In vitro comparison of marginal infiltration between a conventional resin and a bulk-fill resin, in the relocation of cervical margins technique / Comparación in vitro de la infiltración marginal entre una resina convencional y una resina bulk-fill, en la técnica de reubicación de márgenes cervicales

Introduction: Proximal lesions that exceed the cement enamel limit (ACE) under the gingival margin complicate impressions and the adhesive technique. Compare the magnitude of micro infiltration between conventional resin and bulk fill resin in the cervical margin relocation technique. Materials and Methods: 48 samples of human teeth re-ceived two preparations: occluso-mesial (OM) and occluso-distal (OD) under LAC; first they received the cervical margin relocation technique (RMC) with bulk fill and conventional resin; then restored with semi-direct resinous inlays. Sample analysis: immersion in 50% colloidal silver nitrate solution, 24 hours, 37°C and cut mesiodistally. Observed under a stereoscopic magnifying glass to assess dye penetration and digitally photographed, analyzed with "Image J" software. Results: Sample of 96 cavities in two groups of 48 units; control group restored with conventional resin with incremental technique and study group restored with bulk fill resin, mono-incremental technique. Probabilistic sampling. No statistically significant diffe-rences in percentage of microinfiltrated area between Filtek™ Z250™ and Filtek™ Bulk Fill™ (p-value= 0.68). Discussion: Various studies show that the presence of marginal microinfiltration exist independent of: restorative technique, consistency, adhesive mechanism and polyme-rization technique. The research carried out is no exception, observing a similar degree for both systems. Conclusions: Results allow us to conclude that conventi-onal resin and bulk fill resin did not show significant differences in microleakage percentages for the RMC technique. Outside the study framework, bulk fill resins would have comparative advantages; better behavior against light in depths greater than 2 mm, less sensitivity to the "C" factor, and less clinical time.

Introducción: Las lesiones proximales que superan el límite cemento esmalte (ACE) por debajo del margen gingival complican las impresiones y la técnica adhesiva. Comparar la magnitud de la microinfiltración entre la resina convencional y la resina de relleno en la técnica de reubicación del margen cervical. Materiales y Métodos: 48 muestras de dientes humanos recibieron dos preparaciones: ocluso-mesial (OM) y ocluso-distal (OD) bajo LAC, primero recibieron la técnica de reubicación del margen cervical (RMC) con relleno en bloque y resina convencional; luego restaurado con incrustaciones resinosas semidirectas. Análisis de la muestra: inmersión en solución de nitrato de plata coloidal al 50%, 24 horas, 37°C y corte mesiodistal. Observado bajo una lupa estereoscópica para evaluar la penetración del tinte y fotografiado digitalmente, analizado con el software "Image J". Resultados: Muestra de 96 cavidades en dos grupos de 48 unidades; grupo control restaurado con resina convencional con técnica incremental y grupo estudio restaurado con resina bulk fill, técnica mono-incremental. Muestreo probabilístico. No hubo diferencias estadísticamente significativas en el porcentaje de área microinfiltrada entre Filtek™ Z250™ y Filtek™ Bulk Fill™ (p-value = 0,68) Discusión: Diversos estudios evidencian presencia de microinfiltración marginal, independiente de técnica restauradora, consistencia, mecanismo adhesivo y técnica polimerizadora. La investigación realizada no es excepción, observándose grado similar para ambos sistemas. Conclusiones: Los resultados permiten concluir que resina convencional y resina bulk fill no presentaron diferencias significativas en porcentajes de microinfiltración para técnica RMC. Fuera del marco del estudio, resinas bulk fill tendrían ventajas comparativas; mejor comportamiento frente a la luz en profundidades superiores a 2 mm, menor sensibilidad al factor "C", y menor tiempo clínico.

Microleakage of Class II Bulk-Fill Resin Composite Restorations Cured with Light-Emitting Diode versus Quartz Tungsten-Halogen Light: An In Vitro Study in Human Teeth.

Background: Resin composites undergo a certain degree of shrinkage when light-cured with different light sources available on the market, resulting in microleakage of dental restorations. The aim of the present study was to assess microleakage of class II restorations with bulk-fill resin composites cured with LED (light-emitting diode) and QTH (quartz tungsten-halogen light) units, both in cervical and occlusal areas of cavity preparations. Materials and Methods: In the present in vitro experimental study, a total of 30 human molar teeth were used, in which 60 class II cavities were prepared (mesial and distal) and restored with Filtek bulk fill resin composite. Restorations were equally distributed in 3 groups according to type of curing light: A, QTH (Litex 680A Dentamerica®); B, LED (Bluephase N® 3rd generation); and C, LED (Valo® 3rd generation). Each group was further subdivided into subgroups 1 and 2 according to IV-A or IV-B resin composite color. Restored teeth were subjected to 20,000 thermal cycles between 5° and 55 °C, then immersed in 1M silver nitrate solution for 24 h. Subsequently, the teeth were sectioned mesiodistally to obtain samples for observation under stereomicroscope in order to determine microleakage degree. Kruskal-Wallis H and Mann-Whitney U statistical tests were applied with a significance level of 5% (p < 0.05). Results: No statistically significant differences were found in the degree of microleakage of bulk-fill resin composites light-cured with LED and QTH units for both occlusal (p > 0.05) and cervical areas (p > 0.05). Additionally, no significant differences were found when comparing microleakage between occlusal and cervical areas (p > 0.05), regardless of lamp type. In addition, significant differences in microleakage degree were found between bulk-fill resins with IV-A and IV-B shades when they were light-cured with QTH at cervical level (p = 0.023). However, there were no significant differences when comparing these bulk-fill resin composite shades at occlusal level with LED (p > 0.05) and QTH (p > 0.05) units. Conclusions: Class II restorations with bulk-fill resin composite in IV-A and IV-B shades light-cured with third generation LED lamp and QTH showed no significant differences in microleakage when compared in both occlusal and cervical areas. On the other hand, significantly more microleakage was found at the cervical level when a darker shade of resin composite was used and light-cured with the QTH unit.

