New Methodology to Evaluate Bond Strength of Root-End Filling Materials

This study evaluated the bond strength of root-end filling materials to root-end cavities using a new methodology. Twenty maxillary central incisors were subjected to biomechanical preparation (#80 hand file) and sectioned transversally 2 mm short of the apex and 4 mm coronally to this point. The root cylinders were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. Two groups (n=10) were formed according to the root-end filling material: MTA and Super EBA. A gutta-percha cone (#80) was tug-backed at the limit between the canal and the root-end cavity. The cavity was filled and the gutta-percha cone was removed after complete setting of the sealer. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and run at a crosshead speed of 1.0 mm/min for pushing out the root-end filling material. Data were analyzed by ANOVA (α=5%). Super EBA (6.03±1.31) presented higher bond strength (MPa) than MTA (1.81±0.45) (p>0.05). There was a predominance of cohesive failures for Super EBA and mixed for MTA. The protocol of specimen preparation is effective and introduces a specific methodology for assessing bond strength of root-end filling materials to dentin. Among the materials, Super EBA presented the highest bond strength.

Este estudo avaliou a resistência de união de materiais retrobturadores a cavidades retrógradas, usando uma nova metodologia. Vinte incisivos centrais superiores foram submetidos ao preparo biomecânico (lima manual #80) e seccionadas transversalmente a 2 mm do ápice e a 4 mm do primeiro corte. Os cilindros de raízes foram incluídos em resina acrílica e posicionado a 45° em relação ao plano horizontal para confecção das retrocavidades com ponta ultrassônica diamantada. Dois grupos (n = 10) foram formados de acordo com os cimentos utilizados: MTA e Super EBA. Um cone de guta-percha (#80) foi travado no limite da retrocavidade com o canal radicular. A retrocavidade foi preenchida e, após o tempo de endurecimento do cimento utilizado, o cone de guta-percha foi removido. Os espécimes foram fixados na máquina universal de ensaios Instron com a retrobturação voltada para baixo. A haste empregada para pressionar o cimento retrobturador no teste de push-out foi inserida no espaço anteriormente ocupado pela guta-percha e acionada com velocidade de cruzeta de 1,0 mm/min, para extrusão do material retroburador. Os dados foram analisados por meio do teste ANOVA (α=5%). O cimento Super EBA (6,03 ± 1,31) apresentou maior resistência de união (MPa) comparado ao cimento MTA (1,81 ± 0,45) (p> 0,05). Houve predomínio de falhas coesivas para o cimento Super EBA e falhas mistas para o MTA. O protocolo de preparação das amostras é eficaz e apresenta uma metodologia específica para avaliação da resistência de união de materiais retrobturadores à dentina. Dentre os materiais testados, o cimento Super EBA apresentou a maior resistência de união.

Análise físico-química do MTA e do cimento Portland associado a quatro diferentes radiopacificadores / Physicochemical analysis of MTA and Portland cement associated with four different radiopacifiers

Introdução: O Mineral Trióxido Agregado (MTA) é composto por cimento Portland (CP) e um radiopacificador (óxido de bismuto). Objetivo: Avaliar tempo de presa, solubilidade, pH, liberação de íons Cálcio e radiopacidade do cimento Portland puro ou associado a quatro radiopacificadores (sulfato de bário, carbonato de bismuto, óxido de bismuto e iodofórmio), comparados ao MTA branco (Angelus, Londrina, Brasil). Material e Método: A proporção empregada CP/radiopacificador foi de 4:1 em peso, (80% de cimento Portland e 20% de radiopacificador). A especificação 57 da ADA foi usada para avaliação do tempo de presa. A solubilidade foi analisada segundo a especificação ISO 6876/2001. A avaliação do pH foi realizada com peagâmetro digital e a liberação de íons Ca++foi verificada por meio de espectrofotômetro de absorção atômica. A radiopacidade foi determinada em milímetros de alumínio (mm/Al). Os resultados foram submetidos aos testes de Análise de Variância e Tukey, nível de significância 5%. Resultado: O sulfato de bário não alterou o tempo de presa final do CP. Radiopacidade inferior ao mínimo recomendado pelas normas da ADA nº 57 e ISO 6876/2001 foi observada para CP e CP associado com sulfato de bário. O CP associado ao iodofórmio apresentou solubilidade acima dos 3% recomendados pela ISO 6876/2001. Todos os materiais proporcionaram alcalinização do meio e promoveram liberação de íons cálcio. Conclusão: Carbonato de bismuto ou óxido de bismuto proporcionaram tempo de presa inicial, solubilidade, pH, liberação de íons Cálcio e radiopacidade adequados quando associados ao CP. .

