Color and surface gloss stability of bis-acryl and resin composite after exposure to cigarette smoke / Estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas após exposição por fumaça de cigarro

Objective: To evaluate color and surface gloss stability of bis-acryl resins and resin composites, submitted to artificial staining with cigarette smoke. Material and Methods: Specimens of each material were prepared (n=15). Two resin composites (GrandioSO [RCG], Filtek Supreme [RCZ]) and five bis-acryl resins (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] and Yprov [BisYPR]) were tested. Initial color was assessed using a spectrophotometer and surface gloss with a glossmeter. Samples were submitted to smoke exposure (10 cigarettes under 8 minutes per cycle). After 3 and 6 cycles, color and gloss were reassessed. Final readings were performed after brush prophylaxis. Data were analyzed using two-way repeated ANOVA and Tukey's test (p<0.05). Results: Differences and interaction of factors (p<0.01) were detected for both color and gloss readings. Resin composites were the least affected by aging, with gloss reduction after prophylaxis. Differences were detected among bis-acryl resins, with better results for BisLUX and BisPRO. BisPRO and BisSTR, showed reduction in gloss after 60 cigarettes, while BisYPR gloss decreased at all evaluated periods. Conclusion: Resin composites are less susceptible to changes after smoke exposure, while bis-acryl resins results are brand-dependent. Prophylaxis negatively influenced the surface gloss of most of the tested materials (AU)

Objetivo: Avaliar a estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas, submetidos ao manchamento artificial por fumaça de cigarro. Material e Métodos: Foram preparados espécimes de cada material (n=15). Duas resinas compostas (GrandioSO [RCG], Filtek Supreme [RCZ]) e cinco resinas bisacrílicas (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] e Yprov [BisYPR]) foram testados. A cor inicial foi avaliada usando um espectrofotômetro e o brilho de superfície com um medidor de brilho. As amostras foram submetidas à exposição de fumaça de cigarro (10 cigarros com até 8 minutos por ciclo). Após 3 e 6 ciclos, a cor e o brilho foram reavaliados. As leituras finais foram realizadas após a profilaxia escova de robinson. Os dados foram analisados usando de medidas repetidas e teste de Tukey (p<0,05). Resultados: Foram detectadas diferenças e interação de fatores (p<0,01) tanto para leituras de cor quanto para leituras de brilho. As resinas compostas foram as menos afetados pelo envelhecimento, com redução do brilho após a profilaxia. Foram detectadas diferenças entre as resinas bisacrílicas, com melhores resultados para BisLUX e BisPRO. BisPRO e BisSTR, mostraram redução de brilho após 60 cigarros, enquanto que o brilho da BisYPR diminuiu em todos os períodos avaliados. Conclusão: As resinas compostas são as menos suscetíveis a mudanças após a exposição à fumaça, enquanto os resultados das resinas bisacrílicas são dependentes da marca. A profilaxia influenciou negativamente o brilho de superfície da maioria dos materiais testados.(AU)

Development and characterization of a novel bulk-fill elastomeric temporary restorative composite

Abstract Objectives: This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM). Material and Methods: Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans' biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%). Results: The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs. Conclusions: The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials

Abstract The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Substituição dentária conservadora utilizando implantes e o dente pré-existente para provisórios estéticos / Conservative tooth replacement using implants and pre-existing tooth for aesthetic provisional restorations

Objetivo: apresentar, através de um caso clínico, a utilização de coroas de dentes extraídos como provisórios em próteses fixas unitárias maxilares anteriores, favorecendo aspectos como estética, conforto psicológico, perfil de emergência, biocompatibilidade com tecidos moles e durabilidade em relação a provisórios fixos convencionais. Características do paciente: alta demanda estética, apresentando incisivos centrais maxilares com indicação de substituição por implantes, mas com estética coronária satisfatória. Tratamento propriamente dito: através de desgaste seletivo da coroa original, cobertura do intermediário metálico com resina opaca e preenchimento com resina flow, foi possível a utilização das coroas originais da paciente como provisórios imediatos. Conclusão: a utilização de coroas fixas implantossuportadas construídas a partir de coroas naturais pode melhorar aspectos estéticos, biológicos e psicológicos do tratamento, quando corretamente indicadas e aplicadas.

