The effectiveness of EDTA 17% as a cleaning solution for the fiber post space after filling with cements

Aim: To evaluate the resistance of the union between a glass fiber post and radicular dentine after cleaning the root with 17% EDTA and filling with different endodontic cements. Methods: Forty uniradicular bovine incisors were removed to obtain root lengths of 18 mm. Endodontic treatment was performed on all roots using different filling cements (zinc oxide and eugenol-based, OZE; cement based on epoxy resin, AH) and cleaning solutions (saline, SA or EDTA), which made it possible to obtain four groups: OZESA, OZEEDTA, AHSA and AHEDTA. Subsequently, 12 mm of filling material was removed from the roots, and they were prepared to receive fiber posts luted with resin cement. To execute the mechanical cycles (2x106 cycles, 90 N, 4 Hz), coronal reconstruction was performed with a silicon matrix. The roots were then sliced (2-mm thick) to perform the push-out test. The results were analyzed using analysis of variance (one factor and two factors) and Tukey's test (α=0,05). Results: Bond strength (Mpa) was significantly higher for OZEEDTA (9,18) and AHEDTA (8,70) than for OZESA (6,06) AHSA (8,7). OZEEDTA also presented the highest values in the cervical region (15,18) but was significantly lower in the apical region (2,99). However, AHEDTA had a homogeneous bond strength in all thirds. Conclusion: Regardless of the endodontic cement used, EDTA was used as an irrigating solution, culminating in a higher bond strength between the glass fiber post and dentin

Infiltration by Streptococcus mutans in provisional crowns fixed by two types of cementing agents ­ pilot double-blind randomized clinical trial / Infiltração por Streptococcus mutans em coroas dentárias provisórias fixadas por dois tipos de agentes cimentantes ­ estudo clínico randomizado duplo-cego piloto

Objective: When provisional acrylic crowns are used for a long time, they become more susceptible to marginal leakage by cariogenic bacteria. The objectives of this pilot clinical study were to compare cement based on zinc oxide-eugenol and calcium hydroxide by contamination with Streptococcus mutans, and calculate the sample size for the continuation of this study. Methods: Individuals receiving provisional crowns and following inclusion/exclusion criteria, were randomly distributed into 2 groups: zinc oxide-eugenol (n=8); calcium hydroxide (n=9). The temporary crowns were made by a blind researcher and cemented by another. Patients were also blinded by the cement used inside their crowns. After 2 months, a cement sample from the crowns' peripheral inner face was collected, placed in a tube containing 1 mL of sterile saline, serially diluted, plated on Mitis Salivarius Bacitracin agar, and incubated for 48 hours. Colony-forming units (CFU/mL) were counted. A statistical power analysis was performed to calculate sample size (1-ß=80%) and the Mann Whitney test to compare both cements (α=0.05). Results: Both cements were contaminated with S. mutans, with an average of 166.6 x 102 CFU/mL for calcium hydroxide and 435.3 x 102 CFU/mL for zinc oxide-eugenol, with no significant difference (p=0.311). The sample size calculated for this study was 36 per group. Conclusion: This pilot study suggests that there is important contamination inside provisional crowns used for two months, independent of the cement. The continuation of this study is needed, with a bigger sample size, to enable a comparison between the cements.

