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.

Restaurações Biológicas como Alternativa para Reabilitação de Dentes com Extensa Destruição Coronária / Biological Restoration as an Alternative to Rehabilitation of Extensively Compromised Teeth

Objetivo: Descrever reabilitações com coroas biológicas por meio de dois casos clínicos, um dente anterior e um posterior. Material e Método: O estudo apresenta dois casos clínicos em que reabilitações de dentes extensamente destruídos foram realizadas. Em um dos casos é apresentada a reabilitação do dente 14 e no seguinte uma reabilitação simultânea dos dentes 21 e 22. Em ambos os casos foram utilizados dentes humanos provenientes de um banco de dentes humanos (BDH). Para a seleção dos dentes, utilizou-se como parâmetros os diâmetros dos dentes a serem reabilitados, bem como as medidas do dente homólogo contralateral. Os dentes obtidos junto a BDH foram seccionados, a coroa biológica esvaziada e então reembasada com resina composta sobre um modelo de gesso obtido dos pacientes. Após o reembasamento e ajustes oclusais ainda no modelo de gesso, as coroas foram cimentadas com cimento resinoso. Resultados: Em ambos os casos clínicos, os pacientes foram reabilitados adequadamente, de forma rápida e com custo reduzido. Conclusão: Restaurações biológicas podem ser utilizadas para reabilitação de dentes permanentes anteriores e posteriores; além de estimular o correto descarte de futuros dentes extraídos, sendo esses destinados a bancos de dentes humanos.

Objective: To describe rehabilitations with biological crowns by two clinical cases, one anterior and one posterior. Methods: The study presents two clinical cases in which extensively damage teeth were rehabilitated. In one, the rehabilitation of tooth 14 is presented and, in the other, a simultaneous rehabilitation of teeth 21 and 22 was performed. In both cases, human teeth from a human tooth bank (HTB) were used. For teeth selection, the diameters of the teeth to be rehabilitated, as well as, the measurements of the contralateral homologous tooth were used as parameters. The teeth obtained with HTB were sectioned, the biological crown emptied and then relined with composite resin on cast obtained from the patients. After the reline and occlusal adjustments, the crowns were cemented with resin cement. Results: The patients were rehabilitated properly, quickly and with reduced cost. Conclusion: Biological restorations can be used for rehabilitation of anterior and posterior permanent teeth; besides to stimulate the correct discard of extracted teeth, being these destined to human teeth banks.

Restauração de dentes tratados endodonticamente com resinas bulk-fill: revisão integrativa / Endodontically treated teeth restored with bulk-fill resins: integrative review

Objetivo: realizar uma revisão de literatura sobre o uso de resinas bulk-fill para restaurar dentes tratados endodonticamente. Materiais e método: a busca dos estudos, clínicos ou laboratoriais, foi realizada no portal PubMed, utilizando os descritores "bulk fill" e "endodontically treated". Os dados extraídos da literatura foram agrupados em um quadro, que apresenta as características metodológicas e os principais resultados de cada estudo. Resultados: Sete estudos foram incluídos na revisão. Dentre eles, cinco avaliaram a resistência à fratura dos dentes após a restauração, um avaliou a adaptação da resina ao assoalho da câmara pulpar, e um realizou um ensaio clínico com acompanhamento de três anos, comparando o uso de resina bulk-fill com resina convencional. Considerações finais: o desempenho das resinas bulk-fill mostrou-se semelhante ao das resinas convencionais nas características de resistência à fratura dos dentes (in vitro) e longevidade (in vivo). A economia de tempo clínico proporcionada pelas resinas bulk-fill pode justificar o seu emprego para a restauração de dentes tratados endodonticamente. (AU)

