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1.
Acta Odontol Latinoam ; 33(1): 27-32, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32621596

RESUMEN

The aim of this study was to assess the influence of different pre-treatment approaches on glass ionomer cement (GIC) bond strength (BS) to dentine. Sixty bovine incisors were allocated into six groups according to substrate - sound or caries-affected dentine; and substrate pre-treatment approach - no conditioning (control), polyacrylic acid for 10 s and phosphoric acid for 7 s. Teeth in the caries-affected dentine group were previously submitted to cariogenic pH-cycling challenge. After dentine pre-treatment, according to experimental groups, polyethylene tubes were placed on flat dentine surfaces and filled with GIC. Teeth were stored in distilled water for 24 h at 37 °C and then submitted to microshear test (0.5 mm/min). Failure pattern analysis was performed under stereomicroscope (400x). Data were analysed using two-way ANOVA and Tukey's test (α=5%). Statistically significant differences were found for the pre-treatment approach, regardless of substrate (p<0.001). The polyacrylic acid group and control group had similar BS values, and were both better than the phosphoric acid group. In general, GIC had better bonding performance in sound dentine than in caries-affected dentine. In conclusion, dentine pre-treatment with polyacrylic acid did not improve the performance of GIC restoration on clinically relevant substrates.


Asunto(s)
Resinas Acrílicas/farmacología , Recubrimiento Dental Adhesivo/métodos , Dentina/efectos de los fármacos , Cementos de Ionómero Vitreo/química , Animales , Bovinos , Filtración Dental/prevención & control , Dentina/diagnóstico por imagen , Dentina/patología , Ensayo de Materiales
2.
Braz Oral Res ; 34: e045, 2020 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-32401935

RESUMEN

This in vitro study aimed to evaluate the effect of a silane-containing universal adhesive used with or without a silane agent on the repair bond strength between aged and new composites. Forty nanohybrid composite resin blocks were stored in distilled water for 14 d and thermo-cycled. Sandpaper ground, etched, and rinsed speciments were randomly assigned into four experimental groups: silane + two-step etch-and-rinse adhesive system, two-step etch-and-rinse adhesive system, silane + silane-containing universal adhesive system, and silane-containing universal adhesive system. Blocks were repaired using the same composite. After 24 h of water storage, the blocks were sectioned and bonded sticks were submitted to microtensile testing. Ten unaged, non-repaired composite blocks were used as a reference group to evaluate the cohesive strength of the composite. Two-way ANOVA and Tukey's tests were used to analyze average µTBS. One-way ANOVA and Dunnet post-hoc tests were used to compare the cohesive strength values and bond strength obtained in the repaired groups (α = 0.05). The µTBS values were higher for the silane-containing universal adhesive compared to the two-step etch-and-rinse adhesive system (p = 0.002). Silane application improved the repair bond strength (p = 0.03). The repair bond strength ranged from 39.3 to 65.8% of the cohesive strength of the reference group. Using universal silane-containing adhesive improved the repair bond strength of composite resin compared to two-step etch-and-rinse adhesive. However, it still required prior application of a silane agent for best direct composite resin repair outcomes.


Asunto(s)
Resinas Compuestas/química , Cementos Dentales/química , Cementos de Resina/química , Silanos/química , Análisis de Varianza , Recubrimiento Dental Adhesivo/métodos , Ensayo de Materiales , Valores de Referencia , Reproducibilidad de los Resultados , Propiedades de Superficie , Resistencia a la Tracción , Factores de Tiempo
3.
J Appl Oral Sci ; 28: e20190499, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32348441

RESUMEN

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.


Asunto(s)
Cementos Dentales/química , Dentina/química , Inhibidores de la Metaloproteinasa de la Matriz/química , Metacrilatos/química , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Análisis de Varianza , Recubrimiento Dental Adhesivo/métodos , Grabado Dental/métodos , Filtración Dental , Dentina/efectos de los fármacos , Humanos , Ensayo de Materiales , Valores de Referencia , Reproducibilidad de los Resultados , Espectroscopía Infrarroja por Transformada de Fourier , Estadísticas no Paramétricas , Propiedades de Superficie , Resistencia a la Tracción , Factores de Tiempo
4.
Braz Oral Res ; 34: e018, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32187304

