment, be thermal and electrically insulating, have therapeutic potential, and adequate mechanical properties. As these characteristics are not found in all materials, the dentist must know the advantages and disadvantages of those that are available. This study aimed to perform a critical review of the indirect materials indicated for the protection of dentin-pulp vitality (PDPV) to ensure the success of indirect pulp treatment in primary teeth. A search was carried out in books, theses, dissertations, monographs, printed articles and databases, PubMed, SciELO, and MEDLINE. According to the literature, the success in protecting the dentin-pulp vitality is achieved through an excellent marginal seal, preventing bacterial infiltration in the dentin and controlling the progression of caries. Further clinical studies are needed to evaluate other outcomes after indirect pulp treatment. There isn't a material that has all the desired characteristics for PDPV, and recent studies show that the key to PDPV isn't found in the protective material, but in the restorations marginal sealing, enabling the inactivation of the progression of dental caries.

A dentina e a polpa são consideradas substratos interdependentes, conhecido como complexo dentino-pulpar. Frente a injúrias como cárie e traumatismo, deve-se realizar a proteção desse complexo, baseando-se na inserção de materiais restauradores considerados agentes protetores. Os materiais considerados ideais devem apresentar propriedades como: biocompatibilidade, ser antimicrobiano, ser insolúvel ao meio bucal, ser isolante térmico e elétrico, ter potencial terapêutico e propriedades mecânicas adequadas. Como essas características não são encontradas em todos os materiais, é importante que o cirurgião-dentista conheça as vantagens e as desvantagens daqueles que estão disponíveis comercialmente. O objetivo deste trabalho foi realizar uma revisão crítica da literatura sobre os materiais indicados para proteção indireta da vitalidade dentino-pulpar (PVDP), em dentes decíduos. Para isso, foram pesquisados livros, teses, dissertações, monografias, artigos impressos e das bases de dados, PubMed, SciELO e MEDLINE. De acordo com a literatura, observou-se que a garantia de êxito na proteção da vitalidade dentino-pulpar é alcançada por meio de um ótimo selamento marginal, impedindo a infiltração bacteriana na dentina e controlando a progressão da cárie. São necessários mais estudos clínicos que avaliem outros desfechos após o tratamento indireto da polpa. Não existe um material que possua todas as características desejadas para a PVDP, e estudos recentes demonstram que a chave não se encontra no material protetor, mas sim na vedação marginal das restaurações, propiciando a inativação da progressão da cárie dentária.

Microfiltraciones entre ionómero de vidrio y resina compuesta en lesiones clase-V no cariosas / Microfiltration between glass ionomer and composite resin in non-carious class-V injuries / Microfiltrações entre ionômeros de vidro e resina composta em lesões não cariosas de classe V

No se han establecido estándares para el tratamiento de cavidades cervicales no cariosas; un biomaterial adecuado permitirá buena adaptación y longevidad de la restauración. Objetivo: Determinar la microfiltración en cavidades clase V no cariosas restauradas con ionómero de vidrio y resina nanoparticulada. Materiales y métodos: Cavidades clase V realizadas en la superficie vestibular de 80 premolares sanos (1,5 mm de pro-fundidad x 3 mm de altura en sentido ocluso- gingival x 2 mm de ancho en sentido mesio-distal) se restauraron aleatoriamente con dos biomateriales (n = 40): 1) ionómero de vidrio y 2) resina de nano relleno. Después, los especímenes fueron aislados con barniz y sumergidos en azul de metileno por 24 horas. Posteriormente, las muestras se sometieron 500 ciclos de termociclado por 8 horas y 45 minutos con cambios térmicos de 37°, 72° y 75°C, cada ciclo con una duración de 17 segundos. Las muestras fueron lavadas con agua destilada y seccionadas longitudinalmente para determinar el grado de microfiltración utilizando un estereoscopio (Leica M60, Biosystems). Los datos categóricos se analizaron con el test Chi2 en SPSS 24®. Resultados: Se pudo apreciar que la filtración es significativamente menor en resina que con ionómeros de vidrio (p < 0,001). Sin embargo, ninguno de los materiales de restauración probados fue capaz de sellar los márgenes o las paredes de los dientes completamente. Conclusión: como resultado del presente experimento se determina que las restauraciones de clase V obturadas con resina de nano relleno presentan menor microfiltración marginal que las restauradas con ionómero de vidrio.

No standards have been established for the treatment of non-carious cervical cavities; a suitable biomaterial will allow good adaptation and longevity of the restoration. Objective: To determine microfiltration in non-car-ious class V cavities restored with glass ionomer and nanoparticulate resin. Materials and methods: Class V cavities made on the vestibular surface of 80 healthy premolars (1.5 mm deep x 3 mm high in the occlusion-gin-gival direction x 2 mm wide in the mesio-distal direction) were randomly restored with two biomaterials (n = 40): 1) glass ionomer and 2) nano-filled resin. Then, the specimens were isolated with varnish and immersed in methylene blue for 24 hours. Subsequently, the samples were subjected to 500 cycles of thermocycling for 8 hours and 45 minutes with thermal changes of 37°, 72° and 75° C, each cycle with a duration of 17 seconds. The samples were washed with distilled water and sectioned longitudinally to determine the degree of micro-filtration using a stereoscope (Leica M60 Biosystems). Categorical data were analyzed with the Chi2 test in SPSS 24®. Results: It was observed that filtration is significantly lower in resin than in those restored with glass ionomers (p < 0.001). However, none of the restoration materials tested were able to seal the margins or walls of the teeth completely. Conclusion: As a result of the present experiment, it is determined that class V resto-rations sealed with nano-filled resin have less marginal microfiltration than those restored with glass ionomer.

