Bond strength of different endodontic sealers to dentin: push-out test

Objective: The aim of this in vitro study was to evaluate the bond strength of different root canal sealers to dentin. Material and Methods: Forty extracted single-rooted human teeth were examined and the coronal and middle thirds of the canals were prepared with a 1.50 mm post drill (FibreKor Post System, Pentron). The teeth were allocated in two experimental groups, irrigated with 2.5% NaOCl+17% EDTA or saline solution (control group) and instrumented using Race rotary files (FKG) to a size #40 at the working length. Then, the groups were divided into four subgroups and filled with Epiphany sealer (Group 1), EndoREZ (Group 2), AH26 (Group 3) and Grossman's Sealer (Group 4). After 2 weeks of storage in 100% humidity at 37 degrees C, all teeth were sectioned transversally into 2-mm-thick discs. Push-out tests were performed at a cross-head speed of 1 mm/min using a universal testing machine. The maximum load at failure was recorded and expressed in MPa. Results: Means (+/- SD) in root canals irrigated with 2.5% NaOCl and 17% EDTA were: G1 (21.6 +/- 6.0), G2 (15.2 +/- 3.7), G3 (14.6 +/- 4.5) and G4 (11.7 +/- 4.1). Two-way ANOVA and Tukey's test showed the highest bond strength for the Epiphany's group (p < 0.01) when compared to the other tested sealers. Saline solution decreased the values of bond-strength (p < 0.05) for all sealers. Conclusion: Epiphany sealer presented higher bond strength values to dentin in both irrigating protocols, and the use of 2.5% NaOCl and 17% EDTA increased the bond strength values for all sealers.

SEM analysis and push-out bond strength of fiberglass posts luted with different cements of glass-ionomer in humid environment: pilot test

The objective of this study was to evaluate the push-out bond strength of fiberglass resin reinforced bonded with five ionomer cements. Also, the interface between cement and dentin was inspected by means of SEM. Fifty human canines were chose after rigorous scrutiny process, endodontically treated and divided randomly into five groups (n = 3) according to cement tested: Group I – Ionoseal (VOCO), Group II – Fugi I (GC), Group III – Fugi II Improved (GC), Group IV – Rely X Luting 2 (3M ESPE), Group V – Ketac Cem (3M ESPE). The post-space was prepared to receive a fiberglass post, which was tried before cementation process. No dentin or post surface pretreatment was carried out. After post bonding, all roots were cross-sectioned to acquire 3 thin-slices (1 mm) from three specific regions of tooth (cervical, medium and apical). A Universal test machine was used to carry out the push-out test with cross-head speed set to 0.5mm/mim. All failed specimens were observed under optical microscope to identify the failure mode. Representative specimens from each group was inspected under SEM. The data were analyzed by Kolmogorov-Smirnov and Levene’s tests and by two-way ANOVA, and Tukey’s port hoc test at a significance level of 5%. It was compared the images obtained for determination of types of failures more occurred in different levels. SEM inspection displayed that all cements filled the space between post and dentin, however, some imperfections such bubles and voids were noticed in all groups in some degree of extension. The push-out bond strength showed that cement Ketac Cem presented significant higher results when compared to the Ionoseal (P = 0.02). There were no statistical significant differences among other cements.

Influência de diferentes métodos de condicionamento superficial em pinos pré-fabricados resinosos fibro-reforçados em vidro e quartzo na resistência adesiva a compósito de polimerização dual: teste de push-out

