Evaluation of Chitosan-Oleuropein Nanoparticles on the Durability of Dentin Bonding.

Purpose: To evaluate the effects of dentin pretreatment with chitosan-loaded oleuropein nanoparticles (CONPs) on the durability of resin-dentin bonding interfaces. Methods: Eighty freshly extracted non-carious human third molars were randomly divided into four groups (n = 20 each): a de-ionized water (DW) group, a chitosan (CS) group, a chlorhexidine (CHX) group and a CONP group. The dentin in the DW, CS, CHX, and CONP groups were pretreated with de-ionized water, 1.0 mg/L CS solution, 2% chlorhexidine solution, and CONP suspension (prepared with 100 mg/L oleuropein), respectively, followed by the universal adhesive and resin composites. The bonded teeth of each group were randomly divided into two subgroups: an immediate subgroup and an aged subgroup. The bonded teeth of each group were then cut into the bonded beams. We measured their microtensile bond strength (µTBS), observed the characteristics of bonding interface by atomic force microscope, calculated the percentage of silver particles in a selected area for interfacial nanoleakage analysis, and evaluated the endogenous gelatinase activity within the bonding interface for in-situ zymogram analysis. Data were analyzed with two-way ANOVA and LSD multiple comparison test (P < 0.05). Results: Regardless of after 24 h or after thermocycling, CONP exhibited better µTBS (P < 0.05) than the other three groups except that there was not a statistical significance (P > 0.05) in the CONP and CHX groups after 24 h. Besides, the CONP group presented significantly higher modulus of elasticity in the hybrid layers (P < 0.05), lower expression of nanoleakage (P < 0.05), and better inhibitory effect of matrix metalloproteinases than the other three groups before and after thermocycling. Conclusion: Altogether, the CONPs had the potential to act as a dentin primer, which could effectively improve the dentin-resin binding durability.

Influence of two natural cross-linkers on microtensile bond strength durability ­ An in vitro study / Influência de dois reticuladores naturais na durabilidade da resistência de união à microtração ­ Um estudo in vitro

Objective: to investigate the effect of two natural cross-linkers on microtensile bond strength (µTBS) and evaluate their influence on the durability of the resin dentin bonds. Material and Methods: the Moringa oleifera and Centella asiatica plant extracts were qualitatively tested with high-performance thin layer chromatography (HPTLC) for the presence of phenols. The phenolic content ranged from 27 to 30 gallic acid equivalents (GAE), µg/mg of dry weight. After etching, two concentrations (5% and 1%) of these two extracts were prepared and used as pretreatment liners on dentin. They were applied for a min. After restoration with resin composite, dentin resin beams were prepared. The study groups were 5% Moringa, 1% Moringa 5% Centella 1% Centella, and control (without cross-linker application). For each group, half of the samples underwent µTBS testing after 24 hours, while the remaining half were immersed in artificial saliva to assess the bond's longevity after 6 months of ageing. Statistical analysis was performed using one-way ANOVA followed by Tukey's post hoc test. Results: both 5% and 1% Moringa showed a significant difference (p<0.05) compared to the other groups at both intervals. However, after ageing, the specimens in the control and 1% Centella groups resulted in a significant decrease in µTBS. Conclusion: overall, both concentrations of Moringa (5% and 1%) were effective in stabilising the bond during both intervals.(AU)

Objetivo: investigar o efeito de dois reticuladores naturais na resistência de união (µTBS) à microtração e avaliar sua influência na durabilidade da adesão da resina à dentina. Material e Métodos: extratos das plantas Moringa oleifera e Centella asiatica foram qualitativamente testados através de cromatografia em camada fina de alta performance (HPTLC) para a presença de fenóis. O conteúdo fenólico alcançou entre 27 a 30 equivalentes de ácido gálico (GAE), µg/mg de peso seco. Após o condicionamento, duas concentrações (5% e 1%) dos extratos foram preparadas e utilizadas como forros de pré-tratamento em dentina. Eles foram aplicados por um minuto. Após a restauração com resina composta, palitos de dentina e resina foram preparados. Os grupos foram 5% Moringa, 1% Moringa, 5% Centella, 1% Centella e controle (sem aplicação de reticulador). Para cada grupo, metade das amostras foram submetidas ao teste µTBS após 24 horas, enquanto a outra metade foi imersa em saliva artificial para avaliar a longevidade adesiva após 6 meses de envelhecimento. Foi realizada análise estatística através de ANOVA 1-fator, seguido do teste post hoc de Tukey. Resultados: ambas as concentrações de 5% e 1% de Moringa demonstraram diferença significativa (p<0.05) comparadas aos outros grupos em ambos os intervalos. No entanto, após o envelhecimento, os espécimes dos geupos controle e 1% de Centella resultaram em uma redução significativa de µTBS. Conclusão: no geral, ambas as concentrações de Moringa (5% e 1%) foram efetivas em estabelecer a adesão em ambos os intervalos (AU)

Evaluation of dentin microroughness and composite bond strength after multiple uses of diamond burs / Evaluación de la micro rugosidad dentinaria y la resistencia adhesiva de composites tras múltiples usos de fresas de diamante

Abstract Using a bur multiple times to prepare dental structure may produce a smoother final surface on dentin than a new one. This superficial roughness may affect adhesion with resin-based materials by modifying the substrates' characteristics. The aim of this study was to evaluate the effect of multiple uses of diamond burs on dentin's superficial microroughness and bond strength with resin composite when using a self-etch adhesive. Diamond dental burs were used to simulate a preparation (dentin flat surface) on extracted third molars. Samples were distributed into groups according to burs' number of previous uses as follows: 0, 1, 5 and 10. Scanning electron microscopy images at 70x, 350x, and 1000x were used to illustrate burs' deformation. Each specimen's dentin microroughness was measured three times to compare between experimental groups and the micro-shear bond strength test (n=15) was performed for the 0 and 10 uses groups using a universal adhesive in a self- etching mode. Diamond crystals wear and dislodgements were evident among groups where the burs were used more times. As the number of uses increased the mean microroughness of the dentin surface decreased with significant differences between the 0 and 10 uses groups. No statistical differences between experimental groups resulted from bond strength tests. When using a universal adhesive in a self-etching mode, the number of previous uses of a diamond bur seems to have no significant effect on dentin/resin composite bond strength.

