Capacidad de sellado de los conductos laterales con distintas técnicas de obturación del conducto radicular / Sealing capacity of lateral canals with different root canal obturation techniques

Objetivo: Estimar y comparar la eficacia de diferentes técnicas de obturación para impedir el flujo de colorante a través de los conductos laterales. Materiales y métodos: Se emplearon 50 premolares inferiores extraídos y conservados en formol neutro al 5% hasta el momento de su uso, a los cuales se les realizaron conductos laterales artificiales. Una vez instrumentados los conductos principales, los dientes fueron divididos al azar en 5 grupos (n=10) para ser obturados con cuatro técnicas distintas: A) System B + inyección de gutapercha termoplástica del sistema Elements, Extruder; B) obturadores de Thermafil, ProTaper Universal; C) técnica híbrida y D) obturación con inyección de gutapercha termoplástica del sistema Elements, Extruder. Inmersos en tinta china y diafanizadas las raíces, se evaluó la longitud de penetración de la tinta en los conductos laterales. Se empleó el análisis de la varianza para detectar diferencias significativas (P<0,05) entre los niveles medios de penetración del colorante según las técnicas de obturación y las zonas del diente, y se efectuaron pruebas de rango múltiple (HSD de Tukey) para realizar comparaciones dos a dos, manteniendo fija la tasa de error por familia. Resultados: A la técnica B le correspondió el valor medio más bajo (30,63%) de penetración de tinta china. Los valores medios más elevados (54,52% y 51,74%) correspondieron a las técnicas A y C, respectivamente. Conclusión: Ninguna de las técnicas de obturación del conducto radicular empleadas ha sido capaz de impedir la filtración del colorante en los conductos laterales (AU)

Aim: To estimate and compare the different obturation techniques to avoid the flow of colorant through lateral canals. Materials and methods: 50 extracted lower premolars preserved in 5% neutral formol until the moment of use, had artificial lateral canals made. Once canals were instrumented, the teeth were randomly divided into 5 groups (n=10) to be filled with four different techniques: A) System B + injection of thermoplastic gutta-percha, Elements system, Extruder; B) Thermafil, ProTaper Universal obturators; C) hybrid technique, and D) injection of thermoplastic gutta-percha, Elements system, Extruder. Having immersed the premolars in India ink and diaphanized the roots, the penetration length of the India ink inside the canals was assessed. Analysis of variance was used to detect significant differences (P<0.05) between the mean levels of dye penetration according to the filling techniques and tooth areas, and multiple range tests (Tukey's HSD) were performed for two-to-two comparisons, keeping the error rate per family fixed. Results: Technique B had the lowest mean value (30.63%) of penetration. The highest mean values (54.52% and 51.74%) corresponded to techniques A and C, respectively. Conclusion: No obturation technique of the root canal used was able to avoid filtration of colourant in the lateral canals (AU)

Spectrophotometric analysis evaluating apical microleakage in retrograde filling using GIC, MTA and biodentine: an in-vitro study.

BACKGROUND: The present study compares the apical microleakage of three different root-end filling materials in which the retrograde cavity is prepared by two different burs. METHODS: Eighty extracted single rooted maxillary and mandibular premolars were taken. Root canal treatment was completed. Apical 3 mm of all the teeth were resected with diamond disk. The tooth were divided into four groups with two subgroups for each group containing 10 tooth (N = 10) as: Group IA (Negative Control and IB (Positive Control); Group IIA and IIB: Prepared with round carbide bur and round diamond bur respectively, filled with GIC; Group IIIA and IIIB: Prepared with round carbide bur and round diamond bur respectively, filled with MTA; Group IVA and IVB: Prepared with round carbide bur and round diamond bur, filled with Biodentine. After applying two coats of nail varnish leaving apical 3 mm (except for negative control group) all teeth were immersed in 2% methylene blue for 3 days and again in 65% nitric acid for next 3 days for extraction of dye. The obtained solution was then transferred to eppendorf tube and centrifuged in microcentrifuges at 14,000 revolution per minutes (RPM) for 5 min. Optical density or absorbance of the supernatant solution was measured with UV spectrophotometer at 550 nm. RESULTS: The absorbance of the supernatant solution after dye extraction is decreasing in the order of positive control> GIC > MTA > Biodentine> negative control group. The significant difference was observed between GIC and MTA (p = 0.0001) and GIC and Biodentine (p = 0.0001) with two different burs but statistically non-significant difference was observed between MTA and Biodentine with Carbide bur (p = 0.127) and Diamond bur (p = 0.496) respectively. CONCLUSIONS: Within the limitations of the present study, it can be concluded that Biodentine and MTA showed less microleakage as compared to GIC. There is no significant difference between mean microleakage of MTA and Biodentine. However, the mean OD of the Biodentine was least of all evaluated materials. Preparation of the root-end using round carbide bur as well as round diamond burs showed comparable microleakage for all three filling materials.

Microleakage of composite crowns luted on CAD/CAM-milled human molars: a new method for standardized in vitro tests.

