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The current study evaluated the stress distribution in a maxillary central incisor with mid-root fracture after splinting with different intra-radicular posts using 3D-finite element analysis (FEA). Five 3D-FEA models were constructed. Model 1 was an intact tooth with no fracture, Model 2: A tooth with a horizontal mid-root fracture, with no treatment. Model 3: Same as model 2, and intraradicular splinting using fiber post. Model 4: Same as model 2 and intra-radicular splinting using Protaper Gold file F3. Model 5: Same as model 2, and with intraradicular splinting with Ribbond. The FEA of all models was done to obtain the maximum Von-Mises stress in the root canal space, the dentin, the periodontal ligament, and the bone. The highest Von Mises stresses for the root canal space and the dentin were found in Model 3, followed by models 4, 5, and 2, and least in Model 1. The Von Mises stress of the periodontal ligament was the least in model 1. The Von Mises stress of bone was higher in all experimental models than in the baseline model. The results suggest that in cases where intra-radicular splinting is indicated, fiber posts and Ribbond are better alternatives to endodontic files due to the lower stresses exerted.

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INTRODUCTION: Smear layer removal from root canals aid in the penetration of both irrigants and endodontic sealer into the dentinal tubules, thereby improving the efficacy of endodontic treatment. The aim of this in vitro study was to compare the smear layer removal ability of a conventional endodontic irrigation regimen, MTAD (mixture of tetracycline, acid, and detergent), and QMix™ (Dentsply Sirona, Charlotte, North Carolina, United States) with that of a mixture of herbal irrigants, namely, aqueous extracts of Azadirachta indica (neem) and Citrus limon (lemon), evaluated using scanning electron microscopy (SEM). MATERIALS AND METHODS: We selected 40 extracted human premolar teeth for the study, which we randomly divided into five groups (eight samples each) according to irrigation solution: (i) Group A (normal saline); (ii) Group B (conventional endodontic regimen, 3% sodium hypochlorite (NaOCl) + 17% ethylenediamine tetraacetic acid (EDTA) + 2% chlorhexidine (CHX)); (iii) Group C (MTAD); (iv) Group D (QMix 2-in-1); and (v) Group E (aqueous extracts of Azadirachta indica and Citrus limon). After we prepared the canals with ProTaper Universal nickel-titanium (Ni-Ti) rotary files (Dentsply Sirona) and the respective irrigants, we split the teeth longitudinally to evaluate the amount of remnant smear layer in the coronal, middle, and apical thirds using SEM photomicrographs. We performed statistical analyses of the data using the Kruskal-Wallis and Mann-Whitney U tests, where the level of significance was set at 0.05. RESULTS: The SEM analysis of the coronal third showed mean values of 3.83 in Group A, 3.67 in Group B, 2.79 in Group C, 3.63 in Group D, and 4.00 in Group E. The SEM analysis of the middle third showed mean values of 4.00 in Group A, 3.88 in Group B, 3.75 in Group C, 3.50 in Group D, and 3.50 in Group E. The SEM analysis of the apical third showed mean values of 3.92 in Group A, 3.63 in Group B, 3.71 in Group C, 3.88 in Group D, and 3.17 in Group E. Therefore, we found that there were significant statistical differences between the groups when an overall comparison was done for the coronal, middle, and apical third, with a p-value of 0.001. On multiple comparisons across the different tooth-section thirds. Groups A and B showed statistically significant differences in the apical third (p-value=0.017). Groups A and C showed statistically significant differences in the coronal third and middle third (p-values=0.001 and 0.010, respectively). Groups A and D showed statistically significant differences in the middle third (p-value=0.001). Groups A and E showed statistically significant differences in all thirds (p-values=0.039, 0.001, and 0.001, respectively) Conclusion: The conventional needle irrigation with MTAD showed the highest level of smear layer removal ability on the root canal surface, followed by QMix 2-in-1, the Azadirachta indica leaf and Citrus limon extract mixture, and the conventional endodontic regimen. Normal saline showed the lowest smear layer removal effect.

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The aim of this study was to assess adaptation and bonding to root canal dentin of discontinuous (short) glass fiber-reinforced composite to intra-radicular dentin (DSGFRC). METHODS: Seventy virgin human teeth were extracted and then endodontically treated; then samples were randomly divided into 7 groups (n = 10), based on the materials' combinations as follows: Group 1, a two-bottle universal adhesive + DSGFRC; Group 2, a single-component universal adhesive + DSGFRC; Groups 3 and 4, the same materials of Goups 1 and 2 were used but after cleaning of the canal walls with 17% EDTA and final irrigation with 5.25% NaOCl Ultrasound Activated (UA); Group 5, traditional prefabricated fiber posts were luted after being silanized with G-Multi Primer; Groups 6 and 7, like Group 5 but after ultrasonic irrigation (UA). All sample roots were cut 1 mm thick (n = 10) to be evaluated regarding root canal adaptation using a light microscope and scanning electron microscope (SEM) and push-out bond strength. These results were statistically analyzed by Kruskal-Wallis analysis of variance by ranks. The level of significance was set at p < 0.05. RESULTS: Bond strength forces varied between 6.66 and 8.37 MPa and no statistically significant differences were recorded among the groups. By microscopic examination, it was noted that ultrasonic irrigation increased the adaptation of the materials to the dentin surface. CONCLUSIONS: Within the limitations of this in vitro study, it may be concluded that when DSGFRC was used for intracanal anchorage in the post-endodontic reconstruction, similar push-out retentive force and strength to those of traditional fiber posts cemented with particulate filler resin composite cements were achieved.