RESUMEN

The objective of this study was to evaluate the influence of hydrofluoric acid (HF) concentration, etching time, and application of phosphoric acid (PA) followed by neutralization with sodium bicarbonate on the bond strength between a feldspar ceramic and resin cement. Thus, 80 blocks (10 x 12 x 2 mm) of glass ceramic (VM - Vita Mark II - Vita Zahnfabrik) were made and randomly assigned to eight groups (n = 10) according to the factors: HF concentration (5 and 10%), etching time (60 and 120 s), and use of phosphoric acid (PA) (with and without). According to the experimental group, 37% PA (Condac, FGM) was applied after HF etching for 60s. Afterwards, samples were immersed in sodium bicarbonate for 1 min then in an ultrasonic bath in distilled water (5 min) for cleaning. After surface bonding treatment, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block. The samples were then stored in water (37ºC) for 90 days and submitted to the shear bond test (50 KgF, 1 mm/min). Failure analysis was performed by stereomicroscope and scanning electron microscopy. Data (MPa) were analyzed with 3-way ANOVA and Tukey's test. Only the factor "HF concentration" was significant (p = 0.02). Most failures were of cohesive in ceramic (40%) and mixed types (42.5%). The 10% HF resulted in higher shear bond strength value than the 5% HF. Surface cleaning with phosphoric acid followed by sodium bicarbonate and HF time (60 or 120 seconds) did not influence the resin bond strength to feldspar ceramic.


Asunto(s)
Silicatos de Aluminio/química , Recubrimiento Dental Adhesivo/métodos , Ácido Fluorhídrico/química , Ácidos Fosfóricos/química , Compuestos de Potasio/química , Análisis de Varianza , Porcelana Dental/química , Ensayo de Materiales , Metacrilatos/química , Microscopía Electrónica de Rastreo , Valores de Referencia , Reproducibilidad de los Resultados , Cementos de Resina/química , Resistencia al Corte/efectos de los fármacos , Silanos/química , Propiedades de Superficie , Factores de Tiempo
5.
Braz Oral Res ; 34: e001, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32022221

RESUMEN

This study analyzed the effect of prior application of copaiba oil (CO) emulsions as a dentin cleaning substance on microleakage and microtensile adhesive strength. Twenty-five premolars and sixty-four molars were used for microleakage and microtensile assays. For the microleakage assays, specimens with standard class V cavities were divided (n = 5), according to the tested CO emulsions: CO10%X, CO10%Y, and CO10%Z, as well as chlorhexidine 2% (CHX) and distilled water (DW), as positive and negative controls, respectively. Restorations were performed using the Adper Single Bond® and/or Clearfil SE Bond® systems. Cervical, occlusal, distal and mesial sections were assessed for tracer penetration degree at the composite/tooth interface. For the microtensile assay, healthy molars were divided into sixteen groups, in which artificial caries were induced in half of the groups. Dentin surfaces were treated with CO10%X and CO10%Y, CHX and DW. Microtensile bond strength was measured by fixing each sample to the plate of a universal testing machine operated at a speed of 0.5 mm/minute until failure. Dentin treated with CO10%X showed a lower infiltration rate than dentin treated with the other CO emulsions, CHX2% and DW. According to the microtensile assay, both healthy and affected dentin treated with CO10%X and Adper Single Bond® adhesive system presented higher adhesive strength. CO emulsion, used as a dentin biomodifier, interfered positively in microleakage and improved adhesive strength after acid etching in the Adper Single Bond® adhesive system, or before applying the Clearfil SE Bond® self-etching system.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Dentina/efectos de los fármacos , Fabaceae/química , Aceites Vegetales/química , Análisis de Varianza , Clorhexidina/química , Resinas Compuestas/química , Cementos Dentales/química , Filtración Dental , Dentina/química , Emulsiones/química , Humanos , Ensayo de Materiales , Reproducibilidad de los Resultados , Cementos de Resina/química , Estadísticas no Paramétricas , Propiedades de Superficie , Resistencia a la Tracción
6.
Braz Oral Res ; 34: e004, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32022223

RESUMEN

The aim of this study was to analyze the structural, morphological and mechanical properties of two different lithium disilicate glass-reinforced ceramics for CAD-CAM systems (IPS e.max CAD and Rosetta SM). Five methodologies were used for both ceramics: microstructure (n = 2) was analyzed using x-ray diffraction (XRD); morphological properties (n = 2) were analyzed by scanning electron microscopy (SEM), with and without hydrofluoric etching; porosity (n = 3) was assessed using 3D micro-computed tomography (micro-CT); flexural strength was measured (n =1 0) using the three-point bending test; and bond strength was determined with self-adhesive resin cement (n = 10), using a microshear bond test. After performing all the tests, the data were analyzed using t-Student test and two-way ANOVA. All the tests used a significance level of α = 0.05. High peak positions corresponding to standard lithium metasilicate and lithium disilicate with similar intensities were observed for both ceramics in the XRD analysis. Morphological analysis showed that the crystalline structure of the two ceramics studied showed no statistical difference after acid etching. Additionally, no significant differences were recorded in the number or size of the pores for the ceramics evaluated. Moreover, no differences in flexural strength were found for the ceramic materials tested, or in the bond strength to ceramic substrates for the resin cements. Based on the study results, no significant differences were found between the two CAD-CAM lithium disilicate glass-reinforced ceramics tested, since they presented similar crystalline structures with comparable intensities, and similar total porosity, flexural strength and bond strength.