OBJECTIVES: To investigate debonding of full crowns made of CAD/CAM composites, CAD/CAM technology was applied to manufacture standardized test abutments to increase the reproducibility of human teeth used in in vitro studies. MATERIALS AND METHODS: A virtual test abutment and the corresponding virtual crown were designed and two STL data sets were generated. Sixty-four human third molars and CAD/CAM blocks were milled using a CNC machine. Crowns of four different composite blocks (Lava Ultimate (LU), Brilliant Crios (BC), Cerasmart (CS), Experimental (EX)) were adhesively bonded with their corresponding luting system (LU: Scotchbond Universal/RelyX Ultimate; BC: One Coat 7 Universal/DuoCem; CS: G-PremioBond/G-Cem LinkForce; EX: Experimental-Bond/Experimental-Luting-Cement). Half of the specimens were chemical-cured (CC) and the others were light-cured (LC). Afterwards, specimens were artificially aged in a chewing simulator (WL-tec, 1 million cycles, 50-500 N, 2 Hz, 37 °C). Finally, a dye penetration test was used to detect debonding. For inspection, the specimens were sliced, and penetration depth was measured with a digital microscope. Data were analyzed with the Mann-Whitney U test. RESULTS: No cases of total debonding were observed after cyclic loading. However, the LC specimens showed a significantly lower amount of leakage than the CC ones (p < 0.05). Furthermore, the CC specimens exhibited broad scattering. Only the LC-EX blocks showed no debonding. The CC-CS blocks showed the highest leakage and scattering of all tested specimens. CONCLUSIONS: Natural human teeth can be manufactured by CAD/CAM technology in highly standardized test abutments for in vitro testing. For CAD/CAM composites, light curing should be performed. CLINICAL RELEVANCE: The success of a restoration depends on the long-term sealing ability of the luting materials, which avoids debonding along with microleakage. For CAD/CAM composites, separate light curing of the adhesive and luting composite is highly recommended.

Influência do tipo de preparo na adaptação interna e infiltração marginal em laminados cerâmicos / Influence of the design preparation on the internal adaptation and marginal infiltration in ceramic laminate veneers

Este estudo laboratorial teve como objetivo avaliar a infiltração marginal, adaptação interna e gap cervical de laminados cerâmicos, em função da realização ou não de preparo. Método: Vinte e quatro incisivos centrais superiores hígidos, com volumes e tamanhos padronizados, foram subdivididos em dois grupos, n=12, de acordo com o tipo de preparo. GRUPO CP - minimamente invasivo com linha de término na extensão do preparo; GRUPO SP ­ sem preparo, somente remoção de áreas retentivas. Todos os espécimes foram moldados com silicone de adição (Virtual Ivoclar - Vivadent), e sobre os modelos obtidos foram confeccionados laminados em cerâmica de Dissilicato de Lítio (Emax Press Ivoclar-Vivadent) com espessuras entre 0.3/0.7mm. Após ajustes, as peças foram cimentadas com cimento resinoso fotopolimerizável (Variolink Esthetic LC Ivoclar ­ Vivadent), seguindo as recomendações do fabricante. Em seguidas os espécimes foram envelhecidos em cicladoras térmica, 6.000 ciclos de 5 a 55ºC, e mecânica com 100N por 100.000 ciclos. Após o término das ciclagens todos foram imersos em substância corante por 24 horas e cortados paralelamente ao eixo do dente e horizontalmente para avaliação da infiltração marginal, adaptação interna e gap cervical em esteriomicroscópio. Os resultados apontaram que, na infiltração marginal, o grupo CP teve a maior média na região cervical (1,601 mm) comparado ao grupo SP (1,471 mm), porém não estatisticamente significante. Em ambos os grupos a infiltração marginal na região cervical foi maior que na proximal, diferindo estatisticamente. A adaptação interna foi melhor no grupo CP nos três terços analisados, porém somente no terço cervical houve diferença estatisticamente significante. O gap cervical teve menores valores no grupo SP, porém sem diferença estatisticamente significante. Conclui-se que o tipo de preparo não apresentou influência significativa em termos de infiltração marginal e adaptação, mostrando que ambas as situações podem ser clinicamente aceitáveis(AU)

This laboratory study aimed to evaluate the marginal infiltration, internal adaptation and cervical gap of ceramic laminate venners, by whether or not preparation. Method: Twenty-four upper central incisors with standard volumes and sizes were subdivided into two groups, n = 12, according to the type of preparation. CP GROUP - minimally invasive with finishing line in preparation extension; GRUPO SP - without preparation, only removal of retentive areas. All the specimens were molded with addition silicone (Virtual Ivoclar - Vivadent), on the obtained models laminates in ceramic of Lithium Dissilicate (Emax Press Ivoclar - Vivadent) were made with thicknesses between 0.3 / 0.7mm. After adjustments, the pieces were cemented with photopolymerizable resin cement (Variolink Esthetic LC Ivoclar - Vivadent), following the manufacturer's instructions. Then the specimens were aged in thermal cycling machine, 6,000 cycles of 5 to 55ºC, and mechanical with 100N per 100,000 cycles. After the cycling, all specimens were immersed in dye substance for 24 hours and cut parallel to the axis of the tooth and horizontally for evaluation of marginal infiltration, internal adaptation and cervical gap in stereomicroscope. The results showed that, in marginal infiltration, the CP group had the highest mean in the cervical region (1.601 mm) compared to the SP group (1.471 mm), but not statistically significant. In both groups the marginal infiltration in the cervical region was greater than in the proximal one, differing statistically. Internal adaptation was better in the CP group in the three thirds analyzed, but only in the cervical third there was a statistically significant difference. The cervical gap had lower values in the SP group, but without statistically significant difference. It was concluded that the type of preparation did not have significant influence in terms of marginal infiltration and adaptation, showing that both situations can be clinically acceptable(AU)

Influence of Iatrogenic Gaps, Cement Type, and Time on Microleakage of Cast Posts Using Spectrophotometer and Glucose Filtration Measurements.