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Abstract Considering the side effects in the oral cavity and dental structures of radiotherapy (RDT) for head and neck cancer, this study aimed to evaluate the effects of RDT on the root dentin concerning the obliteration of dentinal tubules, the inorganic composition of intra-radicular dentin, and the integrity of collagen fibers. Thirty human canines were selected from a biobank and randomly divided into two groups (n=15). The samples were sectioned buccolingually, and a hemisection was used for structural analysis by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Low-vacuum SEM images were obtained at 2000-x magnification to observe the obliteration of the dentinal tubules. Moreover, compositional evaluation was performed using EDS. After RDT, the SEM and EDS analyses were repeated using the same methodology. RDT was applied fractionally at 2 Gy per day, 5 days per week, for 7 weeks, resulting in a total dose of 70 Gy. The collagen integrity of the irradiated and non-irradiated samples was analyzed using Masson's trichrome and picrosirius red staining polarization microscopy. Samples subjected to RDT exhibited dentinal tubule obliteration (p < 0.001); low integrity of type I and III collagen fibers (p < 0.05); compositional reduction of calcium (p = 0.012), phosphorus (p = 0.001), and magnesium (p < 0.001); an increased Ca/P ratio (p < 0.001). RDT affects the structure of dentinal tubules, the inorganic composition of intra-radicular dentin, and the collagen fiber integrity in the root dentin, which may interfere with the effectiveness and durability of dental procedures.

Resumo Considerando os efeitos colaterais na cavidade oral e estruturas dentárias da radioterapia (RDT) para o câncer de cabeça e pescoço, este estudo teve como objetivo avaliar os efeitos da RDT sobre a dentina radicular quanto à obliteração dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas. Trinta caninos humanos foram selecionados de um biobanco e divididos aleatoriamente em dois grupos (n=15). As amostras foram seccionadas no sentido vestíbulo-lingual, e uma hemissecção foi utilizada para análise estrutural por microscopia eletrônica de varredura (MEV) e espectrômetro de raios X de dispersão de energia (EDS). Imagens de MEV de baixo vácuo foram obtidas com aumento de 2500x para observar a obliteração dos túbulos dentinários. Além disso, a avaliação composicional foi realizada usando EDS. Após a RDT, as análises em MEV e EDS foram repetidas usando a mesma metodologia. A RDT foi aplicada fracionada a 2 Gy por dia, 5 dias por semana, durante 7 semanas, resultando em uma dose total de 70 Gy. A integridade do colágeno das amostras irradiadas e não irradiadas foi analisada usando microscopia de polarização de coloração com tricrômio de Masson e picrosirius red. As amostras submetidas a RDT apresentaram obliteração dos túbulos dentinários (p < 0,001); baixa integridade das fibras colágenas tipo I e III (p < 0,05); redução composicional de cálcio (p = 0,012), fósforo (p = 0,001) e magnésio (p < 0,001); e uma relação Ca/P aumentada (p < 0,001). A RDT afeta a estrutura dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas na dentina radicular, o que pode interferir na eficácia e durabilidade dos procedimentos odontológicos.

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BACKGROUND: Hydraulic materials are used in Endodontics due to their hydration characteristics namely the formation of calcium hydroxide when mixing with water and also because of their hydraulic properties. These materials are presented in various consistencies and delivery methods. They are composed primarily of tricalcium and dicalcium silicate, and also include a radiopacifier, additives and an aqueous or a non-aqueous vehicle. Only materials whose primary reaction is with water can be classified as hydraulic. OBJECTIVES: Review of the classification of hydraulic materials by Camilleri and the literature pertaining to specific uses of hydraulic cements in endodontics namely intra-coronal, intra-radicular and extra-radicular. Review of the literature on the material properties linked to specific uses providing the current status of these materials after which future trends and gaps in knowledge could be identified. METHODS: The literature was reviewed using PUBMED, and for each clinical use, the in vitro properties such as physical, chemical, biological and antimicrobial characteristics and clinical data were extracted and evaluated. RESULTS: A large number of publications were retrieved for each clinical use and these were grouped depending on the property type being investigated. CONCLUSIONS: The hydraulic cements have made a difference in clinical outcomes. The main shortcoming is the poor testing methodologies employed which provide very limited information and also inhibits adequate clinical translation. Furthermore, the clinical protocols need to be updated to enable the materials to be employed effectively.

