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1.
Niger J Clin Pract ; 23(9): 1266-1273, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32913167

RESUMEN

Aims: This study evaluated the effect of oxygen plasma and argon plasma treatments with different application times on tensile bonding of a silicone-based denture liner to polymethylmetacrylate (PMMA). Methods: Seven groups (n = 5) were prepared and six of them treated by argon plasma or oxygen plasma with 30s, 60s, and 120s, respectively; one group was left untreated served as control. After processing of denture liner, the specimens were deflasked and stored dry for 24 h, and they were then subjected to tensile bond strength testing. Differences in tensile bond strength values were determined using one-way ANOVA (α = 0.05). Results: Highest tensile bond strengths were observed in the oxygen plasma groups, followed by untreated group and argon plasma groups in turn in order. Tensile bond strenght were increased with time for both type of plasma applications tested. Conclusion: This study suggests that the adhesion between PMMA and denture liner is improved under conditions of oxygen plasma treatment with extended exposure time rather than argon plasma treatment.


Asunto(s)
Coagulación con Plasma de Argón , Recubrimiento Dental Adhesivo/métodos , Alineadores Dentales , Polimetil Metacrilato/química , Siliconas/química , Resistencia a la Tracción , Argón , Bases para Dentadura , Humanos , Ensayo de Materiales , Oxígeno , Propiedades de Superficie
2.
Niger J Clin Pract ; 23(8): 1148-1154, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32788494

RESUMEN

Aims: The effect of mechanical loading on the microtensile bond strength (µTBS) of universal adhesives to dentin was evaluated in this study. Methods and Materials: Human molar teeth had the occlusal dentin surfaces exposed and were allocated into ten groups (five experimental groups and five control groups) that used the following universal adhesive systems in self-etch mode: All-Bond Universal (ABU), Single Bond Universal (SBU), Gluma Bond Universal (GBU), Tetric N-Bond Universal (TBU), and Clearfil Universal Bond (CUB). Following the bonding procedures and build-ups, the specimens were either stored in water at 37°C for 24 h or were mechanically loaded (50 N for 60,000 cycles) prior to the µTBS test. Data were analyzed using the one-way analysis of variance (ANOVA) and Tukey's posthoc test (P = 0.05). Results: Both the adhesive type and mechanical loading had significant effects on the µTBS (P < 0.05). The µTBS values of SBU and ABU were significantly higher than the values of the other adhesives (P < 0.05). However, the µTBS values of ABU decreased significantly after mechanical loading (P < 0.05). Conclusions: With the exception of ABU, mechanical loading had no deleterious effects on the µTBS of the universal adhesive systems examined in this study.


Asunto(s)
Adhesivos/química , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Bisfenol A Glicidil Metacrilato , Resinas Compuestas , Glutaral , Humanos , Ensayo de Materiales/métodos , Diente Molar , Ácidos Polimetacrílicos , Cementos de Resina/química , Resistencia a la Tracción
3.
BMC Oral Health ; 20(1): 180, 2020 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-32600325

RESUMEN

BACKGROUND: Bonded retainers are widely used as they are esthetically pleasing, easily acceptable, provide greater stability, compliance free and causes no soft tissue irritation and speech problems. Though, fracture and bond failure are their shortcomings. Therefore, the objectives of this study were to evaluate the number of bond failures and type of failure pattern between two types of mandibular canine-canine bonded retainers. METHODS: Total 60 subjects were recruited initially and were assessed for eligibility, out of which 6 were excluded and 2 were lost to follow up. They were randomly divided into two groups. Fiber reinforced composite (FRC) retainers were inserted in group 1 subjects while group 2 subjects received multistranded stainless steel (MSW) retainers. The subjects were recalled after every 3 months over a period of 1 year. Bond failure rate and failure pattern based on adhesive remnant index were evaluated at each visit. The bond failure rate and failure pattern were compared between the two retainers by using Chi-square test. RESULTS: The bond failure rates were 42.94% for FRC retainer and 31.41% for MSW retainer. Hence, total number of bond failures in both retainers were 37.17%. The difference of bond failure between two groups was statistically significant (p = 0.012). Type "0" failure pattern was detected commonly with both types of retainers (p <  0.001). CONCLUSION: Our findings indicate that multistranded stainless steel wire retainer is a superior option to be used for fixed lingual retention in mandibular arch as it exhibited lower bond failure as compared to fiber reinforced composite retainer. Adhesive failure is the most common type of bond failure observed with both types of fixed retainers. TRIAL REGISTRATION: ID NCT03881813 ( https://clinicaltrials.gov/ ); March 19, 2019, retrospective registration.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Materiales Dentales/química , Diseño de Aparato Ortodóncico , Retenedores Ortodóncicos , Adhesividad , Adulto , Diente Canino/anatomía & histología , Esmalte Dental , Femenino , Humanos , Masculino , Aparatos Ortodóncicos Fijos , Alambres para Ortodoncia , Estudios Retrospectivos
4.
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
5.
PLoS One ; 15(6): e0233536, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32479553

