Prueba de Push-Out para Evaluar la Fuerza de Adhesión entre dos Tipos de Postes Estéticos

Posterior a un tratamiento endodóntico, muchas veces el remanente es insuficiente para la retención de un material de restauración, por este motivo es necesario la colocación de un sistema de poste-muñón para otorgar retención a la restauración final. Con la aparición de diversos materiales para las restauraciones estéticas, se utilizan actualmente resinas reforzadas con fibra de vidrio como sistemas de postes y muñones para la restauración de dientes tratados endodónticamente. El objetivo del presente trabajo fue comparar la fuerza de adhesión en la prueba push-out de dos diferentes tipos de postes de fibra de vidrio; 3M RelyX y Rebilda Post GT (VOCO) adheridos con cementos duales correspondientes a la marca de los postes; RelyX U-200® Automix (3M ESPE) y Rebilda DC (VOCO). Se llevó a cabo un análisis de ANOVA de dos vías para comparar la fuerza adhesiva con la prueba push-out entre ambos grupos de estudio. Pese a que se observó que los postes Rebilda presentaron una media de fuerza de adhesión ligeramente mayor en comparación con los postes 3M (sin diferencia estadística significativa P>0,05) los últimos son clínicamente más fáciles de colocar, lo cual pudiera ser un factor decisivo para el clínico en el momento de la elección de un poste y su sistema de adhesión.

After an endodontic treatment, many times the remnant is insufficient for the retention of a restorative material, for this reason it is necessary to place a post-stump system to provide retention to the final restoration. With the advent of various materials for esthetic restorations, fiberglass-reinforced resins are now used as post and core systems for the restoration of endodontically treated teeth. The objective of the present work was to compare the bond strength in the push-out test of 2 different types of fiberglass posts; 3M RelyX and Rebilda Post GT (VOCO) bonded with dual cements corresponding to the post brand; RelyX U-200® Automix (3M ESPE) and Rebilda DC (VOCO). A 2-way ANOVA analysis was performed to compare push-out strength between both study groups. Although it was observed that the Rebilda posts presented a slightly higher mean bond strength compared to the 3M posts (with no significant statistical difference P>0.05), the latter are clinically easier to place, which could be a decisive factor for the clinician at the time of choosing a post and its adhesion system.

Ex Vivo Analysis of MTA FLOW® Biomineralization and Push-Out Strength: A Pilot Study / Análisis ex vivo del proceso de biomineralización y resistencia al desplazamiento del MTA FLOW®: Estudio piloto

Abstract: This study evaluated the biomineralization processes and push-out strength of MTA Flow® with radicular dentine in three different consistencies. The push-out test was performed on an ex vivo model, using 2mm thick dentin discs from the middle third of the root with standardized cavities of 1.5 mm. Samples were filled with MTA-Angelus (Angelus Dental, Brazil), Biodentine (Septodont, France), MTA Flow® Putty (Ultradent, USA), MTA Flow® Thick or MTA Flow® Thin. The samples were divided into 3 groups: subgroup 1 (n=5), analysis of the biomineralization process; 2 (n=20), evaluation of the bonding strength and push-out resistance; and 3 (n=5), evaluation of the cement/ dentin interface. The samples filled with Biodentine had a higher precipitation of carbonate apatite. However, there was no significant difference between MTA-Angelus, MTA Flow® Putty, or Thick (p=0.0536), but there was a significant difference in the Thin group (P<0.05). The samples with Biodentine displayed the greatest release of calcium ions. The formation of a partially carbonated intermediate apatite layer was observed in all groups. Zones of biomineralization were observed at the interface but were not continuous. After 72 hours, a significant difference was found between the Biodentine and MTA Flow® Thin groups (p=0.0090) in the push-out test. The samples submerged in phosphate-buffered saline (PBS) for 15 days showed a significant difference between all groups and MTA Flow® Thin (p=0.0147). Putty or Thick consistencies presented a similar bonding strength to MTA-Angelus and Biodentine. MTA Flow® Putty and Thick consistencies show a good adaptation to dentin, similar to MTA-Angelus. However, the thickness of the interface was lower compared to that of Biodentine. MTA Flow® Thin, despite their tubular infiltration, results in gaps and a defective peripheral seal.Therefore, MTA Flow®, in Putty or Thick consistencies, presents a biomineralization process and push-out strength similar to MTA Angelus and Biodentine, however, both characteristics decreases considerably in Thin consistency.

