A new method of adhesive system application improves the bond strength between fiber post and root dentin

Abstract This study evaluated a new method of adhesive system application on the bond strength between fiber post and root dentin using two adhesive systems. The canals of sixty bovine incisors were prepared and obturated. The roots were divided into six groups (n=10) according to the adhesive system (Clearfil SE - CSE and Single Bond Universal - SBU) and the application strategy (microbrush - MB; rotary brush - RB; and ultrasonic tip - US). The glass fiber posts were cemented with resin cement (RelyX ARC). The roots were sectioned perpendicularly to their long axis, and three slices per root were obtained. Previously to the push-out test, confocal laser scanning microscopy (CLSM) was performed to illustrate the interfacial adaptation of the cement to the root canal walls. Failure patterns were analyzed with 40x magnification. Shapiro-Wilk indicated a normal distribution of the data. The bond strength values were compared using one-way ANOVA and Tukey's tests. Student's T test analyzed the differences between the adhesive systems within each third and protocol. A significance level of 5% was used. CSE with RB showed higher mean bond strength values compared to MB (conventional technique) (P < 0.05). US application resulted in intermediate bond strength values for CSE (P > 0.05). The application of SBU using RB generated higher mean bond strength values compared to MB and US (P < 0.05). Adhesive failures were predominant (65.5%). CSE and SBU application with the new rotary brush improved the bond strength of fiber posts to root dentin compared to the conventional strategy.

Resumo Este estudo avaliou o efeito de um novo método para aplicação do sistema adesivo na resistência de união entre pino de fibra e dentina radicular usando dois sistemas adesivos. Os canais de sessenta incisivos bovinos foram preparados e obturados. As raízes foram divididas em seis grupos (n=10) de acordo com o sistema adesivo (Clearfil SE - CSE e Single Bond Universal - SBU) e com a estratégia de aplicação (microbrush - MB, escova rotatória - RB e inserto ultrassônico - US). Os pinos de fibra foram cimentados utilizando cimento resinoso (RelyX ARC). As raízes foram seccionadas perpendicularmente ao seu longo eixo e três fatias foram obtidas. Previamente ao teste de push-out, foi realizada microscopia de varredura confocal a laser para ilustrar a adaptação interfacial do cimento às paredes do canal radicular. Os padrões de falha foram analisados com magnificação de 40x. O teste de Shapiro-Wilk indicou distribuição normal dos dados. Os valores de resistência de união foram comparados usando o teste ANOVA de uma via e post hoc de Tukey. As diferenças entre os sistemas adesivos em cada terço e de acordo com cada protocolo foram analisadas pelo teste T de Student. O nível de significância foi de 5%. CSE aplicado com RB apresentou maiores valores médios de resistência de união do que quando aplicado com MB (técnica convencional) (P<0,05). Aplicação com US apresentou valores intermediários de resistência de união para o CSE (P>0,05). A aplicação do SBU utilizando RB gerou maiores valores médios de resistência de união comparados com MB e US (P<0,05). Falhas adesivas foram predominantes (65,5%). A aplicação do CSE e SBU com a nova escova rotatória melhorou a resistência de união dos pinos de fibra à dentina radicular comparados com a estratégia convencional.

Research progress on the mechanical compatibility of restorative materials with dental tissue / 口腔疾病防治

@#As the main means of mastication, teeth can withstand countless functional contacts. The mechanical properties of teeth are closely related to their tissue structure. Enamel and dentin have a high hardness and modulus of elasticity, and their graded structure allows them to withstand bite forces without being susceptible to fracture. When tooth tissue is defective, full crown restoration is often needed to restore the normal shape and function of the tooth. Metal materials, ceramic materials, and polyetheretherketone (PEEK) materials are commonly used for crown restoration. Metal materials have certain disadvantages in terms of aesthetics and are relatively rarely used in clinical practice. Ceramic materials with different compositions exhibit differences in performance and aesthetics, but their elastic modulus and hardness are much higher than those of dental tissue, resulting in mismatching mechanical properties. In contrast, the elastic modulus of PEEK is lower than that of tooth tissue and similar to that of bone tissue, but its properties can be improved by fiber reinforcement. Notably, when the mechanical properties of a restoration material and tooth tissue are not fully matched, the interface between them often forms a potential weak link, which ultimately affects the stability and long-term effect of the restoration. This article introduces the mechanical properties and corresponding structural characteristics of enamel and dentin. On this basis, the advantages and limitations of existing restoration materials are analyzed, and the possibility of biomimetic design of full crowns is further explored.

Effect of sodium/calcium hypochlorite on adhesion and adaptation of fiber posts luted with a dual resin cement

Abstract This study aimed to evaluate the effect of different concentrations of sodium hypochlorite (NaOCl) and calcium hypochlorite [Ca(OCl)2] on the bond strength and adaptation of glass fiber posts luted with a dual-curing resin cement. Fifty decoronated premolars were sectioned 14 mm from the apex and endodontically treated. The root canal filling was partially removed. The specimens were divided into 5 groups (n=10) according to the irrigant for post space irrigation: 0.9% sodium chloride (NaCl), (control); 2.5% NaOCl; 5.25% NaOCl; 2.5% Ca(OCl)2; and 5.25% Ca(OCl)2. For each group, irrigation was performed with 5 ml of solution. Afterward, the posts were luted with a dual-curing resin cement. One slice from each third was obtained and submitted to the push-out test and failure modes analysis. An additional slice from the middle third was submitted to confocal images for analysis of adaptation failures (gaps). Two-way ANOVA, Tukey's post-hoc, Kruskal-Wallis with Bonferroni adjusted, and chi-square tests, analyzed data. The group treated with 5.25% NaOCl showed lower bond strength values and generated more cohesive failures compared to the control (p < 0.05). Bond strength decreased from coronal to apical in the post space (p < 0.001). The groups treated with NaOCl had the highest percentages of gaps compared to the control (p < 0.05). Regardless of concentration, Ca(OCl)2 did not influence the bond strength and the occurrence of gaps (P > 0.05). Ca(OCl)2 is a good option for irrigating the post space before luting a fiber post with a dual-curing resin cement.