Ainda não foram estabelecidos padrões para o tratamento de cavidades cervicais não cariosas; um biomate-rial adequado permitirá boa adaptação e longevidade da restauração. Objetivo: Determinar a microfiltração em cavidades não cariosas da classe V restauradas com ionômero de vidro e resina nanoparticulada. Materi-ais e métodos: Cavidades de classe V feitas na superfície vestibular de 80 pré-molares saudáveis (1,5 mm de profundidade x 3 mm de altura na direção oclusão-gengival x 2 mm de largura na direção mesio-distal) foram restaurados aleatoriamente com dois biomateriais (n = 40): 1) ionômero de vidro e 2) resina nano-híbrida. Em seguida, as amostras foram isoladas com verniz e imersas em azul de metileno por 24 horas. Posteriormente, as amostras foram submetidas a 500 ciclos de termociclagem por 8 horas e 45 minutos com alterações tér-micas de 37°, 72° e 75° C, cada ciclo com duração de 17 segundos. As amostras foram lavadas com água destilada e seccionadas longitudinalmente para determinar o grau de microfiltração usando um estereoscópio (Leica M60, Biosystems). Os dados categóricos foram analisados com o teste Chi2 no SPSS 24®. Resul-tados: Observou-se que a filtração é significativamente menor na resina do que nos ionômeros de vidro (p <0,001). No entanto, nenhum dos materiais de restauração testados foram capazes de selar completamente as margens ou paredes dos dentes. Conclusão: como resultado do presente experimento, determina-se que restaurações de classe V seladas com resina nano-preenchida possuem menos microfiltração marginal do que aquelas restauradas com ionômero de vidro.

Effect of flowable composite or glass ionomer liners on shrinkage stress of a composite resin / Efecto de recubrimientos con resinas de baja viscosidad o ionómero vitreo sobre la tensión por contracción de una resina compuesta

ABSTRACT The aim of this study was to evaluate the effect of flowable composite or glass ionomer liners on the shrinkage stress of a restorative composite resin. Fifteen previously sandblasted metal boxes were attached to a universal mechanical testing machine (INSTRON 1011, Instron Corporation). Five of these boxes were filled with Filtek Z350 XT (FXT) Universal Restorative A2 (3M ESPE) (Group 1 or Control). Two further groups of 5 boxes were prepared by interposing a layer of Vitrebond Light Cure Glass Ionomer 3M ESPE (VGI) (Group 2 or G.I.) or Filtek Z350 XT Flowable Restorative A2 3M ESPE (FFR) (Group 3 or Flowable) between the box and the composite resin, completing with the same volume of composite as in Group 1. Upon activating lightcuring, the filled boxes mounted on the testing machine were videoed for 60 seconds (40 s photoactivation and 20 s postcuring), timed with a digital chronometer. Force values were recorded in newtons and converted into stress according to contact surface. Stress values were recorded every 10 s. Results were analyzed using repeated measures ANOVA. Mean and standard deviation in kPa (stress) recorded for each group were: Control group: 126.2 (30.8); G.I.: 48.4 (18); Flowable: 27.9 (19.5). Statistical analysis showed significant differences between the control group and the rest (p<0.01), with no significant difference between groups with glass ionomer liners and flowable resin liners (G.I. and Flowable). Under the experimental conditions of this study, it can be concluded that polymerization shrinkage stress can be reduced by the presence of a liner between the preparation and the restorative material.

RESUMEN El objetivo de este trabajo fue evaluar el efecto de la colocación de una capa de Composite flow o Ionómero vítreo sobre la tensión de contracción de un composite para restauración. Se utilizaron 15 cajas metálicas previamente arenadas y conectadas a la máquina universal para ensayos mecánicos (INSTRON 1011, Instron Corporation). Cinco de estas cajas (G1) se rellenaron con Filtek Z350 XT (FXT) Universal Restorative A2 3M ESPE. Al iniciar la activación de la unidad de curado se comenzaba a registrar con una cámara de video y un cronómetro digital desde el comienzo de la activación de la lámpara hasta 60 s después, registrando los valores post curado durante 20 s. Los valores de fuerza generados por la polimerización fueron registrados en newton de cada 10 s para los 15 ensayos. Los valores fueron convertidos en tensión de contracción según la superficie de contacto. Se realizaron además dos grupos de cajas (5 en cada una) en los cuales se colocaron una capa inicial de Vitrebond Light Cure Glass Ionomer 3M ESPE (VGI) (G2 o IV) y Filtek Z350 XT Flowable Restorative A2 3M ESPE (FFR) (G3 o Flow) y se completó con el mismo volumen de composite de las del GI. Los resultados obtenidos fueron analizados por medio de ANOVA para mediciones repetidas. La media y la desviación estándar en kPa (tensión o estrés de contracción) registrado para cada grupo fueron: Grupo control: 126.2 (30.8); IV: 48.4(18); Flow: 27.9(19.5). El análisis estadístico mostró diferencias estadística mente significativas entre el grupo control y el resto (p=0.00), pero no hubo diferencias significativas entre la presencia de Ionómero vítreo o Composite Flow (IV y Flow). En las condiciones experimentales de este trabajo puede concluirse que la tensión de contracción generada durante la polimerización puede ser disminuida por la presencia de algún material interpuesto entre la preparación y el composite restaurador.