Resumen: El objetivo de este estudio fue evaluar, en un modelo ex vivo, el proceso de biomineralización y fuerza de adhesión del MTA Flow® en sus tres diferentes consistencias por medio de la prueba de resistencia al desplazamiento (Push-out). Se utilizaron discos de dentina de 2mm de espesor del tercio medio radicular con cavidades estandarizadas de 1.5mm de diámetro, las cuales se obturaron con diferentes materiales entre ellos: MTA Angelus (Angelus Dental, Brasil), Biodentine (Septodont, Francia), MTA Flow® Consistencia Putty (Ultradent, E.E.U.U), MTA Flow® Consistencia Thick (Ultradent, E.E.U.U) y MTA Flow® Consistencia Thin (Ultradent, E.E.U.U). Las muestras se sometieron al proceso de biomineralización y a pruebas de Push-out. Las muestras obturadas con Biodentine promovieron una mayor precipitación de apatita carbonatada, sin embargo, no se presentó diferencia estadística significativa con respecto al MTA Angelus, MTA Flow® Putty ni Thick (p=0.0536). No obstante, si presentó una diferencia significativa con respecto al grupo de MTA Flow® consistencia Thin (P<0.05). Las muestras con Biodentine presentaron la mayor liberación de iones calcio. De acuerdo a las pruebas de resistencia al desplazamiento, a las 72 horas post-obturación, solamente se encontró diferencia significativa entre las muestras obturadas con Biodentine y las correspondientes al MTA Flow consistencia Thin (p=0.0090), sin embargo las muestras sumergidas 15 días en PBS presentaron diferencia significativa entre todos los grupos con respecto al MTA Flow Thin (p=0.0147). En general se observaron zonas de biomineralización en la interface, sin embargo, no fueron continuas. Se concluye que el MTA Flow en consistencia Putty o Thick presenta un proceso de biomineralización y una resistencia al desplazamiento similar al MTA Angelus y al Biodentine, sin embargo, esta última disminuye considerablemente en presentación Thin.

Resin push-out bonding strength to root canal dentin: effect of the irrigation solution application prior to post cementation / Resistência de união ao push-out entre resina e dentina radicular: efeito utilização da solução irrigadora antes da cimentação do pino

Objective: To evaluate the effect of different irrigation solutions prior to post cementation on the resin bonding to bovine root dentine. Material and Methods: 60 bovine roots (16 mm) were prepared to 12 mm with specific drill of a double-tapered fiber post system, included in PMMA, and divided into 6 groups, considering the irrigation solutions (IS) prior to cementation: Gr1- saline solution (control), Gr2- NaOCl 0.5 %, Gr3- NaOCl 1 %, Gr4- NaOCl 2.5 %, Gr5- NaOCl 5 %, Gr6- Chlorexidine 2 % (solution). The root canals were irrigated with IS 20 ml during 10 min. Then they were rinsed with 20 ml of distilled water and dried with paper points. One fiber post was molded with polyvinylsiloxane and 60 posts made of resin cement (PRC) were obtained moments before the cementation. The root canal dentin was etched with H2PO3 37 %/15 s + washing/drying, a multi-bottle etch&rinse adhesive system was applied and the PRC were resin luted with dual resin cement (DuolinkTM, Bisco). Each specimen was cut into 4 slices of ±1.8mm in thickness and submitted to push-out test (1 mm/min). Results: ANOVA showed that bond strength was significantly affected by IS (P < 0.0001). The highest bond strengths (MPa) were those for the groups 4 (3.51 ± 1.52) and 5 (3.0 ± 1.16). The groups 1 (0.70 ± 0.30), 2 (0.80 ± 0.24), 3 (1.26 ± 0.57) and 6 (0.90 ± 0.41) were statistically similar to each other. Conclusion: The resin bonding to the root dentine was higher when higher concentrations of hypochlorite solutions were used. (AU)