Objective: to present a case report of the use of extracted teeth as provisional crowns in fixed maxillary prosthesis, favoring aesthetics, psychological comfort, emergency profile, soft tissue biocompatibility and durability in relation to conventional fixed prosthesis. Patient characteristics: patient with high aesthetic demand, presenting maxillary central incisors with indication for replacement with implants, but with satisfactory dental aesthetics. Proposed treatment: through selective wear of the original crown, coating of the metallic abutment with opaque resin and filling with flow resin, it was possible the use of the patient's original crowns as immediate prosthesis. Conclusion: the option to use implantsupported fi xed crowns constructed from natural crowns can help patients with aesthetic, biological and psychological aspects of the treatment, as long as correctly indicated and applied.

Cytotoxicity Evaluation of Two Bis-Acryl Composite Resins Using Human Gingival Fibroblasts

Abstract Bis-acryl resins are used for temporary dental restorations and have shown advantages over other materials. The aim of this work was to evaluate the in vitro cytotoxicity of two bis-acryl composite resins (Protemp 4 and Luxatemp Star), obtained at 1, 7 and 40 days after mixing the resin components, using a standardized assay employing human primary cells closely related to oral tissues. Human gingival fibroblast cell cultures were exposed for 24 h to either bis-acryl composite resins, polystyrene beads (negative control) and latex (positive control) extracts obtained after incubation by the different periods, at 37 °C under 5% CO2. Cell viability was evaluated using a multiparametric procedure involving sequential assessment (using the same cells) of mitochondrial activity (XTT assay), membrane integrity (neutral red test) and total cell density (crystal violet dye exclusion test). The cells exposed to the resin extracts showed cell viability indexes exceeding 75% after 24 h. Even when cells were exposed to extracts prepared with longer conditioning times, the bis-acryl composite resins showed no significant cytotoxic effects (p>0.05), compared to the control group or in relation to the first 24 h of contact with the products. There were no differences among the results obtained for the bis-acryl composite resins evaluated 24 h, 7 days and 40 days after mixing. It may be concluded that the bis-acryl resins Protemp 4 and Luxatemp Star were cytocompatible with human gingival fibroblasts, suggesting that both materials are suitable for use in contact with human tissues.

Resumo Resinas bisacrílicas são usadas em restaurações dentárias provisórias e têm mostrado vantagens em relação a outros materiais. O objetivo deste trabalho foi avaliar a citotoxicidade in vitro de duas resinas compostas bisacrílicas (Protemp 4 e Luxatemp Star), obtidas após 1, 7 e 40 dias da mistura com os componentes da resina, usando um ensaio padronizado empregando células primárias humanas fortemente relacionadas aos tecidos orais. Culturas de células de fibroblastos gengivais humanos foram expostas por 24 h aos extratos das resinas bisacrílicas, esferas de poliestireno (controle negativo) e látex (controle positivo), obtidos após diferentes períodos de incubação, a 37 °C e com 5% CO2. A viabilidade celular foi avaliada usando procedimentos multiparamétricos que envolvem a avaliação sequencial (usando as mesmas células) da atividade mitocondrial (ensaio XTT), a integridade de membrana (teste do vermelho neutro) e a densidade celular total (teste de exclusão do corante cristal violeta). As células expostas aos extratos mostraram viabilidade celular acima de 75% depois de 24 h. Mesmo quando as células foram expostas aos extratos com aumento do tempo de condicionamento, as resinas bisacrílicas não apresentaram efeitos citotóxicos significativos (p<0,05), comparadas ao grupo controle ou em relação às primeiras 24 h de contato com os produtos. Não houve diferença entre os resultados obtidos para as resinas bisacrílicas avaliadas entre as 24 h, 7 e 40 dias depois da mistura. Concluímos que as resinas bisacrílicas Protemp 4 e Luxatemp Star foram citocompatíveis com os fibroblastos gengivais humanos, sugerindo que ambos materiais são adequados para uso em contato com tecidos humanos.

Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns

ABSTRACT Objective This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns. Material and Methods An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone “PEEK”, Telio CAD-Temp, and Protemp™4 (control group). The crowns were divided into four groups (n=10), Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0. Results The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99) µm, PEEK 46.75 (±8.26) µm, Telio CAD-Temp 56.10 (±5.65) µm, and Protemp™4 193.07(±35.96) µm (P<0.001). The average internal fit was: VITA CAD-Temp® 124.94 (±22.96) µm, PEEK 113.14 (±23.55) µm, Telio CAD-Temp 110.95 (±11.64) µm, and Protemp™4 143.48(±26.74) µm. The average fracture strength was: VITA CAD-Temp® 361.01 (±21.61) N, PEEK 802.23 (±111.29) N, Telio CAD-Temp 719.24 (±95.17) N, and Protemp™4 416.40 (±69.14) N. One-way ANOVA test showed a statistically significant difference for marginal gap, internal gap, and fracture strength between all groups (p<0.001). However, the mode of fracture showed no differences between the groups (p>0.05). Conclusions CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns.

Evaluation of an alternative technique to optimize direct bonding of orthodontic brackets to temporary crowns

OBJECTIVE: To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces.METHODS: The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamond bur followed by conventional direct bonding by means of light-cured composite resin; discs in group 3 were bonded by means of CAAR (alternative adhesive); and discs in group 4 had surfaces roughened with a diamond bur followed by direct bonding by means of CAAR. Shear bond strength values were determined after 24 hours by means of a universal testing machine at a speed of 0.5 mm/min, and compared by analysis of variance followed by post-hoc Tukey test. Adhesive remnant index (ARI) was measured and compared among groups by means of Kruskal-Wallis and Dunn tests.RESULTS: Groups 3 and 4 had significantly greater shear bond strength values in comparison to groups 1 and 2. Groups 3 and 4 yielded similar results. Group 2 showed better results when compared to group 1. In ARI analyses, groups 1 and 2 predominantly exhibited a score equal to 0, whereas groups 3 and 4 predominantly exhibited a score equal to 3.CONCLUSIONS: Direct bonding of brackets to acrylic resin surfaces using CAAR yielded better results than light-cured composite resin. Surface preparation with diamond bur only increased shear bond strength in group 2.

OBJETIVO: comparar a resistência ao cisalhamento de diferentes técnicas para colagem direta de braquetes ortodônticos em superfície de resina acrílica.MÉTODOS: sessenta e quatro (64) discos de resina acrílica ativada quimicamente (RAAQ) foram divididos aleatoriamente em qautro grupos: grupo 1 = colagem com resina composta fotopolimerizável (adesivo convencional); grupo 2 = superfície abrasionada com broca diamantada e colagem com resina composta fotopolimerizável; grupo 3 = colagem com RAAQ (adesivo alternativo); grupo 4 = superfície abrasionada com broca diamantada e colagem com RAAQ. A resistência ao cisalhamento foi avaliada 24h após a colagem, utilizando-se uma máquina universal de ensaios, operando a uma velocidade de 0,5mm/min, e comparada por meio da análise de variância, seguida pelo teste post-hoc de Tukey. O índice de adesivo remanescente (IAR) foi mensurado e comparado entre os grupos por meio dos testes Kruskal-Wallis e Dunn.RESULTADOS: os grupos 3 e 4 demonstraram resistência ao cisalhamento significativamente maior do que os grupos 1 e 2. Os grupos 3 e 4 apresentaram resultados similares. O grupo 2 apresentou melhores resultados do que o grupo 1. Na análise do IAR, observou-se predominância do escore 0 para os grupos 1 e 2 e do escore 3 para os grupos 3 e 4.CONCLUSÕES: a colagem do braquete em superfície de resina acrílica utilizando-se a RAAQ apresentou melhores resultados do que a colagem com resina composta fotopolimerizável. A abrasão da superfície com broca diamantada apenas aumentou a resistência ao cisalhamento no grupo 2.