Microleakage of chairside moulded, 3D-printed and milled provisional restorations using a curve-fit approach

Abstract The purpose of this study was to evaluate and measure the microleakage inhibiting quality of provisional restorations manufactured using computer-aided manufacturing, 3D printing, and chairside molded provisional restorative materials. Fifteen provisional restorations each from 3D printed, milled, and chairside molded were manufactured. All restorations were cemented onto sintered zirconia abutment dies and adhered with zinc-oxide non-eugenol temporary cement. Artificial aging was conducted by thermocycling for 800 cycles to simulate 1 month of clinical use. All specimens were submerged in 2% (w/w) methylene blue for 24 hours at 37°C, sectioned, and analyzed digitally for the distance of dye penetration through image analysis. The data were analyzed using the Kruskal-Wallis test with Dunn-Bonferroni post-hoc. Significant differences in dye penetration depth were observed between all groups except milled vs chairside molded. Light microscopy revealed differences in mean cement thickness for 3D printed, milled, and chairside molded of 83.6 µm (1σ = 31.9 µm), 149.1 µm (1σ = 88.7 µm) and 137.9 µm (1σ = 67.2 µm) respectively. Conclusion: 3D printed provisional restorations were found to have the least amount of microleakage compared to milled and chairside molded provisional restorations.

Resumo O objetivo deste estudo foi avaliar e medir a qualidade de inibição de microinfiltração de restaurações provisórias fabricadas usando manufatura assistida por computador, impressão 3D e materiais de restauração provisória moldados no consultório. Foram fabricadas 15 restaurações provisórias impressas em 3D, fresadas e moldadas em consultório. Todas as restaurações foram cimentadas em matrizes de pilar de zircônia sinterizada e aderidas com cimento temporário de óxido de zinco sem eugenol. O envelhecimento artificial foi conduzido por termociclagem por 800 ciclos para simular 1 mês de uso clínico. Todos os espécimes foram submersos em azul de metileno a 2% (p/p) por 24 horas a 37°C, seccionados e analisados digitalmente quanto à distância de penetração do corante por meio de análise de imagem. Os dados foram analisados usando o teste de Kruskal-Wallis com post-hoc de Dunn-Bonferroni. Foram observadas diferenças significativas na profundidade de penetração do corante entre todos os grupos, exceto entre fresado e moldado na cadeira. A microscopia óptica revelou diferenças na espessura média do cimento para as restaurações impressas em 3D, fresadas e moldadas em cadeira de 83,6 µm (1σ = 31,9 µm), 149,1 µm (1σ = 88,7 µm) e 137,9 µm (1σ = 67,2 µm), respectivamente. Conclusão: As restaurações provisórias impressas em 3D apresentaram a menor quantidade de microinfiltração em comparação com as restaurações provisórias fresadas e moldadas no consultório.

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.

[Analysis of root sealing using methylene blue in different endodontic obturation techniques. Literature review]. / Análisis del sellado radicular utilizando azul de metileno en distintas técnicas de obturación endodóntica. Revisión de la literatura.

One of the biggest drawbacks in endodontic filling is the problem of insufficient root sealing, due to the microleakage of bacteria into the canal. The objective of the research was to carry out a narrative review of the characteristics of the use of methylene blue as an evaluator of microleakage in studies that compared the quality of root sealing with different endodontic filling techniques. The research method used was literature review. Methylene blue was used in experimental in vitro studies, which compared filling techniques such as lateral condensation, cold injectable gutta-percha, thermomechanics, among others, the sealed dental pieces were immersed in a 1% methylene blue dye at 5% concentration. This procedure allowed reevaluating the samples in different periods of time. In conclusion, for endodontic filling penetration testing, methylene blue is an easy-to-use and reliable option.

Microleakage in class II restorations of two bulk fill resin composites and a conventional nanohybrid resin composite: an in vitro study at 10,000 thermocycles.

BACKGROUND: The contraction presented by resin composites causes an increase in stress at the tooth-resin interface, causing micro-gaps that allow microleakage. This study aims to evaluate the degree of in vitro marginal microleakage in class II restorations with two bulk fill resin composites compared to a conventional nanohybrid resin composite. METHODS: The present study was an in vitro experimental design. A total of 30 standardized class II cavities were prepared in 15 human molars (mesially and distally). These cavities were later distributed in 3 groups according to the type of resin. Groups A and B were restored with bulk fill resin composites (Filtek-3 M/ESPE and Tetric N-Ceram-Ivoclar/Vivadent respectively) in a single increment of 4 mm. Group C was restored with the Filtek Z350 XT - 3 M/ESPE resin composite and two increments of 2 mm. Later, the restorations were subjected to 10,000 thermocycles between 5 °C to 55 °C and immersed in a silver nitrate solution (1 M for 24 h). The crowns were then sectioned mesiodistally and observed under the stereomicroscope to determine the degree of marginal microleakage at the occlusal and cervical areas. The results were analyzed with the Kruskal-Wallis and the Mann-Whitney U statistical tests. RESULTS: There were no statistically significant differences regarding the degree of microleakage between the three types of resin composites in the occlusal and cervical areas (p > 0.05). Similarly, there were no significant differences after comparing each resin type in its occlusal and cervical area (p > 0.05). CONCLUSION: Filtek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites showed no statistically significant differences with the conventional nanohybrid resin composite Filtek Z350XT at both occlusal and cervical areas.

Analysis of microleakage and marginal gap presented by new polymeric systems in class V restorations: An in vitro study.

OBJECTIVE: Evaluating the contraction of polymerization effect of silorane-based composite on dental interface in enamel. MATERIALS AND METHODS: Eighty class V cavities were confectioned in forty extracted molar teeth and restored with different combinations of resinous-based and bond system. They were divided into the following groups: (G1) three-step etch-and-rinse adhesive system and methacrylate-based resin, (G2) two-step etch-and-rinse adhesive system and methacrylate-based resin, (G3) Filtek P-90 self-conditioning adhesive system and methacrylate-based resin, (G4) Adper SE Plus self-conditioning adhesive system and methacrylate-based resin, (G5) three-step etch-and-rinse adhesive system and silorane-based resin, (G6) two-step etch-and-rinse adhesive system and silorane-based resin, (G7) Filtek P-90 self-conditioning adhesive system and silorane-based resin, (G8) Adper SE Plus self-conditioning adhesive system and silorane-based resin. RESULTS: Group 7 showed lower marginal leakage when compared with all other groups (p = 0.001). CONCLUSIONS: The results allows suggesting that silorane-based resinous system is adequate to promote more satisfactory marginal sealing than any other combination, since the system is combined with its own bond system.