Asunto(s)
Cerámica/química , Diseño Asistido por Computadora , Porcelana Dental/química , Vidrio/química , Análisis de Varianza , Recubrimiento Dental Adhesivo/métodos , Resistencia Flexional , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Porosidad , Valores de Referencia , Reproducibilidad de los Resultados , Cementos de Resina/química , Resistencia al Corte , Propiedades de Superficie , Difracción de Rayos X
7.
J Appl Oral Sci ; 28: e20190371, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32049135

RESUMEN

OBJECTIVE: This study aims to evaluate the influence of different air-abrasion pressures and subsequent heat treatment on the flexural strength, surface roughness, and crystallographic phases of highly translucent partially stabilized zirconia (Y-PSZ), and on the tensile bond strength of resin cement to Y-PSZ. METHODOLOGY: Fully sintered zirconia specimens were ground with SiC paper (control) and/or air-abraded with 50 µm particles of alumina at 0.1, 0.15, 0.2, or 0.3 MPa or left as-sintered. After air-abrasion at 0.2 MPa (0.2AB), additional specimens were then heated to 1500°C, and held for one hour at this temperature (0.2AB+HT1h). Flexural strength and surface roughness were evaluated. Crystalline phase identification was also carried out using X-ray diffraction. Bonded zirconia specimens with self-adhesive resin cement were stored in distilled water at 37°C for 24 h, either with or without aging (thermal cycling 4-60°C/20000). Results were analyzed statistically by ANOVA and Tukey-Kramer tests. RESULTS: The flexural strength decreased with the increase in air-abrasion pressure, while in contrast, the surface roughness increased. The lowest flexural strength and the highest roughness value were found for the 0.2AB and 0.3AB groups, respectively. All groups contained cubic-, tetragonal ( t )-, and rhombohedral ( r )-ZrO2 phases with the exception of the as-sintered group. Upon increasing the air-abrasion pressure, the relative amount of the r -ZrO2 phase increased, with a significant amount of r -ZrO2 phase being detected for the 0.2AB and 0.3AB groups. The 0.2AB+HT1h group exhibited a similar flexural strength and t -ZrO2 phase content as the as-sintered group. However, the 0.2AB group showed a significantly higher tensile bond strength (p<0.05) than the 0.2AB+HT1h group before and after aging. CONCLUSION: Micromechanical retention by alumina air-abrasion at 0.2 MPa, in combination with chemical bonding of a resin to highly translucent Y-PSZ using a MDP-containing resin cement may enable durable bonding.


Asunto(s)
Abrasión Dental por Aire/métodos , Óxido de Aluminio/química , Recubrimiento Dental Adhesivo/métodos , Cementos de Resina/química , Circonio/química , Análisis de Varianza , Resistencia Flexional , Calor , Ensayo de Materiales , Microscopía Confocal/métodos , Valores de Referencia , Reproducibilidad de los Resultados , Propiedades de Superficie , Resistencia a la Tracción , Difracción de Rayos X/métodos
8.
Niger J Clin Pract ; 23(1): 110-115, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31929216

RESUMEN

Objective: The aim of this study was to compare to effect of phototherapy and surface flattening after immediately bleaching on the shear bond strength to bleached enamel. Methods: Ninety-six human upper incisors were divided into 4 groups (n = 24). Group NB: no bleached, group P: phototherapy with YSGG laser, group F: 0.5 mm surface flattening, group PF: 0.5 mm surface flattening and phototherapy with Er;Cr:YSGG laser. Then, each group was assigned to 2 subgroups according to adhesive mode (n = 12) as; subgroup S (self-etching mode), subgroup T (total-etching mode) which are universal adhesives. All surface conditionings and restorations were performed with composite resin materials immediately after bleaching. Shear bond strength test was performed by using universal testing machine. The surfaces were also evaluated with SEM. The data were statistically analyzed with one-way ANOVA post-hoc Tukey tests. Results: The lowest SBS values were achieved in FS (13.72 ± 2.29) while the highest ones in PT (28.01 ± 6.81). However, the differences were not significant (P > 0.05). All surface conditioning methods provided SBS values similar to the control (P > 0.05). All subgroups of self-etching mode were significantly lower than their total-etching counterparts (P < 0.05). Conclusions: The present study showed that surface removal and phototherapy have a potential clinical application for eliminate to undesirable effect of bleaching treatment. Surface conditioning with either flattening and/or phototherapy may provide clinicians to restore bleached teeth at the same visit with bleaching and reduce chair-time.


