RESUMEN
PURPOSE: To evaluate effect of air-particle abrasion protocol and primer on surface topography and bond strength of resin cement to high-translucent zirconia ceramics. MATERIALS AND METHODS: Two hundred disk-shaped high-translucent zirconia specimens of 5Y-PSZ were prepared. The specimens were assigned to 5 groups in terms of particle type and air-particle abrasion pressure: (1) control, (2) alumina with 0.2 MPa-air pressure [AB-0.2], (3) alumina with 0.4 MPa-air pressure [AB-0.4], (4) glass beads with 0.2 MPa-air pressure [GB-0.2], and (5) glass beads with 0.4 MPa-air pressure [GB-0.4]. Two different primers 1% MDP (Experimental) and MDP-silane primer (Clearfil Ceramic Primer Plus) was also tested. Stainless steel rods were bonded to the 5Y-PSZ specimens with PANAVIA V5. For each group, the tensile bond strength (TBS) was measured after 24-hour water storage (n = 10) and after 5000 thermal-cycling (n = 10) at crosshead speed of 2 mm/min. The data were statistically analyzed using Weibull analysis. Surface roughness (Sa) was measured using a 3D-Laser Scanning Confocal Microscope (n = 5) and analyzed by t-test with Bonferroni correction. Surface topography using scanning electron microscopy (SEM) and surface elemental analysis using energy dispersion spectroscopy (EDX), and cross-section SEM at the interface with composite cement were also investigated. RESULTS: In MDP-silane groups, the highest TBS was observed in AB-0.4 after 24 hours and GB-0.4 after thermal-cycling (p < 0.05). In MDP groups, AB groups resulted in the significantly higher TBS than GB groups (p < 0.05). AB-0.4 group showed the highest Sa value compared to all groups (p < 0.005), meanwhile GB groups did not show different Sa compared to control (p > 0.005). CONCLUSION: Air-abrasion with different particle and blasting pressure can improve bonding to zirconia with proper primer selection. Particularly, glass beads abrasion followed by MDP-silane primer and alumina abrasion followed by MDP primer alone provided stable bond strength of resin cement to high-translucent zirconia after aging. High-translucent zirconia abraded with glass beads achieves a desirable bonding performance without creating surface microcracks which may hinder zirconia's mechanical properties.
Asunto(s)
Recubrimiento Dental Adhesivo , Óxido de Aluminio/química , Cerámica , Recubrimiento Dental Adhesivo/métodos , Análisis del Estrés Dental , Ensayo de Materiales , Cementos de Resina/química , Cementos de Resina/uso terapéutico , Resistencia al Corte , Propiedades de Superficie , Circonio/químicaRESUMEN
OBJECTIVE: The aim of this study was to assess the influence of different silicatization protocols with various silane treatment methods on the bond performance to high-translucent zirconia. MATERIALS AND METHODS: High-translucent zirconia specimens were assigned to five groups according to mechanical surface pretreatment: as-sintered (Con), 0.2 MPa alumina sandblasting (AB2), tribochemical silica coating (TSC), 0.2 and 0.4 MPa glass bead air abrasion (GB2) and (GB4). Each group was subjected to 4 different cementation protocols: Panavia SA Universal (SAU), Panavia SA plus (SAP), silane + SAP (S-SAP), and Universal adhesive + SAP (U-SAP). Tensile bond strength (TBS) was measured after 24 h and 10,000 thermocycling (TC). Surface topography, surface energy, and elemental composition of the abraded zirconia surface analyses were completed. TBS data was analyzed using the Weibull analysis method. Surface roughness and surface energy were compared by one-way ANOVA analysis of variance (α = 0.05). RESULTS: After 24 h, higher TBS was achieved with all cementation protocols in AB2 and TSC, also, in GB2 with all protocols except U-SAP, and in GB4 with SAU and S-SAP. After aging, GB4/S-SAP, GB2/S-SAP, AB2/U-SAP, and TSC/S-SAP showed the highest bond strength. GB groups showed the lowest surface roughness and highest surface energy. CONCLUSION: Glass bead abrasion achieved the durable bond strength to high-translucent zirconia using a separate silane coupling agent while altered surface chemistry, surface energy, and roughness without effect on morphology. CLINICAL RELEVANCE: Glass bead air abrasion is an alternative to alumina sandblasting and tribochemical silica coating and improves bond strength to high translucent zirconia.
Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Abrasión Dental por Aire , Óxido de Aluminio/química , Cerámica , Recubrimiento Dental Adhesivo/métodos , Análisis del Estrés Dental , Ensayo de Materiales , Cementos de Resina/química , Dióxido de Silicio/química , Propiedades de Superficie , Circonio/químicaRESUMEN
OBJECTIVES: Translucent zirconia has brought the advantages such as less tooth preparation, biological compatibility, high strength, good mechanical properties, and less antagonist wear. This study's aim was to elucidate how clinically relevant surface treatments; alumina-abrasion and priming effect on bond strength of Y-PSZ in three different translucency grades after long-term water storage. MATERIALS AND METHODS: Three highly translucent Y-PSZ grades were ground flat with #600-grit SiC paper. Four different surface treatments (untreated, alumina blasting at 0.1 MPa or 0.2 MPa or 0.4 MPa) and two resin cements (PANAVIA V5 and PANAVIA SA CEMENT PLUS AUTOMIX) were tested. The bonded specimens were stored in water for 1 day, 30 days and 150 days and tensile bond strength (TBS) were measured with universal testing machine at a crosshead speed of 2 mm/min (n=10). The surface roughness (Sa) measurement and surface morphology analysis without alumina-blasting pressure (untreated) and with alumina-blasting pressures (0.1 MPa, 0.2 MPa and 0.4 MPa) for three different zirconia grades were evaluated with 3D-Laser Scanning Confocal Microscope. RESULTS: Different alumina-blasting pressures and different storage periods affected the bonding of resin cement to translucent zirconia. The Weibull moduli increased in some groups after 150 days storage. After 1 day and 30 days storage, 0.4 MPa alumina-blasting pressure provided superior bond strength, however, after 150 days, 0.2 MPa gave reliable and stable bond strength. SIGNIFICANCE: Alumina-blasting pressure of 0.2 MPa was the most effective for reliable and durable bonding performance to translucent zirconia after long-term water storage.
Asunto(s)
Óxido de Aluminio , Recubrimiento Dental Adhesivo , Análisis del Estrés Dental , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie , CirconioRESUMEN
The aim of this study was to evaluate the time elapsed bond strength of the CAD/CAM resin block (CRB) to bovine dentin after alumina blasting. CRB (KATANA AVENCIA BLOCK) slices were ground with #600-SiC paper and divided into three groups according to alumina blasting pressure -0.1 MPa, 0.2 MPa or untreated- and then divided into two subgroups according to the time elapsed after alumina blasting -same-day or one-week "dry-storage" at controlled laboratory conditions before cementation. The CRB slices were then cemented to bovine dentin with Panavia V5 (Kuraray Noritake Dental), and divided into two subgroups -light curing or chemical curing. After 24 h storage in distilled water at 37°C, the specimens were then subjected to micro-tensile bond strength (µTBS) testing. One-week group showed a significant decrease in µTBS. The µTBS values showed that CRBs must be cemented with light curing immediately after alumina blasting at 0.1 or 0.2 MPa to obtain a stable adhesion.
Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Óxido de Aluminio , Animales , Bovinos , Resinas Compuestas , Análisis del Estrés Dental , Dentina , Recubrimientos Dentinarios , Ensayo de Materiales , Resistencia a la TracciónRESUMEN
The aim of this study was to evaluate how alumina-blasting pressure affects the bond strength of CAD/CAM resin blocks (CRBs) to bovine dentin using two different types of resin cements. CRB slices were divided into three groups by alumina-blasting pressure, namely, untreated and 0.1 MPa and 0.2 MPa, and further divided into three subgroups by combination of CRBs surface treatment and types of cement: Scotchbond Universal and RelyX ultimate (RXB), Scotchbond Universal and RelyX unicem2 (U2B), ceramic primer and RelyX unicem2 (U2C). The CRB slices were then cemented to bovine dentin, microtensile bond strength test was performed and evaluated. Regardless of the alumina-blasting pressure, RXB group have the highest µTBS and bond strength tends to increase with increasing alumina-blasting pressure. Alumina-blasting to CRB surface by at an appropriate pressure and use of conventional resin cement were required to obtain strong adhesion with the tooth structure.
Asunto(s)
Óxido de Aluminio/química , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Cementos de Resina/química , Animales , Bovinos , Diseño Asistido por Computadora , Técnicas In Vitro , Ensayo de Materiales , Presión , Propiedades de Superficie , Resistencia a la TracciónRESUMEN
AIM: Mussel-mimetic, bioadhesive polymers are synthesized from plant-derived sources. The strong adhesive action is caused by interactions between the catechol groups at the end of the polymer terminal chains and the substrate surface. Here, we present a preliminary study of the adhesion properties and a discussion of the adhesion mechanism. METHODS: Two bioadhesive polymers were synthesized from natural plant-derived monomers by the transesterification of: (a) caffeic acid (3,4-dihydroxycinnamic acid; DHCA) and p-coumaric acid (4-hydroxycinnamic acid; 4HCA) to produce poly(DHCA-co-4HCA); and (b) 4-dihydroxyhydrocinnamic acid (DHHCA) and 3-(3-hydroxyphenyl) propionic acid (3HPPA) to produce poly(DHHCA-co-3HPPA). Thermoplastic poly(DHCA-co-4HCA) or poly(DHHCA-co-3HPPA) was placed between glass, carbon, steel, or bovine dentin substrates, and a lap shear adhesion test was conducted to compare them using conventional cyanoacrylate glue and epoxy resin. RESULTS: The greatest adhesion for all tested substrates was exhibited by poly(DHHCA-co-3HPPA), followed by epoxy resin adhesive, poly(DHCA-co-4HCA), and cyanoacrylate adhesive. The adhesive strength of poly(DHHCA-co-3HPPA) was greater than 25.6 MPa for glass, 29.6 MPa for carbon, 15.7 MPa for steel, and 16.3 MPA for bovine dentin. CONCLUSION: The adhesion of poly(DHHCA-co-3HPPA) might be the strongest reported for a mussel-mimic adhesive system, and could be a feasible alternative to petroleum adhesives.
Asunto(s)
Adhesivos/química , Materiales Biomiméticos/química , Biopolímeros/química , Preparaciones de Plantas/química , Adhesividad , Animales , Ácidos Cafeicos/química , Carbono/química , Catecoles/química , Bovinos , Cinamatos/química , Ácidos Cumáricos/química , Cianoacrilatos/química , Dentina/química , Resinas Epoxi/química , Esterificación , Vidrio/química , Polimerizacion , Propionatos , Proteínas/química , Acero/química , Estrés MecánicoRESUMEN
OBJECTIVES: This study aimed to investigate deproteinizing effect of sodium-hypochlorite (NaOCl) and mild acidic hypochlorous-acid (HOCl) pretreatment on smear layer-covered dentine and to evaluate their effects on morphological characteristics of resin-dentine interface with self-etch adhesive. METHODS: Human coronal-dentine discs with standardized smear layer were pretreated with 6% NaOCl or 50ppm HOCl for 15s or 30s. Their deproteinizing effects at the treated smear layer-covered dentine surfaces were determined by the measurement of amide:phosphate ratio using ATR-FTIR analysis. In addition, using TEM, micromorphological alterations of hybridized complex and nanoleakage expression were evaluated at the interface of a self-etch adhesive (Clearfil SE Bond) to the pretreated dentine surface with or without subsequent application of a reducing agent (p-Toluenesulfinic acid salt; Accel(®)). RESULTS: Both pretreatments of NaOCl and HOCl significantly reduced the amide:phosphate ratio as compared with the no-pretreated group (p<0.05), coincident with the elimination of the hybridized smear layer on their bonded interfaces. Nanoleakage within the hybrid layer was found in the no-pretreated and NaOCl-pretreated groups, whereas the subsequent reducing agent application changed the reticular nanoleakage to spotted type. HOCl-pretreated groups showed less nanoleakage expression in a spotted pattern, regardless of reducing agent application. CONCLUSIONS: NaOCl and HOCl solutions could remove the organic component on the smear layer-covered dentine, which could eliminate the hybridized smear layer created by self-etch adhesive, leading to the reduction of nanoleakage expression within hybrid layer. CLINICAL SIGNIFICANCE: Smear layer deproteinizing could modify dentine surface, giving an appropriate substrate for bonding to self-etch adhesive system.
