Abstract Objectives To compare the microtensile bond strength (µTBS) and depth of cure (DOC) of bulk-fill composites cured by monowave (MW) and polywave (PW) LED units using different curing times. Methodology Three composites were tested: Tetric EvoCeram Bulk Fill (TBF), Filtek Bulk Fill (FBF), and Tetric EvoCeram (T; control). Flat dentin surfaces treated with adhesive (AdheSE Universal®, Ivoclar Vivadent) were bonded with 4 mm cylindrical samples of each bulk-fill composite material (n=6) and cured with monowave (Satelec) or polywave (Bluephase Style) curing units for 10 or 20 seconds. After 24 hours, teeth were sectioned into individual 0.9 mm2 beams and tested for µTBS. Failure modes were analysed. Moreover, the DOC scrape test (IOS 4090) was completed (n=5) following the same curing protocols. Two-way ANOVA (a=0.05) was performed, isolating light-curing units. Results For samples cured with the MW light-curing unit, no significant effects were observed in the µTBS results between any of the resin composite brands and the curing times. Conversely, when resins were cured with a PW light unit, a significant effect was observed for TBF resin. In general, bulk-fill composites presented greater DOC and longer curing time resulted in higher DOC for all composites. Conclusion The µTBS of the composites to dentin was not affected by the curing mode of the resins, except for TBF cured with PW light unit. Bulk-fill composites exhibit greater DOC than conventional resin-based composites.

Abstract Due to increasing of aesthetic demand, ceramic crowns are widely used in different situations. However, to obtain long-term prognosis of restorations, a good conversion of resin cement is necessary. Objective: To evaluate the degree of conversion (DC) of one light-cure and two dual-cure resin cements under a simulated clinical cementation of ceramic crowns. Material and Methods: Prepared teeth were randomly split according to the ceramic's material, resin cement and curing protocol. The crowns were cemented as per manufacturer's directions and photoactivated either from occlusal suface only for 60 s; or from the buccal, occlusal and lingual surfaces, with an exposure time of 20 s on each aspect. After cementation, the specimens were stored in deionized water at 37°C for 7 days. Specimens were transversally sectioned from occlusal to cervical surfaces and the DC was determined along the cement line with three measurements taken and averaged from the buccal, lingual and approximal aspects using micro-Raman spectroscopy (Alpha 300R/WITec®). Data were analyzed by 3-way ANOVA and Tukey test at =5%. Results: Statistical analysis showed significant differences among cements, curing protocols and ceramic type (p<0.001). The curing protocol 3x20 resulted in higher DC for all tested conditions; lower DC was observed for Zr ceramic crowns; Duolink resin cement culminated in higher DC regardless ceramic composition and curing protocol. Conclusion: The DC of resin cement layers was dependent on the curing protocol and type of ceramic.

Composite resin and metallic posts are the materials most employed for reconstruction of teeth presenting partial or total destruction of crowns. Resin-based cements have been widely used for cementation of ceramic crowns. The success of cementation depends on the achievement of adequate cement curing. Objectives: To evaluate the microhardness of Variolink® II (Ivoclar Vivadent, Schaan, Liechtenstein), used for cementing ceramic crowns onto three different coronal substrate preparations (dentin, metal, and composite resin), after 7 days and 3 months of water storage. The evaluation was performed along the cement line in the cervical, medium and occlusal thirds on the buccal and lingual aspects, and on the occlusal surface. Material and Methods: Thirty molars were distributed in three groups (N=10) according to the type of coronal substrate: Group D- the prepared surfaces were kept in dentin; Groups M (metal) and R (resin)- the crowns were sectioned at the level of the cementoenamel junction and restored with metallic cast posts or resin build-up cores, respectively. The crowns were fabricated in ceramic IPS e.max® Press (Ivoclar Vivadent, Schaan, Liechtenstein) and luted with Variolink II. After 7 days of water storage, 5 specimens of each group were sectioned in buccolingual direction for microhardness measurements. The other specimens (N=5) were kept stored in deionized water at 37ºC for three months, followed by sectioning and microhardness measurements. Results: Data were first analyzed by three-way ANOVA that did not reveal significant differences between thirds and occlusal surface (p=0.231). Two-way ANOVA showed significant effect of substrates (p<0.001) and the Tukey test revealed that microhardness was significantly lower when crowns were cemented on resin cores and tested after 7 days of water storage (p=0.007). Conclusion: The type of material employed for coronal reconstruction of preparations for prosthetic purposes may influence the cement properties.