Objective: the aim of this study was to review the literature regarding the use of bulk-fill resin to restore endodontically treated teeth. Materials and method: the search was performed at PubMed, using the descriptors "bulk fill" AND "endodontically treated". Clinical and laboratorial studies were included. The extracted data was presented on a table showing the methodological features and results of each study. Results: seven studies evaluated the bulk-fill resin on direct restoration. Five of these seven evaluated the resistance to fracture, one assessed the resin adaptation to the floor chamber, and one was a randomized clinical trial comparing the bulkfill resin to conventional resin. Final considerations: the performance of bulk-fill resins was similar to the conventional resins when compared to the in vitro studies on tooth fracture resistance and in vivo study on longevity of restorations. The economy of clinical time may justify its use to restore endodontically treated teeth. (AU)

Masticatory satisfaction, ability, and performance in partially dentate patients after periodontal therapy / Satisfação, capacidade e performance mastigatória em pacientes parcialmente dentados após terapia periodontal

Introduction: Understanding the effects of periodontal therapy is essential in performance and satisfaction of partially dentate patients. Objective: To assess the effect of subgingival periodontal treatment in performance and masticatory satisfaction and ability as reported by partially dentate patients with untreated chronic periodontitis. Materials and method: Patients were given nonsurgical periodontal treatment and masticatory satisfaction, ability, and performance were evaluated before and after treatment. Performance was assessed based on sieving chewed standardized chewable material, while satisfaction and ability were analyzed using a questionnaire based on OHIP-EDENT. Result: Mean numbers of functional tooth units were 10.36 ± 1.43 anterior and 6.73 ± 0.79 posterior teeth. Masticatory performance did not vary significantly (p = 0.075), and mean particle sizes before and after treatment were 4.23 ± 1.84 mm and 3.90 ± 0.75 mm, respectively. Overall satisfaction and ability scores after treatment were higher (p > 0.05) compared with scores prior to the periodontal intervention. Conclusion: Periodontal treatment improves masticatory satisfaction and ability with no effect on performance.

Introdução: Entender os efeitos da terapia periodontal é fator essencial no desempenho e satisfação de pacientes parcialmente dentados. Objetivo: Avaliar o efeito do tratamento periodontal subgengival na performance ao mastigar e na satisfação e capacidade mastigatória auto-reportadas em pacientes parcialmente dentados. Material e método: Pacientes parcialmente dentados com periodontite crônica não tratada (n=11) receberam tratamento periodontal não-cirúrgico e tiveram a sua satisfação, capacidade e performance mastigatória aferidas antes e após o tratamento. A performance mastigatória foi aferida objetivamente pelo método da peneiragem de um alimento simulado após mastigação seguida da medição do tamanho das partículas. Resultado: A satisfação e a capacidade mastigatória foram mensuradas a partir de um questionário com base no OHIP-EDENT. O número médio de unidades funcionais anteriores foi de 10,36 ± 1,43 e posteriores de 6,73 ± 0,79, sem alterações após o tratamento. A performance mastigatória não apresentou diferença (p = 0,075) (tamanhos de partícula 4,23 ± 1,84 mm e 3,90 ± 0,75 mm antes e após o tratamento periodontal, respectivamente). A satisfação e a capacidade mastigatória apresentaram valores após o tratamento periodontal superiores (p > 0,05) em comparação aos valores prévios aos tratamentos. Conclusão: O tratamento periodontal, considerando a manutenção dos pares funcionais do início do tratamento, promove uma melhoria na satisfação e capacidade mastigatória auto-reportadas, sem afetar a performance mastigatória.

Regionalização dos conteúdos de um curso de especialização em Saúde da Família, a distância: experiência da Universidade Aberta do Sistema Único de Saúde (UNA-SUS/UFCSPA) em Porto Alegre, Brasil / Regionalization of contents of an e-learning Family Health graduate course: the Open University of Brazilian National Health System experience (UNA-SUS/FCSPA), Porto Alegre, Brazil / Regionalización de contenidos de un curso de especialización en Salud de la Familia, a distancia: la experiencia de la Universidad Abierta del Sistema Brasileño de Salud (UNA-SUS/FCSPA) en Porto Alegre, Brasil