Resumen El uso de una fresa múltiples veces para preparar la estructura dental puede producir una superficie final más lisa en la dentina que una fresa nueva. Esta rugosidad superficial modifica las características del sustrato y puede afectar la adhesión con materiales resinosos. El objetivo de este estudio fue evaluar el efecto de los múltiples usos de las fresas de diamante sobre la micro rugosidad superficial de la dentina y la resistencia adhesiva con la resina compuesta cuando se utiliza un adhesivo de autograbado. Se utilizaron fresas dentales de diamante para simular una preparación (superficie plana de la dentina) en terceros molares extraídos. Las muestras se distribuyeron en grupos según el número de usos previos de las fresas de la siguiente manera: 0, 1, 5 y 10. Se utilizaron imágenes de microscopía electrónica de barrido a ×70, ×350 y ×1000 para ilustrar la deformación de las fresas. Se midió la micro rugosidad de la dentina de cada espécimen tres veces para comparar entre los grupos experimentales y se realizó la prueba de resistencia a la adhesión por micro cizallamiento (n=15) para los grupos de 0 y 10 usos utilizando un adhesivo universal en modo de autograbado. El desgaste de los cristales de diamante y los desprendimientos fueron evidentes entre los grupos en los que las fresas se utilizaron más veces. A medida que aumentaba el número de usos, la micro rugosidad media de la superficie de la dentina disminuyó, con diferencias significativas entre los grupos de 0 y 10 usos. En las pruebas de resistencia adhesiva no se observaron diferencias estadísticas entre los grupos experimentales. Cuando se utiliza un adhesivo universal en modo de autograbado, el número de usos previos de una fresa de diamante no parece tener un efecto significativo en la resistencia de la unión dentina/resina del composite.

Effects of carbodiimide combined with ethanol-wet bonding pretreatment on dentin bonding properties: an in vitro study.

Purpose: This study evaluated the combined effects of Carbodiimide (EDC) and ethanol-wet bonding (EWB) pretreatment on the bond strength and resin-dentin surface. Methods: Phosphoric acid-etched dentin specimens were randomly divided into five groups based on the following pretreatments: deionized water (control), EWB, 0.3M EDC in water (EDCw), EDC water solution combined EWB (EDCw + EWB), and 0.3M EDC in ethanol (EDCe). A scanning electron microscope (SEM) was used to observe the morphology of collagen fibrils on the demineralized dentin matrix in each group after pretreatment. The adhesives Prime & Bond NT (PB) (Dentsply De trey, Konstanz, Germany) or Single bond 2 (SB) (3M ESPE, St. Paul, MN, USA) was applied after pretreatments, and a confocal laser scanning microscope (CLSM) was used to evaluate the quality of resin tags. The degree of conversion (DC) of the adhesive was investigated by Fourier transform infrared spectroscopy (ATR-FTIR). The dentin was first bonded with resin and bathed in water at 37 °C for 24 h. Half of them were subjected to 10, 000 cycles in a thermocycler between 5 °C and 55 °C before a microshear bond strength (µSBS) test. The statistical methods were Analysis of Variance (ANOVA) and a Tukey post hoc test at α = 0.05. Results: The µSBS was significantly affected by pretreatments (p < 0.001), adhesives (p < 0.001), and aging conditions (p < 0.001) as revealed by the three-way ANOVA. The EDCw, EDCw + EWB, and EDCe groups significantly increased the µSBS; the EDCw + EWB and EDCe groups produced the highest µSBS. In the EDC-containing groups, the SEM showed at the collagen fibrils in the dentin matrix formed a three-dimensional network structure in the tubules after cross-linking into sheets, and the hybrid layer formed thicker resin tags under a CLSM. In the EDC-containing groups, the CLSM observed an increase in the length of resin tags. PB showed a higher DC and bonding strength than SB, and the five pretreatment groups tested did not affect the DC of the two adhesives. Conclusions: In etch-and-rinse bonding system, EDC combined with EWB pretreatment can improve the quality of the hybrid layer and enhance the mechanical properties of demineralized dentin matrix. Pretreatment with EDC-ethanol solution may be a new clinically friendly option for enhancing dentin bonding durability.

Evaluation of Stabilized Chlorine Dioxide in Terms of Antimicrobial Activity and Dentin Bond Strength.

BACKGROUND: Antimicrobial agents are recommended for disinfection of the cavity following mechanical dental caries removal prior to application of restorative material. There is limited information about stabilized Chlorine Dioxide (ClO2) as a cavity disinfectant. OBJECTIVES: The objective of this study is to determine the antimicrobial activity and effect on dentin bond strength of ClO2 compared to chlorhexidine digluconate (CHX), sodium hypochlorite (NaOCl) and Ethanolic Propolis Extract (EPE). METHODS: Antimicrobial activities of agents against oral pathogens (Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, Candida albicans, and Saccharomyces cerevisiae) and analyses of EPE were examined. Seventyfive mandibular third molars were sectioned, prepared and divided into five subgroups (n=15/group). Cavity disinfectants (2% CHX, 2.5% NaOCl, 30% EPE, 0.3% ClO2) were applied to etched dentin prior to adhesive and composite build-up. Shear bond strength (SBS) was evaluated with a universal testing machine at a crosshead speed of 0.5 mm/min. The SBS data were analyzed with One-way Analysis of Variance (ANOVA) and Tukey's post-hoc test (p <0.05). The failure modes were evaluated with a stereomicroscope. RESULTS: It was determined that the compared disinfectants were showed different inhibition zone values against oral pathogens. ClO2 exhibited the highest antimicrobial activity, followed by CHX, NaOCI and EPE, respectively. No statistically significant difference was observed in the SBS values between the disinfectant treated groups and control group. The failure modes were predominantly mixed. CONCLUSION: The use of 0.3% stabilized ClO2 as a cavity disinfectant agent exhibited high antimicrobial activity against oral pathogens and no adverse effects on SBS to etched dentin.

