ABSTRACT
Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher µTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.
Subject(s)
Dental Cements/chemistry , Dentin/chemistry , Matrix Metalloproteinase Inhibitors/chemistry , Methacrylates/chemistry , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Analysis of Variance , Dental Bonding/methods , Dental Etching/methods , Dental Leakage , Dentin/drug effects , Humans , Materials Testing , Reference Values , Reproducibility of Results , Spectroscopy, Fourier Transform Infrared , Statistics, Nonparametric , Surface Properties , Tensile Strength , Time FactorsABSTRACT
Abstract Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher μTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.
Subject(s)
Humans , Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Dental Cements/chemistry , Dentin/chemistry , Matrix Metalloproteinase Inhibitors/chemistry , Methacrylates/chemistry , Reference Values , Surface Properties , Tensile Strength , Time Factors , Materials Testing , Reproducibility of Results , Analysis of Variance , Dental Bonding/methods , Spectroscopy, Fourier Transform Infrared , Statistics, Nonparametric , Dental Leakage , Dentin/drug effects , Dental Etching/methodsABSTRACT
The aim of this study was to evaluate the degree of conversion (DC%), water sorption (WS), solubility (SO), and resin-dentin bonding stability of experimental adhesive systems containing ZnCl2. Different concentrations (wt.%) of ZnCl2 were added to a model etch-and-rinse adhesive system consisting of BISGMA, HEMA, UDMA, GDMA, water, and ethanol: Zn0 (0%-control group); Zn2 (2%); Zn3.5 (3.5%); and Zn5 (5%). Adper Single Bond 2 (SB) was used as commercial reference. The samples were light cured for 20s using a quartz-tungsten-halogen unit (650 mW/cm2). DC% (n = 5) was measured using FT-IR spectroscopy, and WS and SO (n = 5) were calculated based on ISO4049. Microtensile bond strength (µTBS) and nanoleakage (NL) were measured after 24 h and 12 months of water storage (n = 10). Data were analyzed using ANOVA and Tukey's HSD test (5%). Zn5 presented the lowest DC% and the highest WS and SO (p < 0.05). Zn0 and Zn2 presented statistically similar DC%, WS, SO, and immediate µTBS. All adhesives containing ZnCl2 maintained a µTBS stability after 12 months, but only Zn2 and Zn3.5 did not suffer an increase in NL. SB presented the highest immediate µTBS but the greatest reduction after 12 months (p < 0.05). The addition of 2 wt.% of ZnCl2 in adhesive formulations seems to be a promising way to improve the resin-dentin bonding stability. Higher concentrations than 2 wt.% could impair some physicochemical properties.
Subject(s)
Chlorides/chemistry , Dental Cements/chemistry , Resins, Synthetic/chemistry , Zinc Compounds/chemistry , Acid Etching, Dental/methods , Chlorides/therapeutic use , Dental Bonding/instrumentation , Dental Cements/therapeutic use , Dentin/chemistry , Humans , Materials Testing , Resin Cements/chemistry , Resin Cements/therapeutic use , Resins, Synthetic/therapeutic use , Tensile Strength , Zinc Compounds/therapeutic useABSTRACT
PURPOSE: To investigate the influence of 4-META concentration and type of solvent on the degree of conversion (DC%) and resin-dentin bond stability of experimental etch-and-rinse adhesives. MATERIALS AND METHODS: Four different concentrations of 4-META (12 wt%, 20 wt%, 30 wt%, 40 wt%) were added to a model adhesive system consisting of TEG-DMA (25 wt%), UDMA (20 wt%), HEMA (30 wt%), water (4 wt%), camphorquinone (0.5 wt%), and tertiary amine (0.5 wt%) dissolved in 20% acetone (A12, A20, A30 and A40) or 20% ethanol (E12, E20, E30 and E40). DC% was evaluated by FT-IR spectroscopy. Human molars were wet ground until the occlusal dentin was exposed, the adhesive systems were applied after 37% phosphoric acid etching, and resin composite buildups were incrementally constructed. After storage in distilled water at 37°C for 24 h, the teeth were cut into resin-dentin beams (cross-sectional area 1 mm2). Microtensile bond strength (µTBS) was evaluated after 24 h, 6 months, and 1 year of water storage at 37°C. The failure mode was categorized as adhesive, mixed, or cohesive. Data were analyzed using ANOVA and Tukey's HSD test (α = 0.05). RESULTS: A12 presented the lowest DC% (p < 0.05). All the other adhesive systems showed statistically similar DC% (p > 0.05). All adhesive systems maintained resin-dentin bond stability after 6 months of water storage, while only A40 and E40 maintained it after 1 year. CONCLUSION: Irrespective of the type of organic solvent, the incorporation of high concentrations of 4-META (40 wt%) improved the resin-dentin bond stability of the experimental etch-and-rinse adhesive systems over a period of 1 year.