Asunto(s)
Adhesivos/farmacología , Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/efectos de los fármacos , Grabado Dental/métodos , Láseres de Estado Sólido/uso terapéutico , Fototerapia , Resistencia al Corte , Blanqueamiento de Dientes , Grabado Ácido Dental/métodos , Resinas Compuestas/química , Materiales Dentales/química , Humanos , Ensayo de Materiales , Blanqueamiento de Dientes/métodos
9.
Lasers Med Sci ; 35(1): 173-179, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31273570

RESUMEN

The purposes of the study were to evaluate the bond strength of bioceramic TotalFill root repair material (RRM) in retrograde cavities prepared using Er:YAG and Er,Cr:YSGG laser and steel bur, and to analyze failure modes. The root canals of 30 single-rooted teeth were endodontically treated, their root-ends were resected using a diamond bur, and the teeth were randomly divided into three groups (N = 10) according to the retrograde cavity preparation technique: (1) Er:YAG laser, (2) Er,Cr:YSGG laser, and (3) steel bur. All retrograde cavities were filled with the TotalFill RRM which was prepared according to the manufacturers' instructions. Push-out test was performed using universal testing machine, and failure mode was analyzed using a scanning electron microscope. The data were analyzed using one-way ANOVA, post hoc analysis with Bonferroni correction, and Fisher-Freeman-Halton exact test (p < 0.05). In the Er:YAG-, Er,Cr:YSGG-, and steel bur-prepared cavities, mean bond strengths (MPa) were 12.76, 8.44, and 6.01, respectively. The bond strength of the TotalFill RRM to dentin was significantly higher in the Er:YAG laser compared with the steel bur-prepared cavities (p = 0.004). The bond strength was not significantly different between the Er:YAG and Er,Cr:YSGG cavities (p = 0.074) and between the Er,Cr:YSGG and bur cavities (p = 0.648). In the cavities prepared by the Er,Cr:YSGG laser and bur, the failure mode of the TotalFill RRM was predominantly mixed, then adhesive and cohesive. In the Er:YAG laser-prepared cavities, the most common failure mode was adhesive, followed by mixed type and no cohesive failure. The bond strength of the TotalFill RRM to dentin was highest in the group of retrograde cavities prepared by the Er:YAG laser.


Asunto(s)
Cerámica/química , Recubrimiento Dental Adhesivo/métodos , Dentina/química , Dentina/efectos de la radiación , Láseres de Estado Sólido , Raíz del Diente/química , Raíz del Diente/efectos de la radiación , Recubrimientos Dentinarios/química , Humanos
10.
J Appl Oral Sci ; 28: e20190005, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31800870

RESUMEN

other: Chitosan is a natural, biocompatible chelating substance with potential for dental use. This study compared the effects of final canal irrigation with chitosan and EDTA on dentin microhardness, sealer dentin tubules penetration capacity, and push-out strength. METHODOLOGY: Fifty canine roots were distributed according to the final irrigation protocol (n=10): G1- 15% EDTA with conventional irrigation; G2- 15% EDTA with Endovac; G3- 0.2% chitosan with conventional irrigation; G4- 0.2% chitosan with Endovac; and G5- without irrigation. Specimens were obturated (AH Plus) and sectioned in 3 slices per root third. The first slice was used for microhardness and sealer penetration assessments under a laser confocal microscope. The second was utilized in a push-out strength test. The third slice was discarded. Data were analyzed using 2-way ANOVA and Tukey's post hoc test (α<0.05). Failure mode was determined at x40 magnification. RESULTS: Microhardness reduction was more significant in groups G2 and G4 (p<0.05). Sealer penetration through dentin was significantly greater in group G2 (p<0.05). There was no significant difference between groups G1, G3, and G4 (p>0.05). In general, all experimental groups presented similar bond resistance (p>0.05) that significantly differed from the control (p<0.001). Mixed type failures were predominant. CONCLUSIONS: In general, 0.2% chitosan and 15% EDTA solutions act in a similar manner with regard to the variables studied. The use of Endovac potentiates the effect of these solutions.


