Clinical longevity of metallic versus fiberglass intraradicular posts: a systematic review / Longevidade clínica de pinos intraradiculares metálicos versus de fibra de vidro: uma revisão sistemática

Objective: This systematic review aims to compare the clinical longevity of metallic and fiberglass intraradicular posts in teeth with severely compromised crowns, utilizing randomized clinical trials and case reports published in the last eleven years. Material and Methods: The research was conducted on PubMed, Medline, Lilacs, and BBO databases using the first search strategy with the descriptors 'dental posts,' 'longevity,' 'fiberglass-reinforced posts' or 'metallic posts.' The second search strategy involved analyzing the references of articles identified by the first search. Both studies were carried out with stringent inclusion and exclusion criteria. Results: No statistically significant and clinically relevant differences in longevity were observed between metallic and fiberglass posts. Conclusion: The clinical success and durability of the restorative procedure using intraradicular posts primarily depend on the remaining amount around the post (ferrule), the type and position of the tooth in the arch (impacting the masticatory forces exerted on the restored tooth), and the correct application of the cementation technique. It is noteworthy that fiberglass posts offer substantial advantages by presenting a modulus of elasticity similar to dental structure, ensuring a more homogeneous distribution of masticatory forces and reducing the risk of fractures. These findings have practical implications for material selection in restorative procedures involving intraradicular posts.(AU)

Objetivo: Esta revisão sistemática visa comparar a longevidade clínica de pinos intrarradiculares metálicos e de fibra de vidro em dentes com coroas severamente comprometidas, através de estudos clínicos randomizados e relatos de casos, publicados nos últimos onze anos. Material e Métodos: A pesquisa foi conduzida nas bases de dados PubMed, Medline, Lilacs e BBO, utilizando a primeira estratégia de busca com os s 'pinos dentais' e 'longevidade' e 'pinos reforçados com fibra de vidro' ou 'pinos metálicos'. A segunda estratégia de busca consistiu na análise das referências dos artigos identificados pela primeira estratégia. Ambos os estudos foram delineados com critérios rigorosos de inclusão e exclusão. Resultados: Não se constataram diferenças estatisticamente significativas e clinicamente relevantes na longevidade entre pinos metálicos e de fibra de vidro. Conclusão: O êxito clínico e a durabilidade do procedimento restaurador empregando pinos intrarradiculares dependem primordialmente da quantidade de remanescente ao redor do pino (férula), do tipo e posição do dente na arcada (o que impacta nas forças mastigatórias exercidas sobre o dente restaurado) e da aplicação correta da técnica de cimentação.Destaca-se que o pino de fibra de vidro oferece vantagens substanciais ao apresentar módulo de elasticidade similar à estrutura dentária, assegurando uma distribuição mais homogênea das forças mastigatórias e reduzindo o risco de fraturas (AU)

Effect of dentin moisture on the adhesive properties of luting fiber posts using adhesive strategies

Abstract The purpose of this study was to evaluate the effect of dentin moisture (moist and dry) on the bonding of fiber posts to root dentin with different adhesive strategies (etch-and-rinse, self-etch, and self-adhesive). Seventy-two extracted single-rooted human teeth were endodontically treated and divided into six groups (n = 12) according to the moisture of dentin surface and adhesive systems as follows: a) etch-and-rinse/moist, b) etch-and-rinse/dry, c) self-etch/moist, d) self-etch/dry, e) self-adhesive/moist, and 6) self-adhesive/dry. The specimens were sectioned into six slices for push-out bond strength (BS), nanoleakage (NL) by SEM, and Vickers microhardness (VHN) of the resin cement. A universal testing machine (AG-I, Shimadzu Autograph) was used at a crosshead speed of 0.5 mm/min until post extrusion, with a load cell of 50 kg for evaluation of the push-out strength. Data on BS, NL, and VHN were evaluated by two-way ANOVA and Tukey's test (α = 0.05). Dentin moisture as the main factor was not significantly different for the push-out test. However, higher BS values can be observed for the etch-and-rinse group. A lower percentage of NL was found in the dry dentin groups. The moisture pattern was not significant in the hardness values for the pre-etching groups. Additional moisture did not increase the evaluated properties.

Survival of severely compromised endodontically treated teeth restored with or without a fiber glass post

Abstract Objective The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated survival rate and failure mode of severely compromised central incisors without ferrule rehabilitated using resin-based composite (RBC) with or without FGP with different diameters. Methodology A total of 60 decoronated bovine incisors without a ferrule were endodontically treated and prepared for 1.4, 1.6, and 1.8 mm diameter FGPs (Whitepost System DC 0.5, Fit 0.4, and DCE 0.5; FGM). Half of the teeth received FGPs cemented using dual-cure resin cement (Allcem Core; FGM), the other half were filled using only bulk-fill RBC (OPUS Bulk Fill; FGM). The crowns were directly restored with RBC. The roots were embedded in polystyrene resin and the periodontal ligament was simulated with polyether impression material. Fatigue testing was conducted under 5 Hz cyclic loading at 30 degrees to the incisal edge, beginning at 50 N (5,000 cycles) as a warmup. After, the load was increased 100 N every 15,000 cycles until fracture occurred. All specimens were subjected to transillumination, micro-CT analysis, and digital radiography before and after fatigue testing. Fracture mode was classified according to severity and repair potential. Data were analyzed with Kaplan-Meier survival test and post hoc log-rank test (α=0.05) for pairwise comparisons. Results Using FGP significantly increased the number of cycles to failure, irrespective of FGP diameters (p=0.001). The FGP diameters had no statistically significant effect on cycles to failure or failure mode. Conclusion Using FGP without ferrule improved survival rate of structurally severely compromised central incisors compared with rehabilitation without FGP. The diameter of the FGPs had no effect on the survival rate and failure mode.