Asunto(s)
Resinas Compuestas/química , Recubrimiento Dental Adhesivo , Materiales Dentales/química , Dentina/efectos de los fármacos , Ácido Hipocloroso/uso terapéutico , Cementos de Resina/química , Irrigantes del Conducto Radicular/uso terapéutico , Capa de Barro Dentinario/tratamiento farmacológico , Hipoclorito de Sodio/uso terapéutico , Amidas/análisis , Colágeno/análisis , Filtración Dental/clasificación , Dentina/química , Humanos , Ensayo de Materiales , Microscopía Electrónica de Transmisión , Fosfatos/análisis , Distribución Aleatoria , Sustancias Reductoras/química , Capa de Barro Dentinario/patología , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Factores de Tiempo , Tolueno/análogos & derivados , Tolueno/químicaRESUMEN
This study aimed to evaluate effectiveness of Phosphoryl-Oligosaccharides of Calcium (POs-Ca) added to apple juice on enamel erosion. Five juices were prepared by adding 0%, 0.5%, 1%, 1.5% or 2% POs-Ca to commercial apple juice, and subjected to Visual Analogue Scale (VAS) taste evaluation and pH and calcium/inorganic-phosphates analyses. To evaluate erosion, polished bovine enamel blocks were immersed in each juice for 5 or 60 min (n=20). Enamel surface loss (SL) and roughness (Ra) were also analyzed. VAS indicated acceptable taste for juices containing up to 1% POs-Ca. POs-Ca addition resulted in increased pH (3.61-3.88), calcium (0.95-25.10 mM), and inorganic-phosphate (1.77-20.44 mM). After 5 min, 0% juice resulted in significant erosion (p<0.05). However even after 60 min, no significant increase was found in Ra and SL compared to water (control) for 1.5-2% juices (p>0.05). Addition of 1-1.5% POs-Ca could significantly reduce enamel erosion by apple juice maintaining an acceptable taste.
Asunto(s)
Bebidas , Fosfatos de Calcio/uso terapéutico , Frutas , Malus , Oligosacáridos/uso terapéutico , Erosión de los Dientes/prevención & control , Animales , Bebidas/análisis , Calcio/análisis , Bovinos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/patología , Concentración de Iones de Hidrógeno , Inmersión , Fosfatos/análisis , Espectrofotometría Atómica , Gusto/fisiología , Factores de Tiempo , Erosión de los Dientes/patología , Agua/químicaRESUMEN
The purpose of this study was to compare the dentin bond strength of three self-adhesive cements with smear layer pretreatments using a calcium-chelating agent (EDTA) and deproteinizing solution (NaOCl) and to evaluate their interfacial characteristics. Smear layer-covered dentin surfaces were pretreated with EDTA for 60 s, NaOCl for 5 and 15 s, or none. Three self-adhesive cements; Clearfil SA luting (Kuraray Medical), Rely X Unicem clicker (3M ESPE) and Breeze (Pentron) were applied to the dentin surfaces. After 24-h water storage, shear bond strengths to dentin were determined. In addition, nanoleakage evaluation at the interface was performed using FE-SEM and EDS. EDTA-pretreatment significantly improved the bond strength of BR (p<0.05) and NaOCl-pretreatment for 15 s significantly improved the bond strength of RX (p<0.05). On the other hand, for SA, both pretreatments significantly decreased bond strength to dentin (p<0.05). Nanoleakage formation was observed in various amounts at the cement-dentin interfaces.