Objetivo: Quando coroas dentais provisórias são utilizadas por um longo período, elas se tornam susceptíveis à infiltração marginal por bactérias cariogênicas. O objetivo deste estudo clínico piloto foi comparar os cimentos a base de óxido de zinco e eugenol e hidróxido de cálcio pela contaminação com Streptococcus mutans e calcular o tamanho amostral para continuação deste estudo. Métodos: Indivíduos recebendo coroas provisórias e seguindo critérios de inclusão/exclusão, foram distribuídos aleatoriamente em dois grupos: óxido de zinco e eugenol (n=8); hidróxido de cálcio (n=9). As coroas provisórias foram feitas por um pesquisador cego e cimentadas por outro. Os pacientes também foram cegos quanto ao cimento utilizado dentro de suas coroas. Depois de 2 meses, amostras de cimentos foram coletadas da face interna periférica das coroas, colocadas em um tubo contendo 1 mL de solução salina estéril, diluídas de forma seriada, plaqueadas em ágar Mitis Salivarius Bacitracina e incubadas por 48 horas. Unidades formadoras de colônias (UFC/mL) foram contadas. Um teste de poder estatístico foi realizado para calcular o tamanho amostral (1-ß=80%) e o teste de Mann Whitney para comparar os dois cimentos (α=0.05). Resultados: Os dois cimentos foram contaminados com S. mutans, com uma média de 166.6 x 102 UFC/mL para o hidróxido de cálcio e 435.3 x 102 UFC/mL para o óxido de zinco e eugenol, com nenhuma diferença significativa (p=0.311). O cálculo amostral para este estudo foi 36 indivíduos por grupo. Conclusão: Este estudo piloto sugere que existe importante contaminação dentro de coroas provisórias utilizadas por 2 meses, independente do cimento. A continuação deste estudo é necessária, com maior tamanho amostral, para possibilitar a comparação entre os cimentos.

Influence of temporary cement in the tensile strenght of fullcrowns cemented with resin cement / Influência do cimento temporário na resistência à tração de coroas totais cimentadas com cimento resinoso

Objetivo: Este estudo avaliou a influência do eugenol residual a resistência à tração na cimentação decoroas cerômero, usando cimento resinoso. Material e Métodos: Trinta e nove terceiros molares foram preparados para coroa total. Para cada dente preparado uma restauração provisória e uma coroa de cerômero foram feitas. Os dentes foram divididos em três grupos de acordo com o cimento provisório (n = 13): [GTB]Temp de Bond; [GTBNE] Temp NE Bond e [GDY] Dycal. Após a cimentação temporária, os dentes foram mantidos em água destilada por uma semana e, em seguida, submetidos ao teste de tração em uma máquina universal de ensaios (EMIC DL 500), usando uma célula de carga 200 kgf em 0,5 mm/min. Após o teste, os dentes foram limpos e receberam a cimentação adesiva final das coroas de cerômero. Em seguida, as amostras foram mantidas em água destilada (37 ºC) durante uma semana e, em seguida, foi realizado o teste de resistência à tração, também a 0,5 mm/ min. A comparação entre grupos foi realizada por análise de variância (ANOVA)seguida pelo teste de Tukey (p < 0,05). Resultados: Os resultados (kgf) de cimentação provisória para grupos GTB, GTBNE e GDY foram respectivamente: 2,75 ± (1.35b), 3,43 ± (1.66ab), e 4,48 ± (1.11a).Os resultados da cimentação adesiva (Kgf) eram respectivamente: 42,71 ± (15.33b), 57,59 ± (15.66a),e 54,75 ± (15.28ab). Conclusão: Concluiu-se que o cimento temporário, contendo eugenol apresentou influência negativa sobre a resistência à remoção de coroas cimentados com cimento de resinoso. Além disso, o dycal apresentou melhor resistência à remoção.

Objectives: This study evaluated the influenceof residual eugenol on the tensile strength in the ceromer crowns cementation, using resin cement. Material and Methods: Thirty-nine third molarswere prepared for a full crown. For each prepared tooth one provisional and one ceromer crown were made. The teeth were divided into three groups according the temporary cement (n = 13): [GT]Temp Bond; [GTBNE] Temp Bond NE and [GDY]Dycal. After temporary cementation, the teeth were kept in distilled water for one week and then submitted to traction test in a universal testing machine (EMIC DL 500), using a 200 Kgf loadcell at 0.5 mm/min. After the test, the teeth werecleaned and received the final adhesive cementationof ceromer crowns. Next, the specimens were keptin distilled water (37 0C) for a week and then the tensile strength test was performed, also at 0.5 mm/min. The comparison among groups was carriedout by variance analysis (ANOVA) followed by theTukey test (p ≤ 0.05). Results: The results (Kgf)of provisional cementation for groups GTB, GTBNEand GDY were respectively: 2.75 ± (1.35b), 3.43± (1.66ab), and 4.48 ± (1.11a). The results of the adhesive cementation (Kgf) were respectively:42.71 ± (15.33b), 57.59 ± (15.66a), and 54.75 ±(15.28ab). Conclusion: It was concluded that the temporary cement containing eugenol presented negative influence on the removal resistance of crowns cemented with resin cement. Furthermore,dycal presented best result for removal resistance.