Asunto(s)
Quelantes/química , Quitosano/química , Recubrimiento Dental Adhesivo/métodos , Dentina/efectos de los fármacos , Ácido Edético/química , Irrigantes del Conducto Radicular/química , Análisis de Varianza , Resinas Epoxi/química , Pruebas de Dureza , Humanos , Ensayo de Materiales , Microscopía Confocal , Persona de Mediana Edad , Valores de Referencia , Reproducibilidad de los Resultados , Materiales de Obturación del Conducto Radicular/química , Resistencia al Corte , Propiedades de Superficie/efectos de los fármacos
11.
Biomed Res Int ; 2019: 2041348, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31828093

RESUMEN

The introduction of resin-based cements and an adhesive-bonding system in daily dental practice has given the opportunity to increase the retention of previously conventional cemented restorations and the optimal results in esthetic. This experimental study employed the 3D Digital Image Correlation Method (3D-DIC) for detecting shrinkage strain in four dual cured composite cements. The aim was to visualize measure, analyze, and compare strain fields in four resin-based cements using the 3D-DIC method. A total of 72 samples were divided into 4 groups considering variations in sample types, diameter, and thickness. Four types of composite cements: RelyX U200 (3 M ESPE, St. Paul, MN, USA), MaxCem Elite (Kerr, Orange, CA, USA), Multilink Automix (Ivoclar Vivadent, Schaan, Liechtenstein), and SeT PP (SDI, Australia) were used. Each type had diameters of 3 mm, 4 mm, and 5 mm, respectively, combined with two different values of thickness: 1 mm and 2 mm. Thickness had an important role on strain detected in all tested materials showing higher strain in samples with 2 mm thickness compared to 1 mm samples. Shrinkage strain values were the highest in Set PP samples indicated the possibility of undesirable de-bonding.


Asunto(s)
Cementos Dentales/química , Resinas Acrílicas/química , Australia , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Análisis del Estrés Dental/métodos , Humanos , Ensayo de Materiales/métodos , Poliuretanos/química , Cementos de Resina/química , Resistencia a la Tracción
12.
Braz Oral Res ; 33: e111, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31800863

RESUMEN

The aim of the present study was to evaluate the microtensile bond strength and the microleakage of a bulk-fill composite resin compared with a conventional incremental composite resin, in permanent molars and under cariogenic challenge using a Streptococcus mutans model. Permanent human third molars (n = 60) with an occlusal cavity of 5×3×2 mm were randomly allocated into four subgroups of restorative treatments: conventional composite resin with (n = 15) and without (n = 15) cariogenic challenge (Z350-E and Z350-C experimental and control groups, respectively), and bulk-fill composite resin with (n = 15) and without (n = 15) cariogenic challenge (Bulk Fill-E and Bulk Fill-C, respectively). Ten specimens from each subgroup were submitted to microtensile strength, and 5, to microleakage. The cariogenic challenge was conducted using the Streptococcus mutans strain (ATCC) for 7 days. The stickers obtained (1 × 1 × 2 mm) were submitted to a microtensile strength test, followed by classification of the fracture mode. Microleakage was performed using a scoring system. The data were analyzed by Kruskal-Wallis and Mann-Whitney tests (p < 0.05). Filtek Z350 XT resin presented higher microtensile bond strength than Bulk Fill resin without (19.02 ± 4.90 and 8.76 ± 3.94MPa, respectively; p < 0.001) and with cariogenic challenge (22.69 ± 7.86 and 13.31 ± 3.38MPa, respectively; p < 0.02). Z350-C and Bulk Fill-C resins presented a higher prevalence of mixed fractures (23 and 14%, respectively) in the specimens submitted to cariogenic challenge than those of the control groups, whereas microleakage was similar (p = 0.85). The conventional composite resin had higher microtensile bond strength than the bulk-fill resin, but both resin types had similar adhesion quality and microfiltration scores.


Asunto(s)
Biopelículas/efectos de los fármacos , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Streptococcus mutans/efectos de los fármacos , Adhesividad , Caries Dental , Esmalte Dental/efectos de los fármacos , Filtración Dental , Restauración Dental Permanente/métodos , Humanos , Ensayo de Materiales , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Propiedades de Superficie , Resistencia a la Tracción/efectos de los fármacos , Factores de Tiempo
13.
Int J Mol Sci ; 20(23)2019 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-31801235