O objetivo desse estudo foi descrever o processo de criação dos conteúdos do Curso de Especialização em Saúde da Família (EspSF) promovido pela UNA-SUS/UFCSPA, modalidade a distância, de acordo com características de cada região onde o curso é ofertado. Parte do curso de EspSF é baseada na aprendizagem a partir de casos clínicos complexos. Alguns casos clínicos do curso foram personalizados de acordo com a região do país (norte, nordeste ou sul) onde o profissional atua, considerando características epidemiológicas e socioculturais de cada região. Com a adaptação de 12 casos complexos às realidades dos estados do Pará e de Sergipe, o curso, que foi inicialmente pensado a partir de características do estado do Rio Grande do Sul, pode ser oferecido aos referidos estados, mantendo a sua característica de fidedignidade às situações, as quais o profissional está exposto no seu cotidiano.(AU)

The objective of this study was to describe the process of creating the contents of the e-learning Family Health graduate course, promoted by the Open University of the Brazilian National Health System/Federal University of Porto Alegre (UNA-SUS/UFCSPA), adapted to the characteristics of each region where the course is offered. Part of this course is based on learning from complex clinical cases. Some clinical cases have been customized according to the regions of the country (North, Northeast and South) where participants exert their activities, considering epidemiological and socio-cultural characteristics of each region. Through the adaptation of 12 complex cases to the realities of the states of Pará and Sergipe, the course, although initially designed regarding the state characteristics of Rio Grande do Sul, can now be offered to those states while maintaining its characteristic of being in compliance with situations that workers experience in their daily lives.(AU)

El objetivo del estudio fue describir el proceso de creación de los contenidos del Curso de Especialización en Salud de la Familia (EspSF) promovidopor Universidad Abierta del Sistema Brasileño de Salud/Universidad Federal de Ciencias de la Salud de Porto Alegre (UNA-SUS/UFCSPA), modalidad a distancia, de acuerdo con características de cada región en donde se ofrece el curso. Parte del curso de EspSF se basa en el aprendizaje a partir de casos clínicos complejos. Algunos casos clínicos del curso se personalizaron de acuerdo con la región del país (norte, nordeste o sur) en donde actúa el profesional, considerando características epidemiológicas y socio-culturales de cada región. Con la adaptación de 12 casos complejos a las realidades de los estados de Pará y Sergipe, el curso que fue inicialmente pensado a partir de características del estado de Río Grande do Sul pudo ofrecerse a los referidos estados, manteniendo su característica de fidelidad a las situaciones a las que el profesional está expuesto en su cotidiano.(AU)

Efeito do ácido peracético sobre a adesão microbiana e as propriedades de tubos endotraqueais

Objetivo: avaliar a influência do número de imersões em ácido peracético na colonização bacteriana, na composição química, na rugosidade e na capacidade de recuperação após a deformação de tubos endotraqueais. Materiais e método: quatro tubos foram sub-metidos a sucessivas imersões em ácido peracético, constituindo quatro grupos: um controle (esterilizado pelo fabricante) e outros submetidos a uma, duas ou três imersões, de forma a simular o reprocessamento dos tubos. Os ensaios realizados foram: espectroscopia de infravermelho, rugosidade superficial, deformação da luz do tubo após compressão e colonização por Staphylococcus aureus. Resultados: o número de imersões (reprocessamento) não influenciou a colonização dos tubos por Staphylococcus aureus (p = 0,235), nem a composição química, nem a rugosidade (p = 0,621). Além disso, não houve diferença na capacidade do tubo em recuperar-se após deformação (p = 0,633). Conclusão: o reprocessamento por até três vezes não traz prejuízo às propriedades do material e não aumenta a colonização bacteriana na superfície dos tubos.