PURPOSE: To determine the influence of iatrogenic gaps, type of cement, and time on microleakage of cast posts using spectrophotometer and glucose filtration measurements. MATERIALS AND METHODS: Forty-eight single-rooted teeth were divided into eight groups of six teeth each. Teeth were instrumented and obturated, and a cast post was fabricated. In addition to two control groups (positive and negative), a total of six groups were prepared: In four groups, an artificial 2- to 3-mm gap was created between post and residual gutta percha (GP), and two groups were prepared with intimate contact between post and residual GP. Posts were cemented with either zinc phosphate cement or resin cement. Leakage through the post after 1, 8, 14, and 20 days was measured using a glucose penetration model with two different reading methods. Mixed analysis of variance tests were performed to analyze the data. RESULTS: The presence of a gap between the apical end of the post and the most coronal portion of the GP remaining in the root canal after post space preparation increased microleakage significantly. However, microleakage was significantly less when the gap was refilled with GP compared to no gap. There was no difference in leakage between luting cements used. CONCLUSION: It was concluded that none of the cements were able to prevent microleakage. However, the addition of GP to residual GP did increase the sealing ability.

Microleakage of Different Adhesive Systems in Primary Molars Prepared by Er: YAG Laser or bur.

BACKGROUND AND AIM: This study aimed to examine the microleakage of class V cavities of primary molars prepared by either a conventional dental bur or Er:YAG laser and one of two different adhesive systems. METHODS: A total of 50 tooth samples from primary molars were used in this study. They were randomly assigned into five experimental groups of 10 samples each, according to the cavity preparation technique and the type of adhesive system applied to the cavities. Following cavity preparation, etching, bonding, and filling steps, samples were dyed using basic fuchsine and were sectioned longitudinally in buccolingual direction. Percentages of dye penetration at gingival and occlusal margins were calculated for each group. RESULTS: Overall, microleakage scores of gingival margins were significantly higher than those of occlusal margins (P < 0.001). The group that underwent laser preparation, laser etch, and self-etch bonding procedures had worse microleakage scores for gingival margins. However, all groups had similar occlusal scores (P > 0.05). CONCLUSION: Self-etch bonding systems and cavity preparation with Er:YAG laser may be an alternative to conventional restoration of primary molars with compomers. Further studies are warranted to fully elucidate the effect of laser-based etching techniques in cavities prepared by laser.

Comparison of Retrograde, Primary and Secondary Bonding Materials with Tooth Substance.

OBJECTIVE: To compare the microleakage of MTA (mineral trioxide aggregate) and resin-modified GIC (glass ionomer vitremer) as retrograde endodontic material. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Operative Department of DIIKIOHS (DUHS) and NED University, Karachi, from February to June 2014. METHODOLOGY: Forty human anterior teeth were divided into four groups. Each tooth was endodontically treated. Apical cavity preparations were performed on all teeth. The retropreparations were filled either with MTA (Group 1), Vitremer (Group 2), or only covered with nail polish (Group 3). The root surfaces of the first three groups were coated with nail polish. In Group 4 (positive control), neither retrograde filling was placed nor the nail polish was applied. The teeth were then suspended in 2% methylene blue dye solution for 10 days at 37°C. Sections were made along the long axis of teeth to determine the depth of linear dye penetration. Using Mann-Whitney test the comparison, p-value <0.05 was considered as statistically significant. RESULTS: MTA had no significant difference in apical dye leakage (p = 0.122) than did the vitremer. CONCLUSION: MTA is equivalent to vitremer in preventing microleakage when used as retrograde filling material.

Influence of a calcium hydroxide-based intracanal dressing on the quality of the root canal filling assessed by capillary flow porometry.

OBJECTIVE: The objective of this study is to evaluate the influence of a calcium hydroxide intracanal dressing (CH) on the short- and long-term sealing ability of the root canal filling using capillary flow porometry (CFP). MATERIALS AND METHODS: To verify the repeatability of the method, five obturated specimens were submitted to CFP. Measurements were repeated three times and compared with the non-parametric Friedman test. Forty-five instrumented palatal roots were randomly divided into three groups. Group 1: specimens were obturated in one step without placement of any dressing. Group 2: CH was placed and removed after 1 week with syringe irrigation before obturation. Group 3: CH was placed and removed after 1 week with ultrasonic activation before obturation. CFP measurements were conducted at 1 week and 6 months after obturation. The inter-group comparisons were performed using the Kruskal-Wallis test and the intra-group comparison over time using the Wilcoxon signed-rank test. Significance level was set at 0.05. RESULTS: In the five specimens, no difference could be detected between the consecutive measurements for minimum, mean flow, and maximum pore diameter indicating repeatability of the method. No difference in sealing ability could be detected neither between the 3 groups at 1 week and at 6 months nor within each group between the 1 week and the 6 months measurements. CONCLUSIONS: Placement of a CH did not affect significantly the short- and long-term sealing ability of the root canal filling. CLINICAL RELEVANCE: The use of an intermediary CH does not negatively influence the quality of the root canal filling.

Avaliação da microinfiltração marginal utilizando um sistema adesivo autocondicionante / Marginal microleakage assessment using a self-etching adhesive system

Este trabalho avaliou, in vitro, a capacidade seladora proporcionada pelo sistema adesivo autocondicionante Single Bond Universal (3M/ESPE) enfocando sua performance em relação à superfície de esmalte. Foram utilizados 20 pré-molares humanos extraídos por razões ortodônticas, reservando 5 dentes para projeto piloto, e os demais divididos em 2 grupos: Grupo ECOM: com condicionamento ácido do esmalte + Single Bond Universal e Grupo ESEM: aplicação exclusiva do sistema adesivo autocondicionante. Foram confeccionados preparos cavitários Classe II padronizados mesial e distal, seguido de limpeza da cavidade, protocolo adesivo seguindo as recomendações do fabricante e restauração em resina composta nanopartículada Z350XT (3M/ESPE) cor A3E pela técnica incremental e fotopolimerização por 20 segundos cada incremento. Em seguida, os espécimes foram impermeabilizados e imersos em solução aquosa de azul de metileno 1% por 24 horas e então lavados. Para coleta dos dados, os espécimes foram seccionados longitudinalmente totalizando 30 amostras, as quais foram analisadas em um contador de colônias manual (Phoenix CP 608) por 2 avaliadores, classificando os graus de infiltração em escores. Os dados foram submetidos à análise estatística pelo teste não paramétrico de Mann Whitney, mostrando que não houve diferença estatisticamente considerável entre os dois grupos (p= 0,89). O estudo concluiu que o condicionamento ácido do esmalte previamente à aplicação do sistema adesivo autocondicionante não reduziu a presença de microinfiltração marginal, não apresentando diferenças estatísticas significantes entre os grupos (AU).