Introduction: Mineral Trioxide Aggregate (MTA) is composed of Portland cement (PC), and a radiopacifier (bismuth oxide). Objective: To evaluate the setting time, solubility, pH, calcium ion release and radiopacity of pure Portland cement and its association to four radiopacifiers, (Barium sulfate, bismuth carbonate, bismuth oxide and iodoform), and White MTA (Angelus, Londrina, Brazil). Material and Method: The ratio CP/radiopacifier used was 4:1 by weight (80% Portland cement and 20% radiopacifier). The setting time was evaluated according the specification ADA 57. The solubility was analyzed according to ISO 6876/2001 specification. The pH was evaluated using a digital pHmeter and the release of Ca++ ions by atomic absorption spectrophotometer. The radiopacity was measured in millimeters of aluminum (mm/Al). The results were submitted to ANOVA and Tukey tests using 5% of significance level. Result: Barium sulfate did not alter the final setting time of the PC. Observed radiopacity was less than the minimum recommended by ADA 57 and ISO 6876/2001 for CP and CP associated with barium sulfate. The PC associated with iodoform showed solubility above the 3% recommended by ISO 6876/2001. All materials provided alkalinization and promoted calcium ion release. Conclusion: Bismuth carbonate and bismuth oxide provided proper initial setting time, solubility, pH, calcium ion release and radiopacity when combined with CP. .

Avaliação da radiopacidade de diferentes materiais utilizados como retrobturadores / Evaluation of radiopacity of different used as root-end filling materials

Objetivo: O presente estudo tem como objetivo avaliar a radiopacidade de três materiais utilizados como retrobturadores. Métodos: Foram avaliados a radiopacidade de três cimentos: Sealer 26, Cimento Portland e Fillapex associado com 50% de cimento Portland.Para a determinação da radiopacidade, foram confeccionados corpos de provas cilíndricos de 10 mm de diâmetro e 1 mm de altura com os cimentos em teste e cilindros de dentina de mesma espessura, de acordo com a norma ISO 6876:2001. Após a sensibilização e processamento das películas, as imagens foram digitalizadas e analisadas quanto a densidade radiográfica no programa Digora 1.51. O valor da radiopacidade foi determinado em densidade radiográfica que foi, também, convertida em milímetros de alumínio (mm Al). Resultados: Os resultados demonstraram que o Sealer 26 possui maior radiopacidade, seguido pelo Fillapex associado com 50% de Cimento Portland e o cimento Portland. Conclusão: Conclui-se que todos os materiais apresentaram radiopacidade maior que a dentina e as normas da ISO, com exceção do cimento Portland.

Aim: The present study aims to evaluate the radiopacity of three used as root-end filling materials. Methods: To evaluated the radiopacity of three cement: Sealer 26, Fillapex associated with 50% of Portland cement and Portland cement. For the determination of radiopacity, cylindrical specimens with 10 mm in diameter and 1mm in thickness were made with the cements under test and dentin cylinders of equal thickness, according to ISO 6876:2001. After the raising and processing of films, the images were digitized andanalyzed for the radiographic density in Digora 1.51. The value of radiopacity was determined in radiographic density that was also converted into millimetres of aluminium (mm Al). Results: The results showed that the Sealer 26 has greater radiopacity, followed by Fillapex associated with 50% of Portland cement and Portland cement. Conclusion: It is concluded that all materials presented radiopacity is greater than the dentin and the ISO standards, with the exception of Portland cement.