Estimation of the autoclave and different surface treatments on microleakage between soft liner and heat-cured acrylic / Estimativa da autoclavagem e diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico termopolimerizável

Objective: The present study was oriented to estimate the effect of different surface treatments on the microleakage between the soft liner and acrylic with and without the use of autoclave as disinfection method. Material and Methods: Sixty samples were split into two groups: the autoclaved groups and non-autoclaved groups. Each one subdivided into three groups: first one without any treatments as a control group; in the second group surface of the samples were treated with CO2 laser (10.6 nm wavelength for 15 seconds), and in the third group the surface was treated with sandblasting (250 µm Al2O3). All the samples exposed to thermocycling, then the microleakage test was evaluated by gauging dye penetration depth between the soft liner and acrylic disc using a digital microscope. Data analyzed statistically by One-way ANOVA and Tukey's post-hoc tests. In addition, t-test was used for comparison between two groups (P-value ≤ 0.05). Results: The maximum mean values for the microleakage were observed in the untreated group (control) followed by the group treated by CO2 laser and the lowest mean value of microleakage was related to the third group for both non-autoclaved and autoclaved groups with significant differences among them. In addition, depending on the use of autoclave, there was non-significant in all studied groups. Conclusions: There was a decrease in the microleakage when the surface treated with CO2laser and sandblast. The use of autoclave did not badly change the microleakage between the soft liner and denture base. (AU)

Objetivo: O presente estudo teve como objetivo estimar o efeito de diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico usando ou não a autoclve como método de desinfecção. Material e Métodos: Sessenta amostras foram divididas em dois grupos: grupo com uso da autoclave e grupo sem uso da autoclave. Cada um subdivide em três grupos: o primeiro sem nenhum tratamento como grupo controle; no segundo grupo, a superfície das amostras foi tratada com laser de CO2 (comprimento de onda de 10,6 nm por 15 segundos) e, no terceiro grupo, a superfície foi tratada com jateamento (250 µm Al2O3). Todas as amostras foram expostas à termociclagem, em seguida o teste de microinfiltração foi realizado medindo-se a profundidade de penetração do corante entre o soft liner e o disco de acrílico em microscópio digital. Os dados foram analisados estatisticamente por One-way ANOVA e testes post-hoc de Tukey. Além disso, o teste t foi usado para comparação entre dois grupos (P-valor ≤ 0,05). Resultados: Os valores médios máximos de microinfiltração foram observados no grupo não tratado (controle) seguido pelo grupo tratado com laser de CO2 e o valor médio mínimo de microinfiltração foi relacionado ao terceiro grupo para ambos os grupos não autoclavado e autoclavado com diferenças significativas entre eles. Além disso, dependendo do uso de autoclave, não houve significância em todos os grupos estudados. Conclusão: Houve diminuição da microinfiltração quando a superfície foi tratada com laser de CO2e jateamento. O uso de autoclave não alterou a microinfiltração entre o soft liner e a base da prótese (AU)

Estudio in vitro de la relación entre resistencia de unión a esmalte dental y microfiltración en resinas compuestas fotopolimerizables / In vitro study of the relationship between bond strength to dental enamel and microleakage in photopolymerizable composite resins

Objetivos. Evaluar y comparar la relación entre la resistencia de unión inmediata a esmalte y microfiltración de dos sistemas restauradores a base de resina compuesta. Métodos. 40 terceros molares se dividieron aleatoriamente en dos grupos: 20 molares restaurados utilizando el sistema Adper Single bond 2 + Filtek Z250 XT (3M ESPE; ST PAUL, MN, USA); y 20 molares restaurados con el sistema Tetric N Bond + Tetric N Ceram (Ivoclar Vivadent; Schaan, Liechtenstein). La mitad de los dientes de cada grupo se utilizaron para un ensayo de microtracción, mientras que la otra mitad fueron utilizados para un ensayo de microfiltración (n = 10). Resultados. Las medias y el desvío padrón de la resistencia de unión a microtracción fueron de 27.93 (±9.55) para Adper Single bond 2 + Filtek Z250 XT MPa y 33.12 (±8.18) MPa para Tetric N Bond + Tetric N Ceram (p = 0,049). En cuanto a los valores de microfiltración, no hubo diferencias estadísticamente significativas entre los grupos (p = 0,478). No fue observada una correlación significativa entre la resistencia de unión a la microtracción y la microfiltración (R2 = 0.0909; p = 0.196). Conclusiones. No se encontró una relación entre los valores de resistencia de unión y el grado de microfiltración.

Objectives. To evaluate and compare the relationship between enamel bond strength and microleakage of two composite based restorative systems. Methods. 40 third molars were randomly divided into two groups: 20 molars restored with the Adper Single bond 2 + Filtek Z250 XT (3M ESPE; ST PAUL, MN, USA) system and 20 with the Tetric N Bond + Tetric N Ceram (Ivoclar Vivadent; Schaan, Liechtenstein) system. "Half of the teeth" in each group were subjected to a bond strength test, while the others were subjected to the microleakage test. Results. The means and standard deviation of the bond strength resistance were 27.93 (± 9.55) MPa for Adper Single bond 2 + Filtek Z250 XT system and 33.12 (± 8.18) MPa for Tetric N Bond + Tetric N Ceram system (p = 0.049). Regarding microleakage values, there were no statistically significant differences between the groups (p = 0.478). No significant correlation was observed between microtensile bond strength and microleakage (R2 = 0.0909, p = 0.196). Conclusions. No relationship was found between adhesive bond values and degree of microleakage.