A randomized clinical trial of cavity liners after selective caries removal: one-year follow-up

Abstract Alternatives for the treatment of caries disease, such as minimally invasive approaches, have been developed in recent years. Objective: To carry out clinical and radiographic evaluations of three cavity liners after selective caries removal. Methodology: Thirty-six primary molars with deep occlusal caries lesions without pulp involvement (from children of both genders, aged between 5 and 8 years) were randomly divided into the following groups: calcium hydroxide cement (CHC) group; mineral trioxide aggregate (MTA) group and Portland cement with added zirconium oxide (PCZ) group. The following-up period was 6- and 12-month. The clinical and radiographic success rates were evaluated through chi-square test. The radiographic measurements were compared by ANOVA followed by Tukey's test (p<0.05). Results: Thirty-six patients were included, but thirty-four returned for 12-month follow-up. The overall success rate of the therapy for the three groups was 94.11% and no statistically significant differences occurred in the comparison among groups (p>0.05). Nineteen radiographs were selected to measure the dentin barrier thickness. The intragroup comparison presented a statistically significant increase of the dentin barrier for all groups, at 12-month follow-up. However, the MTA group showed increase of the dentin barrier, over time, 6- to 12-month follow-up. The intergroup comparison revealed no statistically significant differences (p>0.05). Conclusion: The clinical and radiographic data showed that all cavity liners provided effective treatment of primary teeth after selective caries removal.

Compressive Strength of a Glass Ionomer Cement Under the Influence of Varnish Protection and Dietary Fluids / Resistencia a la compresión de un cemento de ionómero de vidrio bajo la influencia de la protección del barniz y diversos productos alimenticios

RESUMEN El objetivo de este estudio fue evaluar la resistencia a la compresión de un cemento de ionómero de vidrio (GIC) bajo la influencia de la protección del barniz y alimentos. Ochenta muestras cilíndricas de GIC fueron realizadas y se distribuyeron en cuatro grupos (G1, G2, G3, G4) de acuerdo con el alimento. Cada grupo se sub-dividió además en A y B, de acuerdo con la presencia o ausencia de protección de barniz. Las ocho muestras de cada subgrupo se almacenaron en agua destilada durante 30 días y recibieron los siguientes tratamientos durante 14 días: G2A: protección del barniz e inmersión en gaseosas, G2B: sin barniz e inmersión en gaseosas, G3A: protección del barniz e inmersión en jugo de naranja, G3B: sin protección de barniz e inmersión en jugo de naranja, G4A: protección de barniz e inmersión en yogurt, G4B: sin protección de barniz e inmersión en yogur. El procedimiento de inmersión se realizó tres veces al día, durante 15 minutos por 14 días. Las muestras del Subgrupo G1A (con barniz) y G1B (sin barniz) se usaron como controles y se almacenaron en agua destilada. Las muestras se sometieron a una prueba de resistencia a la compresión después del período de inmersión. Los resultados se analizaron usando ANOVA 2, prueba de Tukey (5%) y T de Student (5%). No hubo diferencias significativas entre los subgrupos, a excepción del subgrupo con protección de barniz e inmersión en jugo de naranja, que mostró una resistencia a la compresión GIC reducida.

ABSTRACT The objective of this study was to evaluate the compressive strength of a glass ionomer cement (GIC) under the influence of varnish protection and dietary fluids. Eighty cylindrical test specimens were made from GIC and distributed into four groups (G1, G2, G3, G4) according to the dietary fluid. Each group was further divided into subgroups A and B according to the presence or absence of varnish protection. The eight subgroup samples were stored in distilled water for 30 days and received the following treatments for 14 days: G2A: varnish protection and immersion in soft drink, G2B: no varnish protection and immersion in soft drink, G3A: varnish protection and immersion in orange juice, G3B: no varnish protection and immersion in orange juice, G4A: varnish protection and immersion in yogurt, G4B: no varnish protection and immersion in yogurt. The immersion procedure was performed three times a day, for 15 minutes at a time, for a total of 14 days. The samples from subgroups G1A (with varnish) and G1B (without varnish) were used as controls and stored in distilled water only for 30 days. The samples were submitted to a compressive strength test after the immersion period. The results were analyzed using the ANOVA 2, Tukey test (5%) and Student's t-test (5%). There were no significant differences between the subgroups, except for the subgroup with varnish protection and immersion in orange juice, which showed reduced GIC compressive strength.

Evaluation of calcium release and pH value of light-cured cavity liners for pulp-capping materials / Avaliação da liberação de cálcio e alteração de pH de forradores cavitários fotoativados para capeamento pulpar

Introduction: Cavity liners based calcium hydroxide present low strength and high solubility that is consider a disadvantage. In order to enhance these properties it was developed a light-cured cavity liner based calcium hydroxide containing resin. Objective: The purpose of this study was to evaluate the pH and calcium release of light-cured cavity liners. Material and method: There were prepared specimens (n=10) with the Ultra-Blend ® plus, Biocal® (light cured cements) and Hydro C® (control). The samples were stored in 10 mL of distilled water and maintained at 37 °C. After 24 hours, 7, and 14 days, there were analyzed pH and the release of calcium levels. The data were statistically analyzed by ANOVA and Tukey test (α = 0.05). Result: The results of pH showed Hydro C > Ultra-Blend plus > Biocal. Biocal presented worst calcium release. Conclusion: Light-cured materials present lower calcium release and alteration in pH values.

Introdução: Forradores cavitários à base de hidróxido de cálcio apresentam baixa resistência e alta solubilidade. Para resolver este problema, foi desenvolvido forradores à base de hidróxido de cálcio fotoativáveis contendo resina para melhorar suas propridades. Objetivo: A proposta deste estudo foi avaliar a alteração de pH e liberação de cálcio de forradores fotoativáveis. Material e método: Foram preparadas amostras (n=10) com Ultra-Blend® plus, Biocal ® (cimentos fotoativáveis) e Hydro C® (controle). As amostras foram armazenadas com 10 mL de água destilada e mantidas em estufa à 37 °C. Depois de 24 horas, 7 e 14 dias, foram avaliados os níveis de liberação de cálcio e a alteração de pH. Os dados foram analisados estatisticamente pelo teste ANOVA, seguido do pós teste Tukey (α = 0.05). Resultado: Os resultados de pH mostraram Hydro C > Ultra-Blend plus > Biocal. Biocal apresentou a pior liberação de cálcio. Conclusão: Materiais fotoativados apresentam menor liberação de cálcio e alteração nos valores de pH.