Subject(s)
Acetone/pharmacology , Acid Etching, Dental/methods , Dental Bonding , Dentin-Bonding Agents , Ethanol/pharmacology , Methacrylates , Resins, Synthetic , Solvents/pharmacology , Humans , Materials TestingABSTRACT
PURPOSE: To evaluate the effect of dentin treatment using HEMA phosphate (HEMA-P) on the microtensile bond strength (µTBS) and nanoleakage of an etch-and-rinse adhesive system. MATERIALS AND METHODS: The occlusal surfaces of human molars were wet ground until superficial dentin was exposed. The specimens were then assigned to two groups according to dentin treatment: PA: 37% H3PO4 for 15 s; or HP: HEMA-P for 15 s. Adper Single Bond 2 was applied to the treated dentin surfaces and resin composite buildups were incrementally constructed over them. After 24-h storage in artificial saliva at 37°C, the bonded teeth were cut into resin-dentin sticks with a cross-sectional area of 1 mm², which were submitted to µTBS testing immediately or after 3 months of storage in artificial saliva at 37°C. Nanoleakage was assessed using SEM/EDS, and the interaction between dentin and H3PO4 or HEMA-P was evaluated by combining micro-Raman and FT-IR spectroscopy. The data were analyzed using two-way ANOVA and Tukey's HSD post-hoc test (α = 0.05). RESULTS: HP presented significantly higher µTBS than PA at both times (p < 0.05). Both treatments maintained µTBS stability after 3 months of artificial saliva storage (p > 0.005). At both times, PA presented higher nanoleakage than HP (p < 0.05). CONCLUSIONS: Both dentin treatments maintained µTBS stability after 3 months of artificial saliva storage. The use of HEMA-P was associated with less nanoleakage than was traditional phosphoric-acid etching.
Subject(s)
Dental Bonding , Dental Cements , Dental Etching , Dentin/drug effects , Methacrylates/pharmacology , Dental Leakage , Humans , In Vitro Techniques , Materials Testing , Microscopy, Electron, Scanning , Surface PropertiesABSTRACT
OBJECTIVES: To evaluate the degree of conversion (DC%), water sorption (WS), solubility (SO) and the resin-dentin bonding stability (µTBS) of experimental (EXP) etch-and-rinse adhesive systems containing MMP-inhibitors: Galardin-GAL, Batimastat-BAT, GM1489-GM1 and chlorhexidine diacetate-CHX. METHODS: DC% was measured using FT-IR spectroscopy, while WS and SO were calculated based on ISO4049. Thirty-six human molars were wet ground until the occlusal dentin was exposed. The adhesive systems were applied and resin composite buildups were incrementally constructed. After 24 h immersion in distilled water at 37 °C, the specimens were cut into resin-dentin beams with a cross-sectional area of 1 mm(2). The µTBS was evaluated after 24 h, 6 months and 12 months of water storage at 37 °C. Adper Single Bond 2 (SB2) was used as a commercial control. The data were analyzed using ANOVA and Tukey's HSD test. RESULTS: SB2 presented the highest DC% (p<0.05). CHX presented the lowest WS (p<0.05). GM1, GAL and BAT presented similar WS when compared with SB2 (p>0.05). SO was found to be not significant (p>0.05). All adhesive systems maintained µTBS stability after 6 months of water storage. Only BAT, GM1 and CHX maintained µTBs stability after 12 months of water storage. CONCLUSIONS: The experimental adhesive systems with GM1489 and chlorhexidine diacetate presented the best physicochemical properties and preserved resin-dentin bonding stability after 12 months of water storage. CLINICAL SIGNIFICANCE: GM1489 could be suitable for inclusion as an MMP-inhibitor in etch-and-rinse adhesive systems to maintain resin-dentin bonding stability over time.