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The gold standard for restoring Endodontically Treated Teeth (ETT) with successful clinical longevity requires having minimal invasive preparations and maximal tissue conservation. Many dentists still consider hybrid post/core/crown to be the first choice for restoring ETT. Endocrown is a viable alternative treatment modality to hybrid post/core/crown. This study aims to assess the proper judgment of dentists working in Riyadh, Saudi Arabia on the use of monolithic endocrown versus hybrid post/core/crown for restoring ETT. The IRB of Princess Nourah Bint Abdulrahman University (PNU) Institutional Review Board reviewed this study. The questionnaire was validated and electronically distributed. The participants were pre-informed that their responses are completely anonymous and used for professional purposes only. The questionnaire surveyed dentists working in Riyadh, Saudi Arabia, about their preference for different ETT restorative modalities at various clinical scenarios. Data were analyzed using One-way ANOVA and t-test. All P-values of < 0.05 were considered statistically significant. A total of 275 responses were collected; 61.45% were females and 38.55% males. 56% of them were general practitioners, while 16% were consultants. Prefabricated post/core was the most preferred technique among the participants (18.55%), followed by endocrown (12.36%), and lastly, cast post/core (8.73%). The amount of remaining tooth structure was the most influential in the treatment selection (30.18%), followed by the presence or absence of 1-2 mm ferrule (17.82%). Interocclusal space (12.36%) was the least influential factor. Endocrown recorded 63.27% as the most preferred line of treatment in case of insufficient inter-occlusal space. 40.36% preferred endocrown for patients with occlusal risk factors. The amount of the remaining tooth structure and the tooth position significantly affect the treatment options of the participants. Endocrown was the most preferred treatment modality for restoring ETT for patients with occlusal consideration.

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OBJECTIVES: To evaluate the effect of different intraradicular posts on the dimensions of computed tomography (CT) images in cone-beam and fan-beam equipment. MATERIALS AND METHODS: : A total of 15 root canals of bovine teeth were instrumented up to a file #50 and root-filled by the active lateral condensation technique. The teeth were randomly divided into three groups, according to the type of intraradicular post: 1) tight fiberglass post; 2) anatomical fiberglass post; and 3) metal post. The root canals were desobturated in 10 mm and tomographic images were acquired in two devices, a cone-beam and fan-beam equipment. Then, the intraradicular posts were cemented using an automix self-conditioning and self-adhesive resin cement, and the final acquisitions of the CT images were performed for analysis. The diameter of the canal was compared before and after cementation of the intraradicular posts. The t-test was used between the initial and final measurements of each tomograph and also between the cone-beam and fan-beam tomographs (α = 0.05). RESULTS: The anatomical fiberglass post presented the smallest dimensional change among the initial and final measurements, followed by the tight fiberglass post, with the metal post being the material that showed the most considerable dimensional difference in the cone-beam. CONCLUSION: All of the intraradicular posts used promoted a change in the size of the CT image. The fan-beam scanner promoted greater dimensional change in the images.

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Computer-aided design and computer-aided manufacturing (CAD-CAM) technology may be used to produce custom intraradicular posts, but studies are lacking. The purpose of this in vitro study was to evaluate the flexural properties (strength and modulus), failure mode, superficial morphology, and roughness of two CAD-CAM glass fiber posts (milled at different angulations) compared with a commercially available prefabricated glass fiber post. Three groups were tested (n = 10): PF (control group)- prefabricated glass fiber post; C-Cd-diagonally milled post; and C-Cv-vertically milled post. A 3-dimensional virtual image was obtained from a prefabricated post, which guided the posterior milling of posts from a glass fiber disk (Trilor Blanks; Bioloren). Surface roughness and morphology were evaluated using confocal laser microscopy. Flexural strength and modulus were evaluated with the 3-point bend test. Data were submitted to one-way analysis of variance followed by the Student-Newman-Keuls post hoc test (α = 0.05). The fractured surfaces were evaluated with scanning electron microscopy. The superficial roughness was highest for PF and similar for the experimental groups. Morphological analysis shows different sizes and directions of the glass fibers along the post. The flexural strength was highest for PF (900.1 ±â€¯30.4 > C-Cd - 357.2 ±â€¯30.7 > C-Cv 101.8 ±â€¯4.3 MPa) as was the flexural modulus (PF 19.3 ±â€¯2.0 GPa > C-Cv 10.1 ±â€¯1.9 GPa > C-Cd 7.8 ±â€¯1.3 GPa). A CAD-CAM milled post seems a promising development, but processing requires optimizing, as the prefabricated post still shows better mechanical properties and superficial characteristics.