O objetivo deste estudo foi realizar uma avaliação tridimensional da rugosidade superficial em 3 tipos de pinos de fibra - DT LightPost, FRC Postec Plus e Transluma Post - submetidos a diferentes tratamentos de superfície e avaliar os efeitos dos pré-tratamentos na resistência adesiva a um compósito de presa dual Biscore. Os tratamentos de superfície foram: imersão em ácido hidrofluorídrico, jateamento com óxido de alumínio a 50m, imersão em peróxido de hidrogênio, jateamento com óxido de alumínio a 50m seguido de imersão em ácido hidrofluorídrico e jateamento com óxido de alumínio a 50m seguido de imersão em peróxido de hidrogênio. No experimento 1, 75 pinos foram divididos em 3 grupos (n = 25), de acordo com seu fabricante e subdivididos em cinco subgrupos. A rugosidade superficial foi medida usando um rugosímetro tridimensional e analisada com o software de análise 3D. Os valores de rugosidade foram obtidos antes e após diferentes tratamentos de superfície na área dos mesmos corpos-de-prova. Para o experimento 2, foram utilizados os mesmos corpos-de-prova, os mesmos grupos e subgrupos do experimento 1, tendo sido adicionado o subgrupo de controle (n=90) e a resistência adesiva a um compósito presa dual Biscore foi mensurada através de um teste push-out. A resistência adesiva foi medida em uma máquina universal de ensaios, com uma célula de carga tipo SLBL-5kN em uma velocidade de 0,5 mm / min. Os resultados do experimento 1 foram analisados através de um teste estatístico t-Student. Jateamento e jateamento seguido de imersão em ácido hidrofluorídrico produziram um aumento estatisticamente significante na rugosidade, contudo somente o tratamento por jateamento proporcionou um aumento significativo nos valores de rugosidade. Os resultados do experimento 2 foram obtidos através de um um teste t-unilateral de hipótese com variância desconhecida. Concluiu-se que o jateamento com óxido de alumínio a 50μm em uma distância de 30 mm a 2,5 bar de pressão por 5 segundos foi suficiente para modificar a topografia dos pinos de fibra de vidro e quartzo e que o jateamento com partículas de 50 μ alumina a distância de 30 mm a 2,5 bar de pressão por 5 segundos foi o único tratamento de superfície que aumentou a resistência adesiva do compósito Biscore aos pinos DT Light Post e Transluma Post. Os pinos FRC Postec Plus não demostraram um aumento estatisticamente significante na resistência adesiva em nenhum grupo.

Effect of mechanical cycling on the push-out bond strength of fiber posts adhesively bonded to human root dentin

This study evaluated the effect of mechanical cycling on the bond strength of fiber posts bonded to root dentin. The hypotheses examined were that bond strength is not changed after fatigue testing and bond strength does not present vast variations according to the type of fiber post. Sixty crownless, single-rooted human teeth were endodontically treated, with the space prepared at 12 mm. Thirty specimens received a quartz fiber post (Q-FRC (DT Light-Post), and the remaining 30 specimens received a glass fiber post (G-FRC) (FRC Postec Plus). All the posts were resin luted (All Bond+Duolink), and each specimen was embedded in a cylinder with epoxy resin. The specimens were divided into six groups: G1-Q-FRC+no cycling, G2- Q-FRC+20,000 cycles (load: 50N, angle of 45 degrees; frequency: 8Hz); G3- Q-FRC+2,000,000 cycles; G4- G-FRC+no cycling; G5- G-FRC+20,000 cycles; G6- GFRC+2,000,000 cycles. The specimens were cut perpendicular to their long axis, forming 2-mm thick disc-samples, which were submitted to the push-out test. ANOVA (alpha=.05) revealed that: (a) QFRC (7.1 +/- 2.2MPa) and G-FRC (6.9 +/- 2.1MPa) were statistically similar (p=0.665); (b) the no cycling groups (7.0 +/- 2.4MPa), 20,000 cycles groups (7.0 +/- 2.1MPa) and 2,000,000 cycles groups (7.0 +/- 2.0MPa) were statistically similar (p=0.996). It concluded that mechanical cycling did not affect the bond strength of two fiber posts bonded to dentin.

Comparison of resin push-out strength to root dentin of bovine- and human-teeth

Aim : To compare the push-out strength of bovine- and human-root dentin and, thus, evaluate the suitability of bovine-root dentin to substitute human-root dentin for bond strength testing. Materials and Methods : Ten single-rooted human-teeth and ten bovine incisors were prepared using a #3 bur of a fiber post system (12 mm long). The posts were duplicated with resin cement (Duolink). The root canals were treated with All Bond 2 adhesive system and the resin posts were cemented using Duolink. The specimens were cut perpendicular to their long axis, yielding disc-specimens with 1.5 mm thickness, which were submitted to a push-out test (1 mm/min). Ten bond strength values per group (n = 10) were used for statistical analysis (Student t test, a =.05). Results : Statistically significant differences were found for the bond strength values between bovine- (4.1 1.3 MPa) and human-root dentin (8.6 5.7 MPa) (P =.0001). Conclusion : The push-out strengths of bovine- and human-root dentin were statistically different.