RESUMEN

Fiber-reinforced composite (FRC) retainers are an aesthetic alternative to conventional Stainless Steel splints. They are generally used with a full bonded technique, but some studies demonstrated that they could be managed with a spot bonding technique to significantly decrease their rigidity. In order to propose this FRC spot bonding technique for clinical use, the aim of this study was to evaluate mechanical properties and surface wear of fibers left uncovered. Tests were made by simulating tooth brushing, comparing FRC spot bonding technique splints with stainless steel and FRC traditional technique splints. Specimens were tested both at 0.1 mm of deflection and at maximum load, showing higher values of rigidity for the FRC full bonded technique. After tooth brushing, no significant reduction in values at 0.1 mm deflection was reported, while we found a similar reduction in these values for the Stainless Steel and FRC spot bonding technique at maximum load, and no significant variation for the FRC full bonded technique. SEM images after tooth brushing showed wear for FRC fibers left uncovered, while no relevant wear signs in metal and conventional FRC fibers were noticed. Results showed that FRC spot bonding technique has advantages in mechanical properties when compared to the FRC traditional full bonding technique, also after tooth brushing. However, the surface wear after tooth brushing in the FRC spot bonding technique is considerable and other tests must be performed before promoting this technique for routine clinical use.


Asunto(s)
Resinas Compuestas/análisis , Materiales Dentales/análisis , Fibras Minerales/análisis , Acero Inoxidable/análisis , Resinas Compuestas/síntesis química , Recubrimiento Dental Adhesivo/métodos , Materiales Dentales/química , Humanos , Ensayo de Materiales/métodos , Estrés Mecánico , Propiedades de Superficie
14.
Niger J Clin Pract ; 22(12): 1675-1679, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31793473

RESUMEN

Aims: The aim of this in vitro investigation was to evaluate the efficiency of self-adhering flowable resin composite (Vertise Flow, Kerr, Orange, CA, USA) and different surface treatments in the repair microtensile bond strength (µTBS) of aged nanofill resin composites using a universal adhesive. Materials and Methods: Aged substrates (×5000 thermocycling) were prepared using a nanofill (Filtek Ultimate; 3M ESPE) resin composite and randomly assigned to different surface treatments: (1) no treatment (control), (2) acid etching with 37% phosphoric acid, (3) Al2O3sandblasting, and (4) sandblasting with CoJet (3M ESPE). After surface treatment, specimens were further divided into two groups: no universal adhesive application and universal adhesive application. Vertise Flow was added to the substrates at 2-mm layer increments to a height of 5 mm and light cured. Restored specimens were sectioned to obtain 1.0-mm2 beams for µTBS testing. Data were analyzed with two-way analysis of variance and Tukey's honest significant difference tests (P < 0.05). Results: The lowest µTBS values were recorded in the control and acid etching groups with no universal adhesive application (P < 0.05). Universal adhesive application significantly increased the repair µTBS values of all surface treatments (P < 0.05), except CoJet treatment. There were no significant differences between Al2O3sandblasting, CoJet application, and acid etching groups with the universal adhesive application (P > 0.05). Conclusion: Vertise Flow can be used effectively in the repair of old nanofill resin composites. The usage of universal adhesive with prior acid etching to obtain acceptable repair performance would be the practical choice under clinical conditions.


Asunto(s)
Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/química , Recubrimientos Dentinarios , Dentina/química , Cementos de Resina/química , Adhesivos , Análisis del Estrés Dental , Humanos , Ensayo de Materiales/métodos , Propiedades de Superficie , Resistencia a la Tracción
15.
Niger J Clin Pract ; 22(12): 1758-1764, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31793485

RESUMEN

Aim: The aim of this in vitro study was to compare the effects of the application of three different cavity disinfecting agents to dentin on the micro-shear bond strength (µ-SBS) of one self-etch and two universal adhesive systems. Materials and Methods: In total, 120 caries-free human permanent molar teeth were used in this study. Mid-coronal dentin surfaces were revealed by cutting occlusal enamel and a standard smear layer was obtained by using 600-800-1200 grid silicon carbide abrasive papers. Specimens were randomly assigned to four groups according to the disinfectant used: Group 1: Control (no disinfectant); Group 2: 2% chlorhexidine based (Consepsis); Group 3: 10 ppm ozonated water (TeknO3zone); Group 4: 5% boric acid (Handmade). Each group was divided into three subgroups according to the type of adhesive (Clearfil SE Bond, OptiBond XTR, and Tokuyama Universal). Specimens were bonded using either Clearfil SE Bond, OptiBond XTR or Tokuyama Universal, which were employed according to the manufacturer's instructions. Resin composite microcylinders were bonded using Tygon® tubes for µ-SBS testing. After specimens were stored for 24 h, at 37°C in distilled water, µ-SBS test was measured with a universal test machine (LF Plus, Lloyd, Instrument). µ-SBS results were analyzed by one-way analysis of variance (ANOVA) and Tukey's tests. Results: When the mean microshear bond strength values of the control group were compared, the difference between the subgroups was not significant (P < 0.05). When the mean microshear bond strength values of the chx, ozonated water, and boric acid were compared, the difference between Clearfil SE Bond and Tokuyama Universal was significant (P < 0.05) and the difference between the other groups was not significant (P > 0.05). Conclusion: Ozonated water and boric acid may be as an alternative to other materials used as cavity disinfectants.