This work evaluated in vitro the sealing capacity provided by the self-etching adhesive system Single Bond Universal (3M/ESPE) focusing on its performance in relation to the enamel surface. Twenty human premolars extracted for orthodontic reasons were used, five teeth were set aside for the pilot project, and the others were divided into two groups: ECOM Group: with acid enamel conditioning + Single Bond Universal and ESEM Group: exclusive application of self-etching adhesive system. Distal and mesial standardized Class II cavity preparations were made and subsequently cavity cleaning, adhesive protocol following manufacturer recommendations and restoration of nanoparticle composite resin Z350XT (3M/ESPE) color A3E by the incremental technique and photopolymerization for 20 seconds for each increment. After that the specimens were sealed and immersed in an aqueous solution of methylene blue 1% for 24 hours and then washed. In order to collect data, the specimens were longitudinally sectioned totaling 30 samples that were analyzed in a manual colony counter (Phoenix CP 608) by 2 reviewers, classifying the infiltration degrees in scores. Data was submitted to statistical analyses by the non-parametric Mann Whitney, showing that there was no considerable statistic difference between the two groups (p= 0.89). The study concluded that enamel acid etching prior to self-etching adhesive system application did not reduce the presence of marginal microleakage and did not present significant statistical differences between groups (AU).

Hibridación a esmalte y dentina de los ionómeros de vidrio de alta densidad, estudio con MEB / Enamel and dentin hybridization of high density glass ionomers: a SEM study

De acuerdo con la filosofía de la odontología de mínima intervención, los ionómeros de vidrio están resurgiendo en la odontología restauradora por sus ventajas actuales: dureza, estética y liberación activa defl úor. En la actualidad se ha comprobado mediante estudios y trabajo clínico que estos nuevos ionómeros de vidrio llamados ionómeros de alta densidad tienen un periodo de duración signifi cativo similar a las resinas, pero con más ventajas y con una muy simplifi cada técnica de colocación. El objetivo de este estudio es analizar la adhesión yadaptación marginal de cuatro ionómeros de vidrio de alta densidad, alesmalte y dentina. Material y métodos: Se seleccionaron 16 primeros premolares. A cada uno se le aplicó la preparación convencional de cavidad clase uno de Black de 2 mm de altura por 2 mm de ancho. Se acondicionó la cavidad (esmalte y dentina) con ácido poliacrílico al 10 por ciento por 10 segundos, posteriormente se lavó y secó generosamente y se colocaron los ionómeros de vidrio. Se dividieron en cuatro grupos: 1. Ionofi l Molar® (VOCO), 2. Ketac Molar® (3M ESPE), 3. EQUIA FiL® (GC) y 4. EQUIA Forte® (GC). En la parte final de la obturación,una vez seleccionadas y preparadas las muestras, se analizaron bajo el microscopio electrónico de barrido (MEB). Resultados: Las características encontradas en los cuatro grupos fueron: la integración del ionómero de vidrio a la dentina resultó mejor que al esmalte. Los rellenos inorgánicos de estos materiales se apreciaron mejor definidos en los últimos dos grupos. La adaptación al material de restauraciónse observó bien ajustada en el interior de la cavidad. La formación dehibridación en el esmalte y la dentina fue mejor en los grupos 2, 3 y 4. Conclusión: De los cuatro grupos estudiados el EQUIA FiL y el EQUIA Forte fueron los que presentaron excelente adaptación marginal e hibridación al esmalte y dentina.

According to minimal invasive dentistry philosophy glass ionomers,are making a comeback in restorative dentistry, due to their actualadvantages like: hardness, aesthetics and active fl uor liberation. Nowit has been demonstrated, thanks to studies and clinical trials, thatthe new glass ionomers called high-density glass ionomers have animportant clinical time span, similar to resins, with more advantages;and with a very simplifi ed placement technique. The aim of this studyis to analyze the adhesion and marginal adaptation of four high-densityglass ionomers to the enamel and dentin. Material and methods: 16fi rst premolars were selected. To each one was made the conventionalpreparation class, one cavity of Black of 2 mm of height by 2 mm ofwidth. The cavity (enamel and dentin) was conditioned with 10%polycyclic acid for 10 seconds, then washed and dried generously; andthe glass ionomers were placed. They were divided into four groups; 1.Ionofi l Molar® (VOCO), 2. Ketac Molar® (3M ESPE), 3. EQUIA FiL®(GC), 4. EQUIA Forte® (GC). At the end of the obturation. When thesamples were already selected and prepared, were analyzed by scanningelectron microscopy (SEM). Results: The characteristics found in thefour groups, were as follows: the integration of glass ionomer withthe dentin, was better than the enamel. The inorganic fi llings of thesematerials are better defi ned in the last two groups. The adaptation ofthe restorative material is well observed inside the cavity. The formationof hybridization in the enamel and the dentin, were better in groups2, 3 and 4. Conclusion: Of four studied groups: those that presentedexcellent marginal adaptation, hybridization to the enamel and dentin,were EQUIA FiL and EQUIA Forte, noting that those of group 4(EQUIA Forte) resulted in having the best marginal adaptation, thanany other glass ionomer included in this study.