Influência de soluções irrigadoras na resistência adesiva de pinos de fibra de vidro utilizando cimento resinoso: avaliação através do teste de push-out

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of the Interaction Between Sodium Hypochlorite and Several Formulations Containing Chlorhexidine and its Effect on the Radicular Dentin-SEM and Push-Out Bond Strength Analysis

The aim of the current study was to evaluate the presence of debris and smear layer after endodontic irrigation with different formulations of 2% chlorhexidine gluconate (CHX) and its effects on the push-out bond strength of an epoxy-based sealer on the radicular dentin. One hundred extracted human canines were prepared to F5 instrument and irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Fifty teeth were divided into five groups (n=10), according to the final irrigation protocol with different 2% CHX formulations: G1 (control, no final rinse irrigation), G2 (CHX solution), G3 (CHX gel), G4 (Concepsis), and G5 (CHX Plus). In sequence, the specimens were submitted to scanning electron microscopy (SEM) analysis, in the cervical-medium and medium-apical segments, to evaluate the presence of debris and smear layer. The other 50 teeth were treated equally to a SEM study, but with the root canals filled with an epoxy-based endodontic sealer and submitted to a push-out bond strength test, in the cervical, middle, and apical thirds. G2, G3, G4, and G5 provided higher precipitation of the debris and smear layer than G1 (P<0.05), but these groups were similar to each other (P>0.05), in both segments. The values obtained in the push out test did not differ between groups, independent of the radicular third (P>0.05). The CHXs formulations caused precipitation of the debris and smear layer on the radicular dentin, but these residues did not interfere in the push-out bond strength of the epoxy-based sealer. Microsc. Res. Tech. 77:17-22, 2014. (c) 2013 Wiley Periodicals, Inc.

Influência do uso de hipoclorito de sódio 2,5% e extrato glicólico de sálvia 20% durante o preparo biomecânico sobre a resistência adesiva de retentores intra- radiculares: avaliação através do teste de push-out

The aim of this study it was to evaluate the use of irrigating solution used during root canal preparation on the adhesive cementation of prefabricated fiberglass pins. The bond strength between different regions of the root and the fiberglass pins cemented into the root canal were evaluated by push-out assay. For this study, 36 human teeth were used, all equally prepared. The irrigating solutions used for biomechanical preparation were: saline solution, sodium hypochlorite 2,5% and glycolic extract of salvia 20%. The dual cure resin cement was used for cementation of pins. After cementation, specimens were sectioned to give 3 slices of approximately 2 mm each (cervical, middle and apical), which were submitted to mechanical push-out test. Were performed ANOVA and Tukey's test with a significance level of 5%, for the analysis of mechanical test. Comparing the thirds we observed that the only solution that presented statistical difference in the bond strength was sodium hypochlorite, which showed higher values for the middle and apical third compared with the cervical third, but when compared without taking into consideration the dental thirds, solutions studied showed no differences in bond strength. Therefore, it was concluded that the solutions studied can be used during endodontic treatment without causing harmful effects on the final adhesive restoration

Evaluation of the physicochemical properties and push-out bond strength of mta-based root canal cement

Aim: This study investigated the flowability, setting time, pH, calcium release and bond strength of a MTA-based cement (MTA Fillapex®) compared to AH Plus and Sealapex. Materials and methods: For the flowability test, the ISO 6876:2001 specification was utilized and for the setting time test, the ASTM C266-03 specification was utilized. For the pH and calcium release measurements, 10 samples were prepared for each group and analyzed for several different periods. For the push-out test, dentin disks were distributed into three groups, according to the cement utilized and into three subgroups, according to the root third (n = 10). After obturation, the specimens underwent push-out testing. The data were compared statistically using a significance level of 5%. Results: The flowability of all materials was found to be similar (p > 0.05). The setting times were different among the groups tested (MTA Fillapex < Sealapex < AH Plus) (p < 0.05). At days 7 and 28, the MTA Fillapex presented the higher pH values (p < 0.05). At 24 hours and at 14 days, the calcium release of the MTA Fillapex was similar to that of Sealapex (p > 0.05). AH Plus presented the lowest pH and calcium release values (p < 0.05). In all root thirds, the adhesion to the dentin of the MTA Fillapex and Sealapex were significantly lower than that of AH Plus (p < 0.05). Conclusion: MTA Fillapex and Sealapex presented several similar properties and both were found to be different than AH Plus. Clinical significance: This study evaluated the physicochemical and mechanical properties of new MTA-based root canal cement, in order to use this scaler in root canal fillings. MTA Fillapex showed satisfactory properties for clinical use.