Resistencia a la fractura in vitro de incrustaciones cerámicas usando dos materiales como bases cavitarias / in vitro fractures strength of ceramic inlays, using two types of cavity bases

Las bases cavitarias son usadas en odontología restauradora,varios materiales se recomiendan como base cavitaria en incrustaciones cerámicas. Objetivo: Comparar la resistencia a la fractura in vitro de una cerámica (disilicato de litio) como material restaurativo usando diferentes bases cavitarias en inlays en premolares. Material y métodos: Se elaboraron cavidades estandarizadas para inlays cerámicas MOD en 30 premolares. Se asignaron aleatoriamente tres grupos (n = 10): grupo 1: sin base cavitaria; grupo 2: base ionómero de vidrio reforzado con resina (VitrebondTM, 3M); grupo 3: base resina compuesta (FiltekTM Z350 XT, 3M). Las incrustaciones fueron fabricadas con disilicato de litio (IPS e.max®, Ivoclar) cementadas con (RelyXTM, 3M) y almacenadas en agua bidestilada (37 oC por 24 horas). Semidió la resistencia a la fractura en una máquina universal de pruebas mecánicas (MTS® Alliance RT/30) a una velocidad de 0.5 mm/minuto,fracturadas las muestras se registró bajo microscopia estereoscópica elmodo de fallo. Los datos se analizaron usando ANOVA de una vía y comparaciones post hoc con la prueba Scheffé. (Programa IBM SPSS STATISTICS 21.0). Resultados: El grupo control (sin base) obtuvo la media más alta (105.16 Kgf ± 11.41) siendo estadísticamente significativa con relación al grupo 2 (77.04 ± 19.69). El grupo 3 obtuvo una media (94.81 ± 10.65) siendo estadísticamente diferente del grupo 2 (p = .001). El modo de fallo más común fue el patrón IV (60 por ciento). Conclusiones: La resistencia a la fractura de inlays cerámicas de disilicato de litio es mayor en cavidades sin base cavitaria...

Solubility and bacterial sealing ability of MTA and root-end filling materials

ABSTRACT Objective To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials. Material and Methods The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO2), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level. Results For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO2, and both presented better results than ZOE (p<0.05). Conclusion MTA and CSC/ZrO2 presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

Manejo contemporáneo y preventivo de la caries dental en pacientes pediátricos: revisión de literatura / Contemporary and preventive management of dental caries in pediatric patients: literature review

La caries es una enfermedad infecciosa y contagiosa que por tener un a alta prevalencia a nivel mundial afectando tanto a niños como adultos, es necesario buscar y evaluar nuevas alternativas de tratamiento y prevención, que permitan mejorar la salud bucal de toda la población afectada, en donde el profesional debe estar involucrado.En cuanto a los métodos preventivos se encuentran los barnices con fluoruros y los derivados de la caseína, que se hallan en los productos lácteos, dentífricos y chicles, siendo de gran utilidad para pacientes pediátricos.Aunado a ello, se están utilizando actualmente, diversos métodos para la eliminación de la caries dental que permiten realizar procedimientos poco invasivos y que pueden ser aplicados en pacientes pediátricos o con discapacidad debido a que no requieren la utilización de anestesia local, ni instrumental rotatorio, mejorando la adaptación a la consulta y además obteniendo resultados favorables con respecto a las técnicas convencionales.Los diferentes procedimientos pueden ser mecánicos, químicos-mecánicos y de otros tipos como el láser que en conjunto conforman los métodos no invasivos. Ellos permiten una amplia variedad de opciones dependiendo de la población a la cual vayan dirigidos, tomando en cuenta el acceso a servicios de salud, estatus socio-económico, edad y requerimientos a corto plazo para evitar la extensión de las lesiones que implica perdidas tempranas de estructuras dentales que afectan la salud integral del individuo.

Dental caries is an infectious and contagious disease with an elevated prevalence in children and adults around the world. For that reason it is necessary to evaluate the new methods of prevention and treatment to improve bucal health in this population.In relation to the preventive methods, there are the fluoride varnish and casein derivates that can be in the milk, the tooth pastes and chewing gum and can be use to improve children´s bucal health.Nowadays there are many new methods that are using to eliminate caries in a non-invasive way. Many of them do not need the use of local anesthesia or rotatory handpieces and represent a good alternative to the behavibucal management of pediatric patients.The several methods can be mechanical, chemical & mechanical and others like laser that constitute the non-invasive methods. They give to the professional many options depending to some factors of the patients like age, social and economical status, possibility to access to health services and other requirements to avoid the extension of the caries lesions and the dental structure loss.

Efficacy of flowable composite resin as stress-absorbing liners in Class I cavity restorations / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of flowable composite resin(FCR) as stress-absorbing liners in Class I cavity restorations in vitro.</p><p><b>METHODS</b>Thirty Class I cavities of 4 mm in diameter and 2 mm in depth were prepared in polycarbonate (PC) plates and divided into three groups, ten each. After application of an adhesive, cavities in each group were restored using one of the following methods: A: restored with Charisma without any lining of FCR; B: lined with Revolution Formula 2 twice before restoration with Charisma; C: lined with Teric Flow twice before restoration with Charisma. All cavities were observed under a photoelastic microscope and photoelastic images were recorded at 3 min and 24 h after curing and the shrinkage stresses on the cavity wall were calculated. The polymerization shrinkage(v%) of the three composite resins was measured using bonded discs method and their elastic moduli were measured according to ISO standard.</p><p><b>RESULTS</b>The shrinkage stresses at 3 min and 24 h of the three methods were as follows,A: (4.93 ± 0.28), (5.87 ± 0.40) MPa, B: (4.90 ± 0.30), (5.84 ± 0.33) MPa, and C: (4.76 ± 0.28),(5.83 ± 0.37) MPa.No significant difference was found in results among different groups. The polymerization shrinkage(v%) in group A,B, and C were (2.63 ± 0.04)%, (4.56 ± 0.06)%, and (3.98 ± 0.02)%. The elastic modulus in group A, B, and C were (9.59 ± 0.65), (4.25 ± 0.51), and (5.41 ± 0.79) GPa.</p><p><b>CONCLUSIONS</b>Under present study condition, using a FCR as stress-absorbing liner under composite resin restoration does not significantly decrease the polymerization shrinkage stresses at the cavity wall.</p>