Overlay removable partial denture as temporary restoration of vertical dimension of occlusion in a bruxist patient / Overlay removível como tratamento provisório para restabelecimento da dimensão vertical de oclusão de paciente bruxista

The reestablishment of the vertical dimension of occlusion is an important phase during prosthodontics treatment. Its reduction can be a consequence of severe bruxism, and patient rehabilitation requires complex, expensive, and long treatments. In this context, an overlay removable partial denture is a viable alternative, as it represents a simple manufactured reversible treatment. As a temporary treatment, it does not require tooth wear, reestablishes vertical dimension of occlusion, and allows the patient to adapt to this new dimension until the definitive rehabilitation treatment can be planned and finished. This case report describes the temporary rehabilitation of a maxillary complete edentulous bruxist patient with excessive tooth wear on his lower jaw, seeking treatment at the Removable Prosthodontics Department at State University of Ponta Grossa to replace his upper complete denture. A new complete denture was made ​​and the implementation of an overlay removable partial denture was proposed to be made to the lower arch, which provided aesthetics and function to the patient until the completion of the definitive work. The patient was instructed and guided about the causal factors and consequences of his parafunctional habit and was taught methods for self-perception to control frequency. For the final rehabilitation, ​​a new maxillary complete denture with metal occlusal surfaces will be made as well as metaloceramic crowns with metal occlusal using intraradicular retention with cast posts. An occlusal splint will be inserted in the lower jaw as supportive therapy to control the parafunctional habit.

O restabelecimento da dimensão vertical de oclusão é uma etapa importante e indispensável durante a realização de trabalhos protéticos. Sua diminuição pode ser consequência do bruxismo severo e a reabilitação dos pacientes exige a realização de tratamentos complexos, de alto custo e tempo prolongado para execução. Neste contexto, a prótese parcial removível overlay é uma alternativa viável, pela reversibilidade do tratamento e simplicidade de execução. Como tratamento provisório, não necessita de preparo dental, restabelece a dimensão vertical de oclusão e permite que o paciente se adapte a esta nova dimensão, até que seja planejado e executado o tratamento reabilitador definitivo. O presente caso clínico descreve a reabilitação provisória de um paciente bruxista, desdentado total superior, com desgaste dental excessivo na arcada inferior que procurou tratamento na Clínica de Prótese Removível da Universidade Estadual de Ponta Grossa para substituição de sua prótese total superior. Uma nova prótese total foi confeccionada e proposta a execução de uma prótese parcial removível overlay para o arco inferior, a qual devolveu estética e função ao paciente até a realização do trabalho definitivo. O paciente foi instruído e orientado sobre os fatores desencadeantes e consequências de seu hábito parafuncional e conscientizado no intuito da autopercepção para controle da frequência. Para a reabilitação final, será confeccionada uma nova prótese total superior com superfícies oclusais metálicas, coroas metalocerâmicas com oclusal em metal utilizando retenção intracanal com núcleos metálicos fundidos. Uma placa miorrelaxante será instalada sobre a arcada inferior como terapia de suporte para controle do hábito parafuncional.

Temporary restorative materials used by Brazilian Dental Schools during and after endodontic treatment / Materiais restauradores temporários usados pelas faculdades de Odontologia brasileiras durante e após tratamento endodôntico

Objective: this study aimed at evaluating which temporary restorative materials are recommended by Brazilian Dental Schools (BDS), during and after endodontic treatment completion. Methods: a questionnaire was distributed to all 191 BDS, and returned by 55 (28.8%)schools. Topics of interest included: which temporary restorative materials are advised in different remaining dental conditions and different permanence periods in the mouth, minimum material thickness, intermediate material application, use of matrix band and factors influencing material selection. Results: the answers showed that the remaining coronal tooth structure significantly interferes with the choice of temporary restorative materials. On the other hand, time between ap pointments does not have significant influence on material selection. Still, premixed hygroscopic materials are recommended in cases of simple endodontic access (occlusal or lingual/palatal) if the material will be kept for up to one week in the month. Glass ionomer cement (GIC) is the most commonly used material in long periods, especially for access cavities involving proximal surfaces or fractured cusps. The utilization of an intermediate material is very variable and some schools do not advocate any material. Most BDS recommend a minimum thickness of 3 mm for temporary restorations and the use of matrix band in proximal surfaces. Conclusion: BDS choices with respect to coronal sealing materials are driven especially by remaining dental conditions.

