The effect of smear layer removal on E. faecalis leakage and bond strength of four resin-based root canal sealers.

BACKGROUND: The aim of the study was to assess bacterial sealability and bonding ability of methacrylate-based Resilon (RS, SybronEndo), Endo Rez (ER, Ultradent Products Inc), and epoxy-based AH Plus (AH, Dentsply/DeTrey), MTA Fill Apex (MTAF, Angelus Soluções Odontológicas) root canal sealers, and the effect of the smear layer removal on the sealability. METHODS: One hundred thirty root segments were instrumented up to apical size #60 and rinsed with 2.5% NaOCl. Half of the roots were rinsed with 5ml 17% EDTA to remove the smear layer. All the roots were filled with AH, ER, MTAF sealers and gutta-percha, or RS with Resilon cones. After storage at 37°C for 7 days the samples were mounted into bacterial leakage assay for 50 days. Another 100 roots were instrumented and rinsed as described above, split longitudinally, cut into the cervical, middle and apical parts. The sealers were injected through the plastic mould on the dentin surface. After 7 days of incubation at 37°C, bond strength was tested using a notched-edge test fixture (Crosshead, Ultradent Products Inc.) and a universal testing machine (Lloyd Instruments). RESULTS: AH revealed the longest mean time for bacterial resistance by 29.4 and 36.8 days (with and without smear layer, respectively) followed by RS (15.1 and 24.7 days, respectively). The difference between materials was significant (p<0.001). Bond strength values ranged from 0.2± 0.1 to 3.5± 0.7 MPa and increased from the apical to the cervical third. In the apical third, AH showed the highest mean (SD) bond values 1.4 (0.4) MPa and 1.7 (0.6) MPa (with and without smear, respectively, followed by RS, 0.5 (0.1) MPa and 0.8 (0.1) MPa, respectively. The difference between materials was significant (p=0.001). CONCLUSION: The effect of the smear layer removal on the sealability was material-dependent.

Comparison of the Apical Sealing Ability of Calcium Silicate-Based Sealer and Resin-Based Sealer Using the Fluid-Filtration Technique.

OBJECTIVE: The aim was to evaluate the apical sealing ability of tricalcium silicate-based (MTA Fillapex®) and resin-based (AH Plus®) sealers at 24 h, 7 days and 4 weeks. MATERIALS AND METHODS: Thirty-four extracted human upper anterior teeth were used. All the teeth were sectioned to leave the root 15 mm long, and then all the roots were instrumented using a set of ProTaper® rotary instruments. Four roots were selected randomly as controls, and the remaining 30 were randomly divided into 2 groups of 15 each: MTA Fillapex and gutta-percha (group 1) and AH Plus and gutta-percha (group 2) using a warm vertical compaction technique. The apical sealing ability of the filled root canal was measured using the fluid-filtration method with 200 mm Hg (26.67 KPa) above atmospheric pressure at 24 h, 7 days and 4 weeks. The apical microleakage of the 2 groups was compared using Student's t test. p < 0.05 was considered statistically significant. RESULTS: The mean apical microleakage in group 1 at 24 h, 7 days and 4 weeks was 1.01 ± 0.24, 0.43 ± 0.07 and 0.24 ± 0.08 nl/s. The corresponding values in group 2 were 1.15 ± 0.40, 0.32 ± 0.09, and 0.38 ± 0.10 nl/s. MTA Fillapex had significantly more leakage than AH Plus at 7 days, but at 4 weeks, MTA Fillapex showed a significantly better sealing ability than AH Plus (p < 0.05). CONCLUSIONS: In this study, the tricalcium silicate-based sealer promoted proper sealing when used for filling the root canals.

Microleakage in Class II composite restorations with margins below the CEJ: in vitro evaluation of different restorative techniques.