Asunto(s)
Recubrimiento Dental Adhesivo , Preparación de la Cavidad Dental/métodos , Recubrimientos Dentinarios , Capa de Barro Dentinario , Filtración Dental , Análisis del Estrés Dental , Recubrimientos Dentinarios/química , Ácido Edético , Humanos , Cementos de Resina/química , Resistencia al Corte , Hipoclorito de SodioRESUMEN
OBJECTIVES: The aim of this in vitro study was to investigate the effect of incorporation of natural cross-linkers into the primer of a self-etching adhesive on resin-dentine bond strength. METHODS: Flat dentine surfaces were prepared from extracted human molar teeth and were applied with the following self-etching primers. The 0.5% hesperidin (HPN), 0.5% chlorhexidine (CHX) or 0.5% grape seed extract (GSE) was incorporated into Clearfil SE primer (Kuraray Medical, Inc.) to formulate three experimental primers. The original SE primer served as control. Following primer application, the teeth were bonded with Clearfil SE bond, restored with resin composite and stored in water for 24 h at 37 °C. The bonded specimens were sectioned into beams and subjected to micro tensile bond testing (µTBS). Failure analysis and morphological evaluation of the dentine surfaces were performed using a scanning electron microscope (SEM). Hardness (H) and elastic modulus (EM) were measured using nano-indentation technique to examine the mechanical properties of the bonded interfaces. RESULTS: One-way ANOVA showed significant differences in µTBS, H and EM among the tested and control groups (p < 0.001). Tukey post hoc test revealed that incorporation of HPN significantly increased µTBS, H and EM, when compared with the other groups (p < 0.006). The GSE-incorporated group significantly decreased µTBS, H and EM, when compared with the other groups (p < 0.006); while CHX-incorporated group did not show any statistical significant difference when compared with the control group. CONCLUSION: Incorporation of HPN into Clearfil SE primer had a positive influence on the immediate µTBS and mechanical properties of the bonded interface.
Asunto(s)
Reactivos de Enlaces Cruzados/química , Recubrimiento Dental Adhesivo , Dentina/ultraestructura , Cementos de Resina/química , Clorhexidina/química , Resinas Compuestas/química , Módulo de Elasticidad , Extracto de Semillas de Uva/química , Dureza , Hesperidina/química , Humanos , Ensayo de Materiales , Metacrilatos/química , Microscopía Electrónica de Rastreo , Compuestos Organofosforados/química , Capa de Barro Dentinario , Estrés Mecánico , Propiedades de Superficie , Temperatura , Resistencia a la Tracción , Factores de Tiempo , Agua/químicaRESUMEN
The aims of this study were to investigate the effects of hesperidin, a citrus flavonoid, on human root dentin demineralization and collagen preservation, and compare it with chlorhexidine and grape seed extract. Specimens were assigned to different treatment groups: hesperidin, chlorhexidine and grape seed extract. Specimens were subjected to pH cycling by demineralization for 14 h, incubation in testing solutions for 2 h and remineralization in presence of bacterial-derived collagenase for 8 h, for 8 days. Calcium release was measured by means of an atomic absorption spectrophotometer, and degraded collagen matrix was investigated by hydroxyproline assay. Specimens were assessed longitudinally with transverse micro-radiography to investigate lesion depth and mineral loss. In hesperidin and grape seed extract groups, demineralization was reduced when the collagen matrix was preserved. The hesperidin group showed the lowest value in lesion depth and mineral loss, indicating that hesperidin inhibited demineralization and probably enhanced remineralization even under fluoride-free conditions.
