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This study objectives to evaluate the fracture strength of upper central incisors (UCI) restored with composite resin (CR) in Class III cavities and endodontically treated teeth with or without glass fiber post (GFP), analyzing their failure mode. Sixty human UCI were randomly divided into four experimental groups: endodontically treated teeth without GFP (G1), endodontically treated teeth with GFP (G2), teeth with mesial/distal Class III cavities restored with CR without GFP (G3), and teeth with mesial/distal Class III cavities restored with CR with GFP (G4). The samples were submitted to the fracture strength test in a universal testing machine with a compression shear load applied at speed of 1.0 mm/min until fracture occurred. The data were submitted to one-way ANOVA (α=0.05) and the samples were analyzed for failure mode. The analysis did not show a significant statistical difference in fracture strength between the groups (p>0.05). The results showed that only endodontically treated teeth (G1) (753.4N) presented behavior similar to teeth with GFP (G2) (702.1N). The same occurred when comparing teeth with Class III cavities without GFP (G3) (670.2 N) and with GFP (G4) (746.1N). It can be concluded that glass fiber posts do not change the fracture strength of incisors with endodontic treatment and Class III cavities.

Este estudo objetiva avaliar a resistência à fratura de incisivos centrais superiores (ICS) restaurados com resina composta (RC) em cavidades Classe III e dentes tratados endodonticamente com ou sem pino de fibra de vidro (PFV), analisando seu padrão de fratura. Sessenta ICS humanos foram divididos aleatoriamente em quatro grupos experimentais: dentes tratados endodonticamente sem PFV (G1), dentes tratados endodonticamente com PFV (G2), dentes com cavidades mesiais/distais Classe III restauradas com RC sem PFV (G3), e dentes com cavidades mesiais/distais Classe III restauradas com RC com PFV (G4). As amostras foram submetidas ao teste de resistência à fratura em uma máquina universal de ensaios com uma carga de cisalhamento de compressão aplicada na velocidade de 1,0 mm / min até a ocorrência da fratura. Os dados foram submetidos à ANOVA unidirecional (α=0,05) e as amostras foram analisadas quanto ao modo de falha. A análise não mostrou diferença estatisticamente significativa na resistência à fratura entre os grupos (p>0,05). Os resultados mostraram que os dentes apenas tratados endodonticamente (G1) (753,4N) apresentaram comportamento semelhante aos dentes com PFV (G2) (702,1N). O mesmo ocorreu ao comparar dentes com cavidades Classe III sem PFV (G3) (670.2 N) e com PFV (G4) (746.1N). Pode-se concluir que pinos de fibra de vidro não alteram a resistência à fratura de incisivos com tratamento endodôntico e cavidades Classe III.

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Introdução: Pinos pré-fabricados de fibra de vidro possuem boas propriedades mecânicas e estéticas. Porém, estes podem não se adaptar bem em canais amplos ou excessivamente cônicos prejudicando sua retenção ao canal radicular. Uma alternativa para esta desvantagem, é a utilização da técnica de pino anatômico. Objetivo: O objetivo do relato de caso foi apresentar a técnica de confecção de um pino fibra de vidro anatômico em dente anterior com reduzido remanescente coronário e ampla embocadura do canal radicular. Relato de Caso: Paciente masculino, 49 anos, procurou atendimento odontológico com queixa da aparência estética de seus dentes anteriores superiores. Após remoção de uma coroa metalocerâmica e um pino-núcleo metálico fundido do elemento 12, foram confeccionados um pino de fibra de vidro anatômico, núcleo de preenchimento e coroa provisória. Foram realizadas as facetas em resina composta nos elementos 13, 11, 21, 22 e 23. Uma coroa de cerâmica reforçada por dissilicato de lítio (IPS e.max CAD, Ivoclar Vivadent) foi cimentada no elemento 12. Conclusões: Através da técnica pino de fibra de vidro anatômico, é possível reabilitar dentes anteriores tratados endodonticamente sem a utilização de pinos metálicos, apresentando bons resultados estéticos. Entretanto, uma condição oclusal dentro dos princípios de uma oclusão mutuamente protegida deve ser almejada para garantir longevidade da restauração(AU)