[Effect of chlorhexidine-loaded halloysite nanotube on human dentin bond strength].

PURPOSE: To evaluate the effect of chlorhexidine-loaded halloysite aluminosilicate clay nanotube (HNT) incorporation into a two-step etch-and-rinse (ONE-STEP) and a self-etch (XENO Ⅴ) adhesive on human dentin tensile shear strength (TSS). METHODS: Ten groups (n=12) were prepared according to the adhesive system and amount of CHX/HNT incorporated (5%, 10%, 15%) as follows: XE control(A1), XE experimental control (A2), 5% CHX/HNT-XE (A3), 10%CHX/HNT-XE (A4), 15% CHX/HNT-XE (A5), OS control (B1), OS experimental control (B2), 5% CHX/HNT-OS (B3), 10% CHX/HNT-OS (B4), 15% CHX/HNT-OS (B5). TSS testing was performed after 24 h. Scanning electron microscopy of the resin-dentin interface of selected specimens was carried out. One-way ANOVA was used to evaluate the TSS date in XE groups and OS groups. Two-way ANOVA was used to evaluate the effect of the adhesive system and the CHX/HNT content on dentin TSS with SPSS 19.0 software package. RESULTS: The TSS date of 5% CHX/HNT-XE was significantly higher than the other groups. The TSS date of 10% CHX/HNT-OS was significantly higher than the other groups (P<0.05). No significant difference was detected between adhesive systems and dentin TSS. significant difference was found between CHX/HNT content and dentin TSS. CONCLUSIONS: CHX/HNT addition into dentin adhesive increased bond strength to dentin.

The effect of five different universal adhesives on the clinical success of class I restorations: 24-month clinical follow-up.

OBJECTIVES: The aim of this study was to evaluate the 24-month clinical performance of universal adhesives on the restoration success of Class I carious lesions. MATERIALS AND METHODS: Five different universal adhesives (Gluma Bond Universal (GU), Clearfil Universal (CU), Prime&Bond Elect Universal (PU), All bond Universal (AU), and Single Bond Universal (SU)) were used in the self-etch and etch-and-rinse modes in 42 patients. The study was conducted with 10 groups, with 20 restorations in each group. The restorations were evaluated at baseline and during a 24-month recall using World Dental Federation (FDI) and the US Public Health Service (USPHS) criteria. The changes in the parameters were analyzed using the chi-square test. RESULTS: At the end of 24 months, there was no loss of restoration in any group. According to the USPHS, there was no difference in the baseline and 24-month clinical behavior of the restorations (P Ëƒ 0.05). However, according to the FDI, when adhesives were used in the self-etch mode, three adhesives (GU, SU, PU) showed marginal incompatibility, and one adhesive showed (GU) marginal discoloration between baseline and the 24-month follow-up evaluation (P < 0.05). There was no significant difference after 24 months between etch-and-rinse and self-etch groups according to the results based on both the USPHS and FDI criteria (P Ëƒ 0.05). CONCLUSIONS: The 24-month clinical performance of the evaluated universal adhesives depends on the adhesive strategy. CLINICAL RELEVANCE: This study helps clinicians to decide in which mode (etch-and-rinse or self-etch) universal adhesives can be safely used.

Influence of ethanol-wet dentin, adhesive mode of application, and aging on bond strength of universal adhesive.

The aim of this study was to evaluate the effect of ethanol on the bond longevity of a universal adhesive system to bovine dentin, under different modes of adhesive application and artificial aging. Bovine dentin was exposed, and the smear layer was standardized by sandpaper polishing. Specimens were randomly divided into 2 groups: ethanol (E) and non-ethanol (N). Groups were subdivided according to adhesive mode of application into etch-and-rinse (Er) and self-etching (S). Resin blocks were built onto the treated surface, and the specimens were stored in deionized water at 37°C for 48 h. Half of the specimens (n = 10) were subjected to thermomechanical aging (A for aged and Na for non-aged). Resin/dentin beams were obtained and subjected to microtensile test in a universal testing machine. Data were analyzed using a three-way ANOVA and Tukey's tests (α = 5%). There was interaction among the three factors (p=0.0003). The use of ethanol resulted in higher values, except for the Er and Na groups (E_Er_Na = N_Er_Na). The mode of application was similar, except for the N and A groups (N_S_A > N_Er_A). For the A groups, the values were lower, except in the cases using ethanol, in which the results were not affected. The study concluded that the use of ethanol resulted in higher microtensile bond strength values, even after aging. The mode of adhesive application did not influence the results.

Polymerization shrinkage and porosity profile of dual cure dental resin cements with different adhesion to dentin mechanisms.

This research aims to probe the porosity profile and polymerization shrinkage of two different dual cure resin cements with different dentin bonding systems. The self-adhesive resin cement RelyX U200 (named RU) and the conventional Allcem Core (named AC) were analyzed by x-ray microtomography (µCT) and Scanning Electron Microscopy (SEM). Each cement was divided into two groups (n = 5): dual-cured (RUD and ACD) and self-cured (RUC and ACC). µCT demonstrated that the method of polymerization does not influence the porosity profile but the polymerization shrinkage. Fewer concentration of pores was observed for the conventional resin cement (AC), independently the method used for curing the sample. In addition, SEM showed that AC has more uniform surface and smaller particle size. The method of polymerization influenced the polymerization shrinkage, since no contraction for both RUC and ACC was observed, in contrast with results from dual-cured samples. For RUD and ACD the polymerization shrinkage was greater in the lower third of the sample and minor in the upper third. This mechanical behavior is attributed to the polymerization toward the light. µCT showed to be a reliable technique to probe porosity and contraction due to polymerization of dental cements.

