RESUMO
OBJECTIVE: This study aimed to evaluate the effect of ultrasonic activation of etch-and-rinse and self-etch adhesive systems on the bond strength of resin cement to irradiated root dentin. MATERIALS AND METHODS: Eighty human maxillary anterior teeth were distributed into 8 groups (n = 10), according to the type of adhesive system used (etch-and-rinse and self-etch), the ultrasonic activation of the adhesive systems, and the dentin condition (irradiated or non-irradiated - 70 Gy). Endodontic treatment was performed followed by fiberglass post-space preparation. After fiberglass posts' luting, the roots were transversely sectioned on dentin discs and submitted to the push-out bond strength test (0.5 mm/min). The fractured specimens were analyzed under a stereomicroscope and Scanning Electron Microscope (SEM) for failure mode classification. One of the dentin discs was analyzed under SEM to evaluate the characteristics of the adhesive interface. RESULTS: Irradiated specimens had lower bond strength than non-irradiated specimens (P < 0.0001). Ultrasonic activation of both adhesive systems increased the bond strength of the resin cement to irradiated dentin (P < 0.0001). Radiotherapy significantly affected the failure mode in the middle (P = 0.024) and apical thirds (P = 0.032) (adhesive failure). CONCLUSION: Non-irradiated specimens had a more homogeneous adhesive interface. When ultrasonically activated, both adhesive systems showed a greater number of resinous tags, regardless of the dentin condition. CLINICAL RELEVANCE: Ultrasonic activation of adhesive systems is a feasible strategy to enhance fiberglass posts retention in oncological patients.
Assuntos
Colagem Dentária , Dentina , Teste de Materiais , Microscopia Eletrônica de Varredura , Técnica para Retentor Intrarradicular , Cimentos de Resina , Humanos , Cimentos de Resina/química , Colagem Dentária/métodos , Dentina/efeitos da radiação , Técnicas In Vitro , Adesivos Dentinários/química , Análise do Estresse Dentário , Propriedades de Superfície , Raiz Dentária/efeitos da radiação , Ultrassom , Condicionamento Ácido do Dente , Incisivo , Vidro/químicaRESUMO
The use of fluorescent dyes in microscopy studies is frequent. Therefore, it is important to investigate whether these compounds may alter the physicochemical properties of materials in which they are incorporated to avoid methodological biases. This study evaluated the physicochemical properties of two endodontic sealers containing dry or diluted rhodamine B. Six groups were evaluated: AH Plus and MTA Fillapex in their original composition and mixed with 0.1% dry or diluted rhodamine. Push-out test was applied to assess the bond strength to root dentin. ANSI-ADA No. 57 and ISO No. 6876:2012 specifications were followed to evaluate flowability, setting time, and solubility of the sealers. pH changes were assessed after 24 h, 7, and 30 days. Intergroup comparisons were analyzed by ANOVA complemented by Tukey's post-hoc test; comparisons among periods were analyzed by Wilcoxon and Friedman tests. The incorporation of dry rhodamine decreased the bond strength and prolonged the setting time of AH Plus. The incorporation of diluted rhodamine decreased the setting time and increased the flowability of MTA Fillapex. Diluted rhodamine promoted pH reduction of AH Plus after 24 h and dry rhodamine after 7 days. Rhodamine incorporation promoted pH reduction after 30 days for MTA Fillapex. Solubility was not affected. In conclusion, the incorporation of diluted rhodamine changed the properties of MTA Fillapex, and the incorporation of dry rhodamine changed the properties of AH Plus. Previous dilution of rhodamine did not severely compromise the physicochemical properties of AH Plus and may be suggested to assess its penetrability.