Glycerol Salicylate-based Pulp-Capping Material Containing Portland Cement

The purpose of this study was to evaluate the water sorption, solubility, pH and ability to diffuse into dentin of a glycerol salicylate-based, pulp-capping cement in comparison to a conventional calcium hydroxide-based pulp capping material (Hydcal). An experimental cement was developed containing 60% glycerol salicylate resin, 10% methyl salicylate, 25% calcium hydroxide and 5% Portland cement. Water sorption and solubility were determined based on mass changes in the samples before and after the immersion in distilled water for 7 days. Material discs were stored in distilled water for 24 h, 7 days and 28 days, and a digital pHmeter was used to measure the pH of water. The cement's ability to diffuse into bovine dentin was assessed by Raman spectroscopy. The glycerol salicylate-based cement presented higher water sorption and lower solubility than Hydcal. The pH of water used to store the samples increased for both cements, reaching 12.59±0.06 and 12.54±0.05 after 7 days, for Hydcal and glycerol salicylate-based cements, respectively. Both cements were able to turn alkaline the medium at 24 h and sustain its alkalinity after 28 days. Hydcal exhibited an intense diffusion into dentin up to 40 µm deep, and the glycerol salicylate-based cement penetrated 20 µm. The experimental glycerol salicylate-based cement presents good sorption, solubility, ability to alkalize the surrounding tissues and diffusion into dentin to be used as pulp capping material.

O objetivo deste estudo foi avaliar a sorção e solubilidade em água, pH e habilidade de difusão na dentina de um cimento para capeamento pulpar à base de glicerol salicilato e compará-lo a um cimento comercial para capeamento pulpar à base de hidróxido de cálcio (Hydcal). Um cimento experimental contendo 60% de resina de glicerol salicilato, 10% de salicilato de metila, 25% de hidróxido de cálcio e 5% de cimento Portland foi formulado. Sorção e solubilidade em água foram determinadas a partir da alteração na massa de espécimes antes e após a imersão em água destilada por 7 dias. Discos dos cimentos foram armazenados em água destilada por 24h, 7 dias e 28 dias e o pH da água foi aferido após cada período. A habilidade de difundir-se no interior de dentina bovina foi avaliada por espectroscopia Raman. O cimento à base de glicerol salicilato apresentou maior sorção e menor solubilidade em comparação com o Hydcal. O pH da água de armazenamento dos espécimes aumentou para ambos os cimentos, chegando a 12,59±0,06 e 12,54±0,05 após 7 dias, para o Hydcal e o cimento à base de glicerol salicilato, respectivamente. Os cimentos foram capazes de promover a alcalinização do meio após 24h e sustentaram a alcalinidade após 28 dias. Hydcal exibiu intensa difusão na dentina até 40 μm de profundidade e o cimento à base de glicerol salicilato penetrou 20 μm. O cimento experimental à base de glicerol salicilato apresentou adequada sorção, solubilidade, habilidade de alcalinizar o meio e difundir-se no interior da dentina para uso como um material para capeamento pulpar.

Cimento experimental bioativo à base de glicerol salicilato contendo α -fosfato tricálcico para uso endodôntico / Bioactive cement experimental glycerol based salicylate containing α tricalcium phosphate for endodontic use

O tratamento de canal ideal compreende a desinfecção e selamento do sistema de canais radiculares, de forma a impedir a reinfecção e permitir o reparo dos tecidos periapicais. Para isso é necessário o emprego de materiais que promovam um perfeito selamento, o que até o presente momento não foi completamente alcançado. O objetivo do presente estudo in vitro foi desenvolver um cimento endodôntico à base de resina de glicerol salicilato e α-fosfato tricálcico (αTCP), que apresente potencial de estimular a deposição mineral. Os cimentos foram formulados a partir de 70% em massa de uma resina de glicerol salicilato, obtida a partir da reação de transesterificação do salicilato de metila com o glicerol, e 30% em massa de carga inorgânica, composta de hidróxido de cálcio e αTCP, em diferentes proporções: 30% Ca(OH)2, 25% Ca(OH)2 + 5% αTCP, 20% Ca(OH)2 + 10% αTCP, 15% Ca(OH)2 + 15% αTCP. A resina sintetizada foi caracterizada por cromatografia de exclusão por tamanho, ressonância magnética de prótons e espectroscopia Raman. Os cimentos foram caracterizados quanto ao tempo de presa, degradação in vitro, potencial de alcalinização do meio, citotoxicidade e capacidade de estimular a deposição mineral. A resina de glicerol salicilato foi obtida por meio da reação de transesterificação, com 72% de rendimento. Os grupos avaliados apresentaram um tempo de presa de 240 min a 405 min e capacidade de alcalinizar o meio...