Influence of ethanol-wet dentin, adhesive mode of application, and aging on bond strength of universal adhesive

Abstract The aim of this study was to evaluate the effect of ethanol on the bond longevity of a universal adhesive system to bovine dentin, under different modes of adhesive application and artificial aging. Bovine dentin was exposed, and the smear layer was standardized by sandpaper polishing. Specimens were randomly divided into 2 groups: ethanol (E) and non-ethanol (N). Groups were subdivided according to adhesive mode of application into etch-and-rinse (Er) and self-etching (S). Resin blocks were built onto the treated surface, and the specimens were stored in deionized water at 37°C for 48 h. Half of the specimens (n = 10) were subjected to thermomechanical aging (A for aged and Na for non-aged). Resin/dentin beams were obtained and subjected to microtensile test in a universal testing machine. Data were analyzed using a three-way ANOVA and Tukey's tests (α = 5%). There was interaction among the three factors (p=0.0003). The use of ethanol resulted in higher values, except for the Er and Na groups (E_Er_Na = N_Er_Na). The mode of application was similar, except for the N and A groups (N_S_A > N_Er_A). For the A groups, the values were lower, except in the cases using ethanol, in which the results were not affected. The study concluded that the use of ethanol resulted in higher microtensile bond strength values, even after aging. The mode of adhesive application did not influence the results.

A zinc chloride-doped adhesive facilitates sealing at the dentin interface: A confocal laser microscopy study.

The aim of this study was to ascertain the effect of Zn-doping of dental adhesives and mechanical load cycling on the micromorphology of the resin-dentin interdiffusion zone (of sound and caries affected dentin). The investigation considered two different Zn-doped adhesive approaches and evaluated the interface using a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy. Sound and carious dentin-resin interfaces of unloaded specimens were deficiently resin-hybridized, in general. These samples showed a rhodamine B-labeled hybrid layer and adhesive layer completely affected by fluorescein penetration (nanoleakage) through the porous resin-dentin interface. It was thicker after phosphoric acid-etching and more extended in carious dentin. Zn-doping promoted an improved sealing of the resin-dentin interface, a decrease of the hybrid layer porosity, and an increment of dentin mineralization. Load cycling augmented the sealing of the Zn-doped resin-dentin interfaces, as porosity and nanoleakage diminished, and even disappeared in caries-affected dentin substrata conditioned with EDTA. Sound and carious dentin specimens analyzed with the xylenol orange technique produced a clearly outlined fluorescence when resins were Zn-doped, due to a consistent Ca-mineral deposition within the bonding interface and inside the dentinal tubules. It was more evident when load cycling was applied on specimens treated with self-etching adhesives that were Zn-doped. Micropermeability at the resin-dentin interface diminished after combining EDTA pretreatment, ZnCl2-doping and mechanical loading stimuli on restorations. It is clearly preferable to include the zinc compounds into the bonding constituents of the self-etching adhesives, instead of into the primer ingredients. The promoted new mineral segments contributed to reduce or avoid both porosity and nanoleakage from the load cycled Zn-doped resin dentin interfaces. EDTA+SB-ZnCl2 or SEB·Bd-Zn doping are preferred to treat caries-affected dentin surfaces. ZnO-doping encouraged for etch-and-rinse adhesives.

Influência da contaminação cavitária na adaptação marginal das restaurações de resina composta / Influence of cavity contamination on marginal adaptation of composite resin restorations

Objetivo: avaliar a influencia da contaminação cavitária na adaptação marginal das restauraçõesde resina composta e a associação da lisozima ao sistema adesivo. Materiais e Métodos:Foram selecionados 40 terceiros molares permanentes e confeccionados preparos cavitários classeV com pontas diamantadas cilíndricas 1090 (4 mm de largura, 6 mm de comprimento e 1,5 mmde profundidade). Todos os dentes foram esterilizados e divididos aleatoriamente em 4 grupos(n=10): G1: sistema adesivo (SA) e restauração com resina composta (RC); G2: cavidadescontaminadas com 10 μl de Streptococcus mutans (0,5 de Mc Farland), SA e RC; G3:sistema adesivo associado com lisozima (ADL) e RC e G4: cavidades contaminadas com 10 μlde Streptococcus Mutans (0,5 de Mc Farland), ADL e RC. A lisozima foi adicionada ao SA com ummicrobrush embebido no SA e na lisozima em pó. Os dentes foram impermeabilizados e imersosem azul de metileno por 4 horas a 37ºC. Os dentes foram seccionados e fotografados. Resultados:A avaliação da microinfiltração foi feita por dois avaliadores utilizando o Programa Tpsdig. Paraavaliar a calibração entre os examinadores, foi utilizado o teste de Correlação de Pearson. As médiasdas porcentagens de fendas e bolhas foram submetidas ao teste de Kruskal Wallis com 5% designificância. Conclusão: a contaminação cavitária com Streptococcus mutans acarretou na formaçãode fendas entre a resina composta e as margens cavitárias. A lisozima associada ao sistemaadesivo não influenciou na formação de fendas e bolhas nas restaurações de resina composta.