Objetivo: Avaliar o efeito de diferentes soluções de irrigação antes da cimentação do pino na resistência de união da resina à dentina radicular bovina. Material e Métodos: Foram preparadas 60 raízes bovinas (16 mm) a 12 mm com broca específica de um sistema de pino de fibra com dupla conicidade, incluídas no PMMA, e divididas em 6 grupos, considerando as soluções irrigadoras (IS) antes da cimentação: Gr1-Solução salina (controle), Gr2-NaOCl 0,5 %, Gr3-NaOCl 1 %, Gr4-NaOCl 2,5 %, Gr5-NaOCl 5 %, Gr6-Clorexidina 2 % (solução). Os canais radiculares foram irrigados com 20 ml de IS durante 10 min. Depois, foram lavados com 20 ml de água destilada e secos com pontas de papel. Um pino de fibra foi moldado com polivinilsiloxano e 60 pinos de cimento resinoso (PRC) foram obtidos momentos antes da cimentação. A dentina radicular foi condicionada com H2PO3 37 %/15 s + lavagem/ secagem, aplicou-se o sistema de adesivo e o PRC foi cimentado com cimento resinoso dual (DuolinkTM, Bisco). Cada amostra foi cortada em 4 fatias de ± 1,8 mm de espessura e submetida a teste push-out (1 mm/ min). Resultados: ANOVA mostrou que a força de união foi significativamente afetada pelo IS (P< 0,0001). As maiores resistências de união (MPa) foram para os grupos 4 (3,51 ± 1,52) e 5 (3,0 ± 1,16). Os grupos 1 (0,70 ± 0,30), 2 (0,80 ± 0,24), 3 (1,26 ± 0,57) e 6 (0,90 ± 0,41) foram estatisticamente semelhantes entre si. Conclusão: A resistência de união da resina à dentina radicular foi maior quando foram utilizadas concentrações maiores de soluções de hipoclorito. (AU)

Effect of different adhesive systems and post surface treatments on the push-out bond strengths of fiber-reinforced post / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the push-out bond strength of glass-fiber post cemented with different adhesive systems and surface treatments. MATERIALS AND METHODS: 160 tooth samples made from 48 human maxillary single-rooted teeth with similar root length were divided into 4 groups according to the adhesive system (no adhesive, Adper Single Bond 2, Clearfil SE Bond, Clearfil S3). Each group had 4 subgroups according to the post surface treatment methods (no treatment, sandblast, silane, sandblast and silane). Posts (Parapost Fiber White) were cemented with Rely X Unicem. The teeth were sectioned perpendicular to their long axis into 1-mm thick sections. The push-out tests was performed at a speed of 0.5 mm/min. The results were evaluated by 2-way ANOVA, 1-way ANOVA and multiple comparison procedures (Tukey test) (α=0.05). RESULTS: Tukey test showed that the adhesive system significantly influenced the push-out strength. The Clearfil SE Bond group showed the highest value. Post surface treatments showed no significant effect. CONCLUSION: Bond strength of glass-fiber post cemented with self-adhesive resin cement using Clearfil SE Bond showed significantly higher values compared to other adhesive systems.

Effect of Surface Treatment of Fiberglass Posts on Bond Strength to Root Dentin

This study evaluated the influence of the surface treatments of fiberglass posts on bond strength to root dentin using push-out test. Forty bovine incisor roots were endodontically treated. The surface of the fiberglass posts (Exacto #2, Angelus) were treated using 4 different protocols (n=10): Control - 70% ethanol for 1 min; 37% phosphoric acid for 1 min; 10% hydrofluoric acid for 1 min; and 24% hydrogen peroxide for 1 min. After a silane coupling agent was applied for 1 min and all posts were cemented using self-adhesive resin cement (RelyX Unicem, 3M-ESPE). The roots were sectioned and two 1-mm-thick slices were obtained from each third: cervical, middle and apical. The specimens were subjected to the push-out test with a crosshead speed of 0.5 mm/min. Data were analyzed by repeated measures ANOVA followed by Tukey's HSD tests (=0.05). The surface treatment (p<0.001) and root third region (p=0.007) factors were significant. The retention to root canal was affected by surface treatment type. The post surface treatment with 24% hydrogen peroxide for 1 min yielded significantly higher bond strength when the fiberglass posts were cemented with RelyX Unicem.

Este estudo avaliou a influência de tratamentos de superfície de pinos de fibra de vidro na resistência de união à dentina radicular por meio do teste de push-out. Quarenta raízes de incisivos bovinos foram submetidas a tratamento endodôntico. A superfície dos pinos de fibra de vidro (Exacto #2, Angelus) foram tratadas com 4 protocolos diferentes (n=10): Controle - 70 % de etanol durante 1 min; 37 % de ácido fosfórico durante 1 min, 10% de ácido fluorídrico durante 1 min e 24 % de peróxido de hidrogênio durante 1 min. Depois foi aplicado agente de união silano por 1 min e todos os pinos foram cimentados com cimento resinoso auto-adesivo (RelyX Unicem, 3M- ESPE). As raízes foram seccionadas e foram obtidas duas fatias de 1 mm de espessura em cada terço: cervical, médio e apical. Os espécimes foram submetidos ao teste de push-out com uma velocidade de 0.5 mm/min. Os dados foram analisados pelo teste ANOVA com medidas repetidas, seguido pelo teste de Tukey HSD (=0,05). Os fatores tratamento de superfície (p<0,001) e região do terço radicular (p=0,007) foram significantes; no entanto, a interação entre os dois fatores não foi significante (p=0,827). A retenção ao canal radicular foi afetada pelo tipo de tratamento de superfície. O tratamento de superfície com 24% de peróxido de hidrogênio por 1 min rendeu significativamente maior resistência de união quando os pinos de fibra de vidro foram cimentados com RelyX Unicem.