Use of glass ionomer cement containing antibiotics to seal off infected dentin: a randomized clinical trial

Dental materials with antibacterial properties can prevent the harmful effects caused by oral cariogenic bacteria. This double-blind controlled clinical trial evaluated the performance of a glass ionomer cement (GIC) added with antibiotics for sealing infected dentin in atraumatic restorations of primary molars. The study enrolled 45 children (45 teeth) between 5 and 8 years of age, of both genders, divided into two groups: GC (n=22), where cavities were lined with a conventional GIC (Vidrion F) and GA (n=23), with cavities lined with Vidrion F added with 1% each of metronidazole, ciprofloxacin and cefaclor antibiotic. Both groups were restored with Ketac Molar Easymix. Molars with carious lesions on the inner half of dentin without clinical or radiographic pulp damage were selected. Patients were evaluated clinically (pain, fistulas or mobility) and radiographically (area of caries, periapical region and furcation) after 1, 3, 6 and 12 months. For statistical analysis, chi-squared or Fisher's exact tests were used with a 5% significance level. GA (82.6-95.7%) had better results than GC (12.5-36.4%) in all evaluations (p<0.05) and the difference in the success rate was 46.2-72.5% higher for GA. The use of the antibiotic-containing GIC liner on infected dentin proved satisfactory when applied in deciduous teeth.

Os materiais dentários com propriedades antibacterianas podem proteger os efeitos nocivos causados por bactérias cariogênicas. Este ensaio clínico controlado duplo-cego avaliou o desempenho do cimento de ionômero de vidro (CIV) associado à antibióticos no selamento da dentina infectada em restaurações atraumáticas de molares decíduos. O estudo envolveu 45 crianças (45 dentes) entre 5 e 8 anos de idade, de ambos os sexos, divididos em dois grupos: GC (n=22), onde as cavidades foram forradas com CIV convencional (Vidrion F) e GA (n=23), onde as cavidades foram forradas com Vidrion F contendo 1% de cada um dos antibióticos metronidazole, ciprofloxacina e cefaclor. Ambos os grupos foram restaurados com Ketac Molar Easymix. Molares com lesões de cárie na metade interna da dentina, sem danos pulpares clínicos ou radiográficos foram selecionados. Os pacientes foram avaliados clinicamente (presença de dor, fístulas ou mobilidade) e radiograficamente (área de cárie, região periapical e de furca dos dentes), após 1, 3, 6 e 12 meses. Para a análise estatística o Qui-quadrado ou Exato de Fisher foram utilizados com 5,0% de significância. GA (82,6-95,7%) obteve melhores resultados do que GC (12,5-36,4%) em todas as avaliações (p<0,05) e a diferença na taxa de sucesso foi de 46,2-72,5% maior para GA. O uso do CIV com antibióticos no forramento da dentina infectada foi satisfatório em dentes decíduos.

A Single Medicine for a Disease: Simple Formula of Treasured Mirror of Eastern Medicine, It's Compilation and Succession / 의사학

In this study, I am planning to analyze the contents of Simple formula in Treasured Mirror of Eastern Medicine (TM), and then find out the historical implication of medical science. Simple formula is a prescription that is consisted of a single or three to four kinds of medicines, and this does not follow typical control principles such as 'sovereign, minister, assistant and courier'. While simple formulas are often built after major formulas, TM placed simple formulas to an end of each classified item. It is difficult to find a similar compilation style as that of Simple formula among similar volumes of medical books during the same period of TM. Thus, it can be assumed that TM included simple formulas for special purposes or reasons which are deemed as an important factor in stipulating the features of TM. The tradition of Simple formula, using medicinal herbs which can be easily acquired and trying to make an effect with a small number of herbs, had existed before Goryeo Dynasty. Introduced by Emergency Prescriptions from the Countryside and Samhwaja's Formulary from the Countryside, the tradition of Simple formula is succeeded by Compendium of Prescriptions from the Countryside, and after a while, it is synthetically arranged and recognized through Simple formula of TM. By analyzing simple formulas of TM, I could find out the followings. First, in simple formulas of TM, in which the components are the number of medicinal herbs, the name of prescription, and their application, should be understood as a simply consisted prescription rather than single medicine formulas. Second, simple formulas of TM are 2,001 in total, and are organized in most items. Third, although simple formulas cite a number of formulary, it shows a high degree of dependence to Classified Emergency Materia Medica. This shows that simple formulas that are structured to use medicine according to symptoms based on the effect of each medicinal herb, without understanding or dialectic process of syndrome differentiation. Fourth, while the part of medicinal herbs, Decoction section, focuses on listing the information of each medicinal herb, simple formulas introduce effect, dose, volume and even a mix with other medicinal herbs and an application of them. Therefore, a simple formula evaluates single medicinal herb as a sort of prescription. Fifth, more than half of 33 kinds of medicinal herbs, which are used more than 11 times in simple formulas of TM, are easy to get around the village, and their Korean names of Materia Medica from the Countryside are possible to be seen in Decoction section. However, the fact that Materia Medica from China such as Coptics chinensis and Realgar is included in simple formulas means that they are not limited to Materia Medica from the Countryside, and some of Materia Medica from China were not difficult to be procured in the time of publication of TM. Specific purpose of publishing simple formulas is not written separately. However, through the king's command of King Seonjo (1552-1608) in introduction, the active containing of folk prescriptions, and the emphasis of medicinal herb's volume using simple formulas, it is assumed that the Chosun government at that time tried to provide friendly and practical medical information with simple formulas, to collect and formulate private medical experiences in order to expand their extension of medical information, and to maximize the effect of treatment. The compilation system like TM was highly regarded but was also the target of criticism. In particular, King Jeongjo (1752-1800) criticized the complicatedness of TM and deleted information related to simple formulas through government compilation medical texts such as Explanation of Subtleties for the People's Longevity, New Edition on Universal Relife. However, simple formulas which were not composed of many medicinal herbs could be useful way for treating people who did not have professional medical knowledge and did not have a large range of herbs. In actuality, Secret Works of Universal Benefit, the representative compilation of civil medicinal text which was published after TM included information related to simple formulas, and in Records for rural life of Chosun gentlemen, the framework of simple formulas of TM was maintained and is filled with a vast amount of information. Furthermore, cases of utilizing simple formulas are included in the U-Jam's miscellaneous writings which is a clinical record. In Simple formulas of TM, private medical experiences at the time of Chosun are written first, then recognized by the experts, and finally returned to the public. Although the purpose and the target of these simple formulas publication are not clearly known, it is easy found, does not require any advanced medical knowledge, and above all, the people must have welcomed to the supply of economic simple formulas. Therefore, simple formulas show an aspect of TM, as a medical book for public.