Asunto(s)
Ácidos Bóricos , Recubrimiento Dental Adhesivo/métodos , Cementos Dentales , Desinfectantes Dentales/farmacología , Recubrimientos Dentinarios , Dentina/efectos de los fármacos , Agua , Clorhexidina , Resinas Compuestas/química , Esmalte Dental , Grabado Dental/métodos , Humanos , Cementos de Resina/uso terapéutico , Capa de Barro Dentinario
16.
Int J Mol Sci ; 20(21)2019 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-31671751

RESUMEN

The removal or modification of smear layers that cover the dentin is critical to allow the penetration of adhesive molecules and to ensure a strong bond between resin and dentin. Aiming to establish a model for clinically-relevant dentin-bond testing, we evaluated the effects of smear layers created by abrasives having similar coarseness (180-grit SiC paper; fine-grit diamond bur) and application modes (single application; double application) on the microtensile bond strengths (µTBS) of two currently available universal adhesives (G-Premio Bond; Scotchbond Universal Adhesive) and a two-step self-etch adhesive (Clearfil Megabond 2). Sixty extracted human third molars were used for the µTBS test. Data were analyzed by three-way ANOVA and Tukey's test (α = 0.05). Fracture modes were determined using stereomicroscopy. An additional 24 third molars were prepared for observation of the resin-dentin interface by TEM and adhesive-smear layer interaction by SEM. µTBS was significantly affected by the adhesives and their application modes (p < 0.001), implying that the double application of universal adhesives should be recommended to improve their performance. The effect of smear layers was not significant (p > 0.05), indicating that 180-grit SiC papers could be used to prepare dentin as a substitute for fine-grit diamond burs for dentin-bond testing in laboratory settings.


Asunto(s)
Adhesivos/química , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Capa de Barro Dentinario/química , Estrés Mecánico , Resistencia a la Tracción , Resinas Compuestas/química , Dentina/ultraestructura , Humanos , Ensayo de Materiales , Microscopía Electrónica de Transmisión , Tercer Molar , Cementos de Resina , Propiedades de Superficie
17.
Braz Oral Res ; 33: e120, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31778475

RESUMEN

The objective of this study is to compare the resin-enamel bond strength (mµSBS), in-situ degree of conversion (DC), and the enamel-etching pattern (SEM/EDX) of universal adhesive systems when applied to sound and fluorotic enamel. Ninety-eight human molars were sectioned into 4 parts and divided into 24 groups according to 1) enamel surface (sound or fluorotic enamel), 2) adhesive system (Clearfil Universal Bond [CUB], Futurabond U [FBU], iBond Universal [IBU], and Scotchbond Universal [SBU]), and 3) application mode (etch-and-rinse [ER], active self-etch [Active-SE], and passive self-etch [Passive-SE]). Specimens were stored at 37 °C, for 24 hours and tested at 1.0 mm/min (µSBS). Enamel-resin interfaces were evaluated for in-situ DC. The enamel-etching pattern was evaluated under a SEM/EDX. Data from mµSBS and in-situ DC was analyzed using a three-way ANOVA and Tukey's test at 5 % level of significance. For all adhesives, the ER resulted in a statistically significant higher mean mµSBS than the passive-SE in both substrates (p < 0.001). For all adhesives, active-SE resulted in mean mµSBS (p > 0.31) and in-situ DC (p > 0.45) that were statistically similar to those obtained with the ERs in both substrates. A statistically significant, higher mean mµSBS and in-situ DC were obtained in sound enamel (p < 0.001) than in fluorotic enamel. In general, SBU showed higher mean values for mµSBS and in-situ DC compared to those of CUB and IBU (p < 0.001). ER and active-SE showed the deepest enamel-etching pattern in both substrates. A higher amount of fluor was observed in fluorotic enamel. The active application of universal adhesives in the SE-mode may be a viable alternative to increase the adhesive properties in sound and fluorotic enamel.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/química , Esmalte Dental/efectos de los fármacos , Fluorosis Dental , Cementos de Resina/química , Análisis de Varianza , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Distribución Aleatoria , Valores de Referencia , Reproducibilidad de los Resultados , Resistencia al Corte/efectos de los fármacos , Espectrometría por Rayos X , Espectrometría Raman , Propiedades de Superficie/efectos de los fármacos
18.
Braz Oral Res ; 33: e098, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31664361

RESUMEN

The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (µTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased µTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.