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ctualmente existe controversia en la literatura acerca de la efectividad clínica y adhesiva con respecto a los sistemas adhesivos de refuerzo radicular. Así, el objetivo de este estudio fue evaluar la resistencia de unión mediante la prueba de Push-Out entre el sistema de postes Rebilda® y la dentina intraradicular. Para esto, se utilizaron 28 dientes unirradiculares, que fueron cortados y padronizados en 16 mm. Los segmentos radiculares fueron sometidos a confección de tratamiento endodóntico; posteriormente, se dividieron aleatoriamente en dos grupos, Grupo 1 (n=14): Rebilda® DC+Futurabond DC; Grupo 2 (n=14): RelyX ARC+Adper Scothbond Multipropósito Plus. Seguidamente, diez especímenes de cada grupo se cortaron para ser sometidos al Test de Push-Out. Los restantes 4 especímenes de cada grupo se prepararon para Microscopia Electronica de Barrido con el fin de evaluar la formación de prolongaciones resinosas en la interface poste-cemento-dentina. El grupo 2 obtuvo mejores resultados al compararlo al Grupo 1 en cuanto a resistencia de unión y en formación de prolongaciones resinosas, pero no hubo diferencia estadísticamente significativa (p>0.05). Se concluyó que el Sistema de Postes REBILDA® promueve una adecuada resistencia de unión a dentina intrarradicular.

urrently there is controversy in the literature about clinical and adhesive effectiveness with respect to adhesive systems aimed to root reinforcement. Thus, the objective of this study was to evaluate the Push-Out bond strength between the Rebilda® post system and the intraradicular dentine. Thus, 28 unirradicular teeth were used, cut and standardized in 16 mm. The root segments were submitted to endodontic treatment; and then randomly divided into two groups, Group 1 (n = 14): Rebilda® DC + Futurabond DC; Group 2 (n = 14): RelyX ARC + Adper Scothbond Multipurpose Plus. Ten specimens from each group were submitted to the Push-Out Test. The remaining 4 specimens from each group were prepared for Scanning Electron Microscopy (SEM) in order to evaluate the formation of resinous extensions at the post-cement-dentin interface. Group 2 showed better results when compared to Group 1 regarding bond strength and in formation of resinous extensions or tags, but there was no statistically significant difference (p>0.05). It was concluded that the REBILDA® Post System promotes adequate bond strength to intraradicular dentin.

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Root fracture has been defined as a fracture involving dentin, cementum, pulp and periodontal ligament. Depending on the level of the fracture line various treatment modalities may be employed by the clinician to promote healing. The following case reports highlight how changes in technique allow for conservative management of horizontal root fractures at different levels. This approach allows the patient to retain their natural dentition at an affordable cost and provide a viable alternative to the use of more invasive and expensive alternatives. These patients presented with complaints of pain and mobility in upper front tooth region following trauma. Diagnosis was confirmed on the basis of intra-oral periapical radiographs following which non-surgical root canal treatment was performed.

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CONTEXT: Very recently, diode laser has been used for disinfecting the root canals in endodontic treatment and increasing its success rate and longevity utilizing the thermal effect of laser on surrounding tissues. AIMS: The aim of this study is to evaluate the effect of 980 nm laser irradiation on intra-canal dentin surface - scanning electron microscopic (SEM) - in-vitro study. METHODS: A total of 40 single-rooted freshly extracted permanent teeth were collected. Teeth were sectioned at the cemento-enamel junction using diamond disc. Root canals of all samples were prepared using hand ProTaper, which were randomly assigned into two groups (n = 20 each). Group 1: Receiving no treatment after biomechanical preparation; Group 2: 980 nm diode laser-treated root canals. Teeth were prepared for SEM analysis to check the size of intra-canal dentinal tubule openings. STATISTICAL ANALYSIS USED: Data were analyzed using SPSS V.16 software and compared using Levene's and independent t-test. RESULTS: On statistical analysis, width of intracanal dentinal tubule openings in Group 1 (control) was significantly higher than those observed in Group 2 (diode laser-treated) (P < 0.001). CONCLUSION: This study showed that the application of 980 nm diode laser on intra-radicular dentin resulted in ultrastructural alterations resulting in melting of dentin.