The infection control of post-and-core crown restoration / 华西口腔医学杂志

Post-and-core crown is one of the most common forms of restoration of tooth after root canal therapy (RCT). Infection control is the core objective of RCT, which is usually well realized by endodontists. However, many prosthodontists often neglect the infection control of the tooth and the maintenance of the curative effect of RCT during the process of post-and-core crown, which may lead to the failure of the final restoration. The concept of integrated crown-root treatment advocated recently requires clinicians to consider the RCT and final restoration as a whole, rather than simply divided into two parts-endodontic treatment and restorative treatment. As the core content of integrated crown-root treatment, infection control should be taken seriously by clinicians and implemented throughout the whole treatment process, especially in the restorative treatment that is easily overlooked after RCT. Therefore, this article describes the infection control of post-and-core crown restoration, classifies the tooth requiring post-and-core crown restoration, and puts forward the measures of infection control before and during post-and-core crown restoration, in order to provide reference and guidance for clinical practice.

Novo sistema de retentor pré-fabricado perfurado e de iluminador em fibra óptica: estudo da resistência mecânica frente a variação dos cimentos resinosos / New system of hollow prefabricated post and optical fiber illuminator: study of the mechanical strength by varying resin cements

O presente estudo teve por objetivo avaliar a resistência à flexão de um pino experimental de fibra de vidro vazado, e a resistência adesiva entre este pino experimental à dentina radicular, associando a utilização de um dispositivo iluminador em fibra óptica, sob o processo de envelhecimento, além de determinar a distribuição de tensão pela Análise de Elementos Finitos (FEA). O pino experimental e o dispositivo iluminador de fibra óptica têm por finalidade aumentar a efetividade de fotoativação dos cimentos resinosos nos terços médios e apicais dos canais radiculares. Para o teste de flexão de 3 pontos, estritamente do pino de fibra de vidro, as amostras foram divididas em 4 grupos (n=10): pino convencional (pc), pino experimental sem preenchimento (pp), com preenchimento de cimento resinoso (ppc) e com preenchimento de fibra óptica (ppf). Para o teste de resistência adesiva Pull-out, 100 raízes de dentes bovinos foram restauradas com retentores intrarradiculares e coroas de resina composta, distribuídos em 10 grupos (n=10), tendo como variáveis: o tipo de pino de fibra de vidro [convencional (C) ou perfurado (P)], o sistema de fotoativação [com ou sem o iluminador de fibra óptica (O)], o tipo de cimento resinoso [fotoativado (F) ou polimerização dual (D)] e o envelhecimento das amostras [com e sem ciclagem mecânica (C)]. O processo de envelhecimento foi realizado através da ciclagem mecânica e as amostras foram submetidas ao teste de resistência adesiva Pull-out. A análise do modo de falha foi realizada em Estereomicroscópio. A Análise em Elementos Finitos avaliou a distribuição de tensão pela análise de von Mises, deformação total e tensão máxima principal no Software Ansys 19.3. A análise estatística foi constituída pelo teste de normalidade Shapiro-Wilk, análise de variância (ANOVA) 1, 2 e 3 fatores e teste Tukey 5%. As médias e desvios padrão de resistência à flexão foram (MPa): pc = 677 ± 81,1; ppc = 419 ± 23,2; ppf = 200 ± 32,5 e pp = 177 ± 32,8. As médias e desvios padrão de resistência adesiva foram (MPa): CD = 12,2 ± 1,21; PD = 11,1 ± 1,32; PF = 10,9 ± 1,29; POD = 13,7 ± 1,16; POF = 11,9 ± 1,48; CDC = 10,1 ± 1,33; PDC = 9,25 ± 1,11; PFC = 8,37 ± 1,25; PODC = 10,8 ± 0,95 e POFC = 9,82 ± 1,02. Os resultados do modo de falha foram: adesiva entre pino e cimento (56%), mista predominantemente adesiva entre cimento e dentina (22%), adesiva entre cimento e dentina (14%) e a mista predominantemente adesiva entre pino e cimento (8%). Concluiu-se que entre os pinos experimentais, o grupo do pino perfurado preenchido com cimento resinoso obteve o maior valor de resistência à flexão, a utilização do dispositivo iluminador aumentou os resultados de resistência adesiva nos grupos dos pinos perfurados e não houve diferença na distribuição de tensões entre os grupos. (AU)