Dental root canal treatment comprises the disinfection and complete filling of root canals in order to prevent the reinfection and allows the healing of periapical tissues. The use of materials that promotes an effective sealing has no achieved at the moment. The aim of this in vitro study was to develop a root canal sealer based on a glycerol salicylate resin and α-tricalcium phosphate (αTCP) that presents potential to stimulate mineral deposition. Sealers were formulated based on 70wt% of a glycerol salicylate resin, obtained by transesterification of methyl salicylate and glycerol, and 30wt% of inorganic filler, composed by calcium hydroxide and αTCP, in different proportions: 30% Ca(OH)2, 25% Ca(OH)2 + 5% αTCP, 20% Ca(OH)2 + 10% αTCP, 15% Ca(OH)2 + 15% αTCP. Synthesized resin was characterized by proton nuclear magnetic resonance spectroscopy, size exclusion chromatography and Raman spectroscopy. Sealers were characterized based on setting time, in vitro degradation over time, pH, cytotoxicity and mineral deposition. The glycerol salicylate resin was obtained by transesterification reaction, with 72% yield. Sealers presented setting time ranging from 240 min to 405 min, and basic pH over 8.21 after 28 days. Higher αTCP concentration leads to sealers with low solubility. Cell viability after 48 h in direct contact with sealers was similar to a commercial sealer (AH Plus) used as reference...

Long-term bond strength, degree of conversion and resistance to degradation of a HEMA-free model adhesive

Aim: To evaluate the long-term bond strength, degree of conversion and resistance to degradation in ethanol of HEMA-containing and HEMA-free model adhesive resins of a three-step etch-and-rinse adhesive system. Methods: The superficial dentin of 16 bovine incisor teeth was exposed, and the teeth were divided in two groups according to the HEMA concentration in the experimental adhesive (0% and 15%). In each tooth were made 6 cylindrical composite restorations. Half of the tooth restorations were submitted to microshear bond strength test after 24 h and the other half after 6 months. Degree of conversion of experimental resins was determined by Fourier transform infrared spectroscopy. Crosslink density was indirectly determined by the Knoop hardness of five specimens per group before and after immersion in ethanol for 6 h. Results: The group with 0% HEMA showed no difference in bond strength as compared to the group with 15% HEMA after 24 h or 6 months. There was no difference in degree of conversion and crosslink density between groups. Conclusions: HEMA content of the adhesive resin did not influence the bond strength to dentin, degree of conversion or resistance to degradation in ethanol.

Discrepancies in degree of conversion measurements by FTIR

The purpose of this study was to evaluate the influence of the internal standard peak on the measured degree of conversion (DC) for methacrylate-based resins analyzed by Fourier-transform infrared spectroscopy (FTIR). The influence of different baseline measurement methods was also determined. Different blends were prepared, mixing BisGMA/BisEMA and BisGMA/TEGDMA at proportions of 0% to 100%, in weight. Camphoroquinone and ethyl-4-dimethylamino-benzoate were used to permit the light activation of blends. Degree of conversion was evaluated using FTIR equipped with an attenuated total reflectance (ATR) device. Samples were dispensed onto ATR crystal and light activated for 40 s. The DC was calculated by relating the height of the peak 1637 cm-1 to the intensity of different internal standard peaks (1715, 1608, or 1582 cm-1), measured using two different baseline methods, before and after polymerization. Data were compared by ANOVA at 5% significance. The relationship between DC and monomer ratio was obtained by regression analysis. Double-bond conversion ranged from 32.75% to 78.50% for BisGMA/BisEMA blends, and from 32.75% to 76.22% for BisGMA/TEGDMA blends. For the BisGMA/BisEMA blends, the DC showed a linear association with the composition of the comonomer blends, independent of the internal standard peak and baseline method used. In contrast, the trends in DC for BisGMA/TEGDMA blends were different for each method of measurement. The internal standard peaks and measurement baseline should be taken into account when using FTIR to calculate the DC of methacrylate-based resins, especially comonomer blends containing a high degree of monomers that lack aromatic rings.