OBJECTIVES: The purpose of this in vitro study was to evaluate the microleakage in "deep" Class II composite restorations with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques. STUDY DESIGN: Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable (3MESPE) + Universal Filtek Supreme XTE (3MESPE), Group 2: GrandioSO Heavy Flow (Voco) + GrandioSo (Voco), Group 3: SDR™ (Dentsply Caulk) + Esthet-X® HD (Dentsply Caulk), Group 4: SonicFill (Kerr), Group 5: Grandio (Voco). After thermocycling, the specimens were immersed in a 0.5% basic fuchsine dye solution and incubated at 37°C for 24 hours. The teeth were subsequently sectioned mesiodistally. All specimens were examined at 25 in a stereomicroscope and standardized digital images were obtained. Dye penetration was measured from gingival margins. RESULTS: The results demonstrated no significant leakage differences between Group 4 and Group 5, that both showed significantly higher frequency distribution of Score 0. Group 2 and Group 3 showed a significant prevalence of Score 1, whereas Group 1 showed significantly higher frequency of Score 2. CONCLUSIONS: None of the restorative techniques tested completely eliminated microleakage dye penetration in dentin margins; marginal adaptation in Class II composite restorations with gingival wall below the CEJ varied in both substrates and from different restorative techniques used.

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. Results: A statistically significant difference was observed in microleakage between the two groups (P<0.001). Conclusions: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage (AU)

In vitro study of microleakage of fissure sealant with different previous treatments.

The purpose of this work was to evaluate microleakeage of a sealant after using three different techniques for conditioning the surface to be sealed. Twenty-four caries-free upper and lower premolars were used, which were preserved in distilled water at room temperature. The structural faults were enlarged using a cylindrical conical diamond (ISO 007). Teeth were randomly assigned into three groups of eight. Group I (control) was conditioned with 37% phosphoric acid (Vivadent) for 15 seconds after which the sealant Helioseal F (Vivadent) was applied and cured for 40 seconds. Group II was conditioned in the same way, after which one-step adhesive Te-econom (Vivadent) and the sealant were applied. Group III was conditioned using a self-etching adhesive, Go (SDI), after which the sealant was applied. Adhesive was applied according to the manufacturer's instructions. The samples were thermocycled for 300 cycles between 5 degrees and 55 degreesC and immersed in a 2% methylene blue solution for 48 hs. at standardized temperature of 37 degreesC +/- 1 degree. Then they were rinsed with tap water and ground longitudinally in V-P direction with silica carbide rotatory disks of decreasing grit. The amount of leakage was evaluated under stereoscopic microscope at 40X magnification. The longitudinal penetration of dye into the tooth-sealant interface was scored on a scale of 0 to 3. The results were analyzed by a Kruskal-Wallis non-parametric test. In Group II, 100% of the samples showed low (50%) or no (50%) leakage. Both the other groups had a higher percentage of specimens with high leakage (scores 2 and 3) (P = 0.000). Group II had the best performance, with significant differences (P = 0.0028) compared to the other experimental groups. Marginal leakage was lowest when the tooth was conditioned with phosphoric acid and subsequent application of an adhesive, prior to sealant.

Microleakage of a self-adhesive resin cement after post cementation.

The aim of this study is to evaluate the microleakage a self-adhesive cement recently marketed Rely X U100 (3M ESPE). Thirty roots of bovine teeth with 14 mm long were restored with self-adhesive cement and Glassix fiber post DC3 (FGM). Roots were randomly divided into three groups (n=10) according to the technique of placement of the cementing agent: G1 - Centrix syringe; G2 - Lentulo drill and G3 - Manual technical. After cementation, provisional restorations were fabricated with composite resin (Opallis/FGM) without the use adhesive system. After they were finished, polished and thermo cycled by 1000 cycles, in water at temperature of 5 degrees C and 55 degrees C, 30 seconds in each bath. For microleakage test each group of roots was immersed in recipients with Rodhamine B dye solution buffered at 2%, during 24 hours. After this time, the samples were washed in tap water, sectioned and evaluation of dye leakage. The values of infiltration were obtained by the qualitative method (scoring) and statistical analysis using Kruskal-Wallis test and also by the quantitative method (Image Tool) and statistical analysis using ANOVA one way. For both tests, no significant difference between the techniques of placement of the self-adhesive cement. Based on these findings, micro-infiltration was present in all groups, and the placement technique did not influence the degree of micro-leakage, both for the qualitative analysis as to the quantitative.