RESUMEN

BACKGROUND: Removal of cement-retained implant fixed restorations when needed, can be challenging. Conventional methods of crown removal are time consuming and costly for patients and practitioners. This research explored the use of two different types of pulsed erbium lasers as a non-invasive tool to retrieve cemented zirconia crowns from zirconia implant abutments. MATERIALS AND METHODS: Twenty identical zirconia crowns were cemented onto 20 identical zirconia prefabricated abutments using self-adhesive resin cement. The specimens were divided into two groups for laser assisted crown removal; G1 for erbium-doped yttrium aluminum garnet laser (Er:YAG), and G2 for erbium, chromium-doped yttrium, scandium, gallium and garnet (Er,Cr:YSGG). For the G1, after the first crown removal, the specimens were re-cemented and removed again using the Er:YAG laser. Times needed to remove the crowns were recorded and analyzed using ANOVA (α = 0.05). The surfaces of the crown and the abutment were further examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses. RESULTS: The average times of zirconia crown removal from zirconia abutments were 5 min 20 sec and 5 min 15 sec for the Er:YAG laser of first and second experiments (G1), and 5 min 55 sec for the Er,Cr:YSGG laser experiment (G2). No statistical differences were observed among the groups. SEM and EDS examinations of the materials showed no visual surface damaging or material alteration from the two pulsed erbium lasers. CONCLUSIONS: Both types of pulsed erbium lasers can be viable alternatives for retrieving a zirconia crown from a zirconia implant abutment. Despite operating at different wavelengths, the Er:YAG and Er,Cr:YSGG lasers, perform similarly in removing a zirconia crown from a zirconia implant abutment with similar parameters. There are no visual and elemental composition damages as a result of irradiation with pulsed erbium lasers.


Asunto(s)
Recubrimiento Dental Adhesivo/métodos , Prótesis Dental/métodos , Láseres de Estado Sólido/uso terapéutico , Cromo , Coronas , Erbio , Galio , Humanos , Microscopía Electrónica de Rastreo/métodos , Cementos de Resina , Corona del Diente/fisiología , Itrio , Circonio
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
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
13.
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
14.
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
15.
J Formos Med Assoc ; 119(1 Pt 2): 260-267, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31151854

RESUMEN

BACKGROUND/PURPOSE: The restoration longevity depends on a high dentin-composite bond quality. This study investigated learning outcomes when using etch-and-rinse and self-etch adhesives among general practitioners in a hands-on bonding test course. METHODS: We recruited 30 general practitioners to perform shear bond strength (SBS) tests using five adhesives: one Peak® Universal Bond (PUB) etch-and-rinse and four Futurabond DC, Single Bond universal (SBU), Versa Optibond (VOB), and Tetric-N Bond Self-Etch (TNS) self-etch adhesives. SBS tests were conducted at pre-demonstration (pre-demo), post-demonstration (post-demo), and 24-h storage (delayed bonding) stages. SBS data were analyzed with paired Student's t-tests. We defined 17 MPa as "qualified bond strength (QBS)". The percentages of samples with SBS achieving QBS were analyzed using Mantel-Haenszel chi-square tests. The fracture surfaces of the samples were examined by scanning electron microscopy (SEM). RESULTS: Using PUB caused no significant differences in SBS between pre- and post-demo samples, whereas the SBS of the two self-etch adhesives (SBU and VOB) improved in post-demo samples (p < 0.05). SBU showed the highest percentage of samples with SBS achieving QBS in all three groups (pre-demo = 70%, post-demo = 83%, and delayed bonding = 76.5%). The QBS percentages of VOB and TNS notably improved from 0% (pre-demo) to 71.4% and 23.5% (post-demo), respectively. SEM indicated bubble-like defects at the dentin-resin interfaces in cases of low SBS. CONCLUSION: Bonding performance is both operator- and product-dependent. The continuing education hands-on course does help dentists to improve the bond strength especially when the self-etch system is used.