On Textual and Contextual Position of The Ophthalmological Treatise of Bodhisattva Nagarjuna / 의사학

Medical knowledge in India began to be introduced to China in earliest from the Later Han Dynasty period to the times of Wei-Qin and South & North Dynasties. This is proved by many Buddhist medical books appeared in those days. Of the contents of Indian medicine, the theory of four major elements affected Chinese medicine more than did the theory of body fluids. Based on the theory of four major elements that was began to be introduced in Fu shuo fu yi jing, an attempt to establish a new medical system was made in Zhou hou bai yifang written by Tao Hong-jing and Sun Si-miao who tried to develop etiology further but could not achieve any great outcomes. Unlike the foregoing situation, Indian medicine aroused a large echo in China in the field of ophthalmology with ophthalmological knowledge mentioned in Susrutasamhita and 'Jin-zhen-shu'(cataract couching) introduced as a surgical treatment of cataract. The Susrutasamhita which is one of the three major texts of Indian medicine contains additional information on surgical operations not introduced in the Carakasamhita. The technique of cataract surgery was particularly popular in the Tang and Song dynasty periods in China under the name Long shu pu sa yan lun(The Ophthalmological Treatise of Bodhisattva Nagarjuna) or Long shu lun and was even designated as a subject to educate medical officers. While the original text of Long shu pu sa yan lun was not handed down, the first testimony that show the trace of the introduction of this text into China was the Tian zhu jing lun yan mentioned in Wai tai mi yao(Arcane Essential from the Imperial Library) written by Wang Tao. Long shang dao ren who was mentioned as the compiler of the book is assumed to be Long shu. Although Tian zhu jing lun yan introduced anatomical knowledge about the eyeball that could have not been in the traditional Chinese medicine, this book has only limited quantity of information in this regard. Thereafter, Tai ping sheng hui fang(Holy Prescriptions for Universal Relief) compiled by a national agency at the beginning of the Song Dynasty period introduced Long shu pu sa yan lun without clear indication of the reference. Contemporary with this book, many ophthalmological books such as Mi chuan yan ke long mu lun(Longmu's Ophthalmology Secretly Handed Down) were published. As Chinese culture was spreading out into surrounding countries, medical knowledge was also introduced to Korean peninsula and Japan. The ophthalmological knowledge contained in Long shu pu sa yan lun was also reflected and some parts of it were introduced in I shin bo in Japan. Based on the policy decision of King Sejong, the fourth king of Joseon Dynasty, large scaled promoting projects of medical knowledge was established. It is notable that the Ui bang ryu chwi compiled as a result of the synthesis of the medical treatises available at that time initiated by King Sejong contained a considerable part of Long shu pu sa yan lun in reedited form that had already passed into oblivion in China. The intellectuals in Joseon Dynasty who participated in the compilation of Ui bang ryu chwi not only indicated that Long shu pu sa yan lun was a medical text published in the times of Wei-Qin and South & North Dynasties in China but also clearly indicated the textual reference and left the original text for later generation without modifying the contents. According to the Ui bang ryu chwi, the Long shu pu sa yan lun indicated that the core causes of eye diseases were heat, winds, and three body fluids(tridosa) and contained the analyses of symptoms, related treatments, and several analyses of wrong treatments. In addition, Long shu pu sa yan lun explained diverse eye diseases through more than 30 medical treatments. In particular, this book accurately described golden needle acupuncture for treatment of a Nei-zhang understood to be cataract. Therefore, this book is a significant textual record in the history of ophthalmological medicine in East Asia. Along with the golden needle acupuncture which is a method of removing the crystalline lens in which white turbidity occurred by stabbing the eyeball with a needle, traces of Indian medicine that had been already lost in China were clearly indicated in Long shu pu sa yan lun kept in the Ui bang ryu chwi. In particular, the book indicates that the eyes were directly correlated with the brain and that to treat the internal disorder, treating the brain that lost stability due to heat and bodily wind was indispensable; these are the traces of Indian influence. This textual source demonstrates a case of knowledge exchange in field of medicine with concrete cases of the encounter and clash between the standpoints of understanding human body.