Introduction: Prefabricated glass fiber posts present good mechanical and esthetic proprieties. However, these may not fully fit in large canal or excessively conical damaging your retention in the root canal. An alternative to this disadvantage, it is the use of post anatomic technique. Aim: the aim of the case report was to present the technique to obtain an anatomic glass fiber post in anterior teeth with reduced coronal remaining and large access of the root canal. Case Report: Man patient 49 year-old searched dental care with complaint of the esthetic appearance of your anterior maxillary teeth. After the removal of a metalceramic crown and a cast core and post of the tooth 12, an anatomic glass fiber post, resin core and interim crown were performed. Direct composite resin veneers were performed in the teeth 13, 11, 21, 22 and 23. A crown of reinforced lithium disilicate ceramic (IPS e.max CAD, Ivoclar Vivadent) was luted at tooth 12. Conclusions: It is possible to restore endodontically treated teeth without to use metal posts presenting improved esthetic results using the technique of anatomic glass fiber post. However, an occlusal condition concerning the principles of protected occlusion must be founded to guarantee a long-term restoration(AU)

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PURPOSE: The aim of this study was to evaluate the influence of cement type and relining procedure on push-out bond strength of fiber posts (FPs) after cyclic loading. MATERIALS AND METHODS: Forty bovine incisor roots were divided into four groups: group 1, FP luting with RelyX Unicem; group 2, FP relined with resin composite (FPC) luting with RelyX Unicem; group 3, FP luting with RelyX ARC; group 4, FPC luting with RelyX ARC. Afterwards, half the specimens were exposed to 250,000 cycles in a controlled chewing simulator. With the other half of the specimens in each group, the push-out test was performed 24 hours after FP luting (immediate groups). All roots were sectioned transversely, producing 1-mm-thick slices, and the push-out test was performed. Statistical analysis was performed using ANOVA and the Tukey test for post hoc comparisons (α = 0.05). RESULTS: FPC had higher bond strengths than FP (p < 0.05). RelyX Unicem showed higher bond strength than RelyX ARC (p < 0.05). Cyclic loading did not significantly affect the bond strength value (p > 0.05). CONCLUSION: The relining procedure and the cement type are important factors for the bond strength of FPs to root dentin.

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PURPOSE: This study investigated the influence of collagen removal with calcium hypochlorite on the surface morphology of acid-etched dentin and on the microleakage of composite restorations. In addition, the elemental composition (EC) of dentin after removal of the collagen fibrils was analyzed. MATERIALS AND METHODS: Forty third molars received two cavities and were divided into four groups according to dentin treatment: CTRL-no pre-treatment; Na10-10% NaOCl for 30 s; Ca10-10% CaOCl for 30 s, and Ca15-15% CaOCl for 30 s. The cavities were filled using an acetone-based adhesive system and a resin composite; they were then subjected to thermal cycling for 5,000 cycles, immersed in methylene blue for 4 h and sectioned into 1-mm thick slabs. Two examiners evaluated two slices per tooth using a stereomicroscope and assigned the degree of infiltration (scores 0-3). The data were analyzed using the Kruskal-Wallis (α = 0.05). Four teeth received surface treatment according to the groups and were submitted to SEM and EDS to carry at the EC. RESULTS: There was no significant difference between the experimental groups (P = 0.533). CaOCl alters the morphology and surface composition of the dentin, resulting in an increase in the amount of calcium in the interface. CONCLUSIONS: When used prior to an acetone-based adhesive system, CaOCl did not produce any differences in microleakage when compared to the CTRL group or to the Na10 group.