Asunto(s)
Grabado Ácido Dental/métodos , Recubrimiento Dental Adhesivo/métodos , Esmalte Dental/efectos de los fármacos , Dentina/efectos de los fármacos , Extracto de Semillas de Uva/química , Ácidos Fosfóricos/química , Adolescente , Adulto , Análisis de Varianza , Esmalte Dental/química , Dentina/química , Humanos , Ensayo de Materiales , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Propiedades de Superficie/efectos de los fármacos , Resistencia a la Tracción , Factores de Tiempo , Adulto Joven
19.
Niger J Clin Pract ; 22(10): 1441-1447, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31607737

RESUMEN

Background: There was no enough data about the appropriate surface cleaning of core composite material after temporary cementation. Aim: To evaluate the effects of surface cleaning techniques on initial shear bond strength (SBS) between core composite material and resin nanoceramic crown materials after temporary cementation. Material and Methods: Cubic specimens were prepared from prosthetic materials, including Lava Ultimate. Cylinder-shaped composites were cemented to glass slides with eugenol-free temporary cement, resulting in a total of 44 cylinders (n = 11). The surfaces of composite cylinders were then cleaned with an Er, Cr:YSGG laser, 37% orthophosphoric acid, yellow tape diamond bur, or dental explorer. Cleaned cylinders were bonded to cubic specimens with resin cement. Initial SBS tests were performed with a universal testing machine at 0.5 mm/min crosshead speed. One-way ANOVA and post hoc Tukey tests were used to analyze the obtained data (P =0.05). Results: Initial SBS values were significantly affected by the different surface cleaning methods (P <.05). The highest SBS value was obtained with the laser group (SBS = 17.14), while the lowest was obtained with dental explorer group (SBS = 5.95). There was no significant difference between the diamond bur group and the laser group (P =0.982). Conclusions: Laser irradiation or yellow tape diamond bur cleaning of the core composite surface could be recommended to strengthen bond strength between the resin luting cement and the core composite. Before adhesive or conventional cementation of prosthetic restoration, the core composite surface should be cleaned.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Cementos Dentales/química , Grabado Dental/métodos , Recubrimientos Dentinarios/química , Vidrio/química , Láseres de Estado Sólido/uso terapéutico , Cementos de Resina/química , Cementación , Resinas Compuestas/química , Cementos de Ionómero Vitreo , Humanos , Ensayo de Materiales , Resistencia al Corte , Propiedades de Superficie
20.
Braz Oral Res ; 33: e095, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31618283

RESUMEN

This study evaluates the shear bond strength (SBS) of various resin cements to different ceramics. Composite resin cylinders of Z100 were fabricated and cemented to disks of feldspathic ceramic (Creation), leucite-reinforced feldspathic ceramic (Empress I), and densely sintered aluminum oxide ceramic (Procera AllCeram) using five resin cements: Panavia F (PAN), RelyX ARC (ARC), RelyX Unicem (RXU), RelyX Veneer, and Variolink II. SBS was measured after three days of water storage (baseline) and after artificial aging (180 days of water storage along with 12,000 thermal cycles). Failure mode of fractured specimens also was evaluated. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α=0.05). RXU showed 1) the lowest baseline median SBS to feldspathic ceramic, which was not statistically different from PAN; 2) the lowest median baseline SBS to leucite-reinforced feldspathic and densely sintered aluminum-oxide ceramics. All cements performed similarly after aging, except for ARC (median 0.0 MPa) and PAN (median 16.2 MPa) in the densely sintered aluminum-oxide ceramic group. Resin cements perform differently when bonded to different ceramic substrates. While all test resin cements worked similarly in the long-term to feldspathic and leucite-reinforced feldspathic ceramics, only the MDP-containing resin cement provided durable bonds to densely sintered aluminum-oxide ceramic.


Asunto(s)
Cerámica/química , Recubrimiento Dental Adhesivo/métodos , Cementos de Resina/química , Aluminio/química , Silicatos de Aluminio/química , Ensayo de Materiales , Compuestos de Potasio/química , Valores de Referencia , Reproducibilidad de los Resultados , Resistencia al Corte , Estadísticas no Paramétricas , Propiedades de Superficie
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