Micro-hardness of acrylic resin utilized for provisional crowns: Effect of different polymerization techniques and pH-Cycling / Avaliação da microdureza de resina acrílica para coroas provisórias: Efeito de diferentes técnicas de processamento e ciclos dinâmicos de ph

Objective: This study aimed at evaluating the micro-hardness of an acrylic resin used for provisional crowns. Materials and methods: Five different processing techniques (direct and indirect) were assessed: (I) auto polymerizing resin in sandy stage; (II) auto polymerizing resin in plastic stage; (III) bead-brush technique; (IV) auto polymerizing resin under pressure; (V) heatcured acrylic resin under pressure. Five specimens were made for each test group. For the initial micro-hardness test, the specimens were immersed in deionized water for 48 hours. For the analysis of the final micro-hardness, the specimens were subjected to pH-cycling to simulate the changes in the pH level which occur in the oral cavity. Results: Tests revealed that the micro-hardness was decreased after the pH-cycling. However, no statistical difference was found among the different types of acrylic resin polymerization techniques. Conclusion: It was concluded that the micro-hardness is not directly related to the polymerization technique for making provisional

Objetivo: Avaliou-se a dureza superficial de uma resina acrílica (PMMA) utilizada para a confecção de coroas provisórias. Material e Métodos: Cinco diferentes técnicas de processamento (Direta e Indireta) para polimerização da resina foram testadas: I - autopolimerização após mistura (pó + líquido) em pote dappen e inserção em matriz de silicona na fase arenosa; II - autopolimerização após mistura em pote dappen com inserção em matriz de silicona na fase plástica; III - autopolimerização utilizando a técnica do pincel; IV - autopolimerização sob pressão em matriz de silicona; V - polimerização térmica utilizando líquido de polimerização rápida em mufla. Foram confeccionados cinco corpos-de-prova para cada grupo. Para o teste de microdureza inicial os espécimes foram imersos em água deionizada por 48 horas. Para a análise da dureza final, os espécimes foram submetidos a ciclos dinâmicos de pH, para simular a variação de pH ocorrida na cavidade oral. Resultados: Os testes revelaram que houve diminuição da dureza do material após a ciclagem ácida, porém não foi verificada diferença estatística entre os diferentes tipos de processamento da resina acrílica. Conclusão: Concluiu-se que a microdureza não está relacionada diretamente com a técnica de confecção dos provisórios.

Avaliação do selamento de dois cimentos provisórios fotopolimerizáveis utilizados em Endodontia / Evaluation of sealing ability of two temporary resin-based cements used in Endodontics

Introdução: O sucesso do tratamento endodôntico está interligado à capacidade de selamento da restauração provisória, que busca impedir a infiltração bacteriana e a recontaminação do sistema de canais radiculares. Objetivo: O objetivo deste estudo foi avaliar o selamento de dois cimentos temporários à base de resina: Fill Magic Tempo e Bioplic. Material e métodos: Utilizaram-se 24 terceiros molares, dos quais 22 foram abertos até a câmara pulpar, resultando numa cavidade classe I, e divididos aleatoriamente: o grupo 1 foi restaurado com uso de Fill Magic Tempo (n = 10), e o grupo 2 foi restaurado utilizando Bioplic (n = 10). O grupo controle negativo não teve a câmara aberta (n = 2), e o grupo controle positivo foi aberto mas não foi restaurado (n = 2). Impermeabilizaram-se com esmalte a raiz e o ápice dos dentes, e todas as amostras foram imersas em azul de metileno a 2% e mantidas a 37°C por 72 h. Assim, seccionaram-se os dentes longitudinalmente, e a infiltração linear foi medida em mm, sendo posteriormente aplicada análise estatística com teste de Mann-Whitney com nível de significância de 5%. Resultados: A maior parte das amostras apresentou 1 mm de infiltração, e somente o grupo controle negativo obteve infiltração total. Não se encontrou diferença significante entre os materiais testados. Conclusão: Pode-se concluir que ambos os materiais à base de resina proporcionaram resultados satisfatórios no selamento periférico durante tratamento endodôntico.