Endodontic microleakage studies: correlation among different methods, clinical relevance, and potential laboratory errors.

INTRODUCTION: Creation of a tight seal in endodontically treated root canals is of utmost importance. Clinical and laboratory studies have a great role in the assessment of the sealing ability of endodontic materials. The present review was undertaken to evaluate correlation between different techniques used in microleakage studies in endodontics and the potential laboratory errors. EVIDENCE ACQUISITION: A systematic search was run using Medline, Biosis, Cochrane Database, Embase, Google Scholar, and Web of Science databases. Furthermore, the reference lists of the articles published on the subject were thoroughly searched. There was no language restriction in the search. Two reviewers separately evaluated the titles and abstracts. EVIDENCE SYNTHESIS: All the methods used might have proved useful if the study could have been carried out with a larger sample size, with carefully designed control groups. Furthermore, extra evaluations are recommended on the reliability of the method used. Examinations like glucose reactivity test, assessment of antimicrobial activity of the tested materials and in situ FISH examination for the reliability of bacterial leakage model have been recommended. It has been recommended that two or more methods be considered for each material in the same study. On the other hand, long-term animal studies can be useful with histological and radiographic evaluations for meticulous assessment of leakage. Furthermore, long-term clinical trials on humans might be helpful on the condition that confounding factors are controlled. CONCLUSIONS: Studies on microleakage should be focused on animal studies, clinical trials or laboratory tests. On the basis of available evidence, it appears that despite potential errors on microleakage studies they are very valuable.

Evaluación ex vivo del sellado obtenido a nivel del conducto lateral con el uso de diferentes materiales y técnicas de obturación / Ex vivo evaluation of the sealing obtainedat the lateral canal level using different fillingmaterials and techniques

Objetivo: Evaluar ex vivo el sellado obtenido a nivel deconductos laterales simulados en piezas dentarias con conductosradiculares amplios, obturadas con ProRoot MTA, DensellMTA y gutapercha más AHPlus con termocompactación.Materiales y métodos: Se seleccionaron 45 incisivoscentrales superiores humanos extraídos con ápices maduros.Se realizaron las aperturas coronarias y se instrumentaron losconductos radiculares hasta la longitud de trabajo con limastipo K (Dentsply/Maillefer) y luego con fresas Largo #1, #2y #3 (Dentsply/Maillefer). Durante la preparación, los conductosradiculares se irrigaron con agua destilada. Luego, en35 de los 45 dientes se talló un conducto lateral simulado enla cara mesial, a aproximadamente 3 mm del ápice anatómico,empleando un instrumento Engine Reamer #15 (Dentsply/Maillefer). Las raíces de los 35 dientes fueron recubiertaspor una lámina de gomaespuma y envueltas con una cintade teflón, a fin de simular el ligamento periodontal. En estascondiciones, se dividieron los 45 dientes en cuatro grupos de10 especímenes cada uno y un grupo control de 5 especímenes.Grupo control: conducto radicular no obturado. Grupo1: conducto radicular obturado con ProRoot MTA (Dentsply/Maillefer). Grupo 2: conducto radicular obturado con MTACemento Reparador (Densell). Grupo 3: conducto radicularobturado con AHPlus (Dentsply De Trey) y conos de gutaperchacon la técnica híbrida empleando un Guttacondensor#45 (Dentsply/Maillefer). Grupo 4: comprende los 10 especímenesen los que no se habían tallado los conductos lateralessimulados. Se obturaron los conductos radiculares conel mismo procedimiento que el grupo 3, y posteriormente setallaron los conductos laterales simulados...

Aim: Ex vivo evaluation of the sealing obtained at thelevel of simulated lateral canals in teeth with wide root canals,filled with ProRoot MTA, Densell MTA and AHPlus withthermo-compacted gutta-percha.Materials and methods: Forty-five extracted maxillaryhuman central incisors with mature apices were selected.The canals were instrumented at the working length with Kfiles (Dentsply/Maillefer) and then using Largo burs #1, #2,and #3 (Dentsply/Maillefer). During the preparation, the rootcanals were irrigated with distilled water. Later, in 35 of the45 teeth, a simulated lateral canal was drilled in the mesialsurface of each sample at approximately 3 mm coronally tothe anatomic apex using an Engine Reamer #15 (Dentsply/Maillefer). The surfaces of these 35 teeth were wrapped upwith a thin layer of foam and covered with teflon tape to simulatethe periodontal ligament. The 45 teeth were divided intofour groups of 10 specimens each, and a control group of 5specimens. Control group: unfilled root canal. Group 1: rootcanal filled with ProRoot MTA (Dentsply/Maillefer). Group2: root canal filled with MTA Cemento Reparador (Densell).Group 3: root canal filled with AHPlus (Dentsply) and thehybrid technique using gutta-percha and Guttacondensor#45 (Dentsply/Maillefer). Group 4: this group includes the10 specimens in which the simulated lateral canals were notdrilled. The root canals were filled with the same procedureas group 3 and then the simulated lateral canals were drilled...