Objetivos. Avaliar e comparar a relação entre a resistência de união imediata ao esmalte e a microfiltração de dois sistemas restauradores baseados em resina composta. Métodos. 40 terceiros molares foram divididos aleatoriamente em dois grupos: 20 molares restaurados usando o sistema Adper Single bond 2 + Filtek Z250 XT (3M ESPE; ST PAUL, MN, EUA); e 20 molares restaurados com o sistema Tetric N Bond + Tetric N Ceram (Ivoclar Vivadent; Schaan, Liechtenstein). Metade dos dentes de cada grupo foi utilizada para um teste de resistência de união à microtração, enquanto a outra metade foi utilizada para um teste de microfiltração (n = 10). Resultados. As mídias e o padrão de resistência de união à microtração foram 27,93 (± 9,55) para Adper Single bond 2 + Filtek Z250 XT MPa e 33,12 (± 8,18) MPa para Tetric N Bond + Tetric N Ceram (p = 0,049). Em relação aos valores de microfiltração, não houve diferença estatisticamente significativas entre os grupos (p = 0,478). Não houve correlação significativa observada entre a resistência de união à microtração e a microfiltração (R2 = 0,0909; p = 0,196). Conclusões. Não foi encontrada relação entre os valores de resistência de união e o grau de microfiltração.

Evaluation of microleakage and the degree of conversion of three composite resins polymerized at different power densities / Avaliação da microinfiltração e do grau de conversão de três resinas compostas polimerizadas em diferentes densidades de potência

Objectives: This study aims to evaluate the degree of conversion (DC) and microlekage scores of three different composite resins polymerized with a LED curing device in standard and extra-power mode. Material and Methods: One bulk-fill (Tetric EvoCeram Bulk-Fill ­ TECBF) and two conventional composite materials (Clearfil Majesty Posterior ­ CMP and Tetric EvoCeram ­ TEC) were evaluated. A total of 30 specimens were prepared for six groups (N = 5). These groups were polymerized with a LED curing device as follows: TECBF-6: 3200mW/cm2 for six seconds, TECBF-20: 1000mW/cm2 for 20 seconds, CMP-6: 3200mW/cm2 for six seconds, CMP-20: 1000mW/cm2 for 20 seconds, TEC-6: 3200mW/cm2 for six seconds, TEC - 20: 1000 mW/cm2 for 20 seconds. After 24 hours of water storage, DC was measured by Raman spectroscopy. Microleakage scores of the six groups were bonded to various adhesive systems (Clearfil SE Bond or Adhese Bond Universal) were also evaluated at Class II box cavities (N = 10). Results: While the highest DC was found at the top (TECBF-20= 79.92% and TECBF-6= 79.02%) and bottom surfaces (TECBF-20 = 68.94% and TECBF-6= 71.04%) for TECBF groups, TEC groups (TEC-20top = 59.06%, TEC-6top=49.66%, TEC-20bottom = 43.72% and TEC-6bottom= 40.68%) showed the lowest DC for the both surfaces (p < 0.05). Polymerization of materials in standard or extra-power mode was similar to DC (p > 0.05). Microleakage scores were found to be similar (p > 0.05). Conclusion: According to the results of the study, different power densities of LED curing light did not affect the DC of composite resins and microleakage values of restorations at small Class II cavities (AU)

Objetivo: este estudo tem como objetivo avaliar os graus de conversão (DC) e microinfiltração de três diferentes resinas compostas polimerizáveis com um dispositivo de luz por LED nos modos padrão e no modo de alta-potência. Material e métodos: uma resina bulk-fill (Tetric EvoCeram Bulk-Fill - TECBF) e dois materiais resinosos convencionais (Clearfil Majesty Posterior - CMP e Tetric EvoCeram - TEC) foram avaliados. Um total de 30 espécimes foram preparados e divididos em seis grupos (N = 5). Esses grupos foram polimerizados com um dispositivo de luz de LED da seguinte forma: TECBF-6: 3200mW / cm2 por seis segundos, TECBF-20: 1000mW / cm2 por 20 segundos, CMP-6: 3200mW / cm2 por seis segundos, CMP20: 1000mW / cm2 por 20 segundos, TEC-6: 3200mW / cm2 por seis segundos, TEC - 20: 1000 mW / cm2 por 20 segundos. Após 24 horas de armazenamento em água, a DC foi medida por espectroscopia Raman. Os escores de microinfiltração dos seis grupos dos vários sistemas adesivos (Clearfil SE Bond ou Adhese Bond Universal) também foram avaliados nas cavidades Classe II (N = 10). Resultados: embora a maior CD tenha sido encontrada nas partes superior (TECBF-20 = 79,92% e TECBF-6 = 79,02%) e inferiores (TECBF-20 = 68,94% e TECBF-6 = 71,04%) para grupos TECBF, os grupos TEC (TEC-20top = 59,06%, TEC-6top = 49,66%, TEC-20bottom = 43,72% e TEC-6bottom = 40,68%) apresentaram as menores CD para as ambas as partes (p < 0,05). A polimerização de materiais no modo padrão ou alta-potência foi semelhante à DC (p > 0,05). Os escores de microinfiltração foram semelhantes (p > 0,05). Conclusão: de acordo com os resultados do estudo, diferentes densidades de potência da luz de LED não afetaram as CD das resinas compostas e os valores de microinfiltração das restaurações em pequenas cavidades da Classe II. (AU)

Evaluation of marginal fit and microleakage of monolithic zirconia crowns cemented by bio-active and glass ionomer cements: In vitro study / Avaliação da adaptação marginal e microinfiltração de coroas monolíticas de zircônia cimentadas com cimentos bioativos e ionômero de vidro: estudo in vitro

Objective: to evaluate the marginal fit and microleakage of monolithic zirconia crowns cemented by bio-active cements (Ceramir) compared to that cemented with glass ionomer cement, and to evaluate the effect of thermocycling on marginal fit. Material and Methods: Twenty sound human molar teeth were prepared to receive monolithic zirconia crowns. Teeth were divided randomly into two equal groups according to the type of luting cement: Group I (glass ionomer cement) and group II (Ceramir cement). After cementation, the vertical marginal gap was assessed using stereomicroscope before and after thermocycling. Twenty equidistant measurement points were taken for each crown. Leakage assessment was carried out using Fuchsin dye penetration followed by digital photography under a stereomicroscope. Data were analyzed by Mann-Whitney U test to compare between the two luting cements. Wilcoxon signed-rank test was used to evaluate the effect of thermocycling on the marginal fit (P ≤ 0.05). Results: Whether before or after thermocycling, the results showed no significant difference between the marginal gap values of the two tested groups. For both groups, there was a significant increase in marginal gap values after thermocycling. Also, there was no significant difference between leakage scores of the two tested groups. Conclusion: Similarity in the physical properties and chemical composition of the two cements resulted in a nonsignificant effect on the vertical marginal fit and the extent of microleakage of translucent zirconia crowns. Thermocycling had a negative impact on the vertical marginal gap of the two tested luting agents. (AU)