Influência da técnica de obturação dos canais radiculares e do cimento endodôntico na força de adesão de pinos pré-fabricados de fibra de vidro / Influence of the filling of root canals and endodontic cement on the bond strength of prefabricated fiberglass pins

Comparar a força de adesão por meio de ensaios de cisalhamento por extrusão ("push out") de pinos intrarradiculares de fibra de vidro em canais obturados com os cimentos endodônticos Pulp Canal Sealer EWT® e AHPlus® pelas técnicas de compactação lateral e da onda contínua da guta percha termoplastificada. Foram selecionadas 60 raízes de molares inferiores que foram distribuídas aleatoriamente em 04 grupos com 15 amostras cada: Grupo I, técnica da compactação lateral da guta-percha associada ao cimento Pulp Canal Sealer EWT ®; Grupo II, técnica da compactação lateral da guta-percha associada ao cimento AHPlus®; Grupo III, técnica da onda contínua da guta-percha termoplastificada associada ao cimento Pulp Canal Sealer EWT ®; Grupo lV ­ técnica da compactação de onda contínua da guta-percha termoplastificada associada ao cimento AHPlus®. O pino de Fibra de vidro Whitepost DC® 0,5 foi cimentado com sistema adesivo AMBAR® e com o cimento AllCEM® na proporção 1:1 em todas as raízes. Os ensaios de resistência por extrusão foram realizados em três diferentes níveis: cervical, médio e apical, na máquina de ensaio universal EMIC DL 200 MF, à velocidade de 1,0 mm/min, até a fratura. Para análise dos resultados foram utilizados os testes Kruskal-Wallis, Bonferroni e Wilcoxon. Os quatro grupos avaliados foram significativamente diferentes em relação à força máxima do ensaio "push out" (p< 0,000), sendo os grupos IV e III com maior forca de resistência seguidos pelos grupos II e I. Na analise pareada, só não houve diferença estatisticamente significante entre os grupos I e II (p=0,075) e III e IV (p=0,052). Quando o "push out" dos grupos foi comparado por terços, nos terços cervical, médio e apical, os grupos IV e III foram significantemente maiores do que os grupos II e I (p= 0,00, para todas as comparações). Na comparação da força de cisalhamento dentro de cada grupo, a força máxima de "push out" no grupo IV foi significativamente maior em seu terço cervical quando comparado ao terço médio (p= 0,017), mas não foi observada diferença entre os terços médio e apical. Nos outros três grupos, não houve diferença de push out entre os terços. A técnica de obturação dos canais radiculares da onda contínua da guta percha termoplastificada foi superior à técnica da compactação lateral da guta-percha na aplicação de força de cisalhamento ("push out"). O tipo de cimento obturador dos canais radiculares, não exerceu influência na força máxima do "push out" do pino de fibra.

To compare the adhesion strength by push out test of fiberglass intracanal posts filled with Pulp Canal Sealer EWT ® and AHPlus® sealers the techniques of cold lateral compaction and continuous wave of condensation. Sixty roots of mandibular molars were selected and randomly distributed into 04 groups with 15 sample each: Group I, cold lateral compaction technique of gutta-percha associated with Pulp Canal Sealer EWT ® cement, Group II, cold lateral compaction technique of gutta-percha associated with AHPlus®, Group III, continuous wave of condensation technique of gutta-percha associated with cement Pulp Canal Sealer EWT ®; group IV - continuous wave of condensation technique associated with AHPlus®. The Fibreglass Whitepost pin DC® 0.5 was cemented with an adhesive system and the AMBAR® AllCEM® cement 1:1 in all roots. Push out test were performed at three different levels: cervical, middle and apical in a universal testing machine EMIC DL 200 MF at a speed of 1.0 mm / min until fracture. To analyze the results, the Kruskal- Wallis, Bonferroni and Wilcoxon tests were used. The four study groups were significantly different in respect to the bond strength of the push out test (p < 0.000), and the groups III and IV had greater force of resistance followed by groups II and I. In paired analyzes, there was no statistically significant difference only between groups I and II (p = 0.075) and between groups III and IV (p = 0.052) . When the push out of the groups was compared by thirds, cervical , middle and apical thirds of groups III and IV were significantly higher than groups I and II (p = 0.00, for all comparisons) . Comparing the bond strength within each group, the maximum push out force in group IV was significantly higher in his cervical third when compared to the middle third (p = 0.017), but there was no difference between the middle and apical thirds. In the other three groups, there was no push out difference between the thirds. The technique of filling of the root canals continuous wave of condensation, was superior to the technique of cold lateral compaction of gutta - percha on the application of shear force (push out) . The type of root canal sealer had no influence on the push out ultimate strength of the fiber pin.