OBJECTIVES: To determine the micro-hardness profile of two dual cure resin cements (RelyX - U100®, 3M-eSPe and Panavia F 2.0®, Kuraray) used for cementing fiberreinforced resin posts (Fibrekor® - Jeneric Pentron) under three different curing protocols and two water storage times. MATERIAL AND METHODS: Sixty 16mm long bovine incisor roots were endodontically treated and prepared for cementation of the Fibrekor posts. The cements were mixed as instructed, dispensed in the canal, the posts were seated and the curing performed as follows: a) no light activation; b) light-activation immediately after seating the post, and; c) light-activation delayed 5 minutes after seating the post. The teeth were stored in water and retrieved for analysis after 7 days and 3 months. The roots were longitudinally sectioned and the microhardness was determined at the cervical, middle and apical regions along the cement line. The data was analyzed by the three-way ANOVA test (curing mode, storage time and thirds) for each cement. The Tukey test was used for the post-hoc analysis. RESULTS: Light-activation resulted in a significant increase in the microhardness. This was more evident for the cervical region and for the Panavia cement. Storage in water for 3 months caused a reduction of the micro-hardness for both cements. The U100 cement showed less variation in the micro-hardness regardless of the curing protocol and storage time. CONCLUSIONS: The micro-hardness of the cements was affected by the curing and storage variables and were material-dependent.

OBJECTIVE: To test the hypothesis that the quality of the dentinal sealing provided by two-step etch-and-rinse adhesives cannot be altered by the addition of an extra layer of the respective adhesive or the application of a more hydrophobic, non-solvated resin. MATERIAL AND METHODS: full-crown preparations were acid-etched with phosphoric acid for 15 s and bonded with Adper Single Bond (3M ESPE), Excite DSC (Ivoclar/Vivadent) or Prime & Bond NT (Dentsply). The adhesives were used according to the manufacturers' instructions (control groups) or after application to dentin they were a) covered with an extra coat of each respective system or b) coated with a non-solvated bonding agent (Adper Scotchbond Multi-Purpose Adhesive, 3M ESPE). Fluid flow rate was measured before and after dentin surfaces were acid-etched and bonded with adhesives. RESULTS: None of the adhesives or experimental treatments was capable to block completely the fluid transudation across the treated dentin. Application of an extra coat of the adhesive did not reduce the fluid flow rate of adhesive-bonded dentin (p>0.05). Conversely, the application of a more hydrophobic non-solvated resin resulted in significant reductions in the fluid flow rate (p<0.05) for all tested adhesives. CONCLUSIONS: The quality of the dentinal sealing provided by etch-and-rinse adhesives can be significantly improved by the application of a more hydrophobic, non-solvated bonding agent.

Microleakage can be related to margin misfit. Also, traditional microleakage techniques are time-consuming. This study evaluated the existence of correlation between in vitro margin fit and a new microleakage technique for complete crowns cemented with 3 different luting agents. Thirty human premolars were prepared for full-coverage crowns with a convergence angle of 6 degrees, chamfer margin of 1.2 mm circumferentially, and occlusal reduction of 1.5 mm. Ni-Cr cast crowns were cemented with either zinc phosphate (ZP) (S.S. White), resin-modified glass-ionomer (RMGI) (Rely X Luting Cement) or a resin-based luting agent (RC) (Enforce). Margin fit (seating discrepancy and margin gap) was evaluated according to criteria in the literature under microscope with 0.001 mm accuracy. After thermal cycling, crowns were longitudinally sectioned and microleakage scores at tooth-cement interface were obtained and recorded at ×100 magnification. Margin fit parameters were compared with the one-way ANOVA test and microleakage scores with Kruskal-Wallis and Dunn's tests (alpha=0.05). Correlation between margin fit and microleakage was analyzed with the Spearman's test (alpha=0.05). Seating discrepancy and marginal gap values ranged from 81.82 µm to 137.22 µm (p=0.117), and from 75.42 µm to 78.49 µm (p=0.940), respectively. Marginal microleakage scores were ZP=3.02, RMGI=0.35 and RC=0.12 (p<0.001), with no differences between RMGI and RC scores. The correlation coefficient values ranged from -0.27 to 0.30 (p>0.05). Conclusion: Margin fit parameters and microleakage showed no strong correlations; cast crowns cemented with RMGI and RC had lower microleakage scores than ZP cement.