Assuntos
Materiais Restauradores do Canal Radicular , Materiais Restauradores do Canal Radicular/química , Resinas Epóxi/química , Compostos de Cálcio/química , Óxidos/química , Rodaminas , Solubilidade , Combinação de Medicamentos , Silicatos/química , Teste de MateriaisRESUMO
Abstract Proanthocyanidin (PA) is a promising dentin biomodifier due to its ability to stabilize collagen fibrils against degradation by matrix metalloproteinases (MMPs); however, the most effective protocol to incorporate PA into bonding procedures is still unclear. This study evaluated the effect of dentin biomodification with a PA acid etchant on MMP activity, adhesive interface morphology and resin-dentin microtensile bond strength. Sound extracted human molars were flattened to expose dentin and acid-etched for 15 s according to the groups: EXP - experimental phosphoric acid; EXP+PA - experimental phosphoric acid 10% PA; TE - total-etching system; SE - self-etching system. Samples were restored with composite resin and stored in distilled water (37ºC). MMP activity and interface morphology were analyzed after 24 h by in situ zymography (n=6) and scanning electron microscopy (n=3), respectively. The resin-dentin microtensile bond strength (μTBS) was evaluated after 24 h and 6 months storage (n=6). Significantly higher MMP activity was detected in etched dentin compared with untreated dentin (p<0.05), but no difference among acid groups was found. Resin tags and microtags, indicative of proper adhesive system penetration in dentinal tubules and microtubules, were observed along the hybrid layer in all groups. There was no difference in μTBS between 24 h and 6 months for EXP+PA; moreover, it showed higher long-term μTBS compared with TE and EXP (p<0.05). The results suggest that 15 s of biomodification was not sufficient to significantly reduce MMP activity; nonetheless, EXP+PA was still able to improve resin-dentin bond stability compared with total- and self-etching commercial systems.
Resumo A proantocianidina (PA) é um biomodificador dentinário promissor devido a sua capacidade de estabilizar as fibrilas colágenas contra a degradação por metaloproteinases da matriz (MMPs); no entanto, o protocolo mais eficaz para a incorporação de PA em procedimentos adesivos ainda não está claro. Este estudo avaliou o efeito da biomodificação da dentina com um condicionador ácido contendo PA na atividade de MMPs, morfologia da interface adesiva e resistência à microtração resina-dentina. Molares humanos extraídos foram lixados para exposição da dentina e condicionados com ácido por 15 s de acordo com os grupos: EXP - ácido fosfórico experimental; EXP+PA - ácido fosfórico experimental com 10% PA; TE - sistema total-etch; SE - sistema self-etch. As amostras foram restauradas com resina composta e armazenadas em água destilada (37ºC). A atividade de MMP e morfologia da interface foram analisadas após 24 h por zimografia in situ (n=6) e microscopia eletrônica de varredura (n=3), respectivamente. A resistência à microtração resina-dentina (μTBS) foi avaliada após 24 horas e 6 meses de armazenamento (n=6). Atividade de MMP detectada na dentina condicionada foi significativamente maior em comparação com a dentina não tratada (p <0,05), mas não houve diferenças entre os diferentes ácidos. Tags e microtags de resina, indicativos de uma penetração adequada do sistema adesivo nos túbulos e microtúbulos dentinários, foram observadas ao longo da camada híbrida em todos os grupos. Não houve diferença entre os valores de μTBS de 24 h e 6 meses para EXP+PA; além disso, EXP+PA apresentou maiores valores de μTBS após 6 meses em comparação com TE e EXP (p <0,05). Os resultados sugerem que a biomodificação por 15 s não foi suficiente para reduzir significativamente a atividade de MMP; apesar disso, EXP + PA foi capaz de melhorar a estabilidade da interface resina-dentina em comparação com sistemas total- e self-etch comerciais.
RESUMO
In recent years, research has been conducted in search of alternative adhesives that are less harmful to human health and the environment. Cardanol derived from cashew nut shell liquid (CNSL) has attracted considerable attention due to its chemical and specific characteristics (antioxidant activity, flame resistance, and hydrophobicity). In this sense, this study aimed to evaluate the quality of particleboards using cardanol instead of urea-formaldehyde (UF) adhesive. Different percentages of cardanol were used (0, 20, 40, 60 and 80%) in which its physicochemical properties were evaluated. The panels were produced with particles of Pinus oocarpa and nominal density of 0.75 g/cm3, their physical and mechanical properties were evaluated, wood-adhesive interface evaluation with scanning electron microscopy (SEM), and the combustibility test. It is concluded that the maximum replacement of UF by cardanol is 5%, since, in this situation, the mentioned properties reach the established norms for the commercialization of the boards.