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OBJECTIVE: The purpose of this study was to evaluate the fracture strength of roots that were prosthetically restored with cast post and core with or without any remaining coronal structure and with different finish lines. MATERIALS AND METHODS: Sixty bovine incisors were sectioned below the cementoenamel junction, endodontically treated and randomly divided into six experimental groups (n = 10) containing teeth with or without any remaining coronal structure and with a beveled shoulder, a chanfered or a shoulder finish line design. The cast post and core were luted with dual-cured resin cement. The metal crowns were cemented with zinc phosphate cement. The specimens were subjected to a tangential compressive load (135° angle) at a crosshead speed of 0.5 mm/min until failure, using a universal testing machine. The fracture strength data were analyzed using the ANOVA and LSMeans (least square means) tests (α = 0.05). RESULTS: The data indicated that the teeth with 2 mm of remaining coronal structure showed the highest fracture strength values when compared with the teeth without any remaining structure (p < 0.05). As to the different finish line designs, the highest fracture strength values were obtained for the beveled shoulder, followed by the chanfered and then by the shoulder designs (p < 0.05). CONCLUSIONS: It may be concluded that, to increase fracture strength, a beveled shoulder and 2 mm of remaining coronal structure are the ideal conditions.

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This study evaluated the bond strength of Epiphany(®)/Resilon(®) to radicular dentine and compared this with that of Gutta-percha sealed with Sealer 26 and also Endo Fill(®). Fifteen human single-rooted extracted teeth had their root canals enlarged to a standardised internal root diameter of 1.5 mm. The teeth were filled with: Group I--Epiphany(®)/Resilon(®) cones, Group II--Sealer 26(®)/Gutta-percha cones and Group III--Endo Fill(®)/Gutta-percha cones. Three 2 mm-thick cross-sections were obtained from each tooth (n = 15) and subjected to a push-out test (1 mm min(-1)). The means (MPa) were compared using anova /Newman-Keuls tests. There were no statistically significant differences between Group I and Group II (P > 0.01). Both bond strengths were significantly higher than that of Group III (P < 0.01). The root canal filling system Epiphany(®)/Resilon(®) showed bond strength similar to that of Sealer 26(®)/Gutta-percha. Both were higher than that of Endo Fill(®)/Gutta-percha.

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The purpose of this study was to evaluate the fracture strength of roots that were prosthetically restored with metallic posts with or without any remaining coronal structure and with different finish lines. Sixty bovine incisors were sectioned below the cementoenamel junction, endodontically treated, and randomly divided into six experimental groups (n = 10) containing teeth with or without any remaining coronal structure, and with a beveled shoulder, a bevel, or a shoulder finish line design. The metallic posts were luted with dual-cured resin cement. The cores were made with composite resin, and metal crowns were cemented with zinc phosphate cement. The specimens were subjected to a tangential compressive load (135º angle) at a crosshead speed of 0.5 mm/min until failure, using a universal testing machine. The fracture strength data were analyzed using the ANOVA and LSMeans (least square means) tests (α= 0.05). The data indicated that the teeth with 2 mm of remaining coronal structure showed the highest fracture strength values when compared with the teeth without any remaining structure (p < 0.05). As to the different finish line designs, the highest fracture strength values were obtained for the beveled shoulder, followed by the bevel and then by the shoulder designs (p < 0.05). It may be concluded that, to increase fracture strength, a beveled shoulder and 2 mm of remaining coronal structure are the ideal conditions.

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The aim of this in vitro study was to evaluate the bond strength of a self-etching adhesive system to dentine irrigated with sodium hypochlorite (NaOCl), chlorhexidine solution (CX) and ethylene diamine tetra acetic acid (EDTA) by microtensile testing. Sixty human third molars were sectioned 3 mm below the occlusal level and then randomly divided into six groups: G1(control), without irrigant solution; G2, 1% NaOCl; G3, 1% NaOCl followed by the application of 17% EDTA; G4, 2% CX; G5, 2% CX followed by the application of 17% EDTA and G6, 17% EDTA. The specimens received the self-etching adhesive system were restored with composite resin, then sectioned and trimmed to obtain four hourglass-shaped slabs from each tooth. The specimens were submitted to the microtensile test in a Universal Testing Machine at a crosshead speed of 0.5 mm min(-1) until fracture. The results were submitted to statistical analysis by anova /Newman-Keuls. The means and standard deviations (MPa) were: G1, 26.88 (±3.81); G2, 19.08 (±3.89); G3, 18.16 (±2.21); G4, 18.14 (±4.32); G5, 34.30 (±3.32); G6, 13.61 (±1.21). It was concluded that the application of 2% CX followed by the application of 17% EDTA resulted in increasing the bond strength of the self-etching adhesive system to dentine, when compared with the results obtained for the other tested groups.