Resumo Este estudo teve como objetivo avaliar o efeito de diferentes concentrações de hipoclorito de sódio (NaOCl) e hipoclorito de cálcio [Ca(OCl)2] na resistência de união e adaptação de pinos de fibra de vidro cimentados com um cimento resinoso dual. Cinquenta pré-molares tiveram suas coroas removidas, foram seccionados a 14 mm do ápice e tratados endodonticamente. A obturação do canal radicular foi parcialmente removida. Os espécimes foram divididos em 5 grupos (n=10) de acordo com o irrigante para irrigação do espaço do pino: cloreto de sódio 0.9% (NaCl), (controle); NaOCl 2.5%; NaOCl 5.25%; Ca(OCl)2 2.5%; e Ca(OCl)2 5.25%. Para cada grupo, a irrigação foi realizada com 5 ml da solução. Posteriormente, os pinos foram cimentados com um cimento resinoso dual. Uma fatia de cada terço foi obtida e submetida ao teste push-out e análise dos modos de falha. Um corte adicional do terço médio foi submetido a imagens confocais para análise de falhas de adaptação (gaps). Os dados foram analisados pelos testes ANOVA de duas vias, post-hoc de Tukey, Kruskal-Wallis com ajuste de Bonferroni e qui-quadrado. O grupo tratado com NaOCl 5.25% apresentou menores valores de resistência de união e gerou mais falhas coesivas em relação ao controle (p < 0.05). A resistência de união diminuiu de coronal para apical no espaço do pino (p < 0.001). Os grupos tratados com NaOCl apresentaram os maiores percentuais de gaps em relação ao controle (p < 0.05). Independentemente da concentração, o Ca(OCl)2 não influenciou a resistência de união e a ocorrência de gaps (P > 0.05). O Ca(OCl)2 é uma boa opção para irrigar o espaço do pino antes de cimentar um pino de fibra com um cimento resinoso dual.

Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts? A systematic review / As soluções de irrigação usadas durante a instrumentação do canal radicular influenciam a adesão de pinos de fibra de vidro? Uma revisão sistemática

Statement of problem: the bond strength between adhesive cement and root dentin can be affected by irrigation protocols. Purpose: therefore, the objective of this systematic review was to answer the following question: Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts to root dentin? Material and Methods: this study followed the recommendations of PRISMA 2020 for writing. PubMed, Scopus, Web of Science, and LILACS databases were searched for articles published until 26 January, 2022. Grey literature and a manual search were also performed. The inclusion criteria were based on the PICO strategy: permanent human or animal teeth (P), which were irrigated during root canal instrumentation with endodontic substances (I) and compared to irrigation with sodium hypochlorite at various concentrations (C) to analyze the bond strength of glass fiber posts (O). Two authors independently performed data extraction and the risk of bias. Results: eight articles were included. Four articles were classified as having a high risk of bias, where the others as medium risk. Studies have reported conflicting results regarding the influence of irrigating solutions and the different concentrations of sodium hypochlorite on the adhesion of glass fiber posts to root dentin. Conclusion: the heterogeneity between studies did not allow the conclusion of a true estimate regarding this topic, and further well-designed studies are needed to clarify this issue. Register: CRD42020221835. (AU)

Definição do problema: a resistência de união entre o cimento adesivo e a dentina radicular pode ser afetada pelos protocolos de irrigação. Objetivo: portanto, o objetivo desta revisão sistemática foi responder à seguinte questão: As soluções de irrigação usadas durante a instrumentação do canal radicular influenciam a adesão de pinos de fibra de vidro à dentina radicular? Material e Métodos: este estudo seguiu as recomendações do PRISMA 2020 para sua redação. As bases de dados PubMed, Scopus, Web of Science e LILACS foram pesquisadas para artigos publicados até 26 de janeiro de 2022. A literatura cinza e uma pesquisa manual também foram realizadas. Os critérios de inclusão foram baseados na estratégia PICO: dentes humanos ou animais permanentes (P), que foram irrigados durante a instrumentação do canal radicular com substâncias endodônticas (I) e comparados à irrigação com hipoclorito de sódio em várias concentrações (C) para analisar a resistência de união de pinos de fibra de vidro (O). Dois autores realizaram independentemente a extração de dados e o risco de viés. Resultados:oito artigos foram incluídos. Quatro artigos foram classificados como de alto riscode viés, enquanto os demais como de médio risco. Estudos relataram resultados conflitantes sobre a influência de soluções irrigadoras e as diferentes concentrações de hipoclorito de sódio na adesão de pinos de fibra de vidro à dentina radicular. Conclusão: a heterogeneidade entre os estudos não permitiu a conclusão de uma estimativa verdadeira sobre este tópico, sendo necessários mais estudos bem delineados para esclarecer esta questão. Registo: CRD42020221835 (AU)

Application prospect of polyetheretherketone in postcore crown restorations / 口腔疾病防治

@#Polyetheretherketone (PEEK) is known as a high-grade engineering plastic with good mechanical properties, chemical stability and biocompatibility. Currently, PEEK materials have been widely used in prosthodontics, such as complete dentures and removable partial dentures. The relevant research shows that PEEK posts are superior to glass fiber posts, which have high tensile bond strength and bending strength. At present, few case reports of PEEK postcores have been published, and clinical case reports suggest that PEEK postcores have good oral prosthetic aesthetics and are ideal and reliable postcore crown materials. However, the preparation and surface treatment methods of PEEK require further refinement. A review of the related properties of PEEK and the prospects of its application in the field of postcore crown restoration will be presented in this paper.

Evaluation of The Cleaning Protocol of Post Space on Bond Strength of Glass Fiber Posts

ABSTRACT: This study aimed to compare the effect of four irrigation solutions for post space cleaning on the bond strength between glass fiber post and root dentine. Forty bovine roots were root-filled and randomly divided into four groups (n=10), according to the irrigation solution: CG (Control Group): saline solution; SH (Sodium Hypochlorite Group); CLX (Chlorhexidine group) and EDTA (ethylenediaminetetraacetic acid group). Specimens were submitted to mechanical aging and push-out test. Statistical analysis (ANOVA two-way and Tukey test; p<0.05) was performed. A stereomicroscope was used for failure mode classification. EDTA showed higher bond strength values, differing statistically from SH and CG (p<0.05). Adhesive failure between dentin and resinous cement was predominant, followed by mixed failures. SEM images showed pronounced smear layer removal in the EDTA group. 17 % EDTA was better than other solutions for cleaning of post space when using glass fiber posts.