In vitro study of microleakage of fissure sealants with different previous treatments

El objetivo de este trabajo fue evaluar la microfiltración de un sellador con tres técnicas diferentes de acondicionamientoprevio de la superficie a sellar. Se utilizaron 24 premolares superiores e inferiores, libres de caries, conservados en agua destilada a temperatura ambiente. Los defectos estructuralesfueron ensanchados empleando una piedra de diamante cilindrocónica (ISO 007). Luego los dientes fueron distribuidos aleatoriamente en 3 grupos de 8 elementos cada uno. Grupo I(control): acondicionamiento con ácido fosfórico al 37 por ciento (Vivadent) durante 15 seg. y aplicación del sellador Helioseal F (Vivadent) fotopolimerizándolo durante 40 seg.; Grupo II: se realizó el mismo acondicionamiento, posteriormente seaplicó un adhesivo monoenvase, Te-Econom (Vivadent) y el sellador correspondiente; Grupo III: el acondicionamiento previo al sellador fue realizado empleando un adhesivo deautograbado, Go (SDI). La colocación de los adhesivos se hizo de acuerdo a las instrucciones de los fabricantes. Posteriormente las muestras fueron sometidas a ciclaje térmico por300 ciclos entre 5° y 55°C y sumergidas en una solución de azul de metileno al 2 por ciento durante 48 hs. a una temperatura estandarizada de 37°C ± 1º. Luego se enjuagaron abundantemente con agua corriente, se desgastaron longitudinalmente en sentido V-P sobre discos rotatorios de carburo de silicio de granulometría decreciente. El grado de microfiltración fue evaluado con lupa estereoscópica a 40 X de aumento. La penetración longitudinal del colorante en la interfase dientesella dor, fue registrada de acuerdo a una escala de valores de 0 a 3. Los resultados obtenidos fueron analizados mediante la prueba no paramétrica de Kruskal-Wallis. El tratamiento corres pondiente al grupo II presenta el 100 por ciento de las muestras con poca (50 por ciento) o nula (50 por ciento) filtración (P=0.000)

Ex vivo microscopic assessment of factors affecting the quality of apical seal created by root-end fillings.

AIM: (i) To evaluate the incidence of microcracks around root-end preparations completed with ultrasonic tips and their relationship with the root filling technique and thickness of surrounding dentine. (ii) To investigate the effect of rapid exposure to a water-soluble dye of Intermediate Restorative Material (IRM), Super Ethoxybenzoic Acid (sEBA) and Mineral Trioxide Aggregate (MTA), on the marginal adaptation and microleakage of root-end fillings. (iii) To describe the microstructure of the surface of root-end filling materials. METHODOLOGY: Ninety-two single-rooted teeth were divided into two groups (n = 46) according to the root canal instrumentation/filling techniques. Group 1 consisted of specimens in which canal preparation was completed using a crown-down technique and then filled with the Thermafil system (TF group); Group 2 consisted of specimens in which canal preparation was completed using a step-back technique and lateral condensation (LC group). Following root-end resection and ultrasonic cavity preparation, the samples were further divided into three subgroups (n = 24) for root-end filling with IRM, sEBA or MTA. The ultrasonic preparation time was recorded. Eight teeth were kept as positive and 12 as negative controls. Following immersion in Indian ink for 7 days, all resected root surfaces were evaluated for the presence of microcracks and the cross-sectional area of root-end surface and root-end filling were measured to evaluate the thickness of the dentinal walls. Thereafter, the samples were sectioned longitudinally so as to assess the depth of dye penetration and marginal adaptation of root-end fillings. Negative controls longitudinally sectioned were used to describe microstructural characteristics of the root-end filling materials using scanning electron microscopic (SEM) techniques. RESULTS: Although the thickness of dentinal walls between groups 1 and 2 was similar, the ultrasonic preparation time and number of microcracks were significantly higher (P < 0.001) in the TF group. Both groups had a significant correlation between microcracks and ultrasonic preparation time (P < 0.001). sEBA and IRM had better adaptation and less leakage compared with MTA. A SEM analysis displayed microstructural differences between the root-end filling materials. CONCLUSION: Microcracks can occur independently of the thickness of dentinal walls and may be associated with the prolonged ultrasonic preparation time required for the removal of the root filling during root-end cavity preparation. Although sEBA and IRM had better behaviour than MTA regarding microleakage and marginal adaptation, it is possible that exposure of MTA to a water-soluble dye before achieving full set and its porous microstructure contributed to the results.