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This paper describes the rehabilitation of two traumatised teeth in two patients namely; A maxillary left central incisor with a relatively rare combination of multiple fractures- uncomplicated crown fracture, complicated crown-root fracture along with an oblique fracture in middle third of the root and A traumatised mandibular central incisor with a horizontal fracture in cervical third of the root and complete separation of the fragments. In both cases, initially the fractured crown fragments were extracted which was followed by pulpectomy and placement of fiber posts luted with resin cement. The fractured fragments were then reattached to the respective teeth using resin cement. In the first case, the fractured incisal edge of the fragment was built up with a hybrid composite. Teeth were splinted with fibre splint (Ribbond) in both the cases. The patient was recalled regularly for follow ups for six months in first case. The patient presented with normal clinical and radiographic findings at each visit. In the second case, follow ups were carried out for 3 weeks and being continued and both the cases are still under observation by regular recalls. How to cite this article: Ruchi Arora, B Shivakumar, H Murali Rao, R Vijay. Rehabilitation of Complicated Crown-Root Fracture by Fragment Reattachment and Intraradicular Splinting: Case Reports. J Int Oral Health 2013; 5(5):129-38.

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This paper reports the case of a 15-year-old boy with a horizontal root fracture in the left maxillary central incisor along with class II division 1 malocclusion for whom a fixed orthodontic treatment was planned. The fracture was present at the junction of apical and middle-third as a result of trauma 2 years back. No splinting was carried out at that time and the tooth was found to be vital, asymptomatic and showed a type-1 repair pattern. An intentional root canal treatment was carried out for placement of an intra-radicular fiber splint, nearly 3 mm beyond the fracture line. Orthodontic treatment was initiated after a month; to which the fractured and splinted tooth responded successfully. This report highlights the successful use of an intra-radicular splint for horizontally fractured tooth requiring orthodontic treatment.

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O objetivo do presente estudo foi realizar uma revisão da literatura científica atual, a fim de discutir o comportamento biomecânico e as características inerentes tanto aos núcleos metálicos fundidos, quanto aos pinos pré-fabricados utilizados na prática restauradora dos dentes endodonticamente tratados. Para a identificação dos estudos dessa revisão, foi realizada uma estratégia de busca detalha e avançada para os bancos de dados PubMed e Medline. Foram utilizados como descritores: endodontically treated teeth, post, core, fiber post e metal post. Os critérios de inclusão foram: artigos clínicos, estudos controlados aleatórios, estudos in vitro, revisões de literatura e revisões sistemáticas com e sem meta-análise dos últimos 10 anos, que abordassem o tema proposto. Os critérios de exclusão foram: artigos sem resumo, estudos em animais, artigos cujo idioma não fosse o inglês e artigos de periódicos que não pertencessem à área odontológica. De um total de 211 artigos, após uma análise segundo o critério de inclusão e exclusão, foram selecionados 65 artigos. A maioria da literatura científica atual indica que os pinos pré-fabricados reforçados por fibras e os pinos cerâmicos deveriam ser indicados para os dentes endodonticamente tratados que apresentem uma altura mínima de 2mm de férula. Já os núcleos metálicos fundidos, juntamente com os pinos pré-fabricados metálicos representam uma boa opção protética, quando os dentes a serem restaurados apresentam-se enfraquecidos por qualquer motivo. Apesar do grande número de pesquisas, ainda há uma carência de estudos prospectivos em longo prazo que avaliem a efetividade desses pinos no tratamento de dentes tratados endodonticamente

The aim of this study was to review the current scientific literature to discuss the biomechanical behavior and characteristics inherent to both cast post and core and the prefabricated posts used in the practice of restoring endodontically treated teeth. To identify studies of this review, it was performed a detailed and advanced search strategy to the databases PubMed and Medline. It was used as descriptors: endodontically treated teeth, post, core, fiber post and metal post. Inclusion criteria were: clinical trials, randomized controlled trials, in vitro studies, literature reviews and systematic reviews with or without meta-analysis of the last 10 years that addressed the theme. Exclusion criteria were: articles without abstracts, animal studies, articles whose language was not English and articles from journals that do not belong to the Dentistry field. Of a total of 35 articles, after an analysis according to inclusion and exclusion criteria, 23 articles were selected. Most of the current scientific literature indicates that the prefabricated fiber reinforced and ceramic posts should be appointed for endodontically treated teeth that have a minimum height of 2mm ferrule. As for the cast metal cores, along with pre-fabricated metal represent a good prosthetic option, when weakened teeth have to be restored for any reason. Despite the large number of studies, there is still a lack of longterm prospective studies that evaluate the effectiveness of these posts in the treatment of endodontically treated teeth

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INTRODUCTION: Intra-radicular disc herniations are rare disorders with only few cases reported in literature. In most of these cases there is evidence of some part of the disc in adjacent area. We present a case of completely intra-radicular disc which was misdiagnosed as nerve root tumor as there was no evidence of disc prolapse at the time of diagnosis. CASE PRESENTATION: 51 year old male presented with history of severe back pain radiating to right lower limb since 11/2 month. MRI showed hypointense lesion completely inside the S1 root and a provisional diagnosis of nerve root tumor was done. At surgery, fluffy material was removed from the lesion which was histopathologically confirmed as intervertebral disc. Post operatively all symptoms of patient was relieved except dysesthesia in sole which lasted for a year post surgery. At 5 year follow up patient has no symptoms. CONCLUSION: A diagnosis of intra-radicular disc should be considered in differential of nerve root tumor. Surgical excision of intra-radicular disc gives good clinical and functional results.