Introduction: The outcome of endodontic treatment is related to the sealing ability of temporary dental restoration, which aims to prevent bacterial infiltration and recontamination of the root canal system. Objective: The purpose of this study was to evaluate the sealing ability of two temporary resin-based cements: Fill Magic Tempo and Bioplic. Material and methods: Twenty-four third molars were used, and twenty-two of them were opened to the pulp chamber (resulting in a class I cavity) and randomly divided: group 1 was restored using Fill Magic Tempo (n = 10) and group 2 was restored using Bioplic (n = 10). The negative control group was not opened (n = 2), and the positive control group was opened but not restored (n = 2). Then the root and apex of the teeth were varnished to become impermeable. All samples were immersed in 2% methylene blue and kept at 37°C for 72h. After longitudinal sectioning, the linear leakage was measured in mm. In sequence, the statistical analysis was performed using Mann-Whitney test with a level of significance of 5%. Results: Most part of the samples showed leakage of 1 mm, and only the negative control group showed total leakage. There was no significant difference between the tested materials. Conclusion: It is possible to conclude that both resin-based cements showed satisfactory results on sealing ability during endodontic treatment.

Eficácia do selamento provisório de três materiais restauradores ante a solução de nitrato de prata a 50% / Effectiveness of the temporary sealing of three restorative materials to the 50% silver nitrate solution

Introdução e objetivo: Este estudo teve como objetivo analisar três materiais restauradores provisórios, Coltosol®, Cavit® W e Cimpat®,quanto a sua capacidade seladora ante a solução de nitrato de prata a50%. Material e métodos: Trinta corpos de prova foram divididos em três grupos experimentais. Cada amostra continha em seu interior um disco de antibiograma com 5 mm de diâmetro e 1 mm de espessura e,sobre o disco, 4 mm de um dos três materiais. Depois de realizadas as restaurações, os corpos de prova foram colocados em recipientes contendo nitrato de prata a 50%, sendo levados à estufa a 37ºC, na qual permaneceram por 7 dias. Decorrido esse período e comos materiais restauradores removidos, foram feitas as análises dos discos de antibiograma, que receberam escores conforme a infiltração.Resultados e conclusão: Os dados obtidos foram submetidos ao teste estatístico não-paramétrico Kruskal-Wallis, ao nível de significância de 5%. Os resultados mostraram que o Cimpat® apresentou os maioresníveis de infiltração. Já o Coltosol® e o Cavit® W não diferiram entre si (p > 0.05).

Introduction and objective: The aim of this study was to analyze three temporary restorative materials Coltosol®, Cavit® W and Cimpat®, concerning their sealing capacity to the 50% silver nitrate solution.Material and methods: 30 samples were divided into 3 experimental groups. Inside of each sample there was an antibiogram disc with 5mm of diameter and 1 mm of depth, with 4 mm of one of the three sealing materials on it. After restorations, the samples were insertedinto recipients with 50% silver nitrate solution, which were taken to theheater at 37ºC, where they remained for 7 days. Following this period and with the restorative materials removed, antibiogram disc analyses were performed, which were scored according to the leakage. Results and conclusion: Data obtained were submitted to the Kruskal-Wallisnon-parametric statistical test, with a level of significance of 5%. Results showed that Cimpat® had the greatest levels of leakage, while Coltosol® and Cavit® W did not differ between themselves (p > 0.05).

Microfiltración coronal in vitro contres materiales de obturación temporal utilizados en endodoncia / In vitro coronal microleakage of three temporary filling materials used in endodontics

El propósito de la presente investigación fue evaluar in vitro la microfiltración coronal comparando tres materiales de obturación temporal: IRM, Coltosol y Eco-Temp en piezas monorradiculares por el método electroquímico. Se prepararon 51 piezas dentarias unirradiculares separadas según el tipo de cemento utilizado; obturadas con Eco-temp, obturadas con Coltosol, obturadas con IRM, el control positivo fueron dientes con aperturas camerales sin obturación y control negativo fueron dientes con coronas intactas. A las piezas dentarias solo se les dejo lacorona y el tercio coronal de la raíz, se introdujo un alambre de acero inoxidable en el conducto radicular de cada diente, éste iba conectado a un micro amperímetro. Todos los dientes fueron sumergidos en una solución de KCl al 1% con un alambre de acero inoxidable que iba conectado a una fuente de poder, la cual proporcionaba el potencial de 15 V. La filtración coronal fue medida en microamperios, y el tiempo de evaluación fue al día 1, 2, 4, 6 y 7. Se utilizó para el análisis de datos las pruebas ANOVA y Tukey. Se encontró diferencias estadísticamente significativas (p<0,05) al comparar los tres cementos de obturación temporal. La microfiltración fue menor con el cemento Eco-temp (0,018 mA), seguido del Coltosol (0,037 mA) y porúltimo el IRM (0,054 mA) que presentó la mayor microfiltración.