Evaluación in vitro de la filtración apical de dos cementos y dos procedimientos de obturación con y sin la adición de un adhesivo dentinario / In vitro apical leakage evaluation of two sealers and two obturation techniques both with and without dentin adhesive

El objetivo de este trabajo fue analizar la filtración apical de dos cementos y dos procedimientos de obturación con y sin la adición de un adhesivo dentinario. Para ello se usaron 80 raíces de dientes monoradiculares que fueron instrumentadas mediante el sistema HERO. De las 80 raíces que fueron instrumentadas se formaron 8 grupos, seis de estos fueron grupos experimentales, mientras que los dos restantes se usaron como grupos control. En el grupo 1 se incluyeron 10 raíces que fueron obturadas con cemento EndoREZ y punta única, el grupo 2 fue obturado con EndoREZ, punta única y la adición de un adhesivo, el grupo 3 con cemento EndoREZ y condensación lateral, el grupo 4 con EndoREZ, condensación lateral y adhesivo, el grupo 5 con cemento AH Plus y condensación lateral y el grupo 6 con AH Plus, condensación lateral y adhesivo. En el grupo 7 (control positivo) se incluyeron 10 raíces que fueron instrumentadas pero que no se obturaron. En el grupo 8 (control negativo) se incluyeron 10 raíces las cuales fueron totalmente cubiertas por dos capas de laca de uñas. Todos los dientes fueron sumergidos en azul de metileno durante 48 h, después de lo cual todos los especimenes fueron limpiados con agua y almacenados en medio húmero a 37°C. La evaluación se realizó mediante transparencia de los dientes los cuales fueron examinados mediante un estéreomicroscopio a 60 aumentos. No se hallaron diferencias en cuanto a la filtración. El uso de un adhesivo dentinario tampoco mejoró el sellado del ápice

The aim of the study was to compare the apical microleakage of two kins of cement and two differentobturation procedures, with and without dentin bonding agent. We used 80 monoradicular roots treated instrumentally with the HERO system. Roots were divided in eight groups, six of them experimental, and two controls. Each group included 10 cases each. In group 1 roots were obtured with EndoREZ cement and single point, group 2 was treated as group 1, plus dentin bonding agent. Group 3 was obtured with EndoREZ cement and lateral condensation, group 4 followed same treatment as group 3 but adding dentin bonding agent. Groups 5 and 6 used AH plus cement and lateral condensation, with the later including dentin bonding agent. In our positive control group (group 7) roots were instrumented but not obtured. Instead in the negative control group (group 8) roots were covered by two layers of nails varnish only. All teeth were dipped in metilen blue for 48 hours, washed with water and stored afterwards at 37°C. Cases were evaluated for teeth transparency with a stereomicroscope x60. There was no difference regarding microleakage and the use of an adhesive didn't improve the apex seal

Valoración de la microfiltración de Compoglass® en molares temporales / Evaluation of Compoglass® microleakage in primary molars

El propósito de este estudio ha sido evaluar el sellado marginal que proporciona Compoglass® (Vivadent), una resina compuesta modificada con poliácidos, en molares temporales. Se realizaron 12 cavidades de clase II en la superficie distal de 12 molares temporales exodonciados sanos, obturándolas con Compoglass. Tras someterlas a un proceso de envejecimiento, se sellaron los dientes excepto en la zona de las restauraciones y se sumergieron en azul de metileno al 5 por ciento durante 4 horas. Después, se seccionaron longitudinalmente y se fotografiaron a 40 aumentos. La microfiltración se limitó al esmalte dentario en todas las muestras. Sólo se observó filtración en los márgenes gingivales y únicamente en el 36,36 por ciento de las muestras. Compoglass proporciona un sellado marginal aceptable para su uso clínico en la dentición temporal (AU)

[Coronal leakage reconsidered]. / Nouvelles considérations à propos de la percolation coronaire?