The present study aimed to evaluate the flexural strength of an experimental hollow glass fiber post, and the bond strength between this experimental post and root dentin, associating the use of an optical fiber illuminating device, under the aging process, in addition to determine the stress distribution by Finite Element Analysis (FEA). The experimental post and optical fiber illuminating device are intended to increase the polymerization effectiveness of resin cements in the middle and apical regions of root canals. For the 3-point bending test, strictly of the fiber post, the samples were divided into 4 groups (n=10): conventional post (pc), experimental post without filling (pp), with resin cement filling (ppc) and with optical fiber filling (ppf). For the Pull-out test, 100 roots of bovine teeth were restored with intraradicular retainers and composite resin crowns, distributed into 10 groups (n=10), with the following variables: glass fiber post type [conventional (C) or hollow (P)], the photocuring system [with or without the optical fiber illuminating device (O)], the type of resin cement [light cured (F) or dual cured (D)] and aging of the samples [with and without mechanical cycling (C)]. The aging process was performed by mechanical cycling and the samples were submitted to the Pull-out bond strength test. Failure mode analysis was performed using a stereomicroscope. Finite Element Analysis evaluated the stress distribution by von Mises analysis, total strain and maximum principal stress in Ansys Software 19.3. Statistical analysis consisted of the Shapiro-Wilk normality test, 1-, 2- and 3-way analysis of variance (ANOVA) and Tukey test 5%. The means and standard deviations of flexural strength were (MPa): pc = 677 ± 81.1; ppc = 419 ± 23.2; ppf = 200 ± 32.5 and pp = 177 ± 32.8. The means and standard deviations of bond strength were (MPa): CD = 12.2 ± 1.21; PD = 11.1 ± 1.32; PF = 10.9 ± 1.29; POD = 13.7 ± 1.16; POF = 11.9 ± 1.48; CDC = 10.1 ± 1.33; PDC = 9.25 ± 1.11; PFC = 8.37 ± 1.25; PODC = 10.8 ± 0.95 and POFC = 9.82 ± 1.02. The failure mode results were: adhesive between post and cement (56%), mixed predominantly adhesive between cement and dentin (22%), adhesive between cement and dentin (14%) and mixed predominantly adhesive between post and cement (8 %). It was concluded that among the experimental posts, the hollow post group filled with resin cement obtained the highest flexural strength value, the use of the illuminating device increased the results of bond strength in the hollow post groups and there was no difference in the stress distribution among the groups (AU)

Fiberglass versus cast metal posts: a practical review based on mechanical properties / Pinos de fibra de vidro versus metal fundido: uma revisão prática baseada em propriedades mecânicas

The current review aimed to compare the mechanical properties and clinical behavior of fiberglass and cast metal posts. It included in-vitro studies, finite element analysis, clinical studies, and systematic reviews that evaluated fiberglass and metal posts with reliable methodologies. The reports in the literature diverge on tooth failure modes and stress distributions in the root according to different posts. Investigations suggest that fiberglass posts are preferable because their elastic modulus is similar to dentin. Other studies mention that the flexibility of fiber posts may damage the interface. The fracture load values of different studies could not be compared. The presence of a ferrule seems beneficial. Cast metal posts provide higher characteristic strength to the set but with more unfavorable failures. Intraradicular posts with a lower elastic modulus produce more stress between the cement layer and dentin. In conclusion, fiberglass and cast metal posts can be used with a ferrule. Cast metal posts seem more appropriate for weakened teeth. The presence of a ferrule benefits the system. Weakened teeth tolerate higher loads when restored with cast metal posts, but when these posts fail, the only solution is tooth extraction. Clinical follow-ups cannot yet detect differences between the survival rates of intraradicular fiberglass and cast metal posts (AU)

O objetivo da presente revisão foi comparar as propriedades mecânicas e o comportamento clínico de pinos de fibra de vidro e núcleos metálicos fundidos. Estudos laboratoriais, analise por elementos finitos, estudos clínicos e revisões sistemáticas que avaliaram pinos de fibra de vidro e metálicos, com metodologia confiável foram selecionados. A literatura mostra-se bastante controversa sobre os modos de falha do dente e a distribuição de tensões na raiz de acordo com diferentes tipos de pinos. Algumas investigações sugerem que pinos de fibra de vidro são preferíveis porque seu módulo de elasticidade é semelhante ao da dentina, enquanto outras mencionam que a flexibilidade do pino de fibra pode ser prejudicial à interface adesiva. Os valores de carga de fratura em diferentes estudos não podem ser comparados. A presença de férula é benéfica. O núcleo metálico fundido resulta em maior resistência característica do conjunto, mas falhas mais desfavoráveis. Também, pinos com menor módulo geram mais tensão entre a camada de cimento e a dentina. Em conclusão, verificou-se que tanto pino de fibra de vidro como núcleo metálico fundido podem ser utilizados quando a férula está presente. Os núcleos metálicos fundidos parecem ser mais indicados para dentes fragilizados. É evidente que a presença de férula é benéfica para o sistema. Dentes fragilizados toleram cargas maiores quando restaurados com núcleos metálicos fundidos; porém, quando falham, a única solução é a extração do dente. Os acompanhamentos clínicos ainda não são capazes de detectar diferença entre as taxas de sobrevivência dos pinos de fibra de vidro e núcleos metálicos (AU)

The three-dimension finite element analysis on mandibular first molar restored with different designed fiber post-core and all ceramic crown / 中国医师杂志