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Objective: To evaluate the pull-out strength of endodontically treated teeth restored with glass fiber posts through different techniques in enlarged conduits. Methods: A total of 15 bovine teeth were endodontically treated, divided into three groups. Group 1 - restored with number 1 glass fiber posts, Group 2 - restored with number 3 glass fiber posts, Group 3 - restored with number 3 glass fiber posts associated with accessory glass fiber posts. The pins in all groups were cemented with same self-adhesive resin cement. All test specimens were subjected to the pull-out strength test in the testing machine at a speed of 0.5mm per minute and the results obtained in kilogram-force. Results: The pull-out strength values were as follows: group 1 - 24.47 kilograms-force; group 2 - 25.28 kilograms-force; group 3 - 23.59 kilogramsforce. The following standard deviations were observed: 4.33 kilograms-force for group 1, 4.03 kilograms-force for group 2 and 8.39 kilograms-force for group 3. No statistically significant differences between groups were found using the ANOVA test. Conclusion: The decrease in the thickness of the cement film by using pins of larger diameter and/or accessories, does not interfere with the retention and stability prediction of the rehabilitation of the complex.

Objetivo: Avaliar a resistência à tração de dentes tratados endodonticamente restaurados com glass fiber posts através de diferentes técnicas com condutos alargados. Métodos: Foram utilizados 15 dentes bovinos, tratados endodonticamente, sendo distribuídos em 3 grupos. Grupo 1 - restaurados com pino de fibra de vidro número 1, Grupo 2 - restaurados com pino de fibra de vidro número 3, Grupo 3 - restaurados com pino de fibra de vidro número 3 associados com pinos acessórios. Os pinos de todos os grupos foram cimentados com o mesmo cimento resinoso auto-adesivo. Os espécimes foram submetidos ao teste de resistência a tração na máquina de ensaios a uma velocidade de 0,5 milímetros por minuto e os resultados obtidos em quilograma-força.Resultados: Os valores de resistência a tração obtidos foram: Grupo 1 - 24,47 quilograma-força; Grupo 2 - 25,28 quilograma-força; Grupo 3 - 23,59quilograma-força. Foram verificados os seguintes desvios-padrão: 4,33 quilograma-força para o Grupo 1, 4,03 quilograma-força para o Grupo2 e 8,39 quilograma força para o Grupo 3. Sem diferença estatística significante entre os grupos pelo teste de ANOVA. ConclusãoA diminuição da espessura da película de cimento com o uso de pinos de maior diâmetro e/ou acessórios não interfere de maneira efetiva noprognóstico da retenção e estabilidade do complexo reabilitador.

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Neste estudo avaliou-se a resistência ao cisalhamento por extrusão de pinos de fibra de vidro, reembasados ou não com compósito, cimentados com dois tipos de cimentos resinosos em dentina intra-radicular, avaliando os segmentos cervical, médio e apical. Selecionaram-se 40 incisivos bovinos com dimensões semelhantes, removendo a porção coronária, padronizando o comprimento das raízes em 14 mm. Após, incluiu-se as raízes em resina acrílica, realizando tratamento endodôntico e, então o preparo dos espaços para os pinos, dividindo- as, em seguida, aleatoriamente em quatro grupos com dez amostras cada. Os elementos do grupo 1 receberam retentores de fibra de vidro cimentados com cimento resinoso RelyX ARC, grupo 2 retentores de fibra de vidro cimentados com cimento resinoso RelyX U100, grupo 3 retentores de fibra de vidro reembasados com resina composta e cimentados com cimento resinoso RelyX ARC e grupo 4 retentores de fibra de vidro reembasados com resina composta e cimentados com cimento resinoso RelyX U100. Ao término dos procedimentos de cimentação, realizou-se a secção dos segmentos radiculares, submetendo, então, os corpos-de-prova ao teste push-out em máquina de ensaios universal, através de ponta ativa cilíndrica com 1 mm de diâmetro, à velocidade de 0,5 mm/min, até extrusão do retentor. Obteve-se os seguintes valores médios de resistência de união, em MPa: grupo 1, terços cervical = 6,22 ± 2,64(a), médio = 4,25 ± 2,01(a) e apical = 4,45± 2,81(a); grupo 2, terços cervical = 5,04 ± 2,34(a), médio = 3,06 ± 2,12(a) e apical = 3,26 ± 2,38(a). grupo 3, terços cervical = 11,85 ± 1,67(b), médio = 11,83 ± 3,84(b) e apical = 10,39 ± 2,44(b). grupo 4, terços cervical = 12,05 ± 1,14(b), médio = 11,98 ± 3,23(b) e apical = 10,96 ± 2,14(b). Submeteram-se os valores à análise de variância e ao teste de Tukey com nível de significância de 5% indicadas acima através de letras diferentes. Os pinos de fibra de vidro reembasados com compósito apresentaram valores estatisticamente superiores de união em todos os segmentos radiculares quando comparados com pinos somente cimentados e demonstraram que não houve diferenças entre os cimentos resinosos RelyX ARC e o RelyX Unicem, quando cimentados e reembasados. Observou-se também a ausência de diferença significativa entre os terços radiculares avaliados para cada grupo distintamente. Os resultados demonstraram que a técnica de reembasamento mostrou-se efetiva em melhorar a retenção do pino de fibra de vidro estudado