Efficacy of various cleansing techniques on dentin wettability and its influence on shear bond strength of a resin luting agent

PURPOSE: To evaluate the shear bond strength of resin luting agent to dentin surfaces cleansed with different agents like pumice, ultrasonic scaler with chlorhexidine gluconate, EDTA and the influence of these cleansing methods on wetting properties of the dentin by Axisymmetric drop Shape Analysis - Contact Diameter technique (ADSA-CD). MATERIALS AND METHODS: Forty coronal portions of human third molar were prepared until dentin was exposed. Specimens were divided into two groups: Group A and Group B. Provisional restorations made with autopolymerizing resin were luted to dentin surface with zinc oxide eugenol in Group A and with freegenol cement in Group B. All specimens were stored in distilled water at room temperature for 24 hrs and provisional cements were mechanically removed with explorer and rinsed with water and cleansed using various methods (Control-air-water spray, Pumice prophylaxis, Ultrasonic scaler with 0.2% Chlorhexidine gluconate, 17% EDTA). Contact angle measurements were performed to assess wettability of various cleansing agents using the ADSA-CD technique. Bond strength of a resin luting agent bonded to the cleansed surface was assessed using Instron testing machine and the mode of failure noted. SEM was done to assess the surface cleanliness. Data were statistically analyzed by one-way analysis of variance with Tukey HSD tests (alpha=.05). RESULTS: Specimens treated with EDTA showed the highest shear bond strength and the lowest contact angle for both groups. SEM showed that EDTA was the most effective solution to remove the smear layer. Also, mode of failure seen was predominantly cohesive for both EDTA and pumice prophylaxis. CONCLUSION: EDTA was the most effective dentin cleansing agent among the compared groups.

Avaliação da Influência do Eugenol na Infiltração Marginal em Restaurações de Resina Composta em Dentes Decíduos / Evaluation of the Influence of Eugenol in Dental Leakage in Composite Resins Restorations in Deciduous Teeth

Objetivo: Avaliar a infiltração marginal em restaurações de resina composta, realizadas sobre forramento com óxido de zinco e eugenol em molares decíduos.Método: Foram utilizados 24 molares decíduos divididos em três grupos (n=8/grupo), de acordo com o tempo decorrido até a realização da restauração de resina. G1= imediatamente após inserção do IRM;G2= após 48h e G3= após 28 dias. Uma cavidade oclusal foi realizada em cada dente com ponta montada diamantada 3018 HL. Depois de restaurados, os dentes foram cobertos por uma camada de esmalte e cera, deixando-se livre uma região de 1 mm ao redor da restauração. Os dentes foram, então, imersos no corante rodamina a 0,5% durante 24h. As amostras foram cortadas em máquina de corte (Labcut 1010), avaliadas em Estéreo Microscópio e classificadas por níveis de infiltração de 0 a 3. Os resultados foram submetidos aos teste KruskallWallis e Qui-Quadrado, com nível de significância de 5%. Resultados: Constatou-se significativa associação entre infiltração e período decorrente até a realização da restauração. No período imediato houve menor grau de infiltração enquanto no período de 28 dias houve maior grau de infiltração (p=0,02). Conclusão: É importante que não haja muito tempo entre restauração provisória com IRM e restauração definitiva com resina composta a fim de diminuir a infiltração marginal