Objective: evaluate the influence of cavity contamination on marginal adaptation of compositerestorations and the association of lysozyme to the adhesive system. Materials and Methods:Were selected 40 permanent third molars and made cavity preparations class V with cylindricaldiamond burs 1090 (4 mm wide, 6 mm long and 2 mm deep). All teeth were sterilized and randomlydivided into 4 groups (n = 10): G1: adhesive system (SA) and restoration with compositeresin (CR); G2: cavity contaminated with 10 μl of Streptococcus mutans (0.5 McFarland), SA andRC; G3: adhesive system associated with lysozyme (ADL) and RC and G4: cavity contaminated with10 μl of Streptococcus mutans (0.5 Mc Farland), ADL and RC. Lysozyme was added to the SA witha microbrush embedded in the SA and powdered lysozyme. The teeth were sealed and immersedin a methylene blue for 4 hours at 37 ° C. The teeth were sectioned and photographed. Results:The evaluation of microleakage was made by two reviewers using the Tpsdig Program. To assessthe calibration of examiners, we used the Pearson correlation test. The mean percentages of cracksand bubbles were submitted to Kruskal Wallis test at 5% significance level. Conclusion: the cavityStreptococcus mutans contamination resulted in the formation of cracks between the compositeresin and the cavity margins. Lysozyme associated with the adhesive system did not influence theformation of cracks and bubbles in the composite restorations.

Resistência de união de adesivos all-in-one em diferentes substratos / Bond strength of all-in-one adhesives in different substrates

Introdução: A odontologia adesiva teve seu início no condicionamento ácido do esmalte. Com o rápido desenvolvimento dos novos produtos, os ensaios in vitro tornaram-se valiosos para comparar a RU dos adesivos ao esmalte, dentina e outros substratos - em análises imediatas ou de longo prazo para avaliar a durabilidade da união. Objetivo: avaliar a resistência de união (RU) de adesivos all-in-one em diferentes substratos após uma semana de armazenamento em água destilada. Metodologia: foram utilizados 75 incisivos bovinos e obtidas 25 amostras de esmalte hígido/EH, 25 de esmalte desgastado/ED, 25 de dentina/DE; mais 25 amostras do compósito Filtek Z350 XT/XT. Cinco adesivos foram aplicados nos substratos, e os grupos divididos (n=5): [1]ácido fosfórico 37%+adesivo controle Adper Single Bond 2; adesivos all-in-one [2]BeautiBond/BB; [3] Bond Force/BF; [4]SE One/SE; [5]Single Bond Universal/UN. Quatro matrizes Tygon foram posicionadas sobre os substratos e preenchidas com o Filtek Z350 XT Flow. Após fotopolimerização (20s), as matrizes foram removidas para expor 4 corpos de prova, perfazendo o total de 20 cilindros por grupo. Decorrido uma semana em água 37°C, os corpos de prova foram testados em uma máquina de ensaios. O microcisalhamento foi executado na base dos cilindros (0,5 mm/min). Os resultados foram expressos em MPa, e analisados pela Anova (p<0,001) e teste de Tukey (p<0,05). Resultados: comparando cada substrato, não houve diferença para o ED e para o EH. Para dentina, os adesivos SE e o UN resultaram em maior RU, além do controle. Para o compósito, a maior RU foi observada no UN. Comparando os substratos, a RU foi menor para alguns adesivos no EH e DE. Conclusão: os adesivos all-in-one são substrato-dependentes. A maior RU foi obtida no UN com o compósito XT, e a menor no BF com dentina. A RU nos substratos ED e XT foi mais estável, quando comparada aos demais substratos.

Introduction: the adhesive dentistry had its beginning in the enamel etching. With the rapid development of new products, in vitro tests have become valuable to compare the UK adhesives to enamel, dentin and other substrates - in immediate or long-term analyzes to evaluate the bond durability. Objective: to evaluate the shear bond strength (SBS) of all-in-one adhesives on different substrates after a week storage in distilled water. Methodology: seventy five bovine incisors were used and obtained 25 samples of uncut enamel/UE; 25 of cut enamel/CE; 25 of dentin/DE; more 25 of Filtek Z350XT/XT. Five adhesives were applied, and divided into 5 groups (n=5): [1]37% phosphoric acid + Single Bond 2/SB adhesive control; [2]BeautiBond/BB; [3]Bond Force/BF; [4]One SE/SE; [5]Single Bond Universal/UN. Four Tygon tubings were positioned on the substrates and filled in with Filtek Z350 XT Flow. After 20s VLC, the tubes were removed to expose 4 specimens for each sample (20 cylinders per group). After a week in distilled water 37°C, the specimens were tested in an universal testing machine. The tensile load resulting in shear was performed on the basis of the cylinder at a speed of 0.5 mm/min. The results were expressed in MPa and analyzed by Anova (p<0,001) and Tukey test (p<0.05). Results: comparing each substrate, there was no difference for the UE and the CE. To dentin, the SE and the UN resulted in higher SBS. For the composite substrate, the higher SBS was observed in UN. Comparing the substrates, the SBS was lower to some adhesives in UE and DE. Conclusion: the all-in-one adhesives are substrate-dependents. The highest SBS was obtained for the UN in the composite substrate, and lowest SBS mean to BF in dentin substrate. The SBS in CE and XT was more stable, when compared to other substrates.