This study evaluated the bond strength of fiber posts, relined or not with composite resin, luted with resinous cement to radicular dentin, evaluating cervical, median and apical root segments. Fourty bovine incisors, with similar dimensions, were selected and cut 16 mm from the apical limit. The roots were embedded in acrylic resin and the radicular canals were root treated and post space prepared with a depth of 9 mm. Samples were randomly assigned to two groups of ten roots each. Group 1 received glass fiber posts luted with dual-cure resin cement RelyX ARC in association with a bonding system. In Group 2 the same type of posts were relined with composite for further cementation with resin cement RelyX U100. In Group 3, glass fiber post were relined with composite and cemented with resin cement RelyX ARC and in Group 4 glass fiber posts were relined ith composite and cemented with resin cement RelyX U100. After cementation procedures roots were sectioned transversally and three sections, from cervical, medium and apical thirds were obtained. Push-out test was performed in a universal testing machine with a 1 mm diameter steel rod at cross-head speed of 0,5 mm/min until post extrusion. Collected data was statistically analyzed by two- way ANOVA and Tukey HSD test (p<0,05). The measured retention strengths for cervical, medium and apical thirds were: Group 1, cervical thirds = 6,22 ± 2,64(a), medium = 4,25 ± 2,01(a) e apical = 4,45± 2,81(a); group 2, cervical thirds = 5,04 ± 2,34(a), medium = 3,06 ± 2,12(a) and apical = 3,26 ± 2,38(a). Group 3, cervical thirds = 11,85 ± 1,67(b), medium = 11,83 ± 3,84(b) and apical = 10,39 ± 2,44(b). Group 4, cervical thirds = 12,05 ± 1,14(b), medium = 11,98 ± 3,23(b) and apical = 10,96 ± 2,14(b). Glass fiber composite relined posts presented statistically higher retention values in cervical, medium and apical thirds when compared to nonrelined posts and presented that had no diference between resin cement RelyX ARC and Rely X U100 when cemented and relined. Within each group, no differences were found among radicular thirds. The results indicate that the tested technique showed effective improvement of glass fiber post retention strength

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Objetivo: Avaliar a influência de três sistemas adesivos na resistência de união ao push-out de pinos de fibra cimentados adesivamente à dentina radicular. A hipótese foi de que a resistência de união varia em função do tipo de sistema adesivo. Método: Os canais de 30 dentes bovinos unirradiculares (16mm de comprimento) foram preparados com brocas específicas (FGM) até 12mm. 14 mm de cada raiz foi incluída em resina acrílica e divididas em 3 grupos (n=10), de acordo com o fator ôadesivoõ (3 níveis): Gr1-Scotchbond Multipurpose Plus (3M ESPE), Gr2- One Step (Bisco) and Gr3- Excite DSC (Ivoclar). Os sistemas adesivos foram aplicados com um microbrush, seguindo as recomendações do fabricante. Os pinos de fibra (White Post DC, FGM) foram cimentados com cimento resinoso dual (All-Cem, FGM). Após, os núcleos de resina composta (Llis, FGM) foram confeccionados e cada conjunto raiz/pino/núcleo foi submetido à ciclagem mecânica (Erios, Brazil) (106ciclos, 84N, 4 Hz, inclinação de 45º, 37ºC, sob refrigeração constante). Cada espécime foi seccionado em quatro fatias (1.8mm), as quais foram submetidas ao teste push-out em máquina de ensaio universal (ServoPulser û Shimadzu) (50Kgf, 1mm/min). Os dados (MPa) foram analisados utilizando ANOVA (1-way) e Tukey test (5%). Resultados: O fator ôadesivoõ (p= 0,0352) influenciou significantemente a força de união (ANOVA). O Gr1 (6,8±3,8 MPa)aapresentou valores de resistência de união superior ao Gr2 (3,1±1,5 MPa)be semelhantes ao Gr3 (4,4±3,3)a,b. Além disso, Gr3 e Gr2 foram semelhantes entre si (Tukey). A hipótese foi aceita. Conclusão: Baseado nos resultados concluiu-se que os sistemas adesivos com polimerização química e dual devem ser os selecionados para procedimentos de cimentação adesiva de pinos de fibra