Objective:To evaluate the effect of different numbers and location of fiber post on stress distribution of fiber post-all-ceramic crown restored mandibular first molar, with application of finite element method.Methods:Intact human mandibular first molars were used to build three-dimensional finite element models, restored with fiber post core and all ceramic crown. Three-dimension finite element model with 7 different post designs(according to the numbers and location of fiber post inserted into root canal) were created with soft wares of Mimics, Geomagic and Ansys. The von Mises criterion was applied for comparing the maximum von Mises stress value of dentin and stress concentration areas in 7 models maximum load (F1, 225 N), vertical load (F2, 225 N), inclined load (F3, 225 N) and horizontal load (F4, 225 N).Results:Under maximum load, vertical load, inclined load and horizontal load, the maximum von Mises stress value of dentin were 21.854-22.629 MPa (F1), 20.945-21.369 MPa (F2), 21.637-22.513 MPa (F3) and 37.922-38.277 MPa (F4), when the mandibular first molar defect was restored with fiber post core and all ceramic crown. There was little difference in maximum von Mises stress values and stress distribution among the 7 groups. Increasing the number of Posts has no significant effect on the stress distribution of the original post. The maximal Von Mises stress on dentine increased when the horizontal direct loads increased.Conclusions:The number and location of posts have little influence on maximum stress values and stress distribution, when the mandibular first molar defect was restored with fiber post core and all ceramic crown.

Techniques for removing root canal posts: an vitro study / Técnicas para remoção de pinos intrarradiculares: um estudo in vitro

Objetivo: O objetivo deste estudo foi responder qual é a melhor técnica para remoção de pinos de fibra de vidro e pinos metálicos fundidos considerando tempo, preservação da estrutura dentária e custos. Métodos: Foi realizado um estudo in vitro, randomizado e cego. Sessenta dentes tratados endodonticamente foram randomizados em dois grupos de acordo com o tipo de pino. Uma segunda randomização foi realizada para cada tipo de técnica de remoção (ultrassom, broca ou combinada; n=10). One-way ANOVA foi usado para comparar o tempo de remoção do pino, teste t pareado comparou a quantidade de estrutura dentária removida e Kruskal Wallis seguido pelo teste post hoc de Mann-Whitney foram usados para análise de custo (P = 0,05). Resultados: Não houve diferença no tempo de remoção do pino considerando o tipo ou técnica do pino (P=0,630). A perda média de estrutura dentária na região cervical foi superior a 30% quando apenas uma ponta diamantada foi usada para remover pino de fibra de vidro (P<0,00001) e pino metálico fundido (P=0,008). Conclusão: De acordo com os resultados deste estudo, podemos concluir que a seleção da técnica de remoção dependerá da habilidade do operador, e sempre ocorrerá alguma perda de estrutura dentária, embora seja esperada uma perda maior quando apenas pontas diamantadas são usadas para este fim.(AU)

Objective: The aim of this study was to answer which is the best technique to removing glass fiber post and cast metal post considering time, preservation of tooth structure, and costs. Methods: An in vitro, randomized, blinded study was conducted. Sixty endodontically treated teeth were randomized into two groups according to post type. A second randomization was performed for each type of removal technique (ultrasound, drill, or combined; n=10). One-way ANOVA was used to compare the time to post removal, paired t-test compared the amount of tooth structure removed and Kruskal Wallis followed by post hoc Mann-Whitney test were used for cost analysis (P=0.05). Results: There was no difference in post removal time considering post type or technique (P=0.630). The average loss of tooth structure in the cervical region was greater than 30% when only a diamond bur was used to remove fiber glass post (P<0.00001) and cast metal post (P=0.008). Conclusion: According to the results of this study, we can conclude that the selection of the removal technique will depend on the skill of the operator, and some loss of tooth structure will always occur, although greater loss is expected when only diamond burs are used for this purpose.(AU)

Pinos estéticos de fibra de vidro: técnicas e protocolos clínicos / Aesthetic fiberglass pins: techniques and clinical protocols

Introdução: Os pinos de fibra de vidro (PFVs) apresentam-se como uma alternativa prática e econômica capaz de reabilitar dentes endodonticamente tratados com perdas estruturais superiores a 50%. Objetivo: Realizar uma revisão de literatura sobre o protocolo clínico acerca da utilização dos PFVs, bem como explanar as diferentes técnicas que po-dem ser utilizadas para implementá-los. Materiais e métodos: Realizou-se uma revisão bibliográfica de estudos publicados entre 2000 e 2021 por meio da busca nas bases de dados: PubMED/Medline, Scielo (Scientific Eletronic Library) e Google Acadêmico. Para a pesquisa, foram utilizados os seguintes descritores: Dente não Vital (Non-vital Tooth), Pinos Dentários (Dental Pins) e Técnica para Retentor Intrarradicular (Post and Core Technique). Após criteriosa filtragem, foram selecionados 24 trabalhos para inclusão no estudo, além de 10 livros considerados relevantes para esta revisão. Resultados: Durante o diagnóstico e planejamento, é necessário avaliar determinados fatores para que se obtenha sucesso clínico, como: quantidade de estrutura dentária remanescente, posição dentária e forças oclusais recebidas e necessidades restauradoras e estéticas exigidas pelo caso e pelo paciente. Diante das particularidades de cada caso, o clínico deve selecionar entre as técnicas a mais ideal: Técnica do PFV direto/ técnica convencional; Técnica do pino de fibra de vidro anatômico; ouTécnica direta com PFV associado a pinos acessórios. Conclusão: A técnica do PFV apresenta passos clínicos simplificados e sua correta realização garante sucesso no tratamento. Diante de situações em que o PFV não apresenta correta adaptação, o clínico deve abrir mão da utilização da técnica convencional e utilizar as técnicas de personalização do PFV.