INTRODUÇÃO: A desinfecção das superfícies de dentina é desejada desde que não haja interferência na adesão dos agentes adesivos. OBJETIVO: Testar a hipótese nula de que a resistência adesiva não é afetada pela aplicação prévia de uma solução desinfetante de iodo. MATERIAL AND MÉTODO: Vinte e quatro molares hígidos foram selecionados. O esmalte oclusal destes dentes foi removido, e sobre as superfícies planas de dentina expostas foi aplicada da solução desinfetante de Iodo a 2% (I2DDS), que permaneceu sobre a superfície por 20 s e foi lavada por 20 s com água deionizada. Sobre as superfícies desinfetadas foram aplicados um dos seguintes sistemas adesivos (n=3): Single Bond; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. Os grupos controle (n=3) não tiveram a supeficie de dentina tratada com I2DDS antes dos precedimentos adesivos. Em todos os grupos, após hibridização da dentina, foi construída uma "restauração" de resina composta com cerca de 4 mm de espessura. Após 7 dias de armazenagem em água destilada, os dentes foram secionados de modo a originarem espécimes a serem submetidos ao teste de microtração (palitos). Análise estatística para comparação dos dados foi realizada pelo teste t de student (alfa=0,05). RESULTADOS: De forma geral, os grupos experimentais (tratados com I2DDS) apresentraram resistência adesiva significativamente menor do que os respectivos grupos controle (p<0.05), exceção se fez apenas para o grupo P&BI2, que não diferiu significativamente de seu grupo controle P&BC (p>0.05). Assim, a hipótese nula deve ser rejeitada para os adesivos a base de etanol e/ou a base de água, mas aceita para o adesivo a base de acetona. CONCLUSÃO: O uso da solução experimental de iodo previamente à realização dos procedimentos adesivos afetou a efetividade da união à dentina apenas quando do emprego de sistemas adesivos a base de etanol e/ou água.

INTRODUCTION: Disinfection of dentin surfaces is desirable so long as it does not interfere with subsequent bonding of adhesive resins. OBJECTIVE: To test the null hypothesis that bond strengths to dentin are not affected by previous application of an iodine disinfecting solution. MATERIALS AND METHODS: Twenty-four extracted non-carious molars were selected. Occlusal enamel was removed producing a flat dentin substrate. Test teeth were all treated with 2% Iodine disclosing/disinfecting solution (I2DDS) for 20 sec and rinsed for 20 sec followed by the application of self- or total- etching bonding systems, generating five adhesive groups (n=3): Single Bond; ; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. The control groups (n=3 per adhesive) had no disclosing/disinfectant application prior to adhesive application. A 4-mm thick resin restoration was built up on each tooth for microtensile testing. Statistical analyses between experimental and control groups were performed by student's t-test (alpha= 0.05). RESULTS: In general, experimental groups (previously treated with I2DDS) showed significantly lower bond strength values when compared with their respective controls (p<0.05), except for group Prime &Bond I2 that did not significantly differ from its control (p>0.05). CONCLUSION: Acetone-base adhesive systems seem not to be affected by the application of I2DDS prior to etching and bonding procedures.