Objetivo: avaliar a adapatação marginal e a microinfiltração de coroas monolíticas de zircônia cimentadas com cimentos bioativos (Ceramir) em comparação com o cimento de ionômero de vidro e avaliar o efeito da termociclagem na adaptação marginal. Material e Métodos: Vinte molares humanos sadios foram preparados para receber coroas monolíticas de zircônia. Os dentes foram divididos aleatoriamente em dois grupos iguais, de acordo com o tipo de cimento: Grupo I (cimento de ionômero de vidro) e grupo II (cimento Ceramir). Após a cimentação, a adaptação marginal vertical foi avaliada com estereomicroscópio antes e após a termociclagem. Vinte pontos de medição equidistantes foram obtidos para cada coroa. A avaliação da infiltração foi realizada utilizando a penetração do corante de fucsina, seguida de fotografia digital sob estereomicroscópio. Os dados foram analisados pelo teste de Mann-Whitney para comparação entre os dois cimentos. O teste de Wilcoxon foi usado para avaliar o efeito da termociclagem na adaptação marginal (P ≤ 0,05). Resultados: Antes ou depois da termociclagem, os resultados não mostraram diferença significativa entre os valores de fenda marginal dos dois grupos testados. Para ambos os grupos, houve um aumento significativo nos valores de fenda marginal após a termociclagem. Além disso, não houve diferença significativa entre os escores de infiltração dos dois grupos testados. Conclusão: A similaridade nas propriedades físicas e na composição química dos dois cimentos resultou em um efeito não significativo na adaptação marginal vertical e na extensão da microinfiltração de coroas translúcidas de zircônia. A termociclagem teve um impacto negativo na fenda marginal vertical dos dois agentes de cimentação testados. (AU)

Microleakage in posterior teeth with different materials and different types of cavities.

BACKGROUND: The purpose of this study was to investigate the behavior of a resin-based 2,2-bis (p-[2'-hydroxy-3'-methacryloxypropoxy] phenylene) propane and a composite resin modified with oxirane, regarding the ability of marginal sealing, both with direct restorations and indirect restorations. MATERIALS AND METHODS: To achieve this, mesio- and disto-occlusal cavities were made on the same tooth, totalling 100 cavities. These cavities were restored with two materials, Filtek P90 (3M ESPE) and Opallis (FGM). Then, they were divided into two groups: Fifty direct restorations, each sample restored with the two materials, following the manufacturer's protocol and fifty indirect restorations, and then cemented with a paste obtained by diluting the resin in its adhesive. The templates were thermally cycled, 30 s at 5°C and 30 s at 55°C for 500 cycles and then were immersed in methylene blue for 24 h. Afterward, they were trimmed using a plaster trimmer from occlusal toward a gingival direction. These samples were analyzed with stereomicroscope (×3) by two blinded observers. Then, a system which considers the average number of surrounding walls that have suffered infiltration on a scale of 0-3 was used. RESULTS: Data were subjected to statistical analysis (Mann-Whitney and Kruskal-Wallis tests) with a significance level of 5% maximum. CONCLUSION: It was concluded that the indirect restorations showed the greatest number of restorations with score 0 and 1 (34) and lowest score 2 and 3 (16). This suggests that indirect restorations regardless of the material used behaved more effectively regarding the marginal sealing of restorations.

A perspective of marginal microleakage in class II composite resin restorations using different types and techniques: an in-vitro study / Una perspectiva de la microfiltración marginal en restauraciones de resina compuesta de clase II usando diferentes tipos y técnicas: un estudio in-vitro

The study aimed to introduce a perspective of the essential reason behind why marginal microleakage develops regardless of the composite type, the technique, or the bonding system applied, especially in gingival floor of class II cavities. Materials and Methods: Three types of composite resin materials (CharmfilTM, ParaFillTM, and ProMedica®) were used to evaluate microleakage of class II restorations using two restorative approaches. Twenty four newly extracted bicuspid teeth were divided into two main groups (n=12 each) according to the restoration technique (open or closed sandwich techniques). Teeth of each group were then divided into 3 groups (n= 4 each) according to the type of the composite resin used. The restorations were then subjected to a thermocycling process and then were immersed into methylene blue solution for 12 hours. Mesiodistal sectional cuts were made along the central grooves and assessed under stereomicroscope for marginal microleakage. The data were statistically analyzed with a p-value <0.05 considered significant. Results: There were no statistically significant differences in marginal microleakage between the three examined groups using both techniques (p>0.05). Under the microscope, the marginal microleakage was more obvious at the cervical region than at the occlusal region. Conclusion: There was no effect of the composite type or the application technique used on the occurrence of marginal microleakage. The first portion of the material applied against the cavity floor is the primary factor involved in possibly minimizing marginal microleakage.

El estudio tuvo como objetivo presentar una perspectiva de la razón esencial por la cual se desarrolla microfiltraciones independientemente del tipo de resina compuesta, el sistema de unión aplicado, especialmente en el piso gingival de cavidades de clase II. Materiales y Métodos: Se utilizaron tres tipos de resina compuesta (CharmfilTM, ParaFillTM y ProMedica®) para evaluar la microfiltración de restauraciones de clase II utilizando dos enfoques restaurativos. Veinticuatro dientes bicúspides recién extraídos se dividieron en dos grupos (n=12 cada uno) de acuerdo con la técnica de restauración (técnicas de sándwich abierto o cerrado). Los dientes de cada grupo se dividieron en 3 sub-grupos (n=4 cada uno) de acuerdo con el tipo de resina compuesta utilizada. Las restauraciones se sometieron después a un proceso de termociclado y finalmente se sumergieron en una solución de azul de metileno durante 12 horas. Se realizaron cortes en la sección mesiodistal a lo largo de los surcos centrales y se evaluaron bajo lupa para determinar la ocurrencia de microfiltración marginal. Los datos se analizaron estadísticamente con un valor de p<0,05 considerado significativo. Resultados: No hubo diferencias estadísticamente significativas en la microfiltración marginal entre los tres grupos examinados utilizando ambas técnicas (p>0.05). Bajo la lupa la microfiltración marginal fue más obvia en la región cervical que en la región oclusal. Conclusión: No hubo efecto del tipo compuesto o la técnica de aplicación utilizada en la aparición de microfiltración marginal. La primera porción del material aplicado el piso de la cavidad es el factor principal involucrado en la posibilidad de minimizar la microfiltración marginal.