Introduction: Fiberglass posts (FPs) are presented as a practical and economical alternative capable of rehabilitating endodontically treated teeth with 50% structural losses greater than 50%. Objective: To review the literature on the clinical protocol for the use of FPs, as well as explain the different techniques that can be used. Materials and methods: A literature review of studies published between 2000 and 2021 was carried out through a search on the Scielo (Scientific Electronic Library) and Google Scholar databases. The following descriptors were used for the research: Non-Vital Tooth, Dental Pins, and Technique for Intraradicular Retainer (Post and Core Technique). After careful screening, we selected 24 papers and 10 books, considered relevant for this review. Results: During planning, it is necessary to determine specific factors for clinical success, such as the amount of remaining tooth structure, the tooth position and the occlusal forces received, and restorative and esthetic needs required by the case and the patient. Given each case's particularities, the clinician must select among the most ideal techniques: the direct FP technique/convention-al technique; the Anatomical fiberglass post technique, and the direct technique with FP associated with accessory posts. Conclusion: The FP technique has simplified clinical steps and its correct performance is successful in the treatment. Faced with situations in which the FP does not present adequate adaptation, the clinician must not use the conventional technique, using techniques for personalizing the FP.

Pinos de fibra de vidro ­ aspectos gerais, propriedades e considerações biomecânicas ­ uma revisão de literatura / Fiberglass posts ­ general aspects, properties, and biomechanical considerations ­ a literature review

Introdução: A dentística a cada dia demonstra grandes avanços nas técnicas e materiais, sendo eles aplicados de forma a preservar a estrutura dentária. Neste sentido, os pinos de fibra de vidro (PFVs) se destacam como uma alternativa de pinos intrarradiculares para a reabilitação de dentes endodonticamente tratados com perdas estruturais superiores a 50%. Objetivo: Realizar uma revisão de literatura sobre os pinos de fibra de vidro enfatizando seus aspectos gerais, propriedades e considerações biomecânicas. Materiais e métodos: Realizou-se uma revisão bibliográfica de estudos publicados nos últimos 21 anos (2000-2021), por meio de busca nas bases de dados: PubMED/MEDLINE, SciELO (Scientific Eletronic Library) e Google Acadêmico. Para a pesquisa, foram utilizados os seguintes descritores: Dente não Vital (Tooth, Nonvital), Pinos Dentários (Dental Pins) e Técnica para Retentor Intrarradicular (Post and Core Technique). Após criteriosa filtragem, foram selecionados 30 trabalhos para inclusão no estudo, além de 10 livros considerados relevan-tes para esta revisão. Resultado:Os PFVs demonstram excelentes propriedades estéticas, facilidade de execução da técnica e baixo custo, biocompatibilidade com tecidos dentais e perirradiculares, além de características biomecânicas vantajosas, o que resulta na trans-missão de menos tensão para a estrutura dentária, diminuindo a probabilidade de fratu-ras. Conclusão: As inúmeras vantagens e o excelente comportamento biomecânico desses pinos explicam seu destaque frente aos demais retentores intrarradiculares, sendo esses, quando bem indicados, a primeira opção para a reabilitação de dentes tratados endodonti-camente com extensas perdas coronárias.

Introduction: Every day, dentistry demonstrates great advances in techniques and materials applied to preserve the tooth structure. In this sense, fiberglass posts (FGPs) attract attention as an alternative to intraradicular posts for the rehabilitation of endodontically treated teeth with structural losses greater than 50%. Objective: Review the literature on aesthetic fiberglass posts, emphasizing their general aspects, properties, and biomechanical considerations. Material and Methods: A literature review of studies published in the last 21 years (2000-2021) through a search on the databases: PubMED / Medline, Scielo (Scientific Electronic Library), and Google Academic. The following descriptors were used: Tooth, Nonvital, Dental Pins, and Post and Core Technique. After careful filtering, 30 articles were selected for inclusion in the study, in addition to 10 books considered relevant to this review. Results: The FGPs demonstrate excellent aesthetic properties, eas-iness of execution and low cost, biocompatibility with dental and periradicular tissues, in addition to advantageous biomechanical characteristics, which result in the transmission of less stress to the tooth structure, reducing the probability of fractures. Conclusion: The numerous advantages and excellent biomechanical behavior of these pins explain their prominence concerning other intraradicular retainers, which, when properly indicated, are the first option for the rehabilitation of endodontically treated teeth with extensive coronary loss. Keywords: Tooth, Nonvital. Dental Pins. Post and Core Technique.