Push-out bond strength of a self-adhesive resin cement used as endodontic sealer

OBJECTIVES: The aim of the present study was to investigate the bond strength of RelyX Unicem (3M) to root canal dentin when used as an endodontic sealer. MATERIALS AND METHODS: Samples of 24 single-rooted teeth were prepared with Gates Glidden drills and K3 files. After that, the roots were randomly assigned to three experimental groups (n = 8) according to the filling material, (1) AH Plus (Dentsply De Trey GmbH)/Gutta-Percha cone; (2) Epiphany SE (Pentron)/Resilon cone; (3) RelyX Unicem/Gutta-Percha cone. All roots were filled using a single cone technique associated to vertical condensation. After the filling procedures, each tooth was prepared for a push-out bond strenght test by cutting 1 mm-thick root slices. Loading was performed on a universal testing machine at a speed of 0.5 mm/min. One-way analysis of variance and Tukey test for multiple comparisons were used to compare the results among the experimental groups. RESULTS: Epiphany SE/Resilon showed significantly lower push-out bond strength than both AH Plus/Gutta-Percha and RelyX Unicem/Gutta-Percha (p 0.05). CONCLUSIONS: Under the present in vitro conditions, bond strength to root dentin promoted by RelyX Unicem was similar to AH Plus. Epiphany SE/Resilon resulted in lower bond strength values when compared to both materials.

The effect of different adhesive system applications on push-out bond strengths of glass fiber posts

PURPOSE: Over the past years, the adhesion of fiber posts luted with simplified adhesive systems has been a matter of great interest. The aim of this study was to assess the post retentive potential of a self-adhesive resin cement using different adhesive systems to compare the push-out bond strengths of fiber posts. MATERIALS AND METHODS: The post spaces of 56 mandibular premolar roots were prepared and divided into 4 experimental groups and further divided into 2 subgroups according to testing time (n=7). The fiber posts (Rely X Fiber Post) were luted with a self-adhesive resin cement (RelyX Unicem) and one of the following adhesive systems: no adhesive, a total-etch adhesive resin (Single Bond), a two-step self-etch adhesive resin (Clearfil SE Bond) and a one-step self-etch adhesive resin (Clearfil S3 Bond). Each root was cut horizontally, and 1.5 mm thick six root segments were prepared. Push-out tests were performed after one week or three months (0.5 mm/min). Statistical analysis were performed with three-way ANOVA (alpha=.05). RESULTS: Cervical root segments showed higher bond strength values than middle segments. Adhesive application increased the bond strength. For one week group, the total-etch adhesive resin Single Bond showed higher bond strength than the self-adhesive resin cement RelyX Unicem applied without adhesive resin at middle region. For 3 months group, the two-step self-etch adhesive resin Clearfil SE Bond showed the highest bond strength for both regions. Regarding the time considered, Clearfil SE Bond 3 months group showed higher bond strength values than one week group. CONCLUSION: Using the adhesive resins in combination with the self-adhesive resin cement improves the bond strengths. The bond strength values of two-step self-etch adhesive resin Clearfil SE Bond improved as time passes.

Evaluation of push-out bond strength of surface treatments of two esthetic posts.

Objectives: To evaluate the push-out bond strength of two surface treatments of a glass fiber and zirconia ceramic post. Materials and Methods: Sixty samples were fabricated and divided into two main groups according to the type of esthetic post indicated for maxillary central incisor: glass fiber post and zirconia ceramic post. Each group was subdivided to two subgroups according to the type of bond strength test either between post and root or between post and core. Each subgroup was further subdivided into three classes according to surface treatment: no treatment (control), sandblasting in conjunction with silica particles then silane coating (SB+SIC+SC), etching using hydrofluoric acid then silane coating (E+SC). For the subgroups of the bond strength between post and root, each class was subdivided into two subclasses according to the location of the sample (cervical or apical). Results: Bond strength to root canal or resin core were affected by the type of post, glass fiber post recorded significant higher bond strength than zirconia ceramic. Surface treatment recorded higher values for bond strength, SB+SIC+SC gave higher bond strength than E+SC. Cervical section recorded significant higher bond strength than apical section. Conclusions: Glass fiber posts recorded higher bond strength than glass ceramic post to both root canal and resin core. Surface treatments increase bond strength for glass fiber and zirconia ceramic posts to both root canal and resin core. SB+SIC+SC gave higher bond strength than E+SC. Bond strength at the cervical section is higher than at the apical section.