Evaluación del grado de filtración s nivel de los conductos laterales y su relación con el material de obturación, luego de la instalación de anclajes intrarradiculares / Evaluation of the degree of leakage in lateral canals and its relationship with the filling material after luting intraradicular posts

Objetivo: Evaluar el grado de filtración en conductos laterales simulados y su relación con el material de obturación, luego de la instalación de anclajes intrarradiculares. Materiales y métodos: se usaron 30 premolares humanos cuyos conductos radiculares se instrumentaron con ProTaper Universal (Denstply Maillefer, Ballaigues, Suiza) hasta F3 y se dividieron aleatoriamente en tres grupos. Grupo 1: cionducto lateral obturado con el medio de cementado de resina SmartCem 2 (Dentsply Detrey, Konstanz, Alemania). Los conductos radiculares fueron obturados con un cono de gutapercha F3, conos accesorios y termocompactados con Guttacondensor #45 (Dentsply Maillefer, Ballaigues, Suiza). Como sellador se empleó AH26 (Dentsply Detrey, Konstanz, Alemania). A continuación se realizó la preparación para poste con fresas de Largo (Densply) #1, 2 y 3 y taladros preparadores del poste por emplear. Se talló un conducto lateral simulado por mesial de cada muestra, a 6 mm del borde coronario. Se cementaron, en cada conducto, postes orgánicos de fibra de vidrio cilíndricos Glass Post (Densell/GDK, Buenos Aires, Argentina) con cemento de resina SmartCem 2, introducido a la preparación intrarradicular con un lentulo (Detsply) a baja velocidad. La resina se fotopolimerizó a través del poste durante sesenta segundos con una lámpara halógena Ultralux EL (Dabi Atlante, Riberao Preto, San Pablo, Brasil). En estas condiciones, el conducto lateral simulado quedaba obturado con la resina cementante. Grupo 2: conducto lateral obturado con el material de obturación endodóntico. Se procedió de igual forma que en el Grupo 1, sólo que el tallado del conducto lateral simulado se realizó antes de la obturación endodóntica, de modo que éste estuviese obturado con alguno de los materiales de obturación empleados . Grupo 3: conducto lateral vacío. Se procedió como en el grupo 1, sólo que el tallado del conducto lateral simulado se realizó después del cementado de los postes de fibra de vidrio.

Microfiltración apical in vitro causada por las técnicas de obturación con cono único, System B y condensación lateral clásica / In vitro apical microleakage causade by single-cone, System B and cold lateral condensation obturation techniques

La obtención de un sellado hermético en la obturación del conducto radicular es una etapa coadyuvante del éxito endodóntico. Objetivo: Comparar la microfi ltración apical in vitro, calidad de relleno y presencia de espacios vacíos en conductos radiculares obturados con los métodos de obturación cono único, condensación lateral clásica y System B. Material y métodos: Noventa raíces mesiales de molares inferiores fueron instrumentados con ProTaper a un calibre F3 y asignados aleatoriamente para su obturación a tres grupos (n = 30 raíces), grupo 1: condensación lateral clásica con gutapercha #30.02, grupo 2: cono único con gutapercha F3 y grupo 3: System B con gutapercha #30.02; en todas las técnicas se usó una mezcla de óxido de zinc eugenol como sellador.Obturados los conductos las muestras se sumergieron en azul de metileno al 0.5 por ciento, se centrifugaron a 3,200 rpm durante cinco minutos, se diafanizarony se llevaron al microscopio estereoscópico a 12.5x para la mediciónde microfi ltración apical, calidad de relleno y presencia de espacios vacíospor un observador calibrado. Resultados: No se encontraron diferencias significativas en la microfi ltración apical entre el grupo de condensación lateral clásica y System B (p > 0.05) siendo el cono único la técnica que presenta mayor fi ltración. La técnica que ofrece la menor cantidad de espacios vacíos y mejor calidad de relleno es System B. Conclusiones:El método System B y condensación lateral clásica dejan una baja microfiltración apical y adecuada calidad de relleno comparada con la que sepresenta con cono único utilizando como sellador óxido de zinc eugenol...

Operatoria dental y endodoncia 3: capacidad de sellado marginal de un sistema adhesivo utilizado con o sin el complemento de clorhexidina / Operative dentistry and endodontics 3: marginal sealing properties of an adhesive system used with or without chlorhexidine addition

Objetivo: la biodegradación hidrolítica y enzimática de la interfaz resina/dentina constituye uno de los principales motivos del fracaso a distancia de las restauraciones con resinas compuestas. El objetivo de este ensayo ex vivo fue investigar si el uso de gluconato de clorhexidina al 2,0 por ciento, aplicado previamente al adhesivo, puede mejorar la capacidad de sellado de la interfaz resina/dentina en restauraciones de clase I, frente a la penetración bacteriana. Materiales y métodos: se obtuvieron probetas de dentina en forma de discos de 3 mm de altura a partir de 24 terceros molares humanos sanos, extraídos y utilizados dentro de un período de 30 días posextracción. En cada probeta se preparó una cavidad de clase I de 2 x 4 mm con una profundidad de 3 mm, uniendo de esta forma las superficies superior e inferior. Los especímenes se separaron en dos grupos de 10 probetas cada uno (n=10). En el grupo 1, las cavidades fueron tratadas con ácido fosfórico al 35 por ciento y restauradas mediante el sistema adhesivo Klepp Microhybrid Resin System (Klepp-Raysan Int, Estados Unidos. En el grupo 2, las cavidades se restauraron de manera similar a las del grupo 1, pero, previamente a la aplicación del adhesivo, las paredes dentinarias se trataron con gluconato de clorhexidina al 2,0 por ciento. Dos de las cuatro probetas restantes se utilizaron en el grupo 1 como controles positivos (n=1) y negativos (n=1) y las otras dos fueron empleadas de la misma forma que en el grupo 2. Todos los especímenes fueron termociclados a 5-55ºC (1000 ciclos de 20 segundos de duración cada uno) y tratados mediante un proceso de simulación de la agresión hídrica en el medio oral. Finalmente, se los sometió a un ensayo de filtración bacteriana (Enterococcus faecalis) durante 60 días. Los datos registrados se analizaron con la prueba de Log-Rank, el test de supervivencia de Kaplan Meyer y la prueba exacta de Fischer,c on un nivel de significación de p<0,05.