Efeito da condição do substrato e do tempo de condicionamento na estabilidade da união de sistemas adesivos à dentina de dentes decíduos / Effect of substrate condition and etching time on the bonds stability of adhesive systems to dentin of primary teeth

Este estudo objetivou investigar a influência da redução do tempo de condicionamento na união de sistemas adesivos à dentina hígida e afetada por cárie de dentes decíduos, por meio de testes de microtração, nanoinfiltração e avaliação micromorfológica da interface adesiva. A superfície dentinária de 48 segundos molares decíduos foi exposta e os dentes divididos aleatoriamente em 8 grupos experimentais de acordo com o substrato (dentina hígida e afetada por cárie ciclagem de pH por 14 dias), sistema adesivo (Adper Single Bond 2 adesivo convencional de dois passos e Clearfil SE Bond - sistema autocondicionante de dois passos) e tempo de condicionamento (recomendado pelo fabricante e metade do tempo). Desta forma, o adesivo Adper Single Bond 2 foi aplicado à dentina após condicionamento com ácido fosfórico a 35% por 15 ou 7 segundos e o agente de união do Clearfil SE Bond após 20 ou 10 segundos de aplicação do primer. Blocos de resina composta (Filtek Z250) foram confeccionados e, após 24 horas de armazenamento em água destilada, os dentes foram seccionados para obtenção de espécimes com área de secção transversal de aproximadamente 0,8 mm2. Metade dos espécimes foi submetida imediatamente ao teste de microtração e a outra metade após 12 meses de armazenamento em água destilada. O padrão de fratura foi avaliado em estereomicroscópio com aumento de 400x. Dois espécimes de cada dente nos respectivos períodos de armazenamento foram imersos em nitrato de prata amoniacal por 24 horas e revelados (8 horas) para avaliação da nanoinfiltração em microscopia eletrônica de varredura. Adicionalmente, dois dentes para cada grupo experimental (n=16) foram preparados como descrito para o teste de microtração e seccionados perpendicularmente à interface adesiva, após 24 horas, para análise da micromorfologia e espessura da camada híbrida.

Os valores de resistência de união, expressos em megapascal (MPa), foram submetidos à Análise de Variância (ANOVA) e teste de Tukey ( = 0,05). As demais avaliações foram descritivas. Os sistemas adesivos apresentaram valores similares de resistência de união imediata. Decréscimo dos valores de resistência de união ocorreu após 12 meses de armazenamento em água, exceto para o adesivo Clearfil SE Bond em substrato hígido. A adesão à dentina afetada foi menor em comparação à dentina hígida. A nanoinfiltração também foi mais pronunciada neste substrato. O tempo de condicionamento influenciou apenas a adesão do sistema adesivo Adper Single Bond 2. Maiores valores de resistência de união e menor infiltração de nitrato de prata na interface adesiva foram observados quando o tempo de condicionamento ácido foi reduzido pela metade, independente do substrato. Camadas híbridas mais finas foram produzidas quando a dentina decídua foi condicionada por 7 segundos, especialmente em dentina afetada. Predomínio de fratura adesiva/mista foi observado para todos os grupos experimentais. Em conclusão, o efeito da redução no tempo de condicionamento é material dependente e resulta em maior estabilidade da união de sistema adesivo convencional de dois passos à dentina hígida e afetada de dentes decíduos.

This study aimed to investigate the influence of shortening the etching time on bond of adhesive systems to sound and caries-affected dentin of primary teeth by microtensile and nanoleakage tests, and micromorphological evaluation of the adhesive interface. The dentinal surface of 48 second primary molars was exposed and the teeth were randomly assigned to 8 experimental groups according to substrate (sound and caries-affected dentin - pH-cycling for 14 days), adhesive system (Adper Single Bond 2 two-step etch-and-rinse adhesive system and Clearfil SE Bond two step self-etch adhesive system) and etching time (recommend by manufacturers and half-reduced time). Thus, the adhesive Adper Single Bond 2 was applied to dentin after 35% phosphoric acid etching for 15 or 7 seconds, and the bond of Clearfil SE Bond after 20 or 10 seconds of primer application. Composite resin blocks (Filtek Z250) were built and, after 24 hours of storage in distilled water, the teeth were sectioned to obtain specimens with cross-sectional area of approximately 0.8 mm2. Half of the specimens were immediately subjected to microtensile test and the other half after 12 months of storage in distilled water. The fracture pattern was evaluated with a stereomicroscope at 400x magnification. Two specimens from each tooth in the respective storage periods were immersed in ammoniacal silver nitrate for 24 hours and revealed (8 hours) to evaluate the nanoleakage in scanning electron microscope. Additionally, two teeth for each experimental group (n=16) were prepared as described for the microtensile test and perpendicularly sectioned to the adhesive interface, after 24 hours, for analysis of micromorphology and thickness of the hybrid layer.

Bond strength values, expressed in megapascal (MPa), were submitted to Analysis of Variance (ANOVA) and Tukeys tests ( = 0.05). Other evaluations were descriptive. The adhesive systems presented similar immediate bond strength values. A decrease in bond strength values occurred after 12 months of water storage, except for Clearfil SE Bond in sound substrate. Bonding to caries-affected dentin was lower compared to sound dentin. The nanoleakage was also more pronounced in this substrate. Etching time only influenced the bonding of the adhesive system Adper Single Bond 2. Higher bond strength values and lower infiltration of silver nitrate into adhesive interface were observed when the etching time was half-reduced, irrespective of the substrate. Thinner hybrid layers were produced when the primary dentin was acid etched for 7 seconds, especially in caries-affected dentin.

Influência do uso do digluconato de clorexidina como inibidor de metaloproteinase na resistência adesiva e dureza da camada híbrida e camada de adesivo / The influence of the use of chlorhexidine gluconate as an inhibitor of metalloproteinase bond strength and hardness of the hybrid layer and adhesive layer

Este estudo avaliou a influência do uso do digluconato de clorexidina como inibidor de metaloproteinase na resistência adesiva e dureza da camada de adesivo e camada hibrida de uma resina composta à dentina humana, por meio de ensaio de microtração e nanoedentação. Os fatores de variação estudados foram dois sistemas adesivos com estratégias de aplicação distintas Adper Scotchbond Multi-Purpose (3M ESPE, St. Paul, MN, USA) e Clearfil SE Bond (Kuraray Co., Osaka, Japan), e ainda foram realizados tratamentos no substrato dentinário utilizando duas concentrações de digluconato de clorexidina sendo estas 2% e 0,2% e grupos controle sem tratamento com clorexidina. As unidades experimentais foram compostas por 48 molares humanos hígidos divididos aleatoriamente em 6 grupos (n=8). Nestes foram aplicados os procedimentos adesivos e realizados os tratamentos de superfície, com clorexidina, previamente aos procedimentos adesivos. Após esta etapa foram confeccionadas as restaurações com espessura de 5mm sobre as superfícies dentinárias. Após 24h de armazenamento em água destilada, os dentes restaurados foram cortados para a obtenção de corpos de prova em forma de palito, com secção transversal de aproximadamente 1mm2. De cada grupo foram selecionados aleatoriamente 5 palitos para o ensaio de dureza. O restante dos palitos viáveis de cada dente foram submetidos ao teste de microtração a uma velocidade de 0,5mm/min até que ocorresse a fratura da interface adesiva.