Influência do tipo de cimento endodôntico na adesão de pinos de fibra de vidro: revisão de literatura / Influence of the type of endodontic sealer on glass fiber post adhesion: literature review

Introdução: Pinos de fibra de vidro são bastante utilizados quando dentes tratados endodonticamente apresentam grande perda estrutural e necessitam de suporte para a sua reconstrução coronária. A completa adesão do pino à parede do canal radicular é fundamental para o sucesso dessa restauração. Resíduos de cimento endodôntico que permanecem nas paredes dentinárias, mesmo após o preparo para a cimentação, podem interferir negativamente na sua adesão e contribuir para o seu deslocamento. Objetivo: O objetivo da presente revisão de literatura foi avaliar o efeito de diferentes cimentos endodônticos e o tempo decorrido entre a obturação e a cimentação do pino na resistência de união entre o pino e a parede do canal radicular. Métodos: Essa revisão de literatura incluiu 21 estudos que analisaram a influência de cimentos endodônticos na adesão de pinos de fibra de vidro, entre os quais 9 acrescentaram a variável tempo na sua análise, com pinos cimentados logo após a obturação do canal radicular e dias após a obturação. Resultados: Os dentes obturados com cimentos à base de resina demonstraram maior resistência ao deslocamento dos pinos durante os testes. Parece haver uma predominância de menores valores de adesão quando os pinos são cimentados imediatamente após a obturação com cimentos contendo eugenol. Conclusões: Os tipos de cimento endodôntico e o período entre a obturação e a cimentação do pino podem afetar a força de ligação entre a parede do canal radicular e o pino de fibra de vidro (AU).

ntroduction: Glass fiber posts are widely used when endodontically treated teeth present great structural loss and require support for coronal reconstruction. Complete adhesion of the post to the root canal wall is fundamental for the success of this restoration. Endodontic sealer residues that remain on the dentin walls, even after preparation for cementation, may negatively interfere with the adhesion and contribute for post displacement. This literature review evaluated the effect of different endodontic sealers and the time between obturation and post cementation on the bond strength. Methods: This literature review included 21 studies that analyzed the influence of endodontic sealers on the adhesion of glass fiber posts, among which 9 added the variable time in their analysis. Results: Teeth filled with resin-based sealers showed higher post push-out bond strength during testing. There seems to be predominance of lower adhesion values when the posts are cemented immediately after filling with eugenol-containing sealers. Conclusions: The type of endodontic sealer and period between obturation and post cementation can affect the bond strength between root canal wall and the glass fiber post(AU).

Influence of sonic vibration and cement type on the bond strength of fiberglass posts after aging / Influencia de la vibración sónica y el tipo de cemento en la fuerza de unión de los postes de fibra de vidrio después del envejecimiento

Introduction: This study evaluated the influence of sonic vibration and thermocycling on the bond strength of fiberglass posts using conventional dual-cured and self-adhesive resin cements. Material and Methods: Ninety-six single-rooted endodontically treated teeth were divided randomly into eight groups according to the cement used (dual-cured or self-adhesive resin cement), use of sonic vibration during post accommodation, and aging conditions (24h in distilled water or 5,000 thermal cycles). The fiberglass posts (White Post DC1, FGM) were cleaned with alcohol, treated with silane and cemented with dual-cured (Allcem Core, FGM) or with self-adhesive resin cement (seT, SDI). For groups in which sonic vibration was used, the posts were accommodated, and sonic vibration was applied for 10 s using a special tip placed on top of the post (Sonic Smart Device, FGM). Pull-out tests were performed after storage in distilled water for 24h at 37°C or after thermocycling (5000 cycles, at 5°C and 55°C). The results were evaluated using three-way ANOVA and Tukey's test (α=0.05). Results: Significant differences were not observed between the bond strengths of dual-cured (87.93±41.81 N) and self-adhesive cement (82.53±41.43 N). Bond strength for the sonic vibration groups (100.36±42.35 N) was significantly higher than for groups without sonic vibration (70.13±34.90 N). There were significant differences between specimens subjected to thermocycling (98.33±39.42 N) and those stored for 24h in distilled water (72.16±39.67 N). Conclusion: It can be concluded that both sonic vibration and thermocycling significantly improved bond strength of fiberglass posts with the two evaluated resin cements.

Introducción: Este estudio evaluó la influencia de la vibración sónica y el termociclado en la fuerza de unión de los postes de fibra de vidrio utilizando cementos de resina autoadhesivos y de curado dual convencionales Material y Métodos: Se dividieron aleatoriamente noventa y seis dientes tratados endodónticamente de raíz única en ocho grupos según el cemento utilizado (cemento de resina de curado dual o autoadhesivo), el uso de vibración sónica durante la acomodación posterior y las condiciones de envejecimiento (24 horas agua destilada o 5.000 ciclos térmicos). Los postes de fibra de vidrio (White Post DC1, FGM) se limpiaron con alcohol, se trataron con silano y se cementaron con cemento de curado dual (Allcem Core, FGM) o con cemento de resina autoadhesivo (seT, SDI). Para los grupos en los que se utilizó vibración sónica, se acomodaron los postes y se aplicó la vibración sónica durante 10 s utilizando una punta especial colocada en la parte superior del poste (Sonic Smart Device, FGM). Las pruebas de extracción se realizaron después del almacenamiento en agua destilada durante 24 horas a 37ºC o después del termociclado (5000 ciclos, a 5ºC y 55ºC). Los resultados se evaluaron mediante ANOVA de tres vías y la prueba de Tukey (α = 0.05). Resultados: No se observaron diferencias significativas entre las resistencias de adhesión del cemento de curado dual (87,93 ± 41,81 N) y el cemento autoadhesivo (82,53 ± 41,43 N). La fuerza de unión para los grupos de vibración sónica (100,36 ± 42,35 N) fue significativamente mayor que para los grupos sin vibración sónica (70,13 ± 34,90 N). Hubo diferencias significativas entre los especímenes sometidos a termociclado (98,33 ± 39,42 N) y los almacenados durante 24 h en agua destilada (72,16 ± 39,67 N). Conclusión: Se puede concluir que tanto la vibración sónica como el termociclado mejoraron significativamente la fuerza de unión de los postes de fibra de vidrio con los dos cementos de resina evaluados.