[The influence of the different polishing methods on the marginal sealing property of the computer aided design and computer aided manufacture zirconium dioxide full crown].

OBJECTIVE: To evaluate the influence of different polishing methods on marginal microleakage of zirconium dioxide full crown. METHODS: Thirty extracted premolars were selected and randomly divided into three groups, A, B and C, with 10 in each group. Group A was prepared with MANI TF-13 bur completely without the treatment of shoulder. The shoulder of group B was polished with MANI TR13-EF bur after the preparation using MANI TF-13. The shoulder of group C was polished with the dental pneumatic ultrasonic hand-piece of KaVo SONICflex after the preparation using MANI TF-13 bur. Five specimens after preparation were selected in each group. Fifteen CAD/CAM zirconium dioxide full crowns have been made. The crowns were bonded using PULPDENT resin cement, and the root canals were sealed using nail polish, and apical foramen were closed using flow resin. The test-pieces have been immersed in a 3% solution of methylene blue for 24 h. The condition of shoulder marginal microleakage was observed using light stereomicroscopy and evaluated in classification index. The remaining specimens in each group were used for roughness test and scanning electron microscope(SEM) experiment. The marginal microleakage situations of specimens in three groups was analyzed by SPSS 17.0. The enamel surface of different polishing methods was observed using SEM. RESULTS: The specimens in group C demonstrated the least marginal microleakage, and those in group B showed an intermediate level of marginal microleakage, and those in group A characterized the most serious marginal microleakage (total, χ2=44.610, P<0.01; among the different groups, P<0.05). The roughness experiment showed that specimens in group C achieve the smoothest results ([0.27±0.03] µm). Preparation shoulder polished using the dental pneumatic ultrasonic hand-piece demonstrated the best result under the SEM among the three groups. CONCLUSIONS: The anti-microleakage effectiveness of dental pneumatic ultrasonic hand-piece in shoulder refinement is better than ordinary shoulder treatment.

Avaliação in vitro de infiltração coronária de diferentes cimentos em cavidades complexos / In vitro evaluation of coronal leakage of different sealers in complex cavities

Objetivo: o objetivo do presente estudo foi avaliar in vitro a microin ltração coronária em cavidades complexas seladas com materiais restauradores temporários (MRT). Métodos: as cavidades foram preparadas em 60 pré-molares superiores extraídos de humanos, e os espécimes foram divididos em três grupos, de acordo com o MRT utilizado: G1 = IRM; G2 = Coltosol; G3 = Fill Magic Tempo. Três dentes serviram como controle negativo e não tiveram cavidades preparadas. Antes do selamento das cavidades com o MRT, uma esponja de colágeno foi deixada dentro da câmara pulpar, para avaliação binária da penetração do corante. Dez dentes de cada grupo não foram submetidos à ação de termociclagem e força mecânica oclusal, enquanto outros dez foram submetidos a essas ações. A amostra foi imersa em corante Rodamina B a 0,5% a 37°C, por 7 dias. Resultados: todos os dentes examinados (100%), exceto os controles negativos, apresentaram in ltração pelo corante. Todos os dentes selados com Coltosol (100%) fraturaram após ensaio mecânico, enquanto aqueles com IRM e Fill Magic Tempo mantiveram-se intactos macroscopicamente. A ação ou não das intempéries térmicas e mecânicas não interferiu na penetração do corante nas amostras no presente estudo. Conclusão: nenhum dos materiais testados impediu a in ltração do corante. No entanto, o Coltosol não deve ser indicado para utilização em cavidades complexas onde há incidência de forças mastigatórias, devido ao seu alto índice de fratura.

In vitro evaluation of microleakage of class V cavities restored with new flowable compomers on the primary teeth.

INTRODUCTION: The aim of the study was to evaluate the in vitro microleakage of new flowable compomers in the class V cavities of primary teeth. METHODS: Thirty freshly extracted, non-carious, primary molars without visible defects were used in this study. Class V cavities (n = 60), with the occlusal and cervical margins located in the enamel, were prepared on the buccal and lingual surfaces. The samples were randomly divided into 3 groups of 20 each. Group 1: restored with Twinky Star Flow (Voco, Cuxhaven, Germany), Group 2: restored with Dyract Flow (Dentsply, Konstanz, Germany) and Group 3: restored with R&D Series Nova Compomer Flow (Imicryl, Konya, Turkey) according to the manufacturer's instructions. After a thermocycling regimen of 1000 cycles between 5°C and 55°C, the samples were isolated, immersed in 0.5% basic fuchsine solution for 24 h at 37°C and sectioned longitudinally in a buccolingual direction. The sections were evaluated for values of microleakage with a stereomicroscope. RESULTS: All materials showed microleakage but no statistically significant difference was observed among the groups (p>0.05). The highest microleakage score was observed in group II (1.65 ± 0.49) and group I (1.75 ± 0.44) at occlusal and gingival margins, respectively. CONCLUSIONS: Flowable compomers showed insignificantly least amount of microleakage in class V cavities prepared on primary molars.