Objective: To evaluate the influence of three adhesive systems on the bond strength of fiber post luted to root dentine. The hypothesis was that the bond strength is influenced by the adhesive system. Method: The canals of thirty single-root bovine roots (16mm in length) were prepared using the preparation drill (FGM) until 12mm. 14 mm of each root was embedded with acrylic resin and the specimens were allocated into three groups (n=10), considering the factor ôadhesiveõ (3 levels): Gr1- Scotchbond Multipurpose Plus (3M ESPE), Gr2- One Step (Bisco) and Gr3- Excite DSC (Ivoclar Vivadent). The adhesive systems were applied using a microbrush, according to the manufactureÆs recommendations. The fiber posts (White Post DC, FGM) were luted with dual resin cement (All-Cem,FGM). After, the cores with composite resin (Llis, FGM) were made and each set of root/post/core was submitted to the mechanical cycling (Erios, Brazil) (106cycles, 84N, 4 Hz, inclination of 45º, 37ºC, water). Each specimen was cut in 4 samples (1.8mm in thickness), which were submitted to the push-out test in a universal testing machine (ServoPulser û Shimadzu) (50Kgf, 1mm/min). The data (MPa) were analyzed using ANOVA (1-way) and Tukey test (5%). Results: The factor ôadhesiveõ (P=0.00352) influenced the bond strength significantly (ANOVA). Gr1 (6.8±3.8 MPa)apresented higher bond strength values than Gr2 (3.1±1.5 MPa)band similar to Gr3 (4.4±3.3)a,b. Moreover, Gr3 and Gr2 were similar between them (Tukey). The hypothesis was accepted. Conclusion: Based on the results it was concluded that chemical and dual polymerization adhesive system should be used for the adhesive luting fiber post procedures

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O objetivo deste trabalho foi avaliar "in vitro" a resistência à fratura e o tipo de fratura de dentes desvitalizados, e restaurados com pinos intra-radiculares cônicos, de fibra de carbono e de vidro, através de teste de compressão...

The aim of this study was to evaluate the in vitro resistence and fracture pattern of nonvital human teeth restored with carbon fiber and glass fiber root canal posts (REFORPOST - ANGELUS / BR), using compression test...

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Objective: To check and compare the retention of cast posts cemented with three different kinds of cement. Method: Forty five 45 human permanent maxillary incisors were randomly divided into three groups of 15 teeth. Root canals were prepared for the cast posts up to 8.5mm in length. The cast post obtained randomly were cemented with the help of the three cements (Zinc Phosphate, Glass-ionomer and resin modified Glass-ionomer [hybrid] cement). After cementation, the samples were stored in a physiological solution for seven days, after which we concluded the measure of retentive strength with the help of the universal testing machine (Zwick num. 112627, Ulm-Germany). Results: The hybrid cement has the greatest means value for retention and it is 312.90 N. It is followed by the Glass-ionomer cement with 272.40 N, while the Zinc Phosphate has the least, at 312.90 N. The statistical analysis shows that there is a statistical difference in the retention strength between the Zinc Phosphate cement and the Glass-ionomer (p<0.01), between the Zinc Phosphate cement and the hybrid cement (p<0.01). Conclusion: A significant statistical discrepancy was not manifested between the Glass-ionomer cement and the hybrid cement even though the difference in retention strength for these two cements was around 40 N.

Objetivo: Verificar e comparar a retenção de pinos fundidos cimentados com três diferentes tipos de cimento. Método: Quarenta e cinco incisivos superiores permanentes humanos foram divididos aleatoriamente em três grupos de 15 dentes cada um. Os canais radiculares foram preparados para receberem pinos fundidos de até 8.5 mm de comprimento. Os pinos foram cimentados com um dos três tipos de cimentos a seguir: cimento de fosfato de zinco, cimento de ionômero de vidro e cimento de ionômero de vidro modificado por resina (híbrido). Após a cimentação, as amostras foram armazenadas em solução salina durante 7 dias e então submeti das à análise da força de retenção em máquina universal de ensaios (Zwick num. 112627, Ulm-Germany). Resultados: O cimento híbrido apresentou o maior valor médio de retenção (312.90 N), seguido do cimento de ionômero de vidro (272.40 N) e do cimento de fosfato de zinco (312.90 N). A análise estatística mostrou diferença estatisticamente significante nos valores de retenção entre o cimento de fosfato de zinco e o cimento de ionômero de vidro (p<0,01), e entre o cimento de fosfato de zinco e o cimento híbrido (p<0,01). Conclusão: Não houve discrepância significativa entre o cimento de ionômero de vidro e o cimento híbrido, embora a diferença na força de retenção entre os dois materiais tenha sido de aproximadamente 40 N.

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