RESUMEN: Este estudio tuvo como objetivo comparar el efecto de cuatro soluciones de irrigación para la limpieza del espacio del poste sobre la fuerza de unión entre el poste de fibra de vidrio y la dentina radicular. Se rellenaron cuarenta raíces bovinas y se dividieron aleatoriamente en cuatro grupos (n = 10), según la solu- ción de riego: CG (Grupo Control): solución salina; SH (Gru- po de hipoclorito de sodio); CLX (grupo clorhexidina) y EDTA (grupo ácido etilendiaminotetraacético). Las muestras se sometieron a una prueba de envejecimiento mecánico y de expulsión. Se realizó análisis estadístico (ANOVA bidireccional y prueba de Tukey; p <0,05). Se utilizó un microscopio estereoscópico para la clasificación del modo de falla. EDTA mostró valores de fuerza de unión más altos, difiriendo estadísticamente de SH y CG (p <0,05). Pre-dominó la falla adhesiva entre dentina y cemento resinoso, seguida de fallas mixtas. Las imágenes SEM mostraron una eliminación pronunciada de la capa de frotis en el grupo de EDTA. El EDTA al 17 % fue mejor que otras soluciones para la limpieza del espacio de los postes cuando se utilizan postes de fibra de vidrio.

Evaluation of stress in three different fiber posts with two-dimensional finite element analysis

Introduction: The primary function of corono-radicular post is to provide retention for the core and to reinforce and to replace the remaining coronal tooth structure. There is considerable controversy regarding optimal choice of the material. An ideal post system should exhibit fracture resistance higher than the average masticatory forces. Finite elemental analysis (FEA) method facilitates precise analysis of the distribution and magnitude of stresses at any point of complex and irregular structures. Thus, this FEA study has been undertaken to evaluate the fracture stress distribution patterns in three fiber posts, viz., carbon, glass fiber, and everStick with an FEA. Materials and Methods: The FE stress analysis was performed with the FE software program (CATIA). Three two-dimensional FEA models of central incisor were simulated, and elastic moduli and Poisson's ratio of all the materials were fed to the software. For all the models, a 200 N vertical force was applied on the lingual surface of the tooth at an angle of 45°. Stress concentration and distribution were evaluated and noted down for all the models. To evaluate the stresses within the restored tooth, the modified von Mises failure criterion was used. The equivalent stresses found in the tested models were compared with the tensile strength of the respective materials. Contact stresses in the luting cement–dentin interface were calculated. Results: Finite element method revealed that maximum stress concentration was at the point of stress application. The stress value was highest in carbon fiber post followed by glass fiber post and least stresses found in everStick post. Maximum stress was observed at the labial surfaces of crown. However, the stress values and distribution were more homogenous in everStick post. Conclusion: The present findings suggest that everStick post has uniform stress distribution within tooth structure.

Resistência de união de pinos de fibra de vidro utilizando diferentes tratamentos radiculares / Resistencia a la unión de postes de fibra de vidrio utilizando diferentes tratamientos endodónticos / Bond strength of glass fiber posts using different endodontic treatments

Resumo Introdução: Os pinos de fibra de vidro têm sido amplamente utilizados na reconstrução de elementos com perda excessiva de estrutura dentária. Objetivo: Avaliar a força de adesão de pinos de fibra de vidro após diferentes tratamentos radiculares em diferentes regiões (terço cervical, médio e apical) da dentina radicular. Métodos: Este é um estudo experimental in vitro. Quarenta dentes bovinos foram selecionados, preparados e distribuídos em quatro grupos de acordo com o tratamento de superfície utilizado: adesivo (1), agente quelante (2), ácido poliacrílico (3), não tratado (4). A cimentação dos pinos de fibra de vidro foi realizada com cimento resinosante autocondicionante. Após vinte dias, cada raiz foi cortada em três fatias (um milímetro de espessura) obtidas de três regiões. A resistência de união de cada seção foi determinada usando um teste de resistência da junta de encaixe. Os dados de resistência à flexão (MPa) foram analisados pelos testes ANOVA e Tukey (α = 0,05). Resultados: Na porção cervical, o grupo com tratamento prévio com ácido poliacrílico apresentou menor resistência ao cisalhamento por extrusão (push-out) do que o grupo sem tratamento prévio. O grupo com aplicação do sistema adesivo (28,89 ± 6,64 MPa) e o grupo com tratamento prévio com EDTA (21,58 ± 6,39 MPa) não apresentaram diferenças estatisticamente significantes em relação ao grupo sem tratamento prévio (grupo controle) no terço cervical. Nas porções média e apical, o grupo tratado com adesivo FGM Ambar apresentou maiores valores de ligação em comparação com os outros grupos. Conclusão: A aplicação prévia do adesivo aumentou a resistência de união nos terços médio e apical, em comparação aos outros grupos, podendo ter um efeito benéfico no sucesso clínico do tratamento restaurador(AU)

Resumen Introducción: Los postes de fibra de vidrio se han utilizado ampliamente en la reconstrucción de elementos con pérdida excesiva de estructura dental. Objetivo: Evaluar la fuerza de adhesión de postes de fibra de vidrio después de distintos tratamientos de raíz en diferentes regiones (tercios cervical, medio y apical) de dentina de raíz. Métodos: Estudio experimental in vitro. Se seleccionaron cuarenta dientes bovinos, se prepararon y se distribuyeron en cuatro grupos de acuerdo con el tratamiento de superficie utilizado: (1) adhesivo, (2) agente quelante, (3) ácido poliacrílico, (4) sin tratar. La cementación de los postes de fibra de vidrio se realizó con cemento de resina autograbante. Después de 20 días, cada raíz se seccionó transversalmente en tres rodajas (1 mm de espesor) obtenidas de tres regiones. La resistencia a la unión de cada sección se determinó usando una prueba de resistencia al corte por extrusión (push-out). Los datos de resistencia a la flexión (MPa) se analizaron mediante pruebas ANOVA y Tukey (α = 0,05). Resultados: En la porción cervical, el grupo con tratamiento previo de ácido poliacrílico mostró menor resistencia que el grupo sin tratamiento previo. El grupo con aplicación del sistema adhesivo (28,89 ± 6,64 MPa) y el grupo con tratamiento previo de EDTA (21,58 ± 6,39 MPa) no presentaron diferencias estadísticamente significativas en comparación con el grupo sin tratamiento previo (grupo control) en el tercio cervical. En las porciones media y apical, el grupo tratado con adhesivo Ambar® de FGM Dental Group mostró valores más altos de unión en comparación con los otros grupos. Conclusión: La aplicación previa del adhesivo aumentó la fuerza de unión en los tercios medio y apical, en comparación con los otros grupos, puede tener un efecto beneficioso sobre el éxito clínico del tratamiento restaurador(AU)