Asunto(s)
Dentina/efectos de los fármacos , Hesperidina/farmacología , Desmineralización Dental/prevención & control , Remineralización Dental/métodos , Raíz del Diente/efectos de los fármacos , Análisis de Varianza , Antiinfecciosos Locales/farmacología , Calcio/análisis , Clorhexidina/farmacología , Colágeno/efectos de los fármacos , Dentina/química , Hesperidina/uso terapéutico , Humanos , Extractos Vegetales/farmacología , Semillas , Estadísticas no Paramétricas , VitisRESUMEN
This study evaluated the influence of different light sources on the efficiency of an office bleaching agent containing visible-light activating titanium dioxide photocatalyst (VL-TiO(2)) using an artificial discoloration tooth model. Extracted bovine teeth were stained by black tea. The CIE L*a*b* values were measured before and after nine consecutive treatments by the VL-TiO(2)-containing bleaching agent (TiON in Office, GC, Tokyo, Japan). A halogen light unit (CB; CoBee, GC) or an LED unit (G-light, GC) with two modes (blue and violet: GL-BV, blue: GL-B) were used to activate the bleaching agent in three groups (n=8). Brightness (ΔL) and color difference (ΔE) increased as bleaching repeated in all groups. Two-way ANOVA showed that both number of treatments and light sources significantly affected ΔE (p<0.05). GL-BV showed better bleaching effect than GL-B. In measurement of irradiation spectra, CB showed a wide spectrum (380-530 nm), GL-B had a sharp peak at 470 nm and GL-BV showed an additional peak at 405 nm. It was concluded that the light source influenced the efficiency of the tooth bleaching with VL-TiO(2).
Asunto(s)
Luces de Curación Dental/clasificación , Titanio/uso terapéutico , Blanqueadores Dentales/uso terapéutico , Blanqueamiento de Dientes/instrumentación , Animales , Peróxido de Carbamida , Bovinos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/patología , Dentina/efectos de los fármacos , Dentina/patología , Peróxido de Hidrógeno/uso terapéutico , Oxidantes Fotoquímicos/uso terapéutico , Oxidación-Reducción , Peróxidos/uso terapéutico , Procesos Fotoquímicos , Fármacos Fotosensibilizantes/uso terapéutico , Té , Decoloración de Dientes/tratamiento farmacológico , Decoloración de Dientes/patología , Resultado del Tratamiento , Urea/análogos & derivados , Urea/uso terapéuticoRESUMEN
OBJECTIVES: 45S5 bioglass mixed with 50% phosphoric acid has been suggested to treat dentine hypersensitivity and incipient enamel caries. This study is going to evaluate the biocompatibility of using the aforementioned technique with the rat pulpal cells. METHODS: The relative cytotoxicity of 45S5 bioglass on rat dental pulp cells was compared to the cytotoxicity of a temporary filling material (Caviton; GC, Japan), Type 1 glass ionomer cement (Fuji I; GC, Tokyo, Japan) and commercial desensitising agent (SuperSeal; Phoenix Dental, Fenton, MI, USA) using a transwell insert model. Cell viability was measured by means of a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The number of viable cell counts were compared using one way ANOVA (p<0.05). The morphological alterations of the pulp cells were observed directly by phase contrast microscope. RESULTS: The results of this study indicated that cell viability recorded by the 45S5 bioglass paste group did not differ significantly from those of the Caviton, glass ionomer or superseal, moreover pulpal cells microscopic analysis revealed that 45S5 bioglass elicited minimal toxic effect. CONCLUSIONS: 45S5 bioglass paste can serve as a biocompatible material that can potentially be used safely on dentine.