Effect of glass-fiber post on the biomechanical behavior of teeth with direct veneers / Efeito do pino de fibra de vidro no comportamento biomecânico de dentes com facetas diretas

Objective: This study aimed to evaluate the biomechanical behaviour of endodontically treated teeth with direct veneer that received or not intra-radicular glass fiber post by finite elements analysis. Material and methods: Six models were designed, varying the presence or absence of glass fiber post and the thickness of direct veneer (0.5, 0.7 and 1 mm). Tridimensional models of maxillary central incisors were obtained with CAD software, Rhinoceros 4.0, and transferred to CAE software, ANSYS 17.2, which a 100N load was applied in a 45° on the lingual surface to simulate functional movements. Geometry contacts were bonded, and the structures were isotropic, linear, elastics, and homogeneous. After coherence and convergence analysis of mashes, the chosen fail criterion was the maximum principal stresses. Results: For cement, glass fiber post, the stress distribution was similar independently of glass fiber post presence or veneer thickness. Models with glass fiber post had better stress distribution and lower values of maximum stress for inner dentin and veneers. Veneers with 0.5 and 1 mm had higher stress concentration areas. Conclusions: It can be concluded that glass fiber post is favorable for restored teeth with direct veneers, and very thin or very thick preparations can damage the biomechanical behavior of restorations.(AU)

Objetivo: Este estudo teve como objetivo avaliar o comportamento biomecânico de dentes tratados endodonticamente com faceta direta que receberam ou não pinos de fibra de vidro intrarradicular através de análise de elementos finitos. Material e métodos: Foram desenhados seis modelos, variando a presença ou ausência do pino de fibra de vidro e a espessura da faceta direta (0,5, 0,7 e 1 mm). Modelos tridimensionais de incisivos centrais superiores foram obtidos com o software CAD, Rhinoceros 4.0, e transferidos para o software CAE, ANSYS 17.2, cuja carga de 100N foi aplicada a 45° na superfície lingual para simular movimentos funcionais. Os contatos geométricos foram colados e as estruturas eram isotrópicas, lineares, elásticas e homogêneas. Após análise de coerência e convergência de malhas, o critério de falha escolhido foi a tensão principal máxima. Resultados: Para cimento e pino de fibra de vidro, a distribuição de tensões foi semelhante independentemente da presença do pino de fibra de vidro ou da espessura da faceta. Os modelos com pinos de fibra de vidro apresentaram melhor distribuição de tensão e menores valores de tensão máxima para dentina interna e facetas. Facetas com 0,5 e 1mm apresentaram maiores áreas de concentração de estresse. Conclusões: Pode-se concluir que o pino de fibra de vidro é favorável para dentes restaurados com facetas diretas, e preparações muito finas ou muito espessas podem prejudicar o comportamento biomecânico das restaurações.(AU)

Evaluation of Tensile Bond Strength of Metallic Prefabricated Posts Cemented with Different Luting Agents

Abstract Objective: To assess the tensile bond strength of prefabricated metal posts cemented with different luting agents. Material and Methods: Fifty single-rooted endodontically treated human teeth had their crowns cut, mounted into acrylic-resin blocks and then an 8mm depth post space were prepared. Prefabricated cylindrical metal posts were cemented using different luting agents: a zinc phosphate cement (SS White), a conventional glass ionomer cement (Vidrion C), two resin-modified glass ionomer cements (Vitremer and RelyX Luting 2) and a resin cement (RelyX ARC). Samples were stored in distilled water for seven days and then submitted to a tensile bond strength test until complete dislocation of the post. One-way analysis of variance and Tukey test for pairwise multiple comparisons were used to evaluate differences between luting agents. Results: Tensile bond strength was 563.88±203.41 N for zinc phosphate cement, 336.86 ± 137.64 N for Vidrion C, 515.24 ± 239.48 N for Vitremer, 828.47±433.99 N for RelyX Luting 2 and 1262.51 ± 356.29 for RelyX ARC. The Relyx ARC presented the highest tensile bond strength regard the luting agent tested (p< 0.05). Conclusion: RelyX ARC presented the higher tensile bond strength compared to the other luting agents evaluated.

Effect of Glass Fiber Post Diameter on Fracture Resistance of Endodontically Treated Teeth

Abstract Objective: To determine the fracture resistance of endodontically treated teeth restored with three different diameters of glass fiber posts and metal-ceramic crowns. Material and Methods: Thirty human maxillary canines were selected and subjected to root canal therapy. The teeth were randomly divided into three groups of glass fiber posts with 1.4 mm diameter (Group I), 1.6 mm diameter (Group II), and 2.0 mm diameter (Group III). The teeth were restored with metal-ceramic crowns and subjected to the compressive load applied at 45º angle to the longitudinal axis until fracture. The mode of failure was determined. Data were analyzed using ANOVA, followed by Tukey's post hoc multiple comparisons test (p<0.05). Results: The mean fracture resistance of groups I, II and III was 574 ± 91.2 N, 617 ± 85.21 N and 467 ± 99.43 N, respectively. No significant difference was noted between groups I and II, while the fracture resistance was significantly different between groups I and III (p<0.05) and groups II and III (p<0.05). No case of post fracture alone occurred in any group. Conclusion: The diameter of glass fiber posts can affect the fracture resistance of teeth. Based on the results, increasing the diameter of the post up to 1.6 mm may increase the fracture resistance of root, although excessive diameters are not recommended.