ABSTRACT Introduction: Glass fiber posts have been widely used for the reconstruction of elements with excessive dental structure loss. Objective: Evaluate the bond strength of glass fiber posts after various root dentin treatments in different regions (cervical, middle and apical thirds). Methods: An experimental in vitro study was conducted. Forty bovine teeth were selected, prepared and distributed into four groups according to the surface treatment used: (1) adhesive, (2) chelating agent, (3) polyacrylic acid, (4) not treated. The glass fiber posts were cemented with self-etch resin cement. After 20 days, each root was sectioned crosswise into three slices (1 mm in thickness) obtained from three regions. Bond strength was determined in each section with a push-out bond strength test. Flexural strength data (MPa) were analyzed with ANOVA and Tukey's tests. Results: In the cervical portion, the group with previous polyacrylic acid treatment displayed lower push-out strength than the group without previous treatment. The group with application of the adhesive system (28.89 ± 6.64 MPa) and the group with previous EDTA treatment (21.58 ± 6.39 MPa) did not exhibit any statistically significant differences in comparison with the group without previous treatment (control group) in the cervical third. In the middle and apical portions, the group treated with the adhesive Ambar® of FGM Dental Group showed higher bond values in comparison with the other groups. Conclusion: Previous adhesive application increased bond strength in the middle and apical thirds in comparison with the other groups, and may thus have a beneficial effect on the clinical success of the restorative treatment(AU)

Comparison of the interdiffusion of four self-etching adhesives in resin-aged glass-fiber-reinforced composites / 口腔疾病防治

Objective@#To observe the permeability of four kinds of self-etching adhesives in aged glass-fiber-reinforced composite (GFRC).@*Methods@#After light polymerization following the manufacturers’ instructions, a total of 80 pieces of bisphenol-A-glycodal-methacrylate (Bis-GMA)+ polymethyl methacrylate (PMMA) based GFRC were randomly divided into two main groups: test group and control group, each group was then divided into four subgroups with 10 samples for each subgroup. While the test group was conducted to be aged through thermocycling at 5 ℃/55 ℃, the control group remained fresh. After the addition of a fluorescent dye (rhodamine-B-isothiocyanate), four self-etching adhesives AdperEasy One (AEO), S 3 BOND (S 3B), Tetric N-Bond Self-Etch (TNB), G-Bond (GB) were correspondently applied to the test and control groups and were light polymerized. Specimens were sectioned using hard tissue cutting and grinding system. Slices from each subgroup were observed under a confocal laser scanning microscope, the depth of dye permeation (DDP) under the surface of GFRC in each group was measured and the Results were statistically analyzed.@*Results@#The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @*The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @#The self-etching adhesives of AEO and S 3 B still have good permeation effect in this kind of aged GFRC, which can help to establish a good bond between these aged GFRC and the subsequent repair of composite resin.

Effect of surface treatment reagents and treatment time on bond strength of glass fiber posts to resin cement / 中国组织工程研究

BACKGROUND: At present, there is no uniform standard for the treatment time of chemical reagents for surface treatment of glass fiber posts. Therefore, studying the effect of treatment time of glass fiber post surface treatment reagents on the bond strength between fiber posts and resin cements is of great significance. OBJECTIVE: To evaluate the effect of two chemical agents on the bonding strength of glass fiber post and resin cement after surface pretreatment of glass-fiber posts at different times. METHODS: Forty-eight glass fiber posts were randomly divided into eight groups according to different surface treatment methods, six in each group. Group A received no special treatment; group B was treated with silanization for 1 minute; group C1 underwent a 30% hydrogen peroxide surface treatment for 5 minutes prior to 1-minute silanization; group C2underwent a 30% hydrogen peroxide surface treatment for 10minutes prior to 1-minutesilanization; group C3 underwent a 30% hydrogen peroxide surface treatment for 15 minutes prior to 1-minute silanization; group D1 underwent a 35% phosphoric acid surface treatment for 30 seconds prior to 1-minute silanization; group D2 underwent a 35% phosphoric acid surface treatment for 60 seconds prior to 1-minute silanization; group D3 underwent a 35% phosphoric acid surface treatment for 90 seconds prior to 1-minute silanization. The surface morphology of the treated glass fiber posts was observed under scanning electron microscope. The glass fiber post was bonded to the resin cement to form a cylindrical resin block and cut into a thin sample. The sheet was placed on a universal testing machine for micro-extrusion experiments. The failure mode of the specimens was observed under a stereomicroscope. RESULTS AND CONCLUSION: (1) Scanning electron microscope: the surface of the fiber post had different degrees of matrix dissolution and fiber bundle exposure after hydrogen peroxide and phosphoric acid treatment, but did not destroy the integrity of the fiber bundle. (2) Micro-extrusion experiments: the order of the bonding strength was as follows: group C3 > group C2 > group C1 > group D2 > groupD3 > groupD1> group B > group A, and there was significant difference between groups (P< 0.05) except for groups A and B, groups C2 andC3, and groups D2and D3. (3) Stereo microscope: the failure mode in the groups A and B was almost destruction in adhesion. The other six groups showed destruction in adhesion, but the cohesive failure and mixed failure were increased, and the failure mode changed from destruction in adhesion into cohesive failure and mixed failure. (4) These results indicate that the optimal treatment time of 30% hydrogen peroxide is 10 minutes, and the optimal treatment time of 35% phosphoric acid is 60 seconds. 30% hydrogen peroxide solution treatment of fiber post surface for 10 minutes has great clinical application value.