Asunto(s)
Cerámica/toxicidad , Pulpa Dental/efectos de los fármacos , Desensibilizantes Dentinarios/toxicidad , Animales , Materiales Biocompatibles/toxicidad , Sulfato de Calcio/química , Recuento de Células , Línea Celular , Supervivencia Celular/efectos de los fármacos , Colorantes , Cementos Dentales/química , Pulpa Dental/citología , Vidrio/química , Cementos de Ionómero Vítreo/química , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Ácido Oxálico/química , Ácidos Fosfóricos/toxicidad , Ratas , Materiales de Obturación del Conducto Radicular/química , Sales de Tetrazolio , Tiazoles , Compuestos de Vinilo/química , Óxido de Zinc/químicaRESUMEN
This study aimed to evaluate enamel surface roughness (Ra) and pH before and after erosion by soft drinks. Enamel was exposed to a soft drink (cola, orange juice or green tea) for 1, 5 or 60 min; Ra was measured using contact-stylus surface profilometry (SSP) and non-contact focus variation 3D microscope (FVM). Surface pH was measured using a micro pH sensor. Data were analyzed at significance level of alpha=0.05. There was a significant correlation in Ra between SSP and FVM. FVM images showed no changes in the surface morphology after various periods of exposure to green tea. Unlike cola and orange juice, exposure to green tea did not significantly affect Ra or pH. A significant correlation was observed between surface pH and Ra change after exposure to the drinks. Optical surface analysis and micro pH sensor may be useful tools for non-damaging, quantitative assessment of soft drinks erosion on enamel.
Asunto(s)
Bebidas Gaseosas/efectos adversos , Esmalte Dental/patología , Erosión de los Dientes/patología , Animales , Bebidas/efectos adversos , Bovinos , Citrus sinensis , Esmalte Dental/efectos de los fármacos , Frutas , Concentración de Iones de Hidrógeno , Imagenología Tridimensional/métodos , Micromanipulación/instrumentación , Microscopía/métodos , Propiedades de Superficie , Té , Factores de Tiempo , Erosión de los Dientes/etiologíaRESUMEN
The objective of this study was to evaluate, using methylene blue (MB), the effects of various light sources on the bleaching action of hydrogen peroxide (H(2)O(2)) with two titanium dioxide (TiO(2)) photocatalysts - an ultraviolet light-activated TiO(2) photocatalyst (UVTiO(2)) versus a visible light-activated TiO(2) photocatalyst (VL-TiO(2)). Five experimental solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), H(2)O(2), VL-TiO(2), UV-TiO(2)) were prepared by mixing varying concentrations of H(2)O(2 )and/or TiO(2 )photocatalyst with MB solution. For H(2)O(2)-containing solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), and H(2)O(2)), the concentration of H(2)O(2) was adjusted to 3.5%. For the four different light sources, low- and high-intensity halogen lamps and blue LED LCUs were used. All the experimental solutions were irradiated by each of the light sources for 7 minutes, and the absorbance at 660 nm was measured every 30 seconds to determine the concentration of MB as an indicator of the bleaching effect. On the interaction between the effects of light source and bleaching treatment, the high-intensity halogen with VL-TiO(2)+H(2)O(2) caused the most significant reduction in MB concentration. On the effect of light sources, the halogen lamps resulted in a greater bleaching effect than the blue LED LCUs.
Asunto(s)
Fármacos Fotosensibilizantes/uso terapéutico , Fototerapia , Titanio/uso terapéutico , Blanqueamiento de Dientes/métodos , Terapia Ultravioleta , Absorción , Colorantes , Luces de Curación Dental/clasificación , Humanos , Peróxido de Hidrógeno/efectos de la radiación , Peróxido de Hidrógeno/uso terapéutico , Ensayo de Materiales , Azul de Metileno , Oxidantes/efectos de la radiación , Oxidantes/uso terapéutico , Espectrofotometría , Factores de TiempoRESUMEN
The present study examined the effects on dentin ablation efficiency arising from various pulse durations of Er: YAG laser at a fixed energy fluence. Ten flat human dentin disks were prepared and exposed to an Er: YAG laser at 1 pps for three seconds at pulse durations of 100-500 microsec with 150 mJ/pulse (40.0 J/cm x pulse). The depth and diameter of the ablated dentin were measured and the ablation volume was estimated. Irradiated surfaces and cross-sections were observed using a SEM. Depth of the removed dentin increased and the diameter of the spot decreased without a change in the estimated volume at increased pulse durations. SEM observation of the irradiated surfaces revealed that there were no morphological differences when the pulse duration was changed. When the specimens were cross-sectioned, the ablated dentin had a dome shape and there was a dark layer under the irradiated surface.