Sealing ability, marginal adaptation and their correlation using three root-end filling materials as apical plugs

OBJECTIVE: This study used dye leakage assay and scanning electron microscopy to evaluate, respectively, the sealing ability and marginal adaptation of three root-end filling materials used as apical plugs, as well as the possible correlation between these properties. MATERIAL AND METHODS: Ninety-eight single-rooted human teeth were prepared to simulate an open apex. The teeth were allocated to three experimental groups (n = 30), which received a 5-mm thick apical plug of (1) gray MTA AngelusTM, (2) CPM TM and (3) MBPc, and two controls groups (n = 4). After immersion in 0.2 percent Rhodamine B solution for 48 h, the teeth were sectioned longitudinally and analyzed by Image Tool 3.0 software. The marginal adaptation between apical plugs and the root canal walls were analyzed by SEM. RESULTS: MBPc had significantly less (p<0.05) apical leakage than the other materials. Regarding marginal adaptation, CPM TM showed the best numerical results, though without statistical significance from the other materials (p<0.05). There was no correlation between the two properties. CONCLUSIONS: When used as apical plugs, the tested root-end filling materials had similar marginal adaptation to the dentin walls, but MBPc had the best sealing ability, as demonstrated by the least apical leakage from all tested materials.

A comparative study on radiopacity of canal filling and retrograde root-end filling materials / 대한치과보존학회지

This study was performed to assess the radiopacity of a variety of canal filling and retrograde root-end filling materials according to the specification concerning root canal obturation materials. Ten materials including Gutta-percha pellets, amalgam, Fuji II LC, Dyract(R) AP, Super EBA(R), IRM(R), AH 26(R), Sealapex(TM), Tubli-Seal(TM) and dentin were evaluated in this study. In the first part, densitometric reading of an each step of aluminum step wedge on occlusal film were performed at 60 kVp (0.2, 0.3, 0.4 s), 70 kVp (0.2, 0.3, 0.33 s) to decide appropriate voltage and exposure time. In the second part, ten specimens which are 5 mm in diameter and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mm in thickness, were fabricated from each material studied. The specimens were radiographed simultaneously with an aluminum step wedge under decided condition (60 kVp, 0.2 s). The mean radiographic density values of the materials were transformed into radiopacity expressed equivalent thickness of aluminum (mm Al). The following results were obtained. 1. Among the various conditions including 0.2 s, 0.3 s, 0.4 s at 60 kVp and 0.2 s, 0.3 s, 0.33 s at 70 kVp, the appropriate voltage and exposure time that meet the requirement of density from 0.5 to 2.0 was 0.2 s at 60 kVp. 2. All of the materials in this study had greater radiopacity than the minimun level recommended by ISO No. 4049 standards. 3. Most of the materials had greater radiopacity than 3 mm Al requirement of ANSI/ADA specification No. 57 (2000) and ISO No. 6876 (2001) standards except for Fuji II LC and Dyract. It suggests that all experimental canal filling and retrograde root-end filling materials have a sufficient radiopacity that meet the requirement concerning root canal obturation materials except for Fuji II LC and Dyract.

Spectrophotometric evaluation of sealing effects of several root-end filling materials / 대한치과보존학회지

The purpose of this study is to evaluate the sealing effect of several root-end filling materials using spectrophotometric analysis. 180 single root teeth with one canal were instrumented and canal filled. Root resected and root end preparation was made. Teeth were randomly classified to 5 experimental group(MTA, EBA, IRM, TCP, ZOE) and 1 control group according to root-end filling material MTA group used PRO ROOT MTA, EBA group used Super EBA, TCP group used NEW APATITE LINER TYPE II main component of which is alpha-tricalcium phosphate(TCP). According to manufacture's instruction experimental material was mixed and retrfilled. After 2% methylene blue solution penetration absorbance for each test sample was measured with spectrophotometer (JASCO UV-530, Japan). The mean absorbance of control and experimental group was as follows; MTA : 0.092, IRM : 0.226, Super EBA : 0.255, ZOE : 0.374, Control : 0.425, TCP : 0.501 and the result analyzed by Turkey test at P=0.05 level. Conclusions of this study are as follows; 1. The absorbance increase in follwing sequence MTA, IRM, Super EBA, ZOE, Control, TCP. 2. MTA showed the least leakage but was not significant with IRM or Super EBA and was significant with control or TCP(p<0.05). 3. TCP had the most leakage and was not significant with control group.