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PURPOSE: To evaluate the bond strength of a total-etching adhesive system to dentin irrigated with 1% sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid 17% (EDTA). METHODS: Thirty human molars were sectioned 3mm below the oclusal surface and were randomly divided into 3 groups (n=10): G1, no treatment (control); G2, 1% NaOCl; G3, NaOCl followed by EDTA. The specimens received the total-etching adhesive system, restored with microhybrid composite resin, sectioned and trimmed to create 4 hourglass-shaped slabs of each tooth. The slabs were tested in microtensile bond strength in a universal testing machine (Emic DL 2000) at a crosshead speed of 0.5 mm/min until fracture. The results were analyzed statistically by ANOVA and Newman-Keuls test. G2 samples were not submitted to the test because they fractured just before testing, and its values were considered zero to the statistical analysis. RESULTS: The means and standard deviations (MPa) were: G1, 8.41 (±3.51); G2, 0.0 (±0.00); G3, 8.47 (±3.53). CONCLUSION: It was concluded that the application of the NaOCl irrigating solution significantly decreased the bond strength values. The use of NaOCl followed by EDTA resulted in bond strength values not statistically different from control group.

OBJETIVO: Avaliar a resistência de união de um sistema adesivo condicione-e-lave à dentina irrigada com hipoclorito de sódio 1% (NaOCl) e ácido etilenodiaminotetracético 17% (EDTA). METODOLOGIA: Trinta molares humanos foram seccionados 3mm abaixo da superficie oclusal e aleatoriamente divididos em 3 grupos (n=10): G1 (controle), nenhum tratamento; G2, NaOCl; G3, NaOCl seguido por EDTA. Os especimes foram hibridizados com um sistema adesivo condicione-e-lave, foram restaurados com resino composta microhibrida e seccionados de forma a originar 4 amplulhetas de cada dente. As fatias foram submetidas ao teste de resistência de união à microtraçnao em máquina universal de ensaios (EMIC DL 2000) à uma velocidade de 0,5 mm/min até o momento da fratura. Os resultados foram analisados estatisticamente por ANOVA seguido por Newman-Keuls. As amostras do G2 não foram submetidas aos testes de resistência de união pois fraturaram antes dos testes, e seus valores foram considerados zero para análise estatística. RESULTADOS: A média e desvios-padrão foram (MPa): G1 - 8,41 (±3,51); G2 - 0,0 (±0,00); e G3 - 8,47 (±3,53). CONCLUSÃO: Pode-se concluir que a irrigação com NaOCl diminui significativamente os valores de resistência de união. O uso de NaOCl seguido por EDTA resultaram em valores de resistência de união sem diferença estatística com o grupo controle.

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OBJECTIVE: This study evaluated the effect of ferrule preparation (Fp) on the fracture resistance of endodontically treated teeth, restored with composite resin cores with or without glass fiber posts. MATERIAL AND METHODS: Forty-four bovine teeth were sectioned 19 or 17 mm (2 mm ferrule) from the apex, endodontically treated and assigned to four groups (n = 11): Group 1: Fp and post; Group 2: Fp and without post; Group 3: without Fp and with post; Group 4: without Fp and without post. All specimens were restored with composite resin core and metal crown. Specimens were subjected to fracture resistance testing in a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed by two-way ANOVA and Tukey's tests (α=0.05). RESULTS: The mean fracture resistance values were as follows: Group 1: 573.3 N; Group 2: 552.5 N; Group 3: 275.3 N; Group 4: 258.6 N. Significantly higher fracture resistance was found for the groups with Fp (p<0.001). CONCLUSION: There was no statistically significant interaction between the "Fp" and "post" factors (p = 0.954). The ferrule preparation increased the fracture resistance of endodontically treated teeth. However, the use of glass fiber post showed no significant influence on the fracture resistance.

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