Push-out bond strength of calcium hydroxide and mineral trioxide aggregate based sealers

The adhesiveness of six root canal sealers: Acroseal, Endo CPM, Epiphany, White MTA, Sealapex and Sealer 26 to dentin, was evaluated in a push-out test design. Methods: Twenty eight roots of freshly extracted teeth were gauged with a size 5 Largo drill. With a cutting machine slices of 2 mm were prepared, rinsed with 5.25% NaOCl and a final rinse with 17% EDTA, dried and filled with one of the sealers. After setting their bond strength was measured in a mechanical testing machine. The data were statistically analyzed by using a One Way ANOVA and post hoc Tukey test. Results: The mean and standard deviation from values of bond strength was: Sealapex 2.2±0.4; Endo CPM 3.8±1.3; White MTA 6.0±1.4; Epiphany 10.9±2.6; Sealer 26 12.3±2.3; and Acroseal 12.2±1.4. Acroseal, Sealer 26 and Epiphany presented a significantly (P<0.01) greater bond strength compared with the other sealers. Also White MTA showed higher adhesiveness compared with Endo CPM and Sealapex (P<0.01). Conclusion: The bond strength between endodontic sealers and root dentin was maximal when Acroseal, Sealer 26 and Epiphany were used; Sealapex e Endo CPM, in turn, presented the lowest bond strength mean values.

Effect of calcium hydroxide dressing on push-out bond strength of endodontic sealers to root canal dentin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Push-out strength of root fillings with or without thermomechanical compaction

Carneiro SMBS, Sousa-Neto MD, Rached-Junior FA, Miranda CES, Silva SRC, Silva-Sousa YTC. Push-out strength of root fillings with or without thermomechanical compaction. International Endodontic Journal, 45, 821828, 2012. Abstract Aim To evaluate the influence of thermomechanical compaction (Taggers hybrid technique THT) on the push-out strength of several root filling materials to root dentine. Methodology Root canals of eighty roots in human canines were prepared with the ProTaper system and filled with one of the following materials, using either lateral compaction (LC) (n = 40) or THT (n = 40): AH Plus/gutta-percha (GP) (n = 10), Sealer 26/GP (n = 10), Epiphany SE/Resilon (n = 10) and Epiphany SE/GP (n = 10). Three 2-mm-thick dentine slices were obtained from each third of each root. The root filling in the first slice was subjected to a push-out test to evaluate the bond strength of the materials to intraradicular dentine. Data (in MPa) were analysed using anova and post hoc Tukeys test (P < 0.05). Failure mode was determined at x25 magnification. The other two slices were prepared for scanning electron microscopy (SEM) to examine the surface of the filling materials. Results Lateral compaction (1.34 +/- 1.14 MPa) was associated with a significantly higher bond strength (P < 0.05) than the THT (0.97 +/- 0.88 MPa). AH Plus/GP (2.23 +/- 0.83 MPa) and Sealer 26/GP (1.86 +/- 0.50 MPa) had significantly higher bond strengths than the other materials and differed significantly from each other (P < 0.05). There was a significant difference (P < 0.05) between the coronal (1.36 +/- 1.15 MPa), middle (1.14 +/- 1.05 MPa) and apical thirds (0.95 +/- 0.83 MPa). Considering the technique and root filling material interaction, AH Plus/GP-LC was associated with the highest mean values (2.65 +/- 0.66 MPa) (P < 0.05). Sealer 26/GP-LC (2.10 +/- 0.46 MPa), AH Plus/GP-THT (1.81 +/- 0.78 MPa) and Sealer 26/GP-TH (1.63 +/- 0.44 MPa) had intermediate values that were not significantly different from each other (P > 0.05). Epiphany SE was associated with the lowest mean values (3.70 +/- 0.86 MPa) (P < 0.05), regardless of the root filling technique and type of solid material (cone). Adhesive failures predominated in the specimens filled with Epiphany SE, whilst mixed and cohesive failures were more frequent in those filled with AH Plus and Sealer 26, regardless of the root filling technique. SEM analysis revealed that LC produced a dense and well-compacted filling whilst the use of a hybrid thermomechanical technique resulted in the solid material (GP or Resilon) intermingled within sealer to form a nonhomogenous mass. Conclusion Lateral compaction was associated with higher bond strengths of the materials to intraradicular dentine than a hybrid technique using thermomechanical compaction. The greatest push-out strengths were obtained when the canals were filled with LC of AH Plus and GP cones.