Penetración de tres adhesivos en lesionesinterproximales de caries de mancha blanca: estudio in vitro / Penetration of three adhesives in proximal white-spot carious lesions: an in vitro study

Introducción: el tratamiento de lesiones interproximales de caries temprana representa un reto en la concepción moderna de la cariología y la operatoria. Como respuesta, además del diagnóstico temprano, emergen nuevos materiales para controlar laprogresión de la caries temprana. El objetivo de este estudio fue evaluar in vitro el grado de penetración de tres adhesivos: Excite (Ivoclar-Vivadent), Prime & Bond NT (Dentsply) y Single Bond (3M-ESPE), en el sellado de lesiones interproximales no cavitacionales de mancha blanca.Métodos: 117 premolares humanos extraídos con lesión interproximal de mancha blanca I CDAS-II 2 montados enyeso, simulando la situación en cavidad oral, fueron asignados aleatoriamente a uno de los tres grupos; se sellaron las lesiones con cadamaterial previamente mezclado con azul de metileno; se obtuvieron secciones longitudinales de 250 μm y se analizaron en fotografíasobtenidas bajo estereomicroscopía. Se valoró cubrimiento total de la lesión, profundidad histológica de la lesión en zonas y en micrómetros y, penetración máxima del adhesivo. Resultados: se analizaron 116 dientes. Se encontró cubrimiento total de la lesión en52,5%; 75% se ubicaron en la mitad interna del esmalte, con profundidad promedio de 854 ± 493 μm. La máxima penetración promedio del adhesivoen la lesión fue de 697 ± 412 μm. No hubo diferencias estadísticamente significativas entre grupos para las variables (Kruskal Wallis y correlación de Spearman; p > 0,05). Conclusión:estos tres adhesivos de baja viscosidad, con alto contenido de TEGDMA y HEMA,lograron el cubrimiento y la penetración de material para el sellado de lesiones tempranas de caries interproximal.

Introduction: the treatment of early proximal carious lesions represents a challenge to modern conceptions of cariology and operative dentistry. The possible solutions include, besides an early diagnosis, development of new materials to control early cariesprogression. The objective of this in vitro study was to evaluate the degree of penetration of three adhesives: Excite (Ivoclar-Vivadent), Prime & Bond NT (Dentsply), and Single Bond (3M-ESPE), in the process of sealing white-spot non-cavitated proximal lesions. Methods: 117 extracted human premolars with ICDAS 2 white-spot non-cavitated proximal lesions mounted on plaster, to simulate oral cavityconditions, were randomly sorted out in each of the three groups. The lesions were sealed with each of the materials previously mixed with methylene blue; longitudinal sections of 250 μm were obtained, and they were later analyzed on photographs taken with a stereomicroscope. These variables were evaluated: total lesion coating, lesion’s histologic depth (in micrometers), and the adhesive’s maximum penetration.Results: a total of 116 teeth were analyzed. Entire lesion coating was found in 52.5% of the cases; 75% were located in the enamel’s internal half, with an average depth of 854 ± 493 μm. The adhesive’s maximum average lesion penetration was 697 ± 412 μm. No statistical significant differences were found among the groups (Kruskal Wallis and Spearman correlation; p > 0.05). Conclusion: these three low-viscosity adhesives with high amounts of TEGDMA and HEMA effectively achieved covering and penetrating of the material for sealing early proximal carious lesions.

Protocolo de cepillado y aplicación comunitaria de barniz de flúor para intervención en párvulos / Brushing protocol and application of fluoride varnish community for intervention in toddlers

Una de los principales problemas de salud no resuelto en los niños es la caries dental. La caries dental se considera dentro del grupo de enfermedades crónicas, complejas omultifactoriales, de manera similar a otras enfermedades como cáncer, diabetes o enfermedades cardiacas. Esta enfermedad se manifiesta con lesiones cariosas en los dientes, las que son reversibles antes que se produzca la cavitación. La caries severa sin tratamiento se asocia con dolor, incomodidad, irritabilidad y disturbios del sueño, acompañado con mayores probabilidades de necesitar atenciones de urgencia, hospitalizaciones, restricciones de asistencia a los jardines infantiles o escuelas y barreras para el aprendizaje. Esta situación impacta en la calidad de vida de los niños y por lo tanto en su desarrollo integral. El dolor dental no sólo tiene un impacto en el desarrollo educacional de los niños, sino también en la economía por los altos costos de atención y las ausencias laborales de los padres derivados de esta situación. Niños con caries en la edad parvularia y escolar se encuentran en mayor riesgo de desarrollar caries en el futuro que aquellos libres de caries, determinando que la presencia de caries en la dentición temporal represente un indicador de riesgo para el desarrollo de lesiones en la dentición permanente. La caries dental se inicia desde los primeros años de vida y presentan un importante incremento con la edad. Según estudios nacionales disponibles, a los 2 años la prevalencia de caries es de un 17 por ciento, de 49,6 por ciento a los 4 años y de 70 por ciento a los 6 años. La severidad de caries dental medida por el índice ceod (dientes cariados obturados y perdidos en dentición temporal), es de 0,5 a los 2 años; 2,3 a los 4 y 3,7 a los 6 años(5–7).

Marginal adaptation of indirect restorations using different resin coating protocols

This study evaluated the influence of material combinations used in the resin coating technique (RCT) on the marginal adaptation of indirect restorations with gingival margins in enamel (EM) and cement (CM). Eighty third-molars were used. Two cavities were prepared in each tooth. The cavities were distributed into 16 groups. Cavities with EM were filled with the following material combinations: G1: Single-Bond 2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL) and G8: Clearfil SE Bond + Protect Liner F (CSEBPL). The same combinations were applied to the cavities in CM: G9, G10, G11, G12, G13, G14, G15, G16, respectively. The fillings were performed with the Sinfony-System (3M/ESPE). After 24 h, the teeth were submitted to thermocycling (2,000 cycles, 5° to 55°C) and load-cycling (50,000 cycles, 50 N). Next, the Caries-Detector (Kuraray) was applied to the restoration margins. Images from the proximal margin were evaluated using the Image-Tool 3.0 software. The results were submitted to ANOVA and Tukey's test (α=0.05). The mean values (%) for the groups were: EM: G1=46.68, G2=15.53, G3=19.83, G4=27.53; G5=59.49, G6=25.13, G7=34.37, G8=15.20; CM: G9=38.38, G10=23.25, G11=26.97, G12=25.85, G13=37.81, G14=30.62, G15=29.17, G16=20.31. The highest percentages of marginal gap on EM or CM were found in the groups that did not use a liner. It can be concluded that the most appropriate RCT combinations were the groups that used a liner.