Evaluación de la microfiltración apical de BiodentineTM como material de obturación apical mediante el transporte de fluidos computarizado / Evaluation of the apical microleakage of BiodentineTM when used as an apical sealing material, using computerized fluid dynamics

Objetivo: evaluar la capacidad de BiodentineTM para resistir la microfiltración cuando es usado como material de retroobturación medianteun sistema de transporte de fluidos computarizado. Metodología: En este estudio se utilizaron 60 raíces de dientes unirradiculares, se instrumentaron y obturaron con el sistema de cono único estandarizadodel sistema ProTaper (Dentsply, Maillefer, Suiza) con ultrasonido,utilizando el sellador de conductos radiculares Silco (Silva-Collyan SLP,México). Se hizo la preparación de la cavidad retrógrada con ultrasonidoutilizando la punta E31D del sistema Retro Kit (NSK Company, Japón),con un diámetro de 2 mm. Se llevó a cabo la retroobturación con cada uno de los cementos a evaluar; grupo 1: bturados con Biodentine™ (Septodont, Francia), grupo 2: obturados con MTA Gris (Angelus™, Londrina PR, Brasil), grupo 3: control. Se utilizó un software creado específi camente para evaluar microfi ltración; éste, por medio de sensores infrarrojos, detecta la variación de voltaje de una burbuja de aire dentro de un capilar. El programa expresa el tiempo que tarda la burbuja en pasar por el segundo sensor (mm/min), los cuales se convierten a μL/min, para después expresarlos en unidades de fi ltración, realizándosemediciones en un solo lapso. Resultados: La evaluación en este estudio de la microfi ltración apical de Biodentine™ y MTA Gris Angelus™, arrojó resultados favorables para ambos; se comprobó que no existe diferencia signifi cativa en cuanto a la microfiltración entre ellos; sin embargo, ambos materiales mostraron diferentes características en cuanto a su manipulación, tiempo de fraguado y porosidad. No se presentódiferencia estadísticamente significativa entre los grupos (p = 0.256) U Mann-Whitney y Kruskal Wallis. Conclusión: El Biodentine™ y TA Gris AngelusTM presentan un comportamiento óptimo para la obturación retrógrada. Se requiere realizar otros estudios en cuanto a la interfase con la estructura dentinaria.

Objective: To evaluate, using computational fl uid dynamics, the ability of BiodentineTM to resist microleakage when used as a retro-sealing material. Methodology: In this study, 60 single-rooted teeth were used, which were biomechanically prepared and fi lled using the standardized ProTaper single-cone technique (Dentsply, Maillefer, Switzerland) and ultrasound, using Silco root-canal sealer (Silva-Collyan, SLP, Mexico). The retrograde cavity was prepared using ultrasound and a Retro Kit (NSK Company, Japan) E31D 2 mm-diameter tip. Retrograde fi lling was performed using each of the sealers to be evaluated, as follows: group 1: sealed with BiodentineTM (Septodont, France); group 2: sealed with Grey MTA (AngelusTM, Londrina PR, Brazil); group 3: control. A specially designed software was used, which measures microleakage by using infrared sensors to detect changes in voltage in an air bubble within a capillary tube. The software expresses the time it takes (mm/min) for the bubble to pass through the second sensor, then converts these measurements into μL/min to express the rate of leakage. All of the measurements are taken considering a single interval. Results: The results of the evaluation of the apical microleakage of BiodentineTM and MTA Grey AngelusTM obtained in this study were, in both cases, favorable, proving that there is no signifi cant difference between the two in this respect. However, the characteristics of each in terms of their handling, setting time, and porosity differed. No statistically signifi cant difference between the Mann-Whitney U group and the Kruskal-Wallis group was found (p = 0.256). Conclusion: The performance of Bio-dentineTM and Gray MTA AngelusTM is ideal for retrograde fi lling pur-poses. Further studies are needed, including SEM analysis, in order to determine the quality of the seal, with respect to the interface formed with the dentin structure.

Capacidad de sellado coronario de dos cementos endodónticos a base de óxido de cinc y eugenol: un estudio ex vivo / Coronal sealing ability of two zinc-oxide and eugenol-based endodontic sealers: an ex vivo study

Objetivo: comparar, mediante un modelo de filtración bacteriana, la capacidad de sellado coronario de obturaciones realizadas con conos de gutapercha complementados con Kleppmetthasona (KMS; Klepp/Raysan, Buenos Aires, Argentina); y Pulp Canal Sealer EWT (PCS; Sybron-Endo, Glendora, Estados Unidos). Materiales y métodos: se utilizaron 24 (n=24) premolares humanos sanos extraídos. En todos los casos, los conductos radiculares fueron preparados por medio de instrumentos rotatorios ProTaper Universal (Dentsply/Tulsa Dental, Tulsa, OK, Estados Unidos) hasta un instrumento #F3. Se distribuyeron 20 de los dientes en dos grupos experimentales (Grupo I y Grupo II) de 10 (n=10) especímenes cada uno. En cada grupo se agregaron un especimen de control positivo (n=1) y un especimen de control negativo (n=1). En el grupo 1, los conductos se obturaron con un cono de gutapercha ProTaper de conicidad correspondiente al instrumento #F3 y se complementó mediante la condensación lateral de conos accesorios. El sellador utilizado fue KMS, a base de óxido de cinc y eugenol que incluye un corticoide en su composición. En el Grupo 2 se realizó el mismo procedimiento, pero se utilizó PCS, un sellador a base de óxido de cinc y eugenol convencional. Para cada especimen, el proceso de filtración bacteriana se realizó por medio de un sistema individual de doble cámara, cada uno de las cuales contenía el medio de cultivo. En todos los casos, el medio de la cámara superior se inoculó con un cultivo de Enterococcus faecalis y el sistema se incubó durante 60 días. En la cámara inferior, la filtración bacteriana se controló diariamente hasta la finalización del experimento. Los datos registrados se analizaron con la prueba de supervivencia de Kaplan-Meyer yla prueba de Fischer, con un nivel de significación de P<0.05. Resultados: todos los controles positivos demostraron filtración bacteriana dentro de las primeras 48 horas. No hubo filtración en ninguno de los controles negativos.