In vivo bone response and interfacial properties of titanium-alloy implant with different designs in rabbit model with time.

Background: Using implants for dental applications are well-accepted procedures as one of the solutions for periodontal defect repair. Suitable design and materials, their reaction with the surrounding hard tissues and interfacial biomechanical properties are still considered to be the primary criteria which need to be addressed systematically. In the present study, a thorough and systemic approach was made to identify a suitable implant, considering the above criteria after both in vitro and in vivo animal trials. Materials and Methods: Titanium alloy (Ti-6Al-4V) implants, with thread and without thread models, were implanted to the mid-metaphysial portion of the tibia of the right hind leg of three white Australian Chinchilla rabbit species and their effects and response to the surrounding bone were investigated. Parameters studied included hematological and biochemical features (serum alkaline phosphatase and calcium), both preoperatively and postoperatively, consecutively for 7 days and after 1-3 months. The interfacial integrity and compositional variation along the interface were studied using scanning electron microscope (SEM) with energy dispersive analysis of X-ray (EDAX) and histopathology from 1 to 3 months consecutively. Finally, biomechanical properties were studied with the help of push-out test. Results: Bone remineralization started through the process of electro-physiological ionic exchanges, which helps in formation of osteoblastic cells in the area of bony injury. The SEM-EDAX results confirmed the initial stability for the Ti (with thread) implant, but the regeneration of new bone formation was faster in the case of Ti (Without thread) implant, and hence could be used for faster healing. These have also been substantiated through push-out and histopathlogical tests. Conclusion: From the physico-chemical and biomechanical observations, it was found that that smooth type implants were well accepted in the physiological condition although chances of elemental leaching from the surface were also observed. Increase of the surface roughness can help into the formation of physico-chemical bondage with the surrounding hard tissues.

Efeito da técnica úmida simplificada de adesão com etanol na cimentação intraradicular de pinos de fibra / Push-out bond strength and SEM evaluation of new bonding approach into the root canal

Este estudo avaliou a resistência ao deslocamento vertical push-out de pinos de fibra de vidro cimentados à dentina intra-radicular utilizando uma resina fluida padrão como agente cimentante em combinação com um adesivo dentinário experimental e um adesivo disponível comercialmente. 20 pré-molares unirradiculares humanos foram previamente extraídos e tratados endodonticamente. Os espécimes foram divididos em quatro estratégias de união a dentina: Grupo 1 com adesivo experimental com etanol na proporção em volume 1:1 (resina/etanol) e Grupo 2 com adesivo experimental com etanol na proporção em volume 1:2(resina/etanol); adesivos experimentais aplicados de acordo com a técnica úmida de adesão simplificada com etanol, Grupo 3: One-Step Plus aplicado de acordo com a técnica úmida de adesão simplificada com etanol; Grupo 4: One-Step Plus aplicado seguindo as instruções do fabricante. Os espécimes foram seccionados em fatias de 1 mm de espessura e apos o teste push-out foi realizado. Espécimes representativos foram selecionados para exame ultra-estrutural. Não houve diferença estatística na resistência ao deslocamento push-out entre as estratégias testadas de adesão (p> 0,05). O padrão predominante de fratura foi entre os pinos de fibra e o agente cimentante. A partir deste estudo devemos considerar como promissora a técnica com etanol utilizada na cimentação de pinos no canal radicular devido aos possíveis benefícios das resinas altamente hidrófobas. Mais estudos são necessários para validar o uso da técnica úmida de adesão simplificada com etanol quando cimentados pinos de fibra.

This study evaluated the push-out bond strength of glass fiber posts adhesively bonded to intraradicular dentin using a standard unfilled resin as luting agent in combination with an experimental and a commercially available adhesive. Twenty extracted single-rooted human teeth were endodontically treated. Specimens were assigned to 4 dentin bonding strategies: Group 1 (co-monomers to ethanol on ratio 1:1) and Group 2 (co-monomers to ethanol on ratio 1:2): Experimental adhesives applied in accordance with the simplified ethanol-wet bonding technique; Group 3: One-Step Plus (OSP) applied in accordance with the simplified ethanol-wet bonding technique; Group 4: OSP applied following manufacturers instructions. Bonded specimens were sectioned in 1-mm-thick slices and the push-out test was performed. Representative specimens were selected for ultrastructural examination. No statistical differences in push-out bond strength were found among the tested bonding strategies (p>0.05). The major failure pattern was between the post and the luting cement. From this study the ethanol technique should be considered as a promising approach in the luting of fiber posts into the root canal due to the possible benefits of highly hydrophobic resins. Further studies are needed to validate the use of the ethanol-wet bonding technique when luting a fiber post.