Microleakage of high viscosity glass-ionomer and glass-carbomer with and without coating before and after hydrothermal aging / Microinfiltracao de ionomero de vidro de alta viscosidade e carbômero de vidro com e sem revestimento antes e depois de envelhecimento hidroterma

Objective: The objective of this study was to evaluate the microleakage patterns of GIC and GGC with and without their protective surface coatings on enamel and dentin margins before and after aging. Material and Methods: Two rectangular cavities (height: 2 mm; width: 3 mm; depth: 1.5 mm) were prepared on each tooth at the cemento-enamel junction were prepared on human permanent molars (N=56) and the teeth were randomly assigned to be restored with one of the following: a) high viscosity glass-ionomer cement (GIC) (EQUIA Fil, C Corp., Tokyo, Japan) (n=28), b) glasscarbomer cement (GCC) (Glass Carbomer Products, Leiden, The Netherlands) (n=28). Half of the teeth were further divided into two groups where one group received protective surface coating (SC) (G-Coat Plus, GC Corp) (n=14) and the other group did not (n=14). Half of the teeth were stored for 24 hours (n=7), and the other half was thermocycled (5000 cycles, 5-55°C) (n=7). For microleakage analysis, the teeth were immersed in 5% methylene blue dye for 24 hours, sectioned into two equal halves. Microleakage patterns were evaluated using stereomicroscope and scored on a scale of 0-3 (0: No dye penetration, 1: Dye penetration less than half of the axial wall, 2: Dye penetration more than half the axial wall, 3: Dye penetration spreading along the axial wall). Data were analyzed using Kruskal-Wallis tests at the significance level of 0.05. Results: Compared to 24 h storage, after thermocycling, surface coating on GIC decreased microleakage significantly compared to GCC (p=0.046) but not for GCC. In the thermocycled groups, coated GIC showed significantly less leakage at the enamel margin but no significant difference was found with both GIC and GCC in the dentin margins. Conclusion: The application of surface coating significantly reduced the microleakage scores of GIC but not GCC, within the enamel margins only. (AU)

Objetivo: O objetivo deste estudo foi avaliar os padrões de microinfiltração de GIC e GGC com e sem seus revestimentos protetores superficiais nas margens de esmalte e dentina antes e após o envelhecimento. Material e Métodos: duas cavidades retangulares (altura: 2 mm; largura: 3 mm; profundidade: 1,5 mm) foram preparadas em cada dente na junção cemento-esmalte de molares permanentes humanos (N = 56), sendo aleatoriamente designados para serem restaurados com um dos seguintes: a) cimento de ionômero de vidro (GIC) de alta viscosidade (EQUIA Fil, C Corp., Tóquio, Japão) (n = 28), b) cimento de vidrocarbômero (GCC) Carbomer Products, Leiden, Holanda) (n = 28). Metade dos dentes foram divididos em dois grupos, onde um grupo recebeu revestimento protetor de superfície (SC) (G-Coat Plus, GC Corp) (n = 14) e o outro grupo não (n = 14). Metade dos dentes foram armazenados por 24 horas (n = 7), e a outra metade foi termociclada (5000 ciclos, 5-55 ° C) (n = 7). Para análise de microinfiltração, os dentes foram imersos em corante azul de metileno a 5% por 24 horas, seccionados em duas metades iguais. Os padrões de microinfiltração foram avaliados usando estereomicroscópio e pontuados numa escala de 0-3 (0: Sem penetração de corante; 1: penetração de corante inferior à metade da parede axial; 2: penetração de corante mais do que metade da parede axial; 3: penetração de corante ao longo da parede axial). Os dados foram analisados pelo teste de Kruskal-Wallis ao nível de significância de 0,05. Resultados: em comparação com o armazenamento de 24 h, após a termociclagem, o revestimento de superfície no GIC diminuiu significativamente a microinfiltração em comparação com o GCC (p = 0,046), mas não para o GCC. Nos grupos termociclados, o GIC revestido apresentou significativamente menos infiltração na margem do esmalte, mas não houve diferença significativa para o GIC e o GCC nas margens dentinárias. Conclusão: A aplicação do revestimento de superfície reduziu significativamente os escores de microinfiltração do GIC, mas não do GCC, apenas nas margens do esmalte. (AU)

Análisis del cierre marginal en incrustaciones de cerámicas preformadas / Analysis of the marginal closure of preformed ceramic inlays

El propósito de este trabajo fue analizar el cierre marginal de restauraciones semipermanentes de porcelanas para método directo. Para la metodología, se utilizó un diseño experimental verdadero transversal pues se basó en variables con única medición. Los grupos se conformaron al azar. Las unidades de análisis fueron los sistemas adhesivos y el medio de fijación. Las preparaciones de las muestras se basaron en la norma ISO 11405 tanto para la mantención, confección, número de muestras y valoración. La variable utilizada fue la presión ejercida durante la polimerización del medio de fijación. Para la realización de este trabajo se realizó el análisis colorimétrico a través de la penetración de un colorante en las interfases medio de fijación diente o medio de fijación porcelana; y el análisis microscópico de las interfases producidas entre el sistema adhesivo - medio cementante y material de restauración rígida (AU)

The purpose of this work was to analyze the marginal closure of semi-permanent ceramic restorations for direct method. For the methodology, a true cross-section experimental design was used because it was based on variables with only measurement. The groups were formed randomly. The units of analysis were the adhesive systems and the fixing medium. The sample preparations were based on ISO 11405 standard for both maintenance, preparation, number of samples and assessment. The variable used was the pressure exerted during the polymerization of the fixing medium. In order to carry out this work, the colorimetric analysis was carried out through the penetration of a dye in the interfaces between the teeth or the porcelain fixation medium; and the microscopic analysis of the interfaces produced between the adhesive system - cementing medium and rigid restoration material (AU)

Effect of silver diamine fluoride on adhesion and microleakage of a pit and fissure sealant to tooth enamel: in vitro trial.