Push-out bond strengths of different dental cements used to cement glass fiber posts

Statement of problem: Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. Purpose: The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. Material and methods: Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dualpolymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (?=.05). Results: ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (P<.05). The highest push-out strength results with root location were obtained with Luting and Lining (S3) (19.5 ±4.9 MPa), Ketac Cem (S2) (18.6 ±5.5 MPa), and Luting and Lining (S1) (18.0 ±7.6 MPa). The lowest mean values were recorded with Variolink II (S1) (4.6 ±4.0 MPa), Variolink II (S2) (1.6 ±1.5 MPa), and Rely X ARC (S3) (0.9 ±1.1 MPa). Conclusions: Self-adhesive cements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement.

Influência do sistema de cimentação e do modo de ativação na resistência ao push-out de pinos de fibra de vidro

O objetivo deste estudo foi avaliar a influência do tipo de sistema de cimentação (condicionamento ácido total ou autoadesivo), do modo de ativação (autoativado ou dual), do terço do conduto radicular (cervical, médio ou apical) e da espessura do filme de cimento sobre a resistência de união de pinos de fibra de vidro cimentados em dentes humanos. Quarenta raízes foram incluídas em resina epóxi, submetidas a tratamento endodôntico e obturadas com guta percha e cimento endodôntico sem eugenol. Decorridos sete dias, os condutos foram preparados a uma profundidade de 10mm com brocas padronizadas do sistema dos pinos de fibra (WhitePost DC #2) e aleatoriamente divididos em 4 grupos, conforme o sistema de cimentação e o modo de ativação: (G1) RelyX ARC/Adper Scotchbond Multi-Purpose Plus (condicionamento ácido total), ativação dual, (G2) RelyX ARC/Adper Scotchbond Multi-Purpose Plus, autoativado, (G3) RelyX U100 (autoadesivo), dual e (G4) RelyX U100, autoativado. Após uma semana, cada raiz foi seccionada em máquina de corte, originando 6 fatias de 1 mm de espessura (n=60). Antes do ensaio de push-out cada fatia foi fotografada em ambas as faces, para determinação do raio dos pinos e da espessura do filme de cimento. Após o ensaio mecânico, novas imagens foram capturadas para determinação do modo de falha. Para automatizar a determinação da espessura de cimento, foi desenvolvida uma macro no software KS 400. Os dados foram estatisticamente analisados com ANOVA 3 fatores (resistência de união) e teste de Kruskall-Wallis (espessura do cimento). Comparações múltiplas foram realizadas com o teste Student-Newman-Keuls. Análise de regressão, modelo linear, foi empregada para verificar a correlação entre espessura do cimento e resistência de união. Todos os testes foram aplicados com α = 0,05. O fator cimento exerceu influência significativa para a resistência de união (p = 0,0402): o RelyX U100 apresentou a maior média. A ativação dual elevou os valores de resistência de união em comparação ao modo quimicamente ativado (p < 0,0001). Houve diferenças significantes entre os grupos, sendo G1 (22,4 4,0 MPa) > G3 (20,4 3,6 MPa) > G4 (17,8 5,2 MPa) > G2 (13,5 4,3 MPa). O terço do conduto não exerceu influência significativa sobre a resistência adesiva (p = 0,4749). As espessuras dos filmes de cimento foram estatisticamente diferentes nos diferentes terços: cervical (102 45 m) > médio (75 29 m) > apical (52 28m). Não foi observada forte correlação entre os valores de espessura e os de resistência ao push-out (r = - 0,2016, p = 0,0033). O tipo de falha predominante foi a mista, exceto para o G2, que apresentou 74% das falhas na interface cimento-pino. Dessa forma, o cimento autoadesivo apresentou melhor desempenho que o convencional, e ambos os sistemas duais, sobretudo o RelyX ARC, apresentaram dependência da fotoativação para atingirem maiores valores de resistência de união.