Oval versus circular-shaped root canals: bond strength reached with varying post techniques

Abstract The aim of this study was to compare the bond strength (BS) of glass fiber posts (GFP) luted to oval and circular-shaped root canals rehabilitated using varying post techniques, at different intraradicular levels. Ninety 16-mm-long roots of human mandibular premolars, classified either as having oval or circular-shaped canals, were endodontically treated and prepared for restoration using one of three different post techniques (n=15): 1) single GFP; 2) resin-relined GFP; 3) main GFP associated with accessory posts. GFPs were luted with a dual polymerizing resin cement (RelyX ARC) after the canal had been treated with a 3-step etch-and-rinse adhesive system (Adper Scothbond Multipurpose). The samples were sectioned into three 1-mm-thick sections, which were differentiated by the root level (cervical, middle and apical) and tested for push-out BS. Assessment of failure mode was made under a stereomicroscope. Data were analyzed using repeated measures three-way ANOVA and Tukey's test. The root canal cross-section had a significant influence on BS (p<0.001), with the lowest values being observed in oval-shaped canals. The post technique also significantly affected the BS (p=0.018), with the resin-relined GFPs providing the highest BS values in both oval and circular-shaped canals. Irrespective of the cross-section of the root canal and post technique, there was no significant difference in BS in the cervical, middle and apical third of the root canal (p=0.084). In oval-shaped canals, the BS to intraradicular dentin at cervical, middle or apical level could be increased when the GFPs posts were relined.

Resumo O objetivo deste estudo foi comparar a resistência de união (RU) de pinos de fibra de vidro (PFV), cimentados a condutos com secção transversal ovalada ou circular reabilitados com diferentes técnicas de restauração com PFVs, em função do nível intrarradicular. Noventa raízes de pré-molares inferiores humanos, com 16 mm de altura, classificadas como possuindo canais ovais ou circulares, foram tratadas endodonticamente e preparadas para serem reabilitadas com uma das três técnicas de restauração com PFVs (n=15): 1) PFV único, 2) PFV reembasado com resina composta, e 3) PFV principal associado a pinos acessórios. Os PFVs foram cimentados com um agente resinoso de polimerização dupla (RelyX ARC), após o canal ter sido tratado com um sistema adesivo de condicionamento total de três passos (Adper Scothbond Multiuso). As amostras foram seccionadas em três fatias de 1 mm de espessura, de acordo com o nível da raiz (cervical, médio e apical)e foram submetidas ao teste de RU por push-out. A análise do modo de falha foi realizada com auxílio de um estereomicroscópio. Os dados foram analisados utilizando-se a ANOVA a três critérios para medidas repetidas e o teste de Tukey. A secção do conduto apresentou influência na RU (p<0,001), com os menores valores sendo observados nos condutos ovalados. A técnica de restauração com PFVs afetou significativamente a RU (p=0,018), tendo o PFV reembasado proporcionado os maiores valores de RU, tanto em condutos ovais quanto circulares. Independentemente da secção transversal do conduto radicular e da técnica de restauração com PFV, não houve diferença significativa na RU nos terços cervical, médio e apical (p=0,084). Nos canais de secção transversal ovalada, a RU à dentina intrarradicular nos níveis cervical, médio ou apical aumentou com o emprego de PFVs reembasados.

Alternativa estética ante la pérdida de piezas primarias en el sector anterior: resolución clínica / Esthetic alternative to the loss of primary pieces in the previous sector

La pérdida de piezas permanentes en el sector anterior sigue siendo una preocupación clínica en el tratamiento odontológico de niños y adolescentes. Es importante destacar que la pubertad y la adolescencia son etapas donde las relaciones con los pares son de suma importancia. Las restauraciones protéticas convencionales no cumplen las expectativas estéticas, pero siguen siendo el tratamiento de elección, ya que los implantes solo pueden ser realizados una vez finalizados el crecimiento y el desarrollo. Los sistemas adhesivos mediante cinta de fibra de vidrio han simplificado el trabajo, brindando una alternativa intermedia conservadora y estética. El objetivo de este trabajo es presentar la resolución clínica en dos pacientes que concurrieron a la Cátedra de Odontología Integral Niños luego de haber sufrido traumatismos que provocaron la pérdida de piezas dentarias permanentes logrando la restitución de la longitud de arco, la devolución de la estética y la fonación con la colocación de una prótesis tipo Maryland, realizada con cinta de fibra de vidrio preimpregnada con resina compuesta (AU)

Premature loss of anterior permanent teeth is still a cause for concern in dental treatment of children and adolescents. Social relationships with peers are particularly important during puberty and adolescence. Removable prosthesis has always been a choice but they may not satisfy patients' esthetic expectations and dental implants can only be placed after the jaw has finished growing. Adhesive directly bonded splints with glass fibers reinforced composite resins can be an alternative to conventional space maintainers. The aim of this report is to describe the treatment of two patients who attended at the Department of Comprehensive Children´s Dentistry after suffering traumatic dental injuries using bridges as an approach to restore arch length, esthetics and function (AU)

Application effect of glass fiber pile and cast metal pile in tooth defect repair and its influence on periodontal tissue / 中国基层医药

Objective To analyze the application effect of glass fiber pile and cast metal pile in tooth defect repair and its influence on periodontal tissue.Methods From February 2014 to February 2015,112 patients with dental defect in the Central Hospital of Yiwu were randomly divided into the control group and the research group according to the digital table,with 56 cases in each group.The control group received the casting metal pile repair,the research group was repaired with glass fiber piles.The remediation effect,periodontal tissue status,inflammatory response and adverse reaction were compared between the two groups.Results The success rate of the research group was significantly higher than that of the control group(89.29％vs.66.07％),and there was statistically significant difference(χ2 =8.70,P<0.05).After treatment,the alkaline phosphatase,interleukin-6(IL-6)and interleukin-8(IL-8)levels of the two groups were increased compared with before treatment,which of the research group were obviously lower than those of the control group [(440.75 ±55.75)U/L vs.(491.75 ±62.59)U/L,(18.77 ± 2.21)ng/L vs.(30.65 ±3.97)ng/L,(51.42 ±6.32)μg/L vs.(76.33 ±9.50)μg/L],there were statistically significant differences(t=4.52,19.56,16.33,all P<0.05).After treatment,the periodontal examination depth of the two groups was(2.15 ±0.29)mm and(2.17 ±0.25)mm,respectively,and there was no statistically significant difference(t=0.39,P>0.05).Conclusion The effect of glass fiber pile in tooth defect repair is better than cast metal pile,and its stability and biocompatibility are better,and it is a simple operation,which is worthy of clinical promotion.