Subject(s)
Acid Etching, Dental/methods , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Matrix Metalloproteinase Inhibitors/chemistry , Resins, Synthetic/chemistry , Chlorhexidine/chemistry , Chlorhexidine/pharmacology , Composite Resins/chemistry , Dentin/drug effects , Humans , Materials Testing , Matrix Metalloproteinase Inhibitors/pharmacology , Methacrylates/chemistry , Molar , Resin Cements/chemistry , Water/chemistryABSTRACT
A utilização de resinas associadas a fibras de reforço é uma excelente alternativa para casos de prótese adesiva. Este trabalho apresenta um caso clínico em que foi confeccionada uma prótese fixa reforçada do sistema de pônticos e fibras de vidro Fibrex-Lab (Angelus, Brasil) associada à resina composta Natural Look (DFL, Brasil). O resultado clínico foi altamente satisfatório, oferecendo função e estética ao paciente, o que demonstra a possibilidade da utilização das fibras de vidro como alternativa às ligas metálicas e cerâmicas reforçadas para subestruturas em situações clínicas bem indicadas de próteses parciais fixas. Dessa forma, o trabalho executado foi muito útil para que o emprego desses materiais permita aos dentistas clínicos a escolha de novas alternativas seguras para reabilitar sorrisos.
Subject(s)
Humans , Female , Adult , Composite Resins , Denture, Partial, Fixed, Resin-Bonded , Dental Restoration, Permanent/methods , Denture, Partial, Fixed , Esthetics, Dental , Glass Ionomer CementsABSTRACT
Os pinos de fibra de vidro têm sido extensivamente utilizados em dentes com grande perda de estrutura dentária e canais endodonticamente tratados. Por apresentar seção circular, mesmo com diâmetros diversos, sua linha de cimentação torna-se muito espessa em canais mais elípticos ou alargados. Tal condição poderia aumentar o potencial para a microinfiltração, além de diminuir a resistência à fratura do núcleo. Este artigo mostra a resolução do caso clínico de um incisivo lateral superior com conduto radicular amplo tratado endodonticamente, a partir do emprego de um retentor intra-radicular de fibra de vidro cônico associado a um pino acessório, com objetivo de diminuir a linha de cimentação e aumentar a longevidade do procedimento restaurador.
Subject(s)
Humans , Dental Pins , Post and Core Technique , Tooth, NonvitalABSTRACT
This study analyzed the depth of cure of a composite assessed by microhardness and the degree of conversion as a function of the light cure unit (LCU) used. Two light cure units, one LED (Ultraled-Dabi Atlante) and one quartz-tungsten-halogen (QTH, Optilux 401-Demetron) unit were used to cure 4.0 x 4.0 mm and 5.0 mm deep composite specimens (Filtek Z250, 3M ESPE). After 24 hours storage at 37 degrees C, Knoop microhardness and degree of conversion were measured on the irradiated surface and at each millimeter of the sample's depth. The degree of conversion was determined by using micro-Raman spectroscopy. The specimens cured with the QTH unit presented uniform decay in microhardness up to 4 mm in depth. Beyond 4 mm, the drop was abrupt. With LED photoactivation, uniform decay was observed only up to 2 mm. At higher depths, the decay in microhardness increased rapidly, especially beyond 3 mm. Depth of cure assessed by micro-Raman revealed that the degree of conversion behaved similarly to microhardness for both LCUs. A strong linear regression between microhardness and the degree of conversion, including both LCUs, was established with R2 = 0.980.