The purpose of the present investigation was to evaluate in vitro the frontal microleakage comparing three materials for endodontic temporary obturation: IRM, Coltosol and Eco-Tempin vitro with the electrochemical method. Fifty one teeth were prepared and separated in 3 groups; with Echo - temp, with Coltosol and with IRM. The positive control group of teeth with cameral openings without obturation and the negative control group teeth wuth intact crowns.A stainless steel wire was placed in the root canal of every tooth, and connected to a micro amperimeter. All the teeth were immersed in 1% KCl's solution by a stainless steel wire that was connected to a source of power, which provided 15 volts. The coronal filtration was measured in microamperes, and the time of evaluation were 1, 2, 4, 6 and 7 days. ANOVA and Tukey statistical tests were used. There were statistically significant differences (p <0.05) when compared 3 cements for temporary filling. The microleakage was smaller with the cement Echo - temp (0.018 mA), followed by the Coltosol (0.037 mA) and finally the IRM (0.054 mA) that presented the greatest microleakage.

Influence of different catilever extensions and glass or polyamaramid reinforcement fibers on fracture strength of implant-supported temporary

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Avaliação da infiltração marginal de quatro seladores provisórios após a utilização de substâncias químicas auxiliares da instrumentação endodôntica / Evaluation of marginal leakage of four temporary materials after using irrigating solutions in endodontic treatment

O selamento coronário, juntamente com a obturação do canal radicular, possibilita um ambiente propício ao reparo dos tecidos periapicais, epílogo do tratamento endodôntico. Além disso, um bom selamento temporário impede que haja recontaminação entre as possíveis sessões do tratamento endodôntico, resguardando também a medicação intracanal. Muitos estudos têm sido realizados para investigar o vedamento marginal das restaurações temporárias. Este trabalho se propõe a avaliar a infiltração marginal na porção coronária de dentes que sofreram ação das substâncias químicas usadas no tratamento endodôntico, selados com quatro diferentes materiais provisórios. Para tanto, foram utilizados 60 pré-molares humanos hígidos, divididos em 5 grupos experimentais, conforme o material selador provisório empregado (Bioplic , Coltosol , XTempLC, IRM, Coltosol + Ação das substâncias químicas) , e 2 grupos-controle. Os resultados obtidos indicaram que todos os materiais restauradores temporários avaliados permitiram certo grau de infiltração, sendo o Grupo II (Coltosol) aquele que apresentou o menor índice. Constatou-se também que as substâncias químicas auxiliares empregadas durante o preparo químico mecânico podem influenciar no selamento marginal, aspecto observado no Grupo V que apresentou infiltração coronária estatisticamente mais significante.

The coronary sealing, next to root canal obturation, permits an appropriate environment to the periapical tissues repair, which is the major endodontic treatment’s outcome. Furthermore, good temporary sealing prevents new contamination between sessions of the endodontic treatment, also protecting the intracanal dressing. Many studies have been achieved for examining the marginal sealing of temporary restorations. This study intended to evaluate the marginal leakage in the coronary portion of teeth which suffered action of irrigating solutions used in endodontics, sealed with four different temporary materials. Sixty entire human premolars were divided into 5 experimental and 2 control groups according to each temporary restorative material used (Bioplic, Coltosol, XTempLC, IRM, Coltosol + instrumentation). The results indicated that all temporary materials used allowed a certain degree of infiltration, however, Group II (Coltosol) showed the least index. It was also observed that irrigating solutions used during biomechanical preparation can influence the marginal sealing, such as that observed in Group V which presented the greatest significant marginal leakage.