The aim of the present study was to evaluate the impact of the quality of the coronal restoration and of the root filling on periapical health. In a sample of 937 root filled teeth which had not received restorative treatment in the previous year, the technical quality of the coronal restorations and of the root fillings was radiographically scored; in addition the technical quality of the coronal restorations was clinically scored as well. The data showed that the technical standard of both coronal restoration and root filling were essential to periapical health. The study also showed the relatively limited value of epidemiologic findings. Epidemiologic research is descriptive as well as analytical in approach. According to the present data, endodontic failure cannot be fully explained by radiographic analysis only. Nevertheless, epidemiologic data remain a valuable component to the source of knowledge regarding etiologic factors and proper treatment procedures in order to improve the results of endodontic practice.

Estudio comparativo in vitro de la filtración entre composite y dentina al polimerizar con luz halógena Vs con luz de plasma / In vitro comparative study of filtration between composite resin and dentin after polymerizing with halogen and plasma arc light

Introducción: Justificación y objetivos: existen estudios de polimerización realizados con lámparas de luz halógena en los que se valoran negativamente las altas intensidades de luz por la contracción rápida de la resina que podría provocar despegamientos. Según la información proporcionada por el fabricante de las lámparas de polimerización plasmática rápida, el curado con éstas origina una mayor rigidez del material que limita la contracción al evitar la redistribución cómoda de la estructura molecular. Material y método: se adhirieron 30 cilindros de composite a superficies dentarias lisas; 15 se polimerizaron con lámparas de luz halógena y 15 con lámparas de polimerización plasmática rápida, se sumergieron en azul de metileno y se midió la filtración con estereomicroscopio. Resultados: en el análisis de la varianza se obtuvo un grado de libertad que corresponde a una suma de cuadrados de 112,15, F=0,1403 y P=0,7113. No se han encontrado diferencias en cuanto a la filtración en función de que la polimerización se haya realizado con lámparas de luz halógena o con las de polimerización plasmática rápida (AU)

Evaluación de la filtración marginal en obturaciones con amalgama y obturaciones con resina compuesta utilizando el mismo agente de unión / Evaluation of microleakage in amalgam and composite resin restorations using the same bonding agent

Diversos estudios han demostrado la efectividad de los agentes de unión en cuanto a su sellado marginal, adaptación del material y disminución de la microfiltración. Este estudio se basó en la utilización del Amalgambond como agente de unión en la obturación de cavidades clase II con amalgama y resina compuesta, como materiales restauradores, con el fin de reducir la filtración marginal. Se tomaron 20 dientes naturales, sanos y estraídos recientemente, en los cuales se realizaron cavidades clase II convencional; se obturaron 10 de éstos con amalgama y 10 con resina compuesta, previa aplicación de unión Amalgambond, según instrucciones de la casa fabricante. Microscópicamente, se evaluó la filtración marginal en la pared gingival y en la pared mesial, en tres grados diferentes: grado 0 (no hubo filtración), grado 1 (hasta 1 mm) y grado 2 (mayor de 1 mm). Se encontró filtración grado 1 en ambos materiales obturantes principalmente. Estadísticamente, no hubo diferencias significativas entre éstos, lo cual se determinó mediante la comparación de medias para grupos no relacionados con TStudent. El Amalgambond puede considerarse un agente de unión efectivo para controlar la filtración marginal en obturaciones con amalgama y resina compuesta, teniendo en cuenta factores como la condensación y la técnica de aplicación del agente unión.