Objective: to evaluate dental leakage in composite resin restorations carried through on the lining with zinc oxide and eugenol in molar deciduous. Methods: For the study, had been used 24 deciduous molars, which had been divided in three groups, in accordance with the moment where the resin restoration was carried through: G1= immediately after de insertion of the IRM, G2= after 48 hours and G3= after 28 days. A occlusal socket was carried through, in all the teeth, with a drill 3018 HL (KG Sorensen). After restored, the teeth had been covered enamel layer and wax, leaving itself around exempts a region of 1,, of the restoration. The teeth had been, then, immersed in rodamina dye 0.5% during 24 hours. After it was removed the enamel and the wax, and the teeth had been washed, dried and cut with a machine of precision cut (Labcut 1010). The specimens had been evaluated in a Stereo Microscope (Olympus SZH 10) and classified by levels of infiltration of 0 the 3. Results: Through the analysis statistics, a significant association was evidenced enters the presence of infiltration and the period where the restoration was carried through. It was observed that in the immediate period dental leakage had a minor and in the period of 28 days a bigger infiltration (p=0.02). Conclusion: It is important that there is not much time between temporary restoration with IRM and final restoration with composite resin to decrease microleakage

Effect of eugenol-based endodontic sealer on the adhesion of intraradicular posts cemented after different periods

OBJECTIVE: This study evaluated in vitro the influence of an eugenol-based sealer (EndoFill) on the retention of stainless steel prefabricated posts cemented with zinc phosphate and resin-based (Panavia F) cements after different periods of root canal obturation, using the pull-out test. MATERIAL AND METHODS: Sixty upper canines were decoronated and the roots were embedded in resin blocks. The specimens were distributed into 3 groups, according to the period elapsed between canal obturation and post cementation: Group I - immediately; Group II - 72 h and Group III - 4 months. The groups were subdivided according to the type of cement used for post cementation: A - zinc phosphate and B - Panavia F. Following the experimental periods, specimens were subjected to pullout test in an Instron machine with application of tensile force at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal were recorded (kN) and means were subjected to statistical analysis by 2-way ANOVA and Tukey-Kramer test (á=0.001) RESULTS: There were statistically significant differences (p<0.01) between the posts cemented with zinc phosphate cement (0.2112 kN) and Panavia F (0.0501 kN). However, no statistically significant differences (p>0.05) were found between the three post cementation periods, regardless of the cement. CONCLUSIONS: It was concluded that the eugenol-based sealer influenced the tensile strength of the posts cemented with the resin cement, but had no influence on the time waited between root canal obturation and post space preparation/post cementation.

Microfiltración apical in vitro de tres cementos utilizados en la obturación de conductos radiculares / In vitro apical microleakage of three cements used in the filling of root canals

El propósito de este estudio fue comparar la microfiltración apical in vitro obtenida por los cementos de obturación a base de óxido de zinc-eugenol (Endofill®), resina epóxica (AH-Plus®) y trióxido de minerales agregados (Endo CPM Sealer®). Se prepararon 165 piezas dentarias unirradiculares recientemente extraídas y donadas para el estudio, de conducto único y de Clase I según la clasificación de Zidell, divididas en tres grupos de 53 piezas dentarias por cada cementoy dos grupos control de tres piezas cada uno. Los controles positivos fueron piezas sin obturar y permeables los dos milímetros más apicales, mientras que a los controles negativos no se les instrumentó, solo se les impermeabilizó con barniz de uñas. Todas las piezas fueron sumergidas en tinta china, luego fueron descalcificadas y diafanizadas. La microfiltración apical fue medida cada 0,5mm lineales utilizando un estereomicroscopio. Se encontró diferencia estadísticamente significativa entre los tres grupos de cementos selladores (p < 0,01). Presentaron de mayor a menor microfiltración el cemento a base de óxido de zinc-eugenol (Endofill®), trióxido deminerales agregados (Endo CPM Sealer®) y resina epóxica (AH-Plus®) respectivamente.