Progress in restorative treatments of primary incisor defects / 口腔疾病防治

@#Dental caries and trauma are the most common oral diseases in children, which could result in defects of the teeth or detention. Maintenance of the primary dentition in a nonpathologic condition is important for oral health, craniofacial development, and the overall well-being of the children. In contemporary dentistry, primary anterior teeth defects are mainly treated with drugs, restorative treatments, or both. Restorative treatment is the most preferred method and includes direct restoration, full coronal restoration, post-and-core crowns, etc. This article reviews the available information regarding a variety of restorative treatments for primary incisor defects, including their backgrounds, clinical indications, clinical pathways, and related studies. The literature review shows that intraconal direct restoration is widely used on single surfaces. There are many kinds of full coronal restorations, and each has its own advantages. Pediatric resin-bonded strip crowns and zirconia crowns are the most popular and have excellent aesthetics. The use of post-and-core crowns for primary incisors is controversial. The absorbable post may be the next research hotspot. Therefore, treatment of severely destroyed primary incisors poses a challenge for pediatric dentists, as three important considerations must be kept in mind: children′s behavioral management, preservation of the tooth structure and parental satisfaction.

Operational specification for clinical use of dental intraradicular fiber post / 中华口腔医学杂志

Fiber-reinforced resin composite posts (fiber posts) are used extensively for the restoration of root-treated teeth with excessive loss of coronal structure. However, the longevity of a fiber post restoration still needs to be improved because of the various confounding factors that affect bonding procedures. Operational specification for clinical use of dental intraradicular fiber post was established based on the in-depth discussions by a panel of experts from Society of Prosthodontics, Chinese Stomatological Association. This specification should be helpful in standardizing the clinical technique of fiber post placement and improving the clinical longevity of a fiber post restoration.

Tratamiento multidisciplinario de diente con pronóstico desfavorable. Reporte de caso / Multidisciplinary tooth treatment with unfavorable prognosis. Case report

RESUMEN: Las perforaciones radiculares son uno de los accidentes que pueden ocurrir dentro del tratamiento endodóntico rehabilitador de un diente y comprometen el pronóstico de éste. El objetivo de este reporte es describir el tratamiento y seguimiento de un diente con pronóstico desfavorable, con falsa vía y perforación en el 1/3 medio radicular. El manejo de la perforación se realizó con BiodentineTM y la rehabilitación con prótesis fija unitaria con poste de fibra individualizado. A los controles clínicos y radiográficos de 6, 12 y 24 meses el tratamiento se encontró asintomático y en función, pudiéndose considerar exitoso.

ABSTRACT: A radicular perforation is a mishap that can occur during the Endodontic and Restorative Treatment of a tooth and it can compromise its short and long-term prognosis. The aim of this report is to describe the treatment and follow up of a tooth with an unfavorable prognosis that had a perforation in the radicular middle third. The perforation was repaired with BiodentineTM and a fiber post and crown were placed. The patient had a follow up at 6, 12 and 24 months and the tooth was found asymptomatic and functional, which can be considered a clinical success.

Contaminated Dental Posts and Methods of Disinfection: A Systematic Review

Purpose: The aim of this study is to review the literature for the effect of contaminated posts on the outcome of endodontic therapy and to review the current recommendations available for posts disinfection protocols. Methods: An electronic MEDLINE and PubMed search was conducted using MeSH terms, and the references of the resulted articles were further reviewed for additional articles, eligibility criteria included any published article in a peerreviewed journal assessing posts for signs of contamination or reviewing protocols for posts disinfection prior to cementation. Findings: No articles met the eligibility criteria to be included in this review. Conclusion: There is a lack of evidence regarding the effect of contaminated posts on the success of endodontic treatments, and no protocols were found for disinfecting the posts prior to cementation.

Uso de un poste y núcleo de fibra de vidrio compuesto fabricados con CAD / CAM para restaurar un diente tratado endodónticamente: reporte de caso / Use of a CAD / CAM-fabricated composite fiberglass post and core to restore an endodontically treated tooth: case report

En la actualidad existe un amplio uso de los postes de fibra de vidrio. Sin embargo, tienen la desventaja que su forma no se pueden cambiar y son inadecuadas para casos de dientes con amplia destrucción coronal y conductos radiculares amplios. Este reporte de caso clínico describe el uso de un poste y núcleo de fibra de vidrio fabricados con un sistema CAD/CAM para restaurar un diente premolar inferior tratado endodónticamente. Este poste de fibra de vidrio CAD/CAM se adapta mejor al conducto radicular que un poste prefabricado, sin necesidad de emplear resina compuesta para el muñón y reduce el espesor de la capa de cemento.

Currently, there is a wide use of fiberglass post. However, they have the disadvantage that their shape can not be changed and are inadequate for cases of teeth with extensive coronal destruction and wide root canals. This case report describes the use of a fiberglass post and core manufactured with a CAD / CAM system to restore a lower premolar tooth treated endodontically. This CAD / CAM fiberglass post adapts better to the root canal than a prefabricated post, without the need to use composite resin for the stump and reduces the thickness of the cement layer.