Evaluación de la resistencia adhesiva entre el poste de fibra de vidrio y el muñón de resina utilizando diferentes tratamientos de superficie / Tensile Bond strength evaluation between glass fiber post and resin core using different surface treatments

La calidad de unión entre la superficie del poste de fibra de vidrio y el muñón es esencial para formar un solo núcleo. Si esta unión es afectada, ocasionaría una mala distribución de las fuerzas oclusales. Objetivos: Comparar la resistencia adhesiva entre el poste de fibra de vidrio y muñón de resina utilizando diferentes tratamientos de superficie. Material y métodos: La resistencia adhesiva se evaluó mediante el método de tracción. El diseño del estudio fue analítico, corte transversal y experimental in vitro.La población estuvo conformada por postes de fibra de vidrio estériles. El tamaño muestral fue de 24 postes; fueron divididos en cuatro grupos según el tratamiento de superficie: Grupo I, control negativo, con silano (60s); grupo II, control positivo, con peróxido de hidrógeno al 9%(30 volúmenes, 10min) seguido de lavado y silano (60s); grupo III y IV, grupos experimentales, con ácido fosfórico al 37%(15s) lavado y silano(60s) y con clorhexidina al 2%(60s) lavado y silano (60s).Luego, se elaboró un muñón para cada poste, la muestra fue colocada en la máquina de ensayo universal. La fuerza de tracción fue recopilada en Mpa. Resultados: Se determinó que el grupo silano obtuvo una media de 15,38; peróxido de hidrógeno al 9%+silano 20,28; ácido fosfórico al 37%+silano17,08; y clorhexidina al 2%+silano 13,44 Según la prueba de Shapiro Wilk, los cuatro grupos presentan distribución normal (p>0,05) y siguiendo la prueba de Barlett, se aprobó el supuesto de homogeneidad (p>0,05). Mediante la prueba multivariada de ANOVA; se determinó que existe diferencia estadística (p=0,0194), al menos, en un par de los cuatro grupos. Conclusiones: Existe diferencia estadísticamente significativa entre el grupo de peróxido de hidrógeno al 9%(30 volúmenes, 10 min)+silano(60s) y clorhexidina al 2%(60s)+silano(60s) (p=0,025), siendo el primero, la sustancia con mayor resistencia adhesiva.

The interface quality between the glass fiber post surface and core is essential to form a monoblock. If this interface is affected, a wrong distribution of occlusal forces could be caused. Objectives: To determine the bond strength between the glass fiber post and the resin core using different post surface treatments. Material and methods: The bond strength was evaluated by the traccional method. The study design was analytical, cross-sectional and experimental in vitro. The population were sterilized glass fiber posts. The sample size were 24 posts which were divided into four groups following the post surface treatment: Group I, negative control, with silane (60s); group II, positive control, with 9% hydrogen peroxide (30 volumes, 10min) followed by cleansing and silane (60s); groups III and IV, experimental groups, with phosphoric acid 37%(15s) followed by cleansing and silane(60s) and with clorhexidine 2%(60s) followed by cleansing and silane(60s). Therefore, a resin core was devised for each post, the sample was placed in the universal traction machine. The tensile force was collected in Mpa. Results: It was determined that the silane group obtained a mean of 15.38, 9% hydrogen peroxide+silane group 20.28, phosphoric acid 37%+silane group 17.08, and Clorhexidine 2% + silane group 13.44. According to the Shapiro-Wilk test, all four groups presented normal distribution (p>0.05) and following Barlett's test, the homogeneity of variances assumption was approved (p>0.05). Through the multifactor ANOVA test, it was determined that there is statistically significant difference (p=0.0194), at least in a couple of four groups. Conclusions: There is statistically significant difference between 9% hydrogen peroxide(30 volumes, 10min)+silane(60s) group and the Clorhexidine 2% (60s)+ silane(60s) group (p=0,025). Being the former glass surface treatment, the highest bond strength.

Observation of 120 cases of teeth with severe wedge-shaped defect treated with glass fiber post combined ;with gingival retraction / 中国基层医药

Objective To observe the effect of glass fiber post combined with gingival retraction in the treat-ment of teeth with severe wedge -shaped defect.Methods 53 patients with 120 teeth treated for severe wedge -shaped defect were selected.All the teeth were given root canal treatment,glass fiber post was applied after root canal prepared and resin was applied to fill wedge-shaped defect after gingival retraction.All the teeth were followed up for 2-3 years.Results In 2-3 years follow-up after treatment,there was no adverse outcome such as crown fracture or root fracture,neither filling material falling off in all the 53 patients with 120 teeth.The effect was good and satis-fied.Conclusion The indication should be strictly grasped and then it is convenient to apply glass fiber post com-bined with gingival retraction to treat premolar with severe wedge -shaped defect,and complete coronal restoration should be avoided to reduce the cost of health care.

Comparison of the fracture resistances of glass fiber mesh- and metal mesh-reinforced maxillary complete denture under dynamic fatigue loading

PURPOSE: The aim of this study was to investigate the effect of reinforcing materials on the fracture resistances of glass fiber mesh- and Cr–Co metal mesh-reinforced maxillary complete dentures under fatigue loading. MATERIALS AND METHODS: Glass fiber mesh- and Cr–Co mesh-reinforced maxillary complete dentures were fabricated using silicone molds and acrylic resin. A control group was prepared with no reinforcement (n = 15 per group). After fatigue loading was applied using a chewing simulator, fracture resistance was measured by a universal testing machine. The fracture patterns were analyzed and the fractured surfaces were observed by scanning electron microscopy. RESULTS: After cyclic loading, none of the dentures showed cracks or fractures. During fracture resistance testing, all unreinforced dentures experienced complete fracture. The mesh-reinforced dentures primarily showed posterior framework fracture. Deformation of the all-metal framework caused the metal mesh-reinforced denture to exhibit the highest fracture resistance, followed by the glass fiber mesh-reinforced denture (P<.05) and the control group (P<.05). The glass fiber mesh-reinforced denture primarily maintained its original shape with unbroken fibers. River line pattern of the control group, dimples and interdendritic fractures of the metal mesh group, and radial fracture lines of the glass fiber group were observed on the fractured surfaces. CONCLUSION: The glass fiber mesh-reinforced denture exhibits a fracture resistance higher than that of the unreinforced denture, but lower than that of the metal mesh-reinforced denture because of the deformation of the metal mesh. The glass fiber mesh-reinforced denture maintains its shape even after fracture, indicating the possibility of easier repair.