AIM: To identify the effect of silver diamine fluoride in adhesion and microleakage of a pit and fissure sealant to tooth enamel. METHODS: An in vitro study including 120 human molars without caries, and caries grade 1 was performed. Molars were randomly divided into four groups. Occlusal surfaces of groups 2 and 4 were sealed. In groups 1 and 3 silver diamine fluoride (SDF) was placed in the occlusal surface and then molars were sealed according to manufacturer's instructions. Afterwards, all groups were submitted to the adhesion test. Groups 1 and 2 were placed in a forming cylinder and their roots were submerged in polymethyl methacrylate after that they were stored in deionised water (37 °C ± 1). Subsequently, they were tested by applying a tractional load (Instron machine, speed cross of 1 mm/min). Sealant adhesion was evaluated through: Resistance to the detachment (MPa), residues of sealant area (mm2) and adhesive remaining index (ARI) (0-3 interval). Microleakage test: Groups 3 and 4 were placed in a plastic container and subjected to 2000 cycles at different temperatures one at 6 °C ± 1 and the other at 60 °C ± 1. Later the occlusal surface was immersed for 24 h in 1% toluidine blue. Microleakage was observed by optical microscopy (10×) and was interpreted in micrometres. RESULTS: Of the samples without SDF 18.1 and 23.0% of the sealant remaining and of the samples with SDF present 100% of sealant remaining on enamel. Samples with SDF obtained an average in the test of detachment of 6.89 ± 3.09 MPa, whereas in the group without SDF the average obtained was 6.42 ± 3.35 MPa. Differences were not statistically significant (p = 0.579). Most of the samples not treated with SDF (81.6%) showed microleakage than those treated with SDF in which 47% presented microleakage. CONCLUSIONS: There is an improvement in the retention properties of a fissure sealant applied after treatment with silver diamine fluoride. The application of fissure sealant to improve the aesthetics of teeth treated with SDF is recommended.

Obturación del sistema de conductos radiculares: revisión de la literatura / Root canal system obturation: a review of the literature

Con el paso de los años, diferentes conceptos atribuidos a temáticas del área de la endodoncia sufren modificaciones. Una de estas etapas es la obturación del sistema de conductos radiculares, este procedimiento sumamente minucioso y crítico en la obtención de un resultado exitoso ha tenido en los últimos años importantes aportaciones en términos de aparición de nuevos materiales y técnicas dentro del campo de la endodoncia. La presente revisión de literatura retoma aspectos básicos que junto al más reciente conocimiento sobre obturación endodóncica permitirán al practicante de la endodoncia enfatizar aspectos de la última etapa operatoria del tratamiento de conductos, con el objetivo de contar con diferentes alternativas de información que le permitan actualizar sus conocimientos en el área de la endodoncia (AU)

Over the years, different thematic concepts attributed to the endodontics are modified. One such step is the sealing of the root canal system, this procedure extremely thorough and critical in obtaining a successful result, it has had in recent years important contributions in terms of new materials and techniques in the field of endodontic. This literature review basic aspects resumed by the latest knowledge about endodontic filling, allow the practitioner endodontics, emphasizing aspects of the last operative stage of root canal, aiming to have alternatives that allow them information update their knowledge on the area of endodontics (AU)

Evaluation of Microleakage by Gas Permeability and Marginal Adaptation of MTA and BiodentineTM Apical Plugs: In Vitro Study / Evaluación de la microfiltración por permeabilidad de gas y adaptación marginal de tapones apicales de MTA y BiodentineTM: Estudio in vitro

Abstract The endodontic treatment of teeth with incomplete development is always a complex task. Nowadays, biomaterials such as bioceramics offers promising clinical evidence that supports its use. However, the standardization of its use for apexification purpose still needs a deeper understanding of the materials' behavior. The aim of this investigation was to evaluate the marginal adaptability and microleakage by gas permeability of MTA and Biodentine™ apical plugs in an in vitro model. Materials and methods: Twenty- four single rooted human teeth were selected according to previously stablished inclusion criteria. All samples were prepared obtaining standard cylindrical internal canals with a diameter of 1.3 mm. Root canals were gently rinsed using 5.25% sodium hypochlorite and EDTA 17%. The apical 3mm and remaining coronal dental structure were sectioned to obtain 10mm roots. Roots were randomly assigned to 3 different groups as follows: GROUP A: MTA (n=10), GROUP B: Biodentine™ (n=10) and Group C: Control (positive n=1, negative n=3). MTA and Biodentine™ were prepared according to manufacturer's indications, and apical plugs of 4mm were passively placed in the correspondent teeth. All samples were stored in saline solution for 7 days at 37°C before evaluation. Samples were mounted in cylindrical sample-holders using epoxy resin. Microleakage was evaluated with an automatic permeability detector that calculates nitrogen diffusion between the material-root interphase. After microleakage evaluation, the samples were recovered and analyzed by scanning electron microscopy (SEM). Microleakage results were analyzed using Chi-square and adaptation was evaluated with a descriptive analysis. Results: None of the evaluated materials completely avoided the nitrogen microleakage (positive leakage of 10% and 20% of samples for MTA and Biodentine™ respectively); with no statistical significant difference between groups (p=0.527). All apical plugs showed good adaptation under SEM, at 30x, 200x, 1000x and 2500x; with microscopical structures similar to previous reports. Conclusions: Both bioceramics behave similar when used as apical barriers to avoid permeability, with acceptable marginal adaptation. Further in vivo studies are needed to validate these results.