Assuntos
Antioxidantes , Ureia , Adesivos/química , Formaldeído/química , Humanos , FenóisRESUMO
Este estudo, desenvolvido em duas etapas, avaliou a ação remineralizadora da biopartícula α-wollastonita (BP), a partir da reação com H3PO4 residual Si-O-Ca + H3PO4 â SiO2 + Ca5(PO4)3(OH)n + H2O, na resistência longitudinal de união e características da interface adesiva, quando aplicada na forma de suspensão (etanol 99,5% + 10% de BP em peso) na superfície dentinária previamente condicionada com H3PO4 37%. Na primeira etapa foi realizado um estudo piloto onde, pelas características de precipitação, foi identificada a melhor concentração de biopartículas a serem inseridas na formulação da suspensão. Na segunda etapa, duzentas coroas hígidas de incisivos bovinos foram embutidas em resina acrílica, polidas para padronizar a smear layer e divididas aleatoriamente em 2 grupos (n=100), segundo a estratégia adesiva: A - controle (H3PO4 + Single Bond™ Universal (SB)); WAS (H3PO4 + BP em suspensão + SB). Blocos de resina composta (Filtek Z250; 3M/ESPE) de 4mm foram confeccionados por técnica incremental sobre as áreas tratadas em todos os grupos, utilizando uma matriz de silicona. As amostras foram então seccionadas para obtenção de palitos retangulares (aproximadamente 1mm2 ), armazenadas em água deionizada a 4ºC em recipientes individuais e divididas em 2 subgrupos (n=50) de acordo com o tempo de armazenamento de 24 h (imediato) e 12 meses (longitudinal), seguidos do teste de resistência adesiva à microtração (10 kgf, 0,5mm/min). Os dados foram submetidos ao teste ANOVA 2 fatores (p< 0,05) e teste de Weibull 2 parâmetros. As interfaces adesivas foram analisadas por microscopia eletrônica de varredura (MEV) para avaliar a morfologia da interface resina-dentina, e analisadas por espectroscopia FTIR, para compreensão das interações químicas formadas na superfície dentinária. Os Resultados evidenciaram maiores valores estatisticamente significativos de resistência de união (MPa) para o grupo WAS (37,39 ± 7,48), tratado com BP e armazenado por 24 h, em comparação ao grupo A armazenado por 24 h (27,58 ± 6,43); e, para o grupo WAS armazenado por 12 meses (32,05 ± 10,64) em comparação ao grupo A armazenado por 12 meses (22,84 ± 5,76). Dados do FTIR evidenciaram o efeito da α-wollastonita na preservação do colágeno. A biopartícula mostrou ser promissora na manutenção longitudinal da qualidade da interface adesiva. (AU)
This study, developed in two stages, evaluated the remineralizing action of the αwollastonite (BP) bioparticle, from the reaction with residual Si-O-Ca + H3PO4 â SiO2 + Ca5(PO4)3(OH)n + H2O, on the longitudinal bond strength and characteristics of the adhesive interface, when applied as a suspension (99.5% ethanol + 10% BP by weight) on the dentin surface previously etched with 37% H3PO4. In the first stage, a pilot study was carried out where, due to the precipitation characteristics, the best concentration of bioparticles to be inserted in the suspension formulation was identified. In the second step, two hundred sound bovine incisor crowns were embedded in acrylic resin, polished to standardize the smear layer and randomly divided into 2 groups (n=100), according to the adhesive strategy: A - control (H3PO4 + Single Bond™ Universal (SB)); WAS (H3PO4 + BP in suspension + SB). Composite resin blocks (Filtek Z250; 3M/ESPE) of 4 mm were made by incremental technique on the treated areas in all groups, using a silicone matrix. The samples were then sectioned to obtain rectangular sticks (approximately 1mm2 ), stored in deionized water at 4ºC in individual containers and divided into 2 subgroups (n=50) according to the storage time of 24 h (immediate) and 12 months (longitudinal), followed by the microtensile bond strength test (10 kgf, 0.5 mm/min). Data were submitted to 2-way ANOVA (p<0.05) and 2-parameter Weibull test. The adhesive interfaces were analyzed by scanning electron microscopy (SEM) to evaluate the morphology of the resin-dentin interface, and analyzed by FTIR spectroscopy, to understand the chemical interactions formed on the dentin surface. The results showed higher statistically significant values of bond strength (MPa) for the WAS group (37.39 ± 7.48), treated with BP and stored for 24 h, compared to group A stored for 24 h (27, 58 ± 6.43); and for the WAS group stored for 12 months (32.05 ± 10.64) compared to group A stored for 12 months (22.84 ± 5.76). FTIR data evidenced the effect of α-wollastonite on collagen preservation. The bioparticle showed promise in the longitudinal maintenance of the quality of the adhesive interface (AU)
Assuntos
Animais , Bovinos , Resinas Acrílicas , Análise de Variância , Resinas Compostas , Cimentos Dentários , Técnicas In Vitro , Microscopia Eletrônica de Varredura , ColágenoRESUMO