Influence of the Resin Cement Thickness on the Push-Out Bond Strength of Glass Fiber Posts

Abstract The objective of the present study was to evaluate the influence of resin cement thickness on the bond strength of prefabricated and customized glass fiber posts after storage in distilled water. Thirty human uniradicular roots were treated endodontically. The roots were divided into 3 groups: THIN (thin cement layer) - post space preparation with #0.5 drill and cementation of #0.5 post; THICK (thick cement layer) - post space preparation with #1 drill and cementation of #0.5 post; and CUSTOM (customized cement layer) - post space preparation with #1 drill and cementation of a customized post (#0.5 glass fiber posts customized with resin composite). All posts were luted with self-adhesive resin cement. The push-out test was carried out after storage for 24 h and 90 days in distilled water at 37 °C. The data were analyzed with three-way ANOVA and Tukey's test (a=0.05). Bond strengths were significantly higher for CUSTOM (9.37 MPa), than for THIN (7.85 MPa) and THICK (7.07 MPa), which were statistically similar. Considering the thirds, the bond strength varied in the sequence: apical (7.13 MPa) < middle (8.22 MPa) = coronal (8.94 MPa). Bond strength for 24 h storage was significantly higher (8.80 MPa) than for 90-day storage (7.40 MPa). It may be concluded that the thickness of resin cement influenced the bond strength of glass fiber posts. The customized posts presented higher bond strength. Storage in water for 90 days affected negatively the values of bond strength, especially for thick cement layers in the apical third.

Resumo O objetivo deste estudo foi avaliar a influência da espessura da linha de cimento na resistência de união de pinos de fibra de vidro após armazenamento em água destilada. Trinta dentes humanos hígidos unirradiculares tiveram os canais tratados endodonticamente. As raízes foram distribuídas em três grupos: THIN (linha de cimento fina): conduto preparado com broca 0,5 e cimentação de pino 0,5; THICK (linha de cimento espessa): conduto preparado com broca 1 e cimentação de pino 0,5; e CUSTOM (linha de cimento personalizada): conduto preparado com broca 1 e cimentação de pino personalizada (pino 0,5 personalizado com resina composta). Os pinos foram cimentados com cimento auto-adesivo. Após armazenamento das raízes em água destilada a 37 °C por 24 h e 90 dias, o teste de cisalhamento por extrusão push-out foi realizado. Os resultados foram analisados estatisticamente por ANOVA a três fatores e teste de Tukey (a=0,05). A resistência de união foi significativamente maior para CUSTOM (9,37 MPa), do que para THIN (7,85 MPa) e THICK (7,07 MPa), que foram semelhantes entre si. Considerando-se os terços radiculares, a resistência de união variou na sequência: apical (7,13 MPa) < médio (8,22 MPa) = coronal (8,94 MPa). A resistência de união após 24 h de armazenamento em água foi significativamente maior (8,80 MPa) do que para 90 dias (7,40 MPa). Pode-se concluir que houve influência da espessura da linha de cimento na resistência de união de pinos de fibra de vidro, sendo que o uso de pinos personalizados apresentou maiores valores de resistência de união. O armazenamento em água por 90 dias afetou negativamente os valores de resistência de união, especialmente no terço apical, no grupo com linha de cimento mais espessa.

Resistencia a la fractura de postes de fibra de vidrio vs postes colados en dientes anteriores. Revisión sistemática / Fracture Resistance of fiberglass post vs cast post in anterior teeth. Systematic review

Los dientes anteriores con tratamiento endodóntico y con pérdida de estructura dental usualmente son restaurados con postes de fibra de vidrio o con postes colados, y son susceptibles a presentar fallas que pueden llegar a ocasionar la pérdida dental por no ser rehabilitables. Se propone aquí, identificar cuál entre los dos tipos de postes: prefabricados de fibra de vidrio o postes colados, es más resistente a la fractura debido a las fuerzas biomecánicas compresivas o tensionales que se suceden en los dientes anteriores rehabilitados con coronas respecto a la fractura del poste, de la raíz o el desalojo de este. Se realizó una revisión sistemática de la literatura, con información recolectada desde las bases de datos de los buscadores: PubMed, Scielo, Lilacs y Science Direct. Noventa y tres artículos sobre el tema fueron tamizados según los criterios de selección. Cuatro cumplieron con este procedimiento y se encontró que la resistencia a la fractura tiende a ser mayor en dientes restaurados con postes colados, pero cuando se presenta una fractura es desfavorable para el retratamiento restaurativo. En el caso de los postes de fibra de vidrio se presenta mejor resistencia a la fractura y presentan un patrón por lo general más favorable para un retratamiento en caso de éste fracaso.

Anterior teeth with endodontic treatment and loss of tooth structure are usually restored with glass fiber posts or cast cores, which are susceptible to present failures that may potentially cause tooth loss because they are not able to be restored again. It is proposed here to identify which of the two types of posts: prefabricated fiberglass or cast posts, is more resistant to fracture due to biomechanical forces of compression that occur in the anterior teeth restored with crowns respect to fracture post , root or eviction of this. A systematic review of the literature was conducted with information gathered from the databases of search engines: PubMed, Scielo, Lilacs and Science Direct. Ninety three articles on the topic were screened according to the selection criteria. Four cumplied with this procedure and found that fracture resistance tends to be grater in teeth restored with cast posts, but when a tracture accors is untaorubale for a restorative retreat. In the case of fiberglass posts and greater remaining height structure better fracture resistance is presented, and they present a pattern usually more favorable for retreatment in case of fracture.