Influence of radiopaque fillers on physicochemical properties of a model epoxy resin-based root canal sealer

Objective: To verify the influence of radiopaque fillers on an epoxy resin-based sealer. Material and Methods: Experimental sealers were formulated by adding 20%, 40%, 60%, 80%, 100% and 120% of calcium tungstate, ytterbium trifluoride or barium sulphate by weight to an epoxy-resin-base. Setting time, flow, film thickness, radiopacity, sorption, solubility, pH and push-out bond strength were evaluated. Results: The setting time ranged from 373 to 612.66 min, the flow varied from 13.81±0.49 to 22.49±0.37 mm, and the film thickness ranged from 16.67±5.77 to 33.33±11.54 µm. The lowest pH was 5.47±0.53, and the highest was 6.99±0.03. Radiopacity varied from 0.38±0.04 to 2.57±0.21 mmAl and increased with the amount of filler. Calcium tungstate sealers had a higher sorption and solubility than other sealers. There was no significant difference in the push-out bond strength among the fillers at the 120% concentration. CONCLUSION: The inorganic fillers evaluated and their concentrations affect the physicochemical properties of an epoxy resin-based root canal sealer. .

Impact of the implantation of a new curriculum in the process of learning in a Faculty of Dentistry in Brazil

The aim of the present study was to evaluate two dental curricula at a school of dentistry in southern Brazil. The study population included dentists trained in the last two classes of the institution's old curriculum (n = 98) and graduates of the first two classes of the new curriculum (n = 56). A questionnaire with open and closed questions was used for an overall evaluation of different aspects of the curricula, such as study methods, importance given to basic sciences, quality of theoretical and clinical guidance, perception about skills needed to perform different dental procedures, professional goals and an overall assessment. Students in the new curriculum reported more frequent use of the internet (69.6 percent) and scientific articles (50.0 percent). More importance was given to the basic sciences in the new curriculum. Graduates of the old curriculum alleged themselves to be more capable of both performing conventional (99 percent) and complex amalgam restorations (68.4 percent), as well as three-unit fixed prostheses (62.2 percent). Graduates of the new curriculum alleged higher capability with periodontal surgeries (48.2 percent), treatment of temporomandibular joint (TMJ) disorders (58.1 percent) and public health planning (78.6 percent). Regarding professional goals, the new curriculum was associated with an increase in the graduates' willingness to work in the public health system and to pursue an academic career. New curriculum graduates reported higher overall assessments regarding their educational, as well as theoretical and clinical, outcomes. A new curricular approach was associated with several changes from the perspective of the students.

Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth

The aim of this study was to evaluate the influence of applying 2 percent chlorhexidine for 30 seconds after phosphoric acid conditioning of dentin on the immediate and long-term bond strengths in deciduous teeth. The occlusal enamel was removed from 40 human sound deciduous molars, which were exfoliated by natural means, and the dentin was conditioned with 37 percent phosphoric acid for 15 seconds and washed with running water. The specimens were divided into two groups of 20 teeth. The test group received an application of 2 percent chlorhexidine for 30 seconds prior to a three-step etch-and-rinse adhesive system, whereas the control group received only the adhesive system. Three cylindrical restorations were made with a composite resin for each tooth. Ten teeth in each group were submitted to a microshear bond strength test after 24 hours, while the remaining teeth were stored in distilled water at 37 °C for 6 months before testing the microshear bond strength. The test group had a higher bond strength than did the control group after 6 months of storage. No statistical differences were found when groups with the same dentin treatment were compared at different times. Short applications of chlorhexidine at low concentrations prevent hybrid layer degradation and positively affect bond strength over time.