The purpose of this study was to compare the apical microleakage in vitro obtained by canal sealers based on zinc oxide eugenol (Endofill®), epoxy resin (AH-Plus®) and mineral trioxideaggregate (Endo CPM Sealer®). One hundred sixty five single rooted freshly extracted teeth and class I according to Zidell classification were prepared, divided in three groups of fifty three sampless and two control groups of three root canals each. The samples of the positive control group were not filled and the samples of the negative control group were not instrumented, notfilled and coated with nail varnish. All the specimens were inmersed in India ink and posteriorly were descalcified and cleared. Apical microleakage was measured in lineal millimeters with the use of a stereo microscope. Significant statistical differences were found between the three canals sealers (p less than 0.01). The apical microleakage was from higher to lower: 1) zinc eugenol based canal sealer, 2) MTA based canal sealer and 3) resin based canal sealer.

Influence of eugenol-containing temporary restorations on the microleakage of total-etch and self-etching adhesive systems / Influência de restaurações temporárias contendo eugenol na microinfiltração de sistemas adesivos convencional e autocondicionante

Purpose: This in vitro study evaluated the influence of zinc oxide-eugenol temporary cement (ZOE-TC) on the sealing ability of composite restorations using two adhesive systems. Methods: Standard Class V cavities were prepared in 20 bovine incisors and restored with either ZOE-TC (IRM®) or eugenol-free cement (Cavit®) (n=10/temporary cement type). After 7 days, five teeth per material group were restored using Single Bond® (SB) and five using Adper Prompt® (AP). The cavities were filled with composite (Filtek Z-250), thermal cycled (500 cycles), immersed in basic fuchsine solution, and longitudinally sectioned. Dye penetration was evaluated using optical-microscopy and scored. Data were analyzed by Kruskal-Wallis test (P = 0.05). Results: Overall, leakage in dentin was similar to that in enamel. In enamel margins, only the group with Cavit® cement associated with AP presented significant higher leakage. In dentin margins, AP exhibited higher leakage than the groups restored with SB; there was no significant difference between eugenol-free cement and ZOE-TC. Conclusion: In general, SB showed better marginal sealing than AP, and ZOE-TC did not increase dye leakage. Eugenol in the temporary cement did not affect the marginal sealing of adhesive restorations.

Objetivo: Este estudo in vitro avaliou a influência de um cimento restaurador temporário à base de óxido de zinco-eugenol (CT-OZE) no selamento marginal de restaurações diretas, utilizando dois sistemas adesivos. Metodologia: Cavidades classe V foram preparadas em 20 incisivos bovinos e restauradas com dois cimentos temporários, CT-OZE (IRM®) ou cimento livre de eugenol (Cavit®) (n=10/cimento temporário). Após sete dias, cinco dentes de cada grupo de cimento temporário foram restaurados utilizando o sistema Single Bond® (SB) e os demais cinco com o sistema Adper Prompt® (AP). As cavidades foram restauradas com resina composta (Filtek Z-250), termocicladas (500 ciclos), imersas em fucsina básica e longitudinalmente seccionadas. A penetração do corante foi avaliada em microscópio ótico. Os dados foram analisados por teste de Kruskal-Wallis (P = 0,05). Resultados: A infiltração em dentina foi similar à do esmalte. Em esmalte, o grupo com Cavit® e AP apresentou infiltração significativamente maior. Em dentina, AP exibiu maior infiltração que SB, e não houve diferença entre CT-OZE e Cavit®. Conclusão: Em geral, SB produziu melhor selamento marginal que AP, e CT-OZE não aumentou a penetração de corante. A presença de eugenol no material restaurador temporário não afetou o selamento marginal de restaurações adesivas.