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.

Adhesion of an endodontic sealer to dentin and gutta-percha: shear and push-out bond strength measurements and SEM analysis

The use of an adequate method for evaluation of the adhesion of root canal filling materials provides more reliable results to allow comparison of the materials and substantiate their clinical choice. The aims of this study were to compare the shear bond strength (SBS) test and push-out test for evaluation of the adhesion of an epoxy-based endodontic sealer (AH Plus) to dentin and gutta-percha, and to assess the failure modes on the debonded surfaces by means of scanning electron microscopy (SEM). Three groups were established (n=7): in group 1, root cylinders obtained from human canines were embedded in acrylic resin and had their canals prepared and filled with sealer; in group 2, longitudinal sections of dentin cylinders were embedded in resin with the canal surface smoothed and turned upwards; in group 3, gutta-percha cylinders were embedded in resin. Polyethylene tubes filled with sealer were positioned on the polished surface of the specimens (groups 2 and 3). The push-out test (group 1) and the SBS test (groups 2 and 3) were performed in an Instron universal testing machine running at crosshead speed of 1 mm/min. Means (±SD) in MPa were: G1 (8.8±1.13), G2 (5.9±1.05) and G3 (3.8±0.55). Statistical analysis by ANOVA and Student's t-test (a=0.05) revealed statistically significant differences (p<0.01) among the groups. SEM analysis showed a predominance of adhesive and mixed failures of AH Plus sealer. The tested surface affected significantly the results with the sealer reaching higher bond strength to dentin than to gutta-percha with the SBS test. The comparison of the employed methodologies showed that the SBS test produced significantly lower bond strength values than the push-out test, was skilful in determining the adhesion of AH Plus sealer to dentin and gutta-percha, and required specimens that could be easily prepared for SEM, presenting as a viable alternative for further experiments.

Effect of blood contamination and decontamination procedures on marginal adaptation and bond strength of composite restorations / Efeito da contaminação com sangue e de procedimentos de descontaminação na adaptação marginal e na resistência de união de restaurações de resina composta

Purpose: To evaluate the effect of blood contamination and different decontamination procedures on marginal adaptation and bond strength of a two-step total-etch adhesive system to dentin. Methods: A total of 135 bovine incisors had the labial surfaces ground to receive cylindrical cavities, and were randomly divided into a control and 8 experimental groups (n=15) according to contamination and decontamination procedures. Freshly collected human blood was applied onto the cavity either before or after light-curing of the adhesive. Four decontamination protocols were tested (drying with paper, water rinsing, phosphoric acid etching, and 10% NaOCl rinsing). The cavities were restored with Adper Single Bond and Filtek Z250 (3M ESPE). The specimens were subjected to thermal cycling before the dye staining test. The cavity floor was removed and the restorations were subjected to a push-out test. Data were analyzed by two-way ANOVA and Tukey's test (α=0.05). Results: Blood contamination after adhesive light-curing increased marginal gap and yielded lower push-out bond strength values (P<0.01). Conclusion: Water rinsing seems to be a reliable procedure for cavity decontamination. The decontamination procedures tested do not recover marginal sealing and bond strength when blood contamination occurs after light-curing of the adhesive.

Objetivo: Avaliar o efeito da contaminação com sangue e de procedimentos de descontaminação na adaptação marginal e resistência de união de um adesivo convencional de dois passos à dentina. Metodologia: Um total de 135 incisivos bovinos receberam cavidades cilíndricas na superfície vestibular, previamente desgastada. Os dentes foram divididos em grupo controle e 8 grupos experimentais (n=15), com base no momento da contaminação e nos procedimentos de descontaminação. Sangue recém-coletado foi aplicado nas cavidades, antes ou após a fotoativação do adesivo. Quatro procedimentos de descontaminação foram testados: secagem com papel, lavagem com água, condicionamento com ácido fosfórico e lavagem com hipoclorito de sódio a 10%. As cavidades foram restauradas com Adper Single Bond e Filtek Z250 (3M ESPE). Os espécimes foram submetidos à termociclagem antes da marcação com corante. O assoalho das cavidades foi removido e as restaurações foram submetidas ao teste de push-out. Os dados foram analisados por two-way ANOVA e teste de Tukey (α=0,05). Resultados: A contaminação após fotoativação do adesivo gerou fendas marginais maiores e resistência de união menor (P<0,001). Conclusão: A lavagem com água parece ser um método confiável de descontaminação. Os procedimentos testados não recuperam o selamento marginal e a resistência de união quando a contaminação ocorre após fotoativação do adesivo.