AIM: To evaluate the bond strength and adhesive interface between several resin cements and root dentine immediately and 6 months after radiotherapy. METHODOLOGY: Sixty maxillary canines were selected and randomly assigned to two groups (n = 30): one group was not irradiated and the other one was subjected to a cumulative radiation dose of 60 Gy. The teeth were sectioned to obtain roots 16 mm long and the canals were prepared with the Reciproc system (R50) and filled using a lateral condensation technique with an epoxy resin sealer. Each group was divided into three subgroups (n = 10) according to the resin cement used for fibreglass fibre post cementation: RelyX-U200, Panavia-F2.0 and RelyX ARC. The posts were cemented in accordance with the manufacturer's recommendations. Three 1-mm-thick dentine slices were then obtained from each root third. The first two slices in the crown-apex direction of each third were selected for the push-out test. The failure mode after debonding was determined with a stereo microscope. The third slice from each root third was selected for scanning electron microscopy (SEM) analyses to examine the resin cement-dentine interface with 100, 1000, 2000 and 4000× magnification. Bond strength data were analysed by anova and Tukey's test (α = 0.05). RESULTS: Significantly lower bond strength (P < 0.0001) was obtained after irradiation compared to nonirradiated teeth. RelyX-U200 cemented fibre posts had the higher bond strength (15.17 ± 5.89) compared with RelyX ARC (P < 0.001) and Panavia-F2.0 (P < 0.001). The evaluation after 6 months revealed lower bond strength values compared to the immediate values (P < 0.001) for irradiated and nonirradiated teeth. Cohesive failures occurred in the irradiated dentine. SEM revealed fractures, microfractures and fewer collagen fibres in irradiated root dentine. RelyX-U200 and Panavia-F2.0 were associated with a juxtaposed interface of the cement with the radicular dentine in irradiated and nonirradiated teeth, and for RelyX ARC, hybrid layer formation and tags were observed in both irradiated and nonirradiated teeth. CONCLUSION: Radiation was associated with a decrease in the push-out bond strength and with lower resin cement/root dentine interface adaptation. Self-adhesive resin cement was a better alternative for fibre post cementation in teeth subjected to radiation therapy. The bond strength decreased after 6 months.
Assuntos
Colagem Dentária , Dentina/efeitos dos fármacos , Radioterapia/métodos , Cimentos de Resina/química , Cimentos de Resina/efeitos da radiação , Raiz Dentária/efeitos dos fármacos , Bis-Fenol A-Glicidil Metacrilato/química , Bis-Fenol A-Glicidil Metacrilato/efeitos da radiação , Cimentação/métodos , Cimentos Dentários/química , Cimentos Dentários/efeitos da radiação , Materiais Dentários/química , Materiais Dentários/efeitos da radiação , Análise do Estresse Dentário , Resinas Epóxi/química , Resinas Epóxi/efeitos da radiação , Vidro , Cimentos de Ionômeros de Vidro/química , Cimentos de Ionômeros de Vidro/efeitos da radiação , Humanos , Teste de Materiais , Polietilenoglicóis/química , Polietilenoglicóis/efeitos da radiação , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/efeitos da radiação , Técnica para Retentor Intrarradicular , Materiais Restauradores do Canal Radicular/química , Materiais Restauradores do Canal Radicular/efeitos da radiação , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de SuperfícieRESUMO
OBJECTIVES: To compare the accuracy of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) during the analysis of the adhesive interface integrity and intratubular penetration of root canal sealers to radicular dentine. MATERIALS AND METHODS: Twenty roots of human maxillary incisors were prepared and distributed into two groups (n = 10), followed by filling with gutta-percha and Endofill (G1) or AH Plus (G2). After 7 days, roots were sectioned and analyzed under CLSM and SEM. Score systems were used to evaluate the adhesive interface integrity (0-4) and sealer intratubular penetration (0-3). Data were submitted to Wilcoxon-Mann-Whitney and Kendall correlation statistical tests (α = 5%). RESULTS: In the adhesive interface analysis, CLSM was similar (P = 0.157) to SEM for Endofill; however, the results were different for AH Plus (P = 0.029). Intratubular penetration had significant difference between observational methods for both sealers (P < 0.0001). Correlation analysis between SEM and CLSM for adhesive interface was moderate for Endofill and low for AH Plus. Intratubular penetration was low for both sealers. CONCLUSION: SEM and CLSM analysis had similar results when sealers were compared, with a more homogeneous adhesive interface, and greater intratubular penetration for AH Plus. Comparison between observational methods demonstrated low positive correlation for adhesive interface and intratubular penetration analysis. CLINICAL RELEVANCE: A proper interface formed between sealer and dentine is very important for final quality of root canal filling. Observational methods which allow an accurate analysis of this interface must be selected to assess such features.