Efeito do laser de baixa intensidade na polpa e nos tecidos apicais e periapicais em dentes de macaco / Effect of the laser of low intensity in the pulp and in apical and periapical tissue in teeth of monkey

O presente estudo avaliou o efeito do laser de baixa intensidade diodo semicondutor de arseneto de gálio e alumínio em exposições pulpares induzidas e nos tecidos apicais e periapicais após tratamento endodôntico em dentes de macacos. Nas exposições pulpares, foi avaliado efeito do laser infra-vermelho associado ao hidróxido de cálcio, variando o tempo de aplicação, onde utilizou-se quatro macacos, totalizando 24 dentes, distribuídos em quatro grupos experimentais: Grupo I: Laser 2,5 segundos (dentes incisivos), Grupo II: Laser 40 segundos (dentes incisivos), Grupo III: Laser 40 segundos (dentes prémolares) e Grupo IV: Controle sem Laser (dentes pré-molares), por um período de 55 dias. Quanto ao efeito do laser sobre a agressividade tecidual do cimento endodôntico óxido de zinco e eugenol (OZE), após tratamento endodôntico nos tecidos apicais e periapicais, foi comparando o laser vermelho com o infravermelho, utilizando quatro macacos, totalizando 24 dentes, distribuídos em três grupos experimentais: Grupo I (Laser Vermelho), Grupo II (laser Infra-Vermelho) e Grupo III (Controle: Sem Laser), por um período de 22 dias. Decorrido os períodos experimentais de cada estudo, os animais foram mortos, os dentes ou peças removidas e preparadas para análise histológica. De acordo com a proposta e as condições específicas deste trabalho, os resultados nos permitem concluir que nas exposições pulpares, a irradiação com laser infra-vermelho (40 segundos) diminuiu a reação inflamatória e induziu a organização tecidual, bem como na formação da barreira mineralizada, apresentando diferenças estatísticas significantes entre os grupos (p<0,05), tendo como melhor resultado a irradiação com laser infra-vermelho (40 segundos), já nos tecidos apicais e periapicais a irradiação...

The present study evaluated the effect of the laser of low intensity diode semiconductor of gallium aluminum arsenide in exposed pulp induced in apical and periapical tissues after endodontic treatment in teeth of monkeys. In the exposed pulp, the effect of the laser infra-red associated to the hydroxide of calcium was evaluated varying the time of application, being used 04 monkeys, totaling 24 teeth, distributed in four experimental groups: Group I: Laser 2,5 seconds (incisive teeth), Group II: Laser 40 seconds (incisive teeth), Group III: Laser 40 seconds (premolar teeth) and Group IV: Control without Laser (premolar teeth), for a period of 55 days. As for the effect of the laser on the tissue aggressiveness of the endodontic zinco oxide and eugenol (OZE) sealer, after endodontic treatment o in the apical and Periapical tissues, the red laser was compared with the laser infra-red, using 04 monkeys, totaling 24 teeth, distributed in 03 experimental groups: Group I (Red Laser), Group II (Infra-red laser) and Group III (it Controls: Without Laser), for a period of 22 days. After the experimental periods of each study, the animals were killed, the teeth or pieces were removed and prepared for histological analysis. In agreement with the proposal and the specific conditions of this study work, the results allow to conclude us that in exposed pulp infra-red laser irradiation (40 seconds.) reduced the inflammatory reaction and induced the tissue organization, as well as the mineralized barrier formation and in apical and periapical tissues infra-red laser irradiation stimulated the cells of the periodontal tissue inducing periapical repair.

Avaliação da resistência de união à dentina de restaurações estéticas indiretas: efeito da contaminação e limpeza dentinária / Evaluation of bond strength of indirect restorations to dentin: effect of provisional cementation and dentin cleaning methods