Effect of curing methods of resin cements on bond strength and adhesive interface of post / 대한치과보존학회지

The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No. 3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtenstein) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8); R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way. ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

Adhesion of Epiphany and AH Plus sealers to human root dentin treated with different solutions

This study evaluated comparatively the adhesion of Epiphany and AH Plus endodontic sealers to human root dentin treated with 1 percent NaOCl and 1 percent NaOCl+17 percent EDTA, using the push-out test. Sixty root cylinders obtained from maxillary canines had the canals prepared and were randomly assigned to 3 groups (n=20), according to root dentin treatment: GI - distilled water (control), GII - 1 percent NaOCl and GIII - 1 percent NaOCl+17 percent EDTA. Each group was divided into 2 subgroups (n=10) filled with either Epiphany or AH Plus. Bond strength push-out test data (kN) were obtained and analyzed statistically by ANOVA and Tukey's post-hoc test. There was statistically significant difference between sealers (AH Plus: 0.78 ± 0.13; Epiphany: 0.61 ± 0.19; p<0.01) and among root dentin treatments (distilled water: 0.58 ± 0.19; 1 percent NaOCl: 0.71 ± 0.12; 1 percent NaOCl+17 percent EDTA: 0.80 ± 0.17; p<0.05). In conclusion, AH Plus sealer presented greater adhesion to dentin than Epiphany, regardless of the treatment of root canal walls.

O objetivo do presente estudo foi avaliar a adesividade do cimento Epiphany à dentina radicular previamente tratada com hipoclorito de sódio a 1 por cento e EDTA a 17 por cento, em comparação ao cimento AH Plus, pelo método do "push-out". Foram preparados sessenta cilindros de raízes de caninos superiores humanos que foram distribuídos em 3 grupos (n=20) de acordo com o tratamento da dentina: GI água destilada (controle), GII hipoclorito de sódio 1 por cento e GIII EDTA 17 por cento. Esses grupos de corpos-de-prova foram distribuídos em 2 subgrupos para receber os cimentos obturadores a serem testados: Ephiphany e AH Plus. Foi realizado o teste do "push-out" e os resultados (em kN) foram analisados estatisticamente por ANOVA e o teste "post-hoc" de Tukey. A análise demonstrou diferença estatisticamente significativa entre os cimentos (AH Plus: 0,78 ± 0,13; Epiphany: 0,61 ± 0,19; p < 0,01) e entre as soluções testadas (água destilada: 0,58 ± 0,19; NaOCl: 0,71 ± 0,12; EDTA: 0,80 ± 0,17; p<0,05). Conclui-se que o cimento AH Plus apresentou valores de adesividade superiores aos obtidos pelo cimento Epiphany, independente do tratamento realizado nas paredes dos canais radiculares.

Comparison of bond strength of a fiber post cemented with various resin cements / 대한치과보존학회지

The purpose of this study was to compare the push-out strength of a fiber post cemented with various resin cements. Newly extracted 36 human mandibular premolars which had single root canal were selected and their crown portions were removed. The root canal was instrumented using PROTAPER(TM) system and obturated using continuous wave technique. In each root, a 9-mm deep post space was prepared. #2 translucent fiber post (DT Light post, Bisco Inc., Schaumburg, IL, U.S.A.) was cemented using injection technique with Uni-dose needle tip (Bisco) and six different resin cements. The tested resin cements were Duo-Link (Bisco Inc., Schaumburg, IL, U.S.A.), Variolink II (Ivoclar-Vivadent AG, Schann, Liechtenstein), Panavia F (Kuraray Medical Inc., Okayama, Japan), Multilink Automix (Ivoclar-Vivadent AG, Schann, Liechtenstein), RelyX Unicem (3M ESPE Dental Products, St. Paul, MN, U.S.A.), and Maxcem (Kerr Co., CA, U.S.A.). After storage in distilled water for 24 hours, each root was transversally sectioned into approximately 1-mm thick sections. This procedure resulted in 6 serial sections per root. Push-out test was performed using a universal testing machine (EZ Test, Shimadzu Co.) with a crosshead speed of 1 mm/min. The data were analyzed with one-way ANOVA and Tukey HSD (p=0.05). The push-out strength of the groups which cemented fiber post with Panavia F and Multilink Automix were lower than those of the other groups. But, there were no statistically significant difference among groups at a probability level of 0.05.