Assuntos
Resinas Epóxi/química , Guta-Percha/química , Incisivo/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Varredura , Materiais Restauradores do Canal Radicular/química , Adesividade , Humanos , Técnicas In Vitro , Teste de Materiais , Propriedades de SuperfícieRESUMO
Aim: This study aims to review the concepts and metalloproteinase activation mechanisms and cathepsin cysteine. Material and Methods: The literature review was conducted around the main keywords "cathepsin cysteine", "metalloproteinases", "dentin-adhesive interface" and "degradation". Results: Nineteen articles were collected and included only articles available in its entirety, on english. Conclusions: Many studies are still being conducted incorporating different substances that help by inhibiting the action of these enzymes, however, there is still no consensus on the best element to be used in restorative procedures.
RESUMO
Las propiedades mecánicas del colágeno se deben a agentes intrínsecos de entrecruzamiento [Al-Ammar et al, 2009]. El aumento en el número de enlaces de la molécula de colágeno mejora su estabilidad e integridad, colaborando con el mantenimiento de propiedades adecuadas de la unión adhesiva a lo largo del tiempo [Bedran-Russo et al, 2009; Breschi et al, 2008]. Existen varios enfoques que permiten modificar el sustrato dentinario mediante la promoción de la formación de enlaces exógenos, con el objetivo de aumentar la resistencia de la red de colágeno [Bedran-Russo et al, 2007; Bedran-Russo et al, 2008]. Estos enfoques se dividen en métodos mecánicos [Bedran-Russo et al, 2007; Bedran-Russo et al, 2008; Castellan et al, 2010; Han et al, 2003] y método fotoxidativo [Cova et al, 2011]. Dentro de los primeros, los agentes reticuladores de origen natural son capaces de estabilizar el colágeno de la dentina [Bedran-Russo et al, 2007] sin afectar la resistencia de la unión adhesiva y sin generar toxicidad. Sin embargo, el uso de estos agentes por sí solo no permite asegurar la estabilidad de la unión adhesiva a lo largo del tiempo; porque como es sabido, la longevidad de dicha unión no depende únicamente de las características del sustrato, sino también de propiedades inherentes al sistema adhesivo por un lado, y de la presencia de humedad por otro.
The mechanical properties of collagen are due to intrinsic crosslinking agents [Al-Ammar et al, 2009]. The increase in the number of links of the collagen molecule improves its stability and integrity, collaborating with the maintenance of adequate adhesive bonding properties over time [Bedran-Russo et al, 2009; Breschi et al, 2008]. There are several approaches for modifying the dentin substrate by promoting the formation of exogenous links, in order to increase the strength of the collagen network [Bedran-Russo et al, 2007; Bedran-Russo et al, 2008]. These approaches are divided into mechanical methods [Bedran-Russo et al, 2007; Bedran-Russo et al, 2008; Castellan et al, 2010; Han et al, 2003] and foto oxidating method [Cova et al, 2011]. Within the first, the naturally occurring crosslinking agents are capable of stabilizing the dentin collagen [Bedran-Russo et al, 2007] without affecting the strength of the adhesive bond and without generating any toxicity. However, the use of these agents alone does not ensure the stability of the adhesive bond over time; because as it is known, the longevity of such binding does not only depend on the substrates characteristics, but also on the adhesive systems properties on one side, and the presence of moisture on the other
Assuntos
Humanos , Dentina , Inibidores de Metaloproteinases de Matriz , Reagentes de Ligações Cruzadas , Colagem Dentária , Adesivos , Biomimética , Colágeno , Remineralização Dentária/métodosRESUMO