Asunto(s)
Resinas Compuestas , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios , Odontólogos/educación , Resistencia al Corte , Grabado Ácido Dental , Adhesivos , Competencia Clínica , Análisis del Estrés Dental , Dentina , Humanos , Aprendizaje , Ensayo de Materiales
16.
Microsc Res Tech ; 83(2): 176-185, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31682323

RESUMEN

The aim of this study was to evaluate gap formation after using two universal adhesives, Peak Universal Bond (P), which contains chlorhexidine and Adhese Universal (A), which contains 10-MDP monomer, and to compare them with two gold standard adhesives. The adhesives were tested in different etching modes, etch-and-rinse (ER) or self-etch (SE), and under thermomechanical loading (TML). Two identical Class V cavities were prepared in each of 30 human third molar teeth, and resin-composite restorations were made. Before and after TML, replicas of the restorations were prepared. Gap formation and their frequency according to the modified classification of Blunck and Zaslansky and the width of the maximum marginal gap (MG) were separately evaluated in enamel and dentin. Gap frequency did not differ significantly only in the enamel before TML, despite the use of different adhesives or etching modes. At both timepoints, the highest MG values were obtained with the Peak Universal Bond self-etch (PSE) group in enamel (6.2 µm before TML, 12.2 µm after TML) and the Peak Universal Bond etch-and-rinse (PER) group in dentine (21.3 µm before TML, 35.5 µm after TML). After TML, there was a significant increase of gap frequency for Adhese universal self-etch (ASE) group and MG values for PER, PSE, ASE groups at the resin-enamel interface, and gap frequency and MG values for all groups at the resin-dentin interface. Universal adhesive with 10-MDP monomer have beneficial effect on the resin-dentin interface, while chlorhexidine may reduce the resistance of the universal adhesive system to oral cavity conditions.


Asunto(s)
Resinas Acrílicas/química , Adhesivos/química , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Tercer Molar , Poliuretanos/química , Técnicas de Réplica/métodos , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Tercer Molar/efectos de los fármacos
17.
Int J Mol Sci ; 22(1)2020 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-33396354

RESUMEN

Cavity disinfection becomes an important step before a dental restorative procedure. The disinfection can be obtained cleaning the dental cavity with antimicrobial agents before the use of adhesive systems. The aim of this study was to conduct a systematic review on the effect of different cavity disinfectants on restorations' adhesion and clinical success. A search was carried out through the Cochrane Library, PubMed, and Web of Science. In vitro and in situ studies reporting results on dentin bond strength tests, and clinical studies published until August 2020, in English, Spanish and Portuguese were included. The methodological quality assessment of the clinical studies was carried out using the Revised Cochrane risk-of-bias tool. Chlorhexidine could preserve adhesion to dentin. EDTA and ethanol had positive results that should be further confirmed. Given the significant lack of scientific evidence, the use of lasers, fluoridated agents, sodium hypochlorite, or other products as cavity disinfectants should be avoided. Chlorhexidine is a safe option for cavity disinfection with adequate preservation of adhesion to dentin. Moreover, future researches should be focused on the efficacy of these disinfectants against cariogenic bacteria and their best application methods.


Asunto(s)
Antiinfecciosos Locales/farmacología , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Recubrimientos Dentinarios/química , Dentina/efectos de los fármacos , Desinfectantes/farmacología , Desinfección/métodos , Humanos , Ensayo de Materiales
18.
J. appl. oral sci ; 28: e20190371, 2020. tab, graf
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1090787

RESUMEN

Abstract 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)
Circonio/química , Recubrimiento Dental Adhesivo/métodos , Cementos de Resina/química , Abrasión Dental por Aire/métodos , Óxido de Aluminio/química , Valores de Referencia , Propiedades de Superficie , Resistencia a la Tracción , Difracción de Rayos X/métodos , Ensayo de Materiales , Reproducibilidad de los Resultados , Análisis de Varianza , Microscopía Confocal/métodos , Resistencia Flexional , Calor
19.
J. appl. oral sci ; 28: e20190499, 2020. tab, graf
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1101251

RESUMEN

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.


Asunto(s)
Humanos , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Cementos Dentales/química , Dentina/química , Inhibidores de la Metaloproteinasa de la Matriz/química , Metacrilatos/química , Valores de Referencia , Propiedades de Superficie , Resistencia a la Tracción , Factores de Tiempo , Ensayo de Materiales , Reproducibilidad de los Resultados , Análisis de Varianza , Recubrimiento Dental Adhesivo/métodos , Espectroscopía Infrarroja por Transformada de Fourier , Estadísticas no Paramétricas , Filtración Dental , Dentina/efectos de los fármacos , Grabado Dental/métodos
20.
J. appl. oral sci ; 28: e20190371, 2020. tab, graf
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1056595

RESUMEN

Abstract 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)
Circonio/química , Recubrimiento Dental Adhesivo/métodos , Cementos de Resina/química , Abrasión Dental por Aire/métodos , Óxido de Aluminio/química , Valores de Referencia , Propiedades de Superficie , Resistencia a la Tracción , Difracción de Rayos X/métodos , Ensayo de Materiales , Reproducibilidad de los Resultados , Análisis de Varianza , Microscopía Confocal/métodos , Resistencia Flexional , Calor
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