Este estudo avaliou a influência de diferentes combinações de materiais usados na técnica de selamento dentinário (TSD) sobre a adaptação marginal de restaurações indiretas, cujas margens gengivais localizam-se em esmalte (ME) ou cemento (MC). Oitenta terceiros molares foram selecionados e duas cavidades foram preparadas em cada dente, as quais foram distribuídas em 16 grupos. As cavidades com margem em esmalte foram forradas pelas seguintes combinações de materiais: G1: Single-Bond2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL), G8: Clearfil SE Bond + Protect Liner F (CSEBPL). As mesmas combinações foram aplicadas às cavidades com margens em cemento: G9, G10, G11, G12, G13, G14, G15, G16, respectivamente. As restaurações foram confeccionadas usando o sistema Sinfony (3M/ESPE). Após 24 h, os dentes restaurados foram submetidos à ciclagem térmica (2.000 ciclos - 5° a 55° C) e mecânica (50.000 ciclos, 50 N). Em seguida, Carie-Detector (Kuraray) foi aplicado sobre as margens das restaurações. As imagens obtidas da margem proximal foram avaliadas pelo software Image-Tool 3.0. Os resultados foram submetidos aos testes estatísticos ANOVA e Tukey (p<0,05). As médias (%) observadas para os grupos foram: ME: G1=46,68, G2=15,53, G3=19,83, G4=27,53; G5=59,49, G6=25,13, G7=34,37 e G8=15,20; MC: G9=38,38, G10=23,25, G11=26,97, G12=25,85, G13=37,81, G14=30,62, G15=29,17, G16=20,31. Os maiores valores de desadaptação marginal encontrados em ME e MC foram encontrados nos grupos que não utilizaram um "liner". Desta forma, pôde-se concluir que a combinação mais apropriada para a TSD é aquela que faz uso do "liner".

Adaptação à dentina de materiais forradores sob restauração de resina composta / Liner adaptation to dentin under composite resin restoration

Introdução: Um dos principais problemas na utilização de resina composta é a sua contração de polimerização e consequente tensão transmitida às paredes aderidas e ao material forrador. Foi analisada a adaptação de agentes protetores à dentina associadosà restauração de resina composta fotopolimerizável. Material e Métodos - CavidadesClasse I oclusal foram confeccionadas com profundidade 1,5 mm, em molares humanos hígidos (n=40). Os dentes foram divididos em 4 grupos, segundo o material de forramento utilizado: FF - resina de baixa viscosidade (Fill Magic Flow), HP - cimento de hidróxidode cálcio fotopolimerizável (Hi-Cal Photo), VLC: cimento de ionômero de vidro fotopolimerizável (Vitro Fill LC), VB: cimento de ionômero de vidro fotopolimerizável(Vitrebond). As cavidades foram restauradas com resina composta (Adper Single Bond2/Filtek Z250), inserida em incrementos oblíquos. Após armazenamento em ambiente úmido a 37°C por 7 dias, os molares foram seccionados no longo eixo do dente e obtidas réplicas em negativo de polivinilsiloxana Adsil e em positivo com resina epóxica. Foi utilizada microscopia óptica para mensuração da porcentagem de adaptação linear domaterial forrador e a parede pulpar. Resultados - Os testes de Kruskal-Wallis e Dunnapontaram diferença estatisticamente significante (p<0,05) entre VB (97,7±1,30) e FF(59,3±33,7), e entre HP (5,3±4,9) e VLC (44,3±24,2). Conclusões - A tensão de contração da resina composta causada à interface adesiva durante sua fotoativação provoca fendas entre o material forrador e a parede pulpar, em magnitudes distintas, mesmo quando ainserção da resina se dá por incrementos. O cimento de ionômero de vidro fotoativado Vitrebond obteve a melhor adaptação.

Introduction: One of the main problems when using composite resin is its polymerization shrinkage and resultant stress transmitted to the adhered walls and to the cavity lining material. This work analyzed the adaptation of protective agents to the dentin associated to the composite resin restoration. Material and Methods - Class I occlusalcavities − 1.5 mm deep − were performed in healthy human molars (n=40). The teethwere divided into four groups according to the lining material used: FF – flowable resin(Fill-Magic Flow); HP – light-cured calcium hydroxide cement (Hi-Cal Photo); VLC –resin-modified glass-ionomer liner (Vitro Fill LC); and VB – resin-modified glass-ionomer liner (Vitrebond). The cavities were restored with composite resin (Adper Single Bond2/Filtek Z250) inserted into oblique increments. After storage in a humid environmentat 37°C for seven days, the molars were sectioned to the long axis of the tooth. Negative replicas were obtained through polyvinyl siloxane (Adsil), and positive ones by epoxyresin. Optical microscopy was used for measuring the percentage of linear adaptationof the cavity liner to the pulp wall. Results - Kruskal-Wallis and Dunn tests showed a statistically significant difference (p<0,05) between VB (97,7 ± 1,30) and FF (59,3 ±33,7), and between HP (5,3 ± 4,9) and VLC (44,3 ± 24,2).Conclusions - The shrinkage stress of the composite resin polymerization causes gaps between the cavity liner and the pulp wall even when restored in increments, in distinct magnitude. The resin-modified glass-ionomer liner Vitrebond proved to have the best adaptability.