Asunto(s)
Dentina/cirugía , Terapia por Láser/métodos , Láseres de Estado Sólido/uso terapéutico , Color , Dentina/ultraestructura , Humanos , Microscopía Confocal , Microscopía Electrónica de Rastreo , Capa de Barro Dentinario , Factores de TiempoRESUMEN
This study tested if dentin adhesion is affected by Er:YAG laser. Ninety dentin disks were divided in groups (n = 10): G1, control; G2, Er:YAG laser 150 mJ, 90 degrees contact, 38.8 J/cm(2); G3, Er:YAG laser 70 mJ, 90 degrees contact, 18.1 J/cm(2); G4, Er:YAG laser 150 mJ, 90 degrees non-contact, 1.44 J/cm(2); G5, Er:YAG laser 70 mJ, 90 degrees non-contact, 0.67 J/cm(2); G6, Er:YAG laser 150 mJ, 45 degrees contact, 37.5 J/cm(2); G7, Er:YAG laser 70 mJ, 45 degrees contact, 17.5 J/cm(2); G8, Er:YAG laser 150 mJ, 45 degrees non-contact, 1.55 J/cm(2); and G9, Er:YAG laser 70 mJ, 45 degrees non-contact, 0.72 J/cm(2). Bonding procedures were carried out and the micro-shear-bond strength (MSBS) test was performed. The adhesive surfaces were analyzed under SEM. Two-way ANOVA and multiple comparison tests revealed that MSBS was significantly influenced by the laser irradiation (p < 0.05). Mean values (MPa) of the MSBS test were: G1 (44.97 +/- 6.36), G2 (23.83 +/- 2.46), G3 (30.26 +/- 2.57), G4 (35.29 +/- 3.74), G5 (41.90 +/- 4.95), G6 (27.48 +/- 2.11), G7 (34.61 +/- 2.91), G8 (37.16 +/- 1.96), and G9 (41.74 +/- 1.60). It was concluded that the Er:YAG laser can constitute an alternative tool for dentin treatment before bonding procedures.
Asunto(s)
Adhesividad/efectos de la radiación , Aluminio , Resinas Compuestas/efectos de la radiación , Recubrimiento Dental Adhesivo/instrumentación , Dentina/fisiología , Rayos Láser , Terapia por Luz de Baja Intensidad/instrumentación , Resistencia al Corte , Itrio , Colágeno/efectos de la radiación , Recubrimiento Dental Adhesivo/métodos , Relación Dosis-Respuesta en la Radiación , Erbio , Humanos , Terapia por Luz de Baja Intensidad/métodos , MetacrilatosRESUMEN
This study evaluated the physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination. The artificially demineralized dentin was produced on 84 monkey teeth using a decalcifying solution. Half the samples were left open to the oral cavity for one week, then, all cavities were restored with two glass-ionomer cements: Fuji IX or Fuji II LC improved (n = 7). The nanohardness of the artificially demineralized dentin at 3, 90 and 360 days was measured using a nanoindentation tester (ENT-1100, Elionix) and compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Each mineral (Ca, Mg, P, F) within the demineralized dentin was also analyzed using Electron Probe Microanalysis. For the samples, the mean nanohardness of the three-day samples was significantly lower than the 360-day samples (p < 0.05). Although there was no significant difference in the mean nanohardness within all the bacterially-contaminated groups through the experimental periods (p > 0.05), the mean nanohardness of the bacterial-contaminated samples were significantly lower than the non-bacteria-contaminated samples (p < 0.05). From the EPMA results, fluoride release from both cements to the bottom of the artificially demineralized dentin was detected within three days. Although Ca density was sparse within this demineralized dentin lesion, for the Fuji IX sample, a high Mg density within this lesion was detected at 360 days.