This study evaluated the influence of the use of chlorhexidine gluconate as an inhibitor of metalloproteinase bond strength and hardness of the adhesive layer and hybrid layer of a composite resin to dentin, using microtensile test and nanoindentation. The variation factors studied were two adhesive systems with different implementation strategies Adper Scotchbond Multi-Purpose (3M ESPE, St. Paul, MN, USA) and Clearfil SE Bond (Kuraray Co., Osaka, Japan), and were still held treatments to dentin using two concentrations of chlorhexidine digluconate and these 2% and 0.2% untreated control groups with chlorhexidine. The experimental units were composed of 48 human molars were randomly divided into 6 groups (n = 8). These procedures were applied adhesives and surface treatments performed with chlorhexidine prior to bonding procedures. After this step the restorations were made with 5mm thickness on the dentin surfaces. After 24 hours storage in distilled water, the samples were cut to obtain specimens toothpick shaped cross-section of approximately 1mm2. Each group were randomly selected 5 toothpicks for hardness testing. The remaining viable sticks of each tooth were subjected to microtensile testing at a crosshead speed of 0.5 mm / min until the fracture of the adhesive interface. To test nanohardness each of the five toothpicks referring to six groups received 5 indentations in the adhesive layer and 5 indentations in the hybrid layer with 10m away from each other. These indentations were performed with the equipament DUH-W211S (Shimadzu Co., Tokyo, Japan). The data relating to microtensile test of the six groups were subjected to analysis of variance and Tukey test (p <0,05).

The data relating to microtensile test of the six groups were subjected to analysis of variance and Tukey test (p <0,05). The means of the groups were: Group 1: Clearfil SE control (28.50 ± 0:47), Group 2: Adper Scotchbond control (43.90 ± 7.26); Group3: Clearfil SE / 2% chlorhexidine (30.43 ± 6:59), Group 4: Adper Scotchbond / 2% chlorhexidine (39.21 ± 4.69), Group 5: Clearfil SE 0.2% (27.28 ± 07.05), Group 6: Adper Scotchbond / chlorhexidine 0.2% (35.70 ± 6:43). Comparing the means of the groups it was found that none of the adhesives tested showed a change in its bond strength with the use of chlorhexidine gluconate 2% or 0.2% in immediate analysis. The groups that used Scotchbond showed higher bond strength than the groups that used the adhesive system (Clearfil) regardless of performance or not the surface treatment with chlorhexidine digluconate. The hardness values of the adhesive layer did not show statistically significant differences between the control groups or between treatments, the group previously treated with Clearfil SE/Chlorhexidine 0.2% showed lower hardness value of the hybrid layer.

Detection and quantification of monomers in unstimulated whole saliva after treatment with resin-based composite fillings in vivo.

Resin-based dental restorative materials contain allergenic methacrylate monomers, which may be released into saliva after restorative treatment. Monomers from resin-based composite materials have been demonstrated in saliva in vitro; however, studies analyzing saliva after restorative therapy are scarce. The aim of this study was to quantify methacrylate monomers in saliva after treatment with a resin-based composite filling material. Saliva was collected from 10 patients at four start points--before treatment, and 10 min, 24 h, and 7 d after treatment--and analysed by combined chromatography/mass spectrometry. The monomers bisphenol-A diglycidyl methacrylate (Bis-GMA), 2-hydroxyethyl methacrylate (HEMA), and urethane dimethacrylate (UDMA) were detected and quantified in the samples collected shortly (10 min) after treatment. The amounts detected ranged from 0.028 to 9.65 µg ml(-1) for Bis-GMA, from 0.015 to 0.19 µg ml(-1) for HEMA, and from 0.004 to 1.2 µg ml(-1) for UDMA. Triethyleneglycol dimethacrylate (TEGDMA) was detected in four of the samples. Ethoxylated bisphenol-A dimethacrylate (Bis-EMA) was not detected. Monomers were not detected in saliva samples collected before treatment, or 24 h or 7 d after treatment, with the exception of one sample, 24 h after treatment, in which HEMA was detected. In conclusion, monomers from the investigated resin-based composite and adhesive system were present in saliva shortly after treatment. One week after treatment, no monomers could be detected in patients' saliva samples.

Quantitative analysis of aqueous phase composition of model dentin adhesives experiencing phase separation.

There have been reports of the sensitivity of our current dentin adhesives to excess moisture, for example, water-blisters in adhesives placed on over-wet surfaces, and phase separation with concomitant limited infiltration of the critical dimethacrylate component into the demineralized dentin matrix. To determine quantitatively the hydrophobic/hydrophilic components in the aqueous phase when exposed to over-wet environments, model adhesives were mixed with 16, 33, and 50 wt % water to yield well-separated phases. Based upon high-performance liquid chromatography coupled with photodiode array detection, it was found that the amounts of hydrophobic BisGMA and hydrophobic initiators are less than 0.1 wt % in the aqueous phase. The amount of these compounds decreased with an increase in the initial water content. The major components of the aqueous phase were hydroxyethyl methacrylate (HEMA) and water, and the HEMA content ranged from 18.3 to 14.7 wt %. Different BisGMA homologues and the relative content of these homologues in the aqueous phase have been identified; however, the amount of crosslinkable BisGMA was minimal and, thus, could not help in the formation of a crosslinked polymer network in the aqueous phase. Without the protection afforded by a strong crosslinked network, the poorly photoreactive compounds of this aqueous phase could be leached easily. These results suggest that adhesive formulations should be designed to include hydrophilic multimethacrylate monomers and water compatible initiators.