Resumen El tratamiento endodóntico de dientes con desarrollo incompleto es siempre una tarea compleja. Hoy en día, biomateriales como las biocerámicas ofrecen una evidencia clínica prometedora que apoya su uso. Sin embargo, la estandarización de su uso para fines de apexificación todavía necesita una comprensión más profunda del comportamiento de los materiales. El objetivo de esta investigación fue evaluar la adaptabilidad marginal y microfiltración por permeabilidad de gas de los tapones apicales de MTA y Biodentine™ en un modelo in vitro. Materiales y métodos: Veiticuatro dientes humanos uniradiculares fueron seleccionados meticulosamente según criterios de inclusión previamente establecidos. Todas las muestras fueron preparadas con canales cilíndricos internos estandarizados de 1,3 mm de diámetro. Los conductos radiculares fueron gentilmente lavados con hipoclorito de sodio al 5,25% y EDTA al 17%. La estructura dental apical de 3 mm y la coronal restante se seccionó para obtener raíces de 10 mm de longitud. Las raíces se asignaron aleatoriamente a 3 grupos diferentes de la siguiente manera: GRUPO A: MTA (n = 10), GRUPO B: Biodentine™ (n = 10) y Grupo C: Control (n = 1 positivo, n = 3 negativos). El MTA y Biodentine™ se prepararon de acuerdo con las indicaciones de los fabricantes, y se colocaron pasivamente los tapones apicales de 4 mm en los dientes correspondientes. Todas las muestras se almacenaron en solución salina durante 7 días a 37ºC antes de la evaluación. Las muestras se montaron en porta-muestras cilíndricos utilizando resina epóxica. La microfiltración se evaluó con un detector de permeabilidad automática que calcula la difusión de nitrógeno entre la interfase material-raíz. Después de la evaluación de microfiltración, las muestras fueron recuperadas y analizadas por microscopía electrónica de barrido (SEM). Los resultados de microfiltración se analizaron utilizando una prueba estadística de Chi-cuadrado y la adaptación se evaluó con un análisis descriptivo. Resultados: Ninguno de los materiales evaluados evitó completamente la microfiltración de nitrógeno (fuga positiva de 10% y 20% de muestras para MTA y Biodentine™, respectivamente); sin diferencias estadísticamente significativas entre los grupos (p = 0,527). Todos los tapones apicales mostraron una buena adaptación bajo SEM, a 30x, 200x, 1000x y 2500x; con morfologías similares a las previamente reportadas. Conclusiones: ambas biocerámicas se comportan de forma similar cuando se usan como barreras apicales para evitar la permeabilidad de gas, con adaptación marginal aceptable. Se necesitan más estudios in vivo para validar estos resultados.

Microfiltración en un cemento dental tipo MTA modificado con wollastonita y vidrio bioactivo / Microleakage in MTA-type dental cement modified with wollastonite and bioactive glass

Resumen Un material de retroobturación como el MTA (Mineral Trioxide Aggregate) debe de ser de fácil manejo, biocompatible, tener baja o nula solubilidad y ser dimensionalmente estable para evitar filtraciones asociadas a los cambios volumétricos. Objetivo: Medir la filtración en un cemento dental tipo MTA modificado con wollastonita y vidrio bioactivo. Material y métodos: Se establecieron ocho grupos: MTA Angelus (control), MTA Exp (cemento Portland blanco más 20 wt% de trióxido de bismuto), otros seis grupos se formaron con la adición de 10, 20 y 30 wt% de wollastonita y vidrio bioactivo al MTA Exp. Dientes permanentes uniradiculares, raíz recta y con ápice cerrado fueron preparados con técnica crown-down con fuerzas balanceadas para obtener un diámetro estandarizado a lima apical maestra #40. Se cortaron 3 mm del ápice se prepararon retrocavidades de 3 mm de profundidad con punta de ultrasonido donde fueron colocados los cementos, el extremo apical fue sumergido en solución de azul de metileno al 2% durante 24 horas. Resultados: MTA Exp fue el que presentó menor filtración con un promedio de 0.66 mm, mientras que el grupo de WO10 fue el de mayor con 1.61 mm. MTA Angelus usado como control presentó 0.71 mm de microfiltración, se encontraron diferencias estadísticamente significativas con WO10, (ANOVA p < 0.001, Dunett p < 0.001). Conclusiones: Se observa que en el caso de los cementos con los agregados de wollastonita y vidrio bioactivo la microfiltración disminuye conforme aumenta el porcentaje del agregado, se sugiere el uso de otras técnicas complementarias para medir la microfiltración.

Abstract Retro-filling material such as MTA (mineral trioxide aggregate) should be biocompatible, easy to handle, with low or nil solubility as well as dimensionally stable in order to avoid filtrations associated to volumetric changes. Objective: To measure filtration in a MTA-type dental cement modified with wollastonite and bioactive glass. Material and methods: Eight groups were established: MTA Angelus (control), MTA Exp (white Portland cement plus 20% wt of bismuth trioxide), another six groups were formed with the addition to MTA Exp of 10, 20 and 30% wt of wollastonite and bioactive glass . Single rooted teeth, with straight root and closed apex were prepared with crown-down technique with balanced forces in order to obtain standardized diameter to fit a number 40 master apical file; 3 mm from the apex were excised, 3 mm deep retro-cavities were prepared with ultrasound point, where cements were placed, apical end was submerged in a 2% methylene blue solution for 24 hours. Results: MTA Exp exhibited least filtration with an average of 0.66 mm, WO10 group exhibited the greatest leakage with average of 1.61 mm. MTA Angelus, used as control exhibited 0.71 mm microleakage. Statistically significant differences were found with WO10, (ANOVA p < 0.001), Dunett p < 0.001). Conclusions: It was observed that in the case of cements with aggregate of wollastonite and bioactive glass, microleakage decreased according to the aggregate's percentage. For microleakage measurement, use of other supporting techniques is advised.

Bacterial microleakage at the abutment-implant interface, in vitro study.

INTRODUCTION: In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previous research has shown that oral microbiome can proliferate in this microspace and affect periimplant tissues, causing inflammation in peri-implant tissues. Preventing microbial leakages through the AII is therefore an important goal in implantology. OBJECTIVE: To determine the presence of marginal bacterial microleakage at the AII according to the torque applied to the prosthetic implant in vitro. MATERIAL AND METHODS: Twenty-five Ticare Inhex internal conical implants (MG Mozo-Grau, Valladolid, España) were connected to a prosthetic abutment using torques of <10, 10, 20, 30, and 30 N and then sealed. The samples were submitted to cycles of occlusal loads and thermocycling, then one sample of each group was observed by micro TC, while the rest were mounted on devices according to the bacterial leakage model with Porphyromonas gingivalis. RESULTS: Bacterial leakage was observed only in the <10 and 10 N torque samples, and the same groups presented poor abutment/implant adjustment as determined by micro-CT. CONCLUSION: The different torques applied to the abutment-implant system condition the bacterial leakage at the implant interface. No microleakage was observed at 20 and 30 N.