O objetivo deste estudo foi avaliar o efeito de cimentos provisórios e de métodos de limpeza dentinária na resistência de união de restaurações indiretas em resina à dentina. Foram selecionados 21 terceiros molares recém extraídos e isentos de cárie. A parte da coroa dental correspondente ao esmalte foi removida expondo-se toda superfície dentinária. Os dentes foram divididos aleatoriamente em sete grupos experimentais de acordo com o cimento provisório e o método de limpeza dentinária utilizado: (G1-controle) não recebeu restauração provisória nem limpeza dentinária; (G2) cimentação provisória com Life e limpeza com pasta de pedra-pomes; (G3) cimentação provisória com Life (Kerr) e limpeza com jato abrasivo; (G4) nenhum procedimento de limpeza foi executado após cimentação com Life; (G5) cimentação provisória com Temp Bond e limpeza com pasta de pedra-pomes; (G6) cimentação provisória com Temp Bond (Kerr) e limpeza com jato abrasivo e (G7) nenhum procedimento de limpeza foi executado após cimentação com Temp Bond. Após uma semana de armazenamento em água, restaurações de Solidex (Shofu) foram cimentadas com adesivo Single Bond (3M ESPE) e cimento Rely X ARC (3M ESPE). Todos os produtos foram manipulados de acordo com as instruções do fabricante. Os dentes foram seccionados obtendo-se espécimes de 1,0 mm2 para realização de teste de microtração. Os valores obtidos foram submetidos à análise de variância e teste de Tukey. Os resultados indicaram que o grupo contaminado com hidróxido de cálcio sem realização da limpeza dentinária apresentou os menores valores de resistência e foi estatisticamente diferente do grupo onde não houve contaminação. Qualquer dos cimentos e métodos de limpeza utilizados obteve as maiores médias de resistência, porém sem diferenças significativas entre elas.

The purpose of this study was to evaluate the effect of provisional cements and dentin cleaning methods on the adhesion of resin bonded indirect restorations. Flat dentin surfaces were produced cutting extracted human molars. The teeth were divided randomly in seven experimental groups according with the provisional cement and the used dentin cleaning method: (G1- control) no provisional restoration and no dentin cleaning; (G2) pumice-water slurry cleaning after cementation with Life (Kerr); (G3) aluminum oxide sandblasting after cementation with Life; (G4) no cleaning procedure after Life cementation; (G5) pumice-water slurry cleaning after cementation with Temp Bond (Kerr); (G6) aluminum oxide sandblasting after cementation with Temp Bond and (G7) no cleaning procedure after Temp Bond cementation. After one week of storing in water, Solidex indirect restorations (Shofu) were cemented with Single Bond adhesive system (3M ESPE) and Rely X ARC cement (3M ESPE). All products were handled according with manufacturer’s instructions. The teeth were sectioned resulting in adhesion area of 1,0 mm2 specimens for microtencile tests. The resulted values were submitted to variance analysis and Tukey’s test. These values indicated the group which was contaminated with calcium hydroxide cement and had no dentin cleaning presented the lowest bond strength and was statistically different from the group with no contamination. Any of the used cements and cleaning methods got the highest means of bond strength, but with no relevant differences among them. With these results can be concluded that, after the treatment with provisional cements, the absence of dentin cleaning implies in lower bond strength values.

Assessment of the tensile strength of hexagonal abutments using different cementing agents

The aim of this study was to assess the uniaxial tensile strength after thermal cycling in replicas of CeraOne®abutments (abutment and coping sets), using four types of cements (n = 10). A zinc phosphate cement (Fosfato de Zinco®/ SSW), a resin-modified glass ionomer cement (RelyX®luting / 3M-ESPE), a zinc oxide-eugenol cement (ZOE®/ SSW) and a zinc oxide cement without eugenol (TempBond NE®/ KERR) were used. After cementation, the samples were submitted to thermal cycles (1,000 cycles, 5ºC ± 2º to 55ºC ± 2º) for thirty seconds in each bath. Next, the samples were submitted to the tensile test in a universal test machine (0.5 mm/min). The data were submitted to ANOVA and the Tukey-Kramer test (p < 0.05), and statistically significant difference was found among the cements. The highest tensile strength mean value found was for zinc phosphate cement (33.6 kgf) followed by the resin-modified glass ionomer cement (20.5 kgf), zinc oxide-eugenol cement (8.4 kgf) and the temporary cement (3.1 kgf). Therefore, it was found that the permanent cements presented higher tensile strength, and the temporary cement could be used in situations requiring reversibility and the removal of cemented dental implant-supported prostheses.