Acid Etching and Surface Coating of Glass-Fiber Posts: Bond Strength and Interface Analysis

Abstract The aim of this study was to evaluate the bond strength of a composite resin to glass-fiber post (GFP) treated or not with phosphoric acid, silane coupling agent, and unfilled resin. GFPs were etched or not with 37% phosphoric acid and different surface coating applied: silane coupling agent, unfilled resin, or both. Composite resin blocks were built around a 4-mm height on the GFP. Unfilled resin (20 s) and composite resin (40 s) were light activated by a light-emitting diode unit. The specimens were stored in distilled water at 37 °C for 24 h. Microtensile bond test was performed using a mechanical testing machine until failure (n=10). The data were analyzed using two-way ANOVA followed by Student-Newman-Keuls' test (p<0.05). Failure modes were classified as adhesive, mixed, or cohesive failures. Additional specimens (n=3) were made to analyze the bonded interfaces by scanning electron microscopy. The statistical analysis showed the factor 'surface coating' was significant (p<0.05), whereas the factor 'HP etching' (p=0.131) and interaction between the factors (p=0.171) were not significant. The highest bond strength was found for the silane and unfilled resin group (p<0.05). A predominance of adhesive and cohesive failures was found. Differences regarding the homogeneity and thickness of the unfilled resin layer formed by different GFP surface treatments were observed. The application of silane and unfilled resin can improve the bond strength between GFP and resin composite.

Resumo O objetivo deste estudo foi avaliar o efeito resistência de união de uma resina composta para pinos de fibra de vidro (PFV) tratados ou não com ácido fosfórico, agente de união (silano) e adesivo. PFVs foram condicionados ou não com ácido fosfórico 37% e receberam aplicação de diferentes materiais: um agente de união, um adesivo, ou ambos. Blocos em resina composta foram construídos a 4 mm de altura no PFV. O adesivo (20 s) e a resina composta (40 s) foram fotoativado por um diodo emissor de luz. As amostras foram armazenadas em água destilada a 37 C por 24 h. O teste de microtração foi realizado em uma máquina de ensaio universal (n=10). Os dados foram analisados usando ANOVA dois fatores e teste de Student-Newman-Keuls (p<0,05). Os padrões de fratura foram classificados em falhas adesivas, mistas ou coesivas. Amostras adicionais (n=3) foram feitas para análise da interface de união em microscopia eletrônica de varredura. A análise estatística mostrou que o fator 'recobrimento da superfície' foi significante (p<0,05), enquanto que o fator 'ácido fosfórico' (p=0,131) e a interação entre os fatores (p=0.171) não foram significantes. A maior resistência da união foi encontrada para os grupos silano e adesivo (p<0,05). Uma predominância de falhas adesivas e coesivas foi encontrada. Foram observadas diferenças em relação à homogeneidade e espessura da camada adesiva formada sobre os PFV com os diferentes tratamentos de superfície. Aplicação de silano e adesivo pode melhorar a resistência de união entre PFV e resina composta.

Fracture Resistance of Simulated Immature Teeth after Different Intra-radicular Treatments

The aim of this study was to evaluate the fracture resistance of simulated immature teeth after different intra-radicular treatments. Crowns and roots of bovine incisors were cut transversally and removed to simulate immature teeth. Root canal preparation and flaring were performed using a bur in crown-apex and apex-crown direction. The samples were distributed into 5 groups (n=10): Positive control (PoC) - no root canal flaring or filling; Negative control (NeC) - teeth were sectioned and their root canals were flared; Direct anatomical glass fiber post (RaP) - #2 Reforpost main glass fiber post relined with composite resin; Double tapered conical glass fiber posts (ExP) - #3 Exacto glass fiber post; and #2 Reforpost main glass fiber + Reforpin accessory glass fiber posts (RrP). In RaP, ExP and RrP, 4.0-mm apical plugs were done with MTA Angelus. The specimens were embedded in polystyrene resin inside cylinders and the periodontal ligament was simulated with a polyether-based impression material. The specimens were submitted to compressive fracture strength test (0.5 mm/min at 135° relative to the long axis of the tooth) in a servo-hydraulic mechanical testing machine MTS 810. Data were subjected to one-way ANOVA and Dunnett's C or Tukey's tests (α=0.05). The control groups (PoC and NeC) showed lower fracture strength than the experimental groups. NeC presented the lowest resistance and ExP presented the highest resistance among the experimental groups. The flaring procedures produced a detrimental effect on the fracture resistance of the bovine teeth. Glass fiber intra-radicular posts increased significantly the fracture resistance of simulated immature teeth.

O objetivo deste estudo foi avaliar a resistência à fratura de dentes com rizogênese incompleta simulada após diferentes tratamentos intra-radiculares. A rizogênese incompleta foi simulada pelo seccionamento das coroas e raízes de incisivos bovinos. O preparo e alargamento do canal radicular foram realizados utilizando uma broca no sentido coroa-ápice e ápice-coroa. As amostras foram distribuídas (n=10) em cinco grupos: controle positivo (PoC) - sem preparo do canal radicular e sem obturação; controle negativo (NeC) - os dentes foram seccionados e os canais radiculares foram preparados; pino anatômico direto Reforpost #2 (RaP) - pino de fibra de vidro principal + resina composta; pino de fibra de vidro com dupla conicidade (ExP) - pino de fibra de vidro Exacto #3; e pino de fibra de vidro Reforpost #2 + pinos de fibra de vidro acessórios Reforpin (RrP). Nos grupos RaP, ExP e RrP foram realizados plugs apicais de MTA Angelus com 4,0 mm. As amostras foram incluídas em cilindros com resina de poliestireno e o ligamento periodontal foi simulado com material de moldagem à base de poliéter. As amostras foram submetidas ao teste de resistência à fratura, por meio de força compressiva (0,5 mm/min a 135º em relação ao longo eixo do dente) em uma máquina de ensaios mecânicos MTS 810. Os dados foram submetidos à ANOVA a um critério e aos testes para comparações múltiplas Dunnett C ou Tukey HSD (α=0,05). Os grupos controle (PoC e NeC) apresentaram resistência à fratura inferior aos grupos experimentais, sendo o menor valor médio produzido por NeC. ExP produziu os maiores valores de resistência à fratura entre os grupos experimentais. Os procedimentos de preparo e alargamento produziram efeitos prejudiciais na resistência à fratura de dentes bovinos. A utilização de pinos de fibra de vidro intra-radiculares aumentou significativamente a resistência à fratura de dentes com rizogênese incompleta simulada.