Materiais retrobturadores: avaliação do selamento apical e da adaptação marginal / Retrofilled materials: the marginal adaptation and the sealing ability

O objetivo deste estudo foi avaliar, in vitro, a adaptação marginal e a capacidade seladora do Amálgama, Cimento de Portland Composto, MTA, Super-EBA, IRM e Sealer 26, quando utilizados como materiais retrobturadores. Noventa e quatro caninos superiores foram utilizados nos dois experimentos. Todos os dentes sofreram tratamento endodôntico convencional, foram obturados com a técnica de condensação lateral, apicetomizados, retropreparados com pontas de ultra-som e retrobturados com os materiais propostos. Para avaliação da adaptação marginal, 30 caninos foram divididos aleatoriamente em seis grupos de cinco dentes cada, as amostras foram desidratadas, cobertas com ouro-paládio e examinadas em microscópio eletrônico de varredura. As imagens digitalizadas foram analisadas pelo programa Visio 5.0 Professional ou pela atribuição de escores. Sessenta e quatro caninos superiores restantes foram distribuídos em seis grupos de 10 dentes cada e dois grupos de 2 dentes, compondo os grupos controle negativo e positivo, utilizados para avaliação da capacidade seladora. As cavidades de acesso coronário foram preenchidas com cimento provisório Coltosol. Os espécimes foram impermeabilizados e então imersos em solução de tinta Nanquim em soro fetal bovino por 48h. Após esse período, os dentes foram então seccionados longitudinalmente no sentido vestíbulo-lingual, as suas retrobturações removidas e levados a um perfilômetro, onde se processaram as mensurações do corante infiltrado. A análise estatística revelou que houve diferença estatisticamente significante entre o cimento de Portland e o Sealer 26 ou o MTA, quando avaliada a adaptação marginal. O amálgama e o IRM apresentaram maior grau de infiltração quando comparados aos outros grupos, com diferença estatisticamente significante. Não foram observadas diferenças significantes entre os demais grupos.

The aim of the study was to evaluate, in vitro, the marginal adaptation and the sealing ability of six root-end filling materials: amalgam, Portland cement, MTA, Super-EBA, IRM and Sealer 26. Ninety-four upper cuspids were selected for the two experiments. Every root canal were prepared and obturated using lateral condensation technique, and the roots were than apicoectomized, retroprepared using ultrasonic retrotips, and retrofilled with the test materials. To evaluate the marginal adaptation, 30 upper cuspids were randomly distributed into 6 groups, each containing 5 teeth. Afterwards, the samples were dehydrated, covered with gold-palladium, and observed under scanning electron microscopy. Digitized images were analyzed using Visio 5.0 Professional software or through the attribution of scores. For the evaluation of the sealing ability, the other 64 upper cuspids were distributed into 6 experimental groups of 10 each and 2 control groups ­ positive and negative. The coronal access cavities were filled with temporary cement. The roots were covered with nail varnish and then immersed in solution of black Indian ink in fetal bovine serum by 48 hours. Afterwards, the teeth were longitudinally split, the root-end fillings were removed and examined using a profilemeter with regard to the length of dye penetration. The statistical analysis revealed statistically significant differences between Portland cement and Sealer 26 or MTA, regarding the evaluation of the marginal adaptation. Amalgam and IRM showed significantly higher leakage when compared to the other groups. No other significant differences were observed for the other test materials.