Este estudo avaliou a resistência de união de dois sistemas adesivos ao esmalte e à dentina após a aplicação de agente clareador sobre a união compósito-dente. Dezesseis terceiros molares humanos foram usados nos procedimentos restauradores. Single Bond (SB) e Clearfil SE Bond (CB) foram aplicados no esmalte e na dentina de acordo com as instruções dos fabricantes. Um bloco de compósito foi construído nas superfícies tratadas com os adesivos. Os dentes restaurados foram seccionados em fatias com espessura de 0,7 mm, que receberam constrição na interface de união num formato de ampulheta, com área de secção transversal de ± 0,5 mm². Os espécimes foram distribuídos em 8 grupos (n = 10) de acordo com os fatores em estudo: substrato dental (esmalte e dentina); sistema adesivo (SB e CB) e tratamento (peróxido de carbamida a 10% e controle). O agente clareador (Opalescence) foi aplicado na interface de união por 6 horas durante 14 dias e, após o tratamento diário, os espécimes foram armazenados em saliva artificial. Os espécimes não clareados foram mantidos em saliva artificial por 14 dias. Os espécimes foram testados e os dados foram analisados pela ANOVA (três fatores) e pelo teste Tukey (p < 0,05). A resistência à tração do esmalte tratado com o adesivo CB foi reduzida após aplicação do peróxido de carbamida, entretanto, a resistência de união em dentina para ambos os adesivos não foi modificada. Os resultados sugerem que o clareamento afeta a resistência de união do CB ao esmalte, mas nenhuma influência foi observada em dentina.

In this bond strength study, a bleaching agent containing 10% carbamide peroxide was applied over composite-teeth bonded interfaces of two adhesive systems applied to enamel and dentin. Sixteen human third molars were used for bonding procedures. Single Bond (SB) and Clearfil SE Bond (CB) were applied to enamel and dentin according to the manufacturers' instructions. A resin composite cube-like structure was incrementally built on the bonded surfaces. The restored teeth were sectioned into 0.7 mm thick slices that were trimmed at enamel or dentin bonded interfaces to an hourglass shape with a cross-sectional area of approximately 0.5 mm². Specimens were assigned to 8 groups (n = 10) according to the following factors under study: dental substrate (enamel and dentin); adhesive system (SB and CB) and treatment (10% carbamide peroxide and not bleached/control). The bleaching gel (Opalescence) was applied at the bonded interfaces for 6 hours during 14 days and after daily treatment specimens were stored in artificial saliva. Unbleached specimens were stored in artificial saliva for 14 days. Specimens were tested for tension and the data were analyzed by three-way ANOVA and Tukey's test (p < 0.05). Enamel tensile bond strength of CB was reduced after carbamide peroxide application. The bleaching treatment did not alter dentin bond strength of both adhesives. The results suggest that bleaching significantly affects bond strength of CB to enamel, but no influence on bond strength to dentin was noted for both adhesive systems.

Fatores como o modo de ativação, a técnica restauradora e a configuração cavitária podem afetar a resistência adesiva à dentina. Este estudo avaliou os efeitos dos modos de ativação e das técnicas restauradoras na resistência de união compósito/dentina na parede vestibular de restaurações classe I. O esmalte oclusal dos dentes foi removido para expor uma superfície dentinária planificada. Cavidades oclusais (4 x 3 x 3 mm) foram preparadas em dentina. O adesivo Single Bond foi aplicado de acordo com as instruções do fabricante, e o compósito TPH Spectrum, inserido através de três diferentes técnicas: oblíqua incremental, horizontal incremental ou incremento único. O compósito foi ativado utilizando o método contínuo (600 mW/cm² por 40 s) ou "Soft-Start" (250 mW/cm² por 10 s + 600 mW/cm² por 30 s). O grupo controle foi obtido pela união somente à parede vestibular planificada (fator C = 1). Os dentes foram armazenados por 24 h em água a 37ºC e preparados para o ensaio de microtração (0,5 mm/min). Os espécimes apresentaram na secção transversal uma área de união de aproximadamente 0,8 mm². Os resultados foram analisados pela ANOVA (dois fatores), pelos testes de Tukey e Dunnett (alfa = 0,05). A técnica incremental seguida da ativação com ambas as formas de fotopolimerização produziu maiores valores de resistência de união que a técnica de incremento único (p < 0,05). A resistência de união sempre foi menor quando a restauração foi confeccionada em cavidade (p < 0,05), exceto quando foram utilizadas ativação com "Soft-Start" e técnicas incrementais. A resistência de união às paredes cavitárias é dependente da técnica de inserção e do modo de ativação da resina composta.

Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm) were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm² for 40 s) or Soft-Start (250 mW/cm² for 10 s + 600 mW/cm² for 30 s) modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1). The teeth were stored in water at 37ºC for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm² were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05). Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p < 0.05). Bonding strength tested in the cavities had lower values than those obtained in flat dentin surfaces (control group) (p < 0.05), except for incremental fillings using stepped irradiation. Bonding strength to the cavity walls depends on the filling technique and on the irradiation mode of composite resins.

As técnicas adesivas permitiram inovações nos tratamentos restauradores da atualidade. Este estudo investigou a qualidade de união de diferentes sistemas adesivos ao substrato dentinário afetado e infectado por cárie, através de testes de microtração e microscopia eletrônica de transmissão e varredura (MET). Os resultados sugerem que a resina adesiva pôde infiltrar na dentina infectada e envolver as bactérias na camada híbrida. Esse conceito de controle da cárie foi denominado de "Restauração-Selante Modificada" (RSM). Por outro lado, a empresa Kuraray Med. Inc .(Japão) desenvolveu um sistema adesivo com propriedades anti-bacterianas (ABF), o qual é comercializado nos EUA como Protect Bond. Para avaliar a efetividade do sistema ABF sobre cáries radiculares, empregou-se testes de resistência adesiva e análise por microscopia eletrônica. O sistema ABF foi capaz de formar uma estrutura interfacial semelhante à camada híbrida, através da infiltração na superfície da dentina cariada radicular e os valores de resistência de união foram em média de 23 MPa. Os achados sugerem que a combinação da técnica RSM com o sistema ABF parece ser uma alternativa para o emprego da terapia de mínima invasão em cáries radiculares.

Hybridized dentin permits dental treatments that were previously impossible with conventional techniques, opening new frontiers in modern adhesive dentistry. We have investigated the adhesive property of current bonding systems to caries-infected dentin by a microtensile bond strength test (µTBS) and transmission electron microscopy (TEM), and suggested that bonding resin could infiltrate into caries-infected dentin partially to embed carious bacteria within hybrid layers. We have named this concept of caries control as modified sealed restoration (MSR). On the other hand, Kuraray Medical Inc. (Tokyo, Japan) has developed an antibacterial adhesive system (ABF, now marketed in USA as Protect Bond). So as to evaluate the effectiveness of ABF on root caries control, we have examine the microtensile bond strengths (µTBS) of ABF to normal versus carious root dentin and the interfacial morphology by a scanning electron microscopy (SEM). ABF could form the hybrid-like structures by infiltrating into the surfaces of the root carious dentin, and the mean value of µTBS of ABF to root carious dentin was 23.0 MPa. These results suggested that MSR combined with ABF might be an advantageous minimal invasive therapy for root caries.

Este estudo avaliou in vitro, durante 28 dias, a propriedade de liberação de flúor de cimentos de ionômero de vidro (CIV) restauradores e outros materiais que contêm flúor. Os resultados mostraram que o padrão de liberação de flúor foi semelhante para todos os CIV testados, sendo que houve uma liberação inicial acentuada, seguida por um rápido declínio, tendendo a uma estabilização após 7 dias. Os CIV liberaram mais flúor do que uma resina composta e um selante de cicatrículas e fissuras. Dentre todos os materiais, o Vidrion R foi o que mais liberou flúor.

The aim of this study was to determine the fluoride release from six fluoride-containing materials over 28 days. The results showed that the fluoride release patterns were similar for all glass ionomers tested, i.e., a large initial release was followed by a rapid decline in the amount released within the second day but became relatively stable after seven days. The release from glass ionomer cements was clearly greater than that from a sealant and a composite resin. Vidrion R released the largest amount of fluoride among all tested materials.