Avaliação da resistência de união de reparos de resina composta, utilizando-se diferentes tratamentos de superfície / Evaluation of microtensile bond strength of composite resin repair using different surface treatments

Objetivo: Avaliar a resistência de união de reparos de restaurações em resina composta utilizando-se diferentes tratamentos de superfície. Materiais e Métodos: Foram utilizadas 180 amostras de resina composta Tetric Ceram® (Ivoclar/Vivadent), distribuídas em 9 grupos (n=20/grupo). No momento do reparo, cada grupo recebeu tratamento de superfície específico: ácido fosfórico a 37% (Ivoclar/Vivadent); ácido hidrofluorídrico a 10% (Dentsply) ou microjateamento com partículas de óxido de alumínio de 50μm (Micro Jato VH®). Em seguida, aplicou-se o sistema adesivo Heliobond® (Ivoclar/Vivadent), associado ou não ao agente silanizadorMonobond-S® (Ivoclar/Vivadent). Foram também confeccionados espécimes que não sofreram nenhum tipo de reparo (grupo controle). Os espécimes ficaram armazenados em água deionizada por 18 meses. Posteriormente cada amostra foi submetida ao teste de resistência de união à microtração em máquina de ensaio universal (EMIC DL500BF), a uma velocidade de 0,5 mm/minuto. Os dados obtidos em MPa foram submetidos a avaliação da normalidade da variável microtração por meio do teste Kolmogorov-Smirnov. Considerando quea variável não apresentou distribuição normal (p<0,001) foram realizados os testes de Kruskal-Wallis e Mann-Whitney. O valor de p considerado foi menor que 0,05, exceto, quando se utilizou da correção de Bonferroni(p<0,00138). Resultados: Os espécimes do grupo controle apresentaram resistência à tração estatisticamente superior em relação aos demais grupos. O emprego do ácido fosfórico e posterior inserção do sistema adesivo apresentou resultados estatisticamente significante em relação aos demais grupos reparados. Conclusões: A resistência coesiva da resina composta foi superior às outras técnicas de reparo utilizadas. O emprego do ácido fosfórico e posterior inserção do sistema adesivo demonstrou ser o tratamento ideal para o reparo derestaurações em resina composta.

Solvent composition of one-step self-etch adhesives and dentine wettability.

OBJECTIVES: Our aim was to determine the wettability of dentine by four commercial self-etch adhesives and evaluate their spreading rate on the dentine surface. Any correlation with chemical composition was sought, particularly with the amount of solvent or HEMA present in the adhesive. The adhesives used were AdheSE One, Optibond All.In.One, Adper Easy Bond and XenoV. METHODS: Chemical compositions were determined by proton nuclear magnetic resonance (NMR) spectroscopy of the adhesives dissolved in dimethylsulfoxide. Apparent contact angles for sessile drops of adhesives were measured on dentine slices as a function of time for up to 180s. The water contact angles were determined for fully polymerised adhesives. RESULTS: All adhesives were water-based with total solvent contents ranging from 27% to 73% for HEMA-free adhesives, and averaging 45% for HEMA containing adhesives. The contents in hydrophobic groups decreased as water contents increased. No differences were found in the adhesive contact angles after 180s even though the spreading rates were different for the products tested. CONCLUSION: Water contact angles differed significantly but were not correlated with HEMA or solvent presence. Manufacturers use different approaches to stabilise acid co-monomer ingredients in self-etch adhesives. Co-solvents, HEMA, or acrylamides without co-solvents are used to simultaneously etch and infiltrate dentine. A large proportion of water is necessary for decalcification action.

Performance clínica de dois sistemas adesivos em lesões cervicais não cariosas: 30 meses de acompanhamento / Clinical evaluation of two adhesive systems in noncarious cervical lesions: 30-month clinical trial

Objetivo: Avaliar a performance clínica de dois sistemas adesivos em lesões de Classe V não-cariosas, por 30 meses. Materiais e Métodos: Sessenta e três lesões cervicais não-cariosas foram restauradas com a resina composta Polofil M (Voco) associada aos sistemas adesivos Futurabond NR (Voco) ou Solobond M (Voco). As restaurações foram executadas seguindo dois protocolos adesivos: o adesivo Futurabond NR foi aplicado pela técnica autocondicionante (G1) e o adesivo Solobond M foi utilizado de acordo com a técnica do condicionamento ácido total (G2). As restaurações foram avaliadas após 7 dias, 6, 18 e 30 meses para oscritérios: retenção, descoloração marginal, integridade marginal, sensibilidade pós-operatória e presença de lesão secundária de cárie, de acordo com os critérios USPHS. Os dados foram analisados usando os testes de McNemar e Qui-quadrado (α=0,05). Resultados: Após 30 meses de acompanhamento, 12 restauraçõesforam perdidas, 6 de cada grupo. O percentual de escore alfa para cada grupo foi: retenção (G1: 77,8%; G2:81,2%), descoloração marginal (G1: 66,7%; G2: 80,8%), integridade marginal (G1: 61,9%; G2: 80,8%),sensibilidade pós-operatória (G1: 90,5%; G2: 89,4%) e presença de lesão secundária de cárie (G1: 95,2%;G2: 100%). Não houve diferença estatística entre os grupos para nenhum dos critérios avaliados (p>0,05).Conclusão: Após 30 meses, os dois sistemas adesivos apresentam desempenhos clínicos semelhantes.