OBJETIVO El propósito de esta investigación fue realizar un estudio observacional in vitro, al microscopio electrónico de barrido, de la interfase adhesiva diente-restauración lograda al utilizar un sistema adhesivo universal (Single Bond Universal®, 3M/ESPE, Alemania), con grabado ácido previo y con la técnica de autograbado. MATERIALES Y MÉTODO En las piezas dentarias se realizaron cavidades clase V en las caras vestibular y palatina/lingual. En la cavidad vestibular se realizó la técnica de grabado ácido con H3PO4 al 37% en gel, mientras que en la cavidad palatina o lingual no se realizó grabado ácido. Las piezas restauradas fueron mantenidas en una estufa a 37 °C con 100% de humedad relativa durante 48 h, simulando el medio bucal. Las muestras obtenidas fueron cortadas a través de la restauración y acondicionadas para poder ser observadas al microscopio electrónico de barrido, para evaluar la interfase adhesiva en relación con la presencia de brechas y la formación de tags de resina. RESULTADOS Las imágenes fueron observadas con un aumento progresivo hasta los 2.000×, viéndose diferencias microestructurales en la penetración del adhesivo, aunque sin formación de brechas en la interfase adhesiva. CONCLUSIONES Se observó que, al utilizar ambas técnicas de aplicación se obtiene una interfase sin presencia de brechas. En esmalte, se generó una menor penetración del adhesivo en la estructura cristalina con la técnica de autograbado, mientras que en dentina, con la misma técnica, se genera una capa híbrida de menor espesor y tags de resina de menor longitud.
OBJECTIVE The purpose of this research was to study the tooth-restoration adhesive interface, using a universal adhesive system (Single Bond Universal, 3M/ESPE, Germany), with the techniques of etching and self-etching using scanning electron microscopy. MATERIALS AND METHODS Class V cavities were prepared in buccal and palatine/lingual surface, in human teeth. Etching with 37%H3PO4 was performed in the buccal cavity, with no etching being performed in the palatine or lingual cavity. The samples were placed in an oven at 37 °C and 100% humidity for 48 hours, simulating the oral environment. The samples were cut perpendicularly through the restoration and prepared to be observed by scanning electron microscopy, in order to evaluate the adhesive interface in relation to the presence of breaches and the formation of resin tags. RESULTS Images were observed with a gradual increase to 2000×. Microstructural differences were observed in the penetration of the adhesive but with no formation of breaches in the adhesive interface. CONCLUSIONS An unbreached interface is obtained when using both techniques. In enamel, less penetration was present in the crystal structure of the adhesive with the self-etching technique. While in dentin, with the same technique, a less thick hybrid layer and shorter resin tags were observed.
Assuntos
Humanos , Colagem Dentária/métodos , Resinas Compostas , Fatores de Tempo , Microscopia Eletrônica de VarreduraRESUMO
This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal-Wallis, Mann-Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested.
Assuntos
Incisivo/ultraestrutura , Selantes de Fossas e Fissuras/química , Materiais Restauradores do Canal Radicular/química , Adesividade , Humanos , Microscopia Eletrônica de Varredura , Cloreto de Sódio/química , Propriedades de SuperfícieRESUMO
La bioadhesión es un fenómeno interfacial que ocurre entre un material polimérico y una superficie biológica. Las interacciones entre las fases son el resultado tanto de las propiedades del polímero como de la naturaleza del sustrato. En este documento se estudian los aspectos teóricos fundamentales que permiten entender los mecanismos que se proponen para la interpretación del fenómeno desde cada una de las teorías existentes, considerando los factores que determinan el comportamiento bioadhesivo de un polímero y las características del sustrato. Finalmente se analizan las técnicas experimentales existentes para determinar la bioadhesividad en materiales poliméricos y las aplicaciones en el diseño de algunos sistemas terapéuticos farmacéuticos.
The bioadhesion is an interfacial phenomenon ocurring between a polymer and a biological surface. Due to the complex nature of polymers and molecules present in the biological surfaces, many factors determine the strength and duration of the adhesion. However, the specific interactions in the polymer/biological substrate interface are governed by both, the properties of the polymer and the nature of the substrate. In this document the theoretical fundamentals of the current mechanisms that have been proposed to explain bioadhesion are reviewed. Also, the main factors determining the bioadhesive behavior of a polymer and the properties of the substrate are discussed. Finally, the experimental techniques to evaluate the bioadhesion in polymers are analyzed, and the applications in some therapeutic pharmaceutical systems presented.