RESUMEN

OBJECTIVES: To compare the accuracy of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) during the analysis of the adhesive interface integrity and intratubular penetration of root canal sealers to radicular dentine. MATERIALS AND METHODS: Twenty roots of human maxillary incisors were prepared and distributed into two groups (n = 10), followed by filling with gutta-percha and Endofill (G1) or AH Plus (G2). After 7 days, roots were sectioned and analyzed under CLSM and SEM. Score systems were used to evaluate the adhesive interface integrity (0-4) and sealer intratubular penetration (0-3). Data were submitted to Wilcoxon-Mann-Whitney and Kendall correlation statistical tests (α = 5%). RESULTS: In the adhesive interface analysis, CLSM was similar (P = 0.157) to SEM for Endofill; however, the results were different for AH Plus (P = 0.029). Intratubular penetration had significant difference between observational methods for both sealers (P < 0.0001). Correlation analysis between SEM and CLSM for adhesive interface was moderate for Endofill and low for AH Plus. Intratubular penetration was low for both sealers. CONCLUSION: SEM and CLSM analysis had similar results when sealers were compared, with a more homogeneous adhesive interface, and greater intratubular penetration for AH Plus. Comparison between observational methods demonstrated low positive correlation for adhesive interface and intratubular penetration analysis. CLINICAL RELEVANCE: A proper interface formed between sealer and dentine is very important for final quality of root canal filling. Observational methods which allow an accurate analysis of this interface must be selected to assess such features.

Asunto(s)

Resinas Epoxi/química , Gutapercha/química , Incisivo/ultraestructura , Microscopía Confocal , Microscopía Electrónica de Rastreo , Materiales de Obturación del Conducto Radicular/química , Adhesividad , Humanos , Técnicas In Vitro , Ensayo de Materiales , Propiedades de Superficie

RESUMEN

OBJECTIVES: FT-Raman spectroscopy and scanning electron microscopy (SEM) were employed to test the hypothesis that the beverage consumption or mouthwash utilization would change the chemistry of dental materials and enamel inorganic content. MATERIAL AND METHODS: Bovine enamel samples (n = 36) each received two cavity preparations (n = 72), each pair filled with one of three dental materials (R: nanofilled composite resin, GIC: glass-ionomer cement, RMGIC: resin-modified GIC). Furthermore, they were treated with three different solutions (S: artificial saliva, E: erosion/Pepsi Twist or EM: erosion + mouthwash/Colgate Plax). RESULTS: Reduction of carbonate content of enamel was greater in RE than RS (P < 0.01). Increment of carbonate was greater in GICEM than in GICE and GICS (P < 0.01; P < 0.001). Significant material degradation was found in RE, REM, GICE, and GICEM than in RS and GICS (P < 0.01; P < 0.001). SEM showed clear enamel demineralization after erosion. Material degradation was greater after E and EM than S. GIC and RMGIC materials had a positive effect against acid erosion in the adjacent enamel after remineralization with mouthwash. CONCLUSIONS: The beverage and mouthwash utilization would change R and GIC chemical properties. CLINICAL RELEVANCE: A professional should periodically monitor the glass-ionomer and resin restorations, as they degrade over time under erosive challenges and mouthwash utilization. Microsc. Res. Tech., 2016. © 2016 Wiley Periodicals, Inc. Microsc. Res. Tech. 79:646-656, 2016. © 2016 Wiley Periodicals, Inc.

Asunto(s)

Resinas Compuestas/química , Esmalte Dental , Erosión de los Dientes/patología , Remineralización Dental/métodos , Ácidos/efectos adversos , Animales , Bovinos , Esmalte Dental/efectos de los fármacos , Esmalte Dental/patología , Esmalte Dental/ultraestructura , Restauración Dental Permanente , Incisivo/efectos de los fármacos , Incisivo/patología , Incisivo/ultraestructura , Microscopía Electrónica de Rastreo , Espectrometría Raman

RESUMEN

This study evaluated the structural and morphological differences between human and bovine primary root canals. Primary human maxillary central incisors (H) (n=9) and primary bovine incisors (B) (n=9) were selected. The roots were sectioned in the vestibular-lingual direction, planed and delimited in cervical, middle, and apical thirds. Tubule density (number of tubules per mm2) and diameter were analyzed by scanning electron microscopy (1,000 and 5,000×) using Image J 1.47 software. Data were submitted to two-way repeated measures ANOVA and Tukey tests (α=0.05). The highest tubule density was observed for B (28.527±1.717 mm2) compared with H (15.931±0.170 mm2) (p<0.01). Regarding root thirds, the cervical third presented a greater tubule density (26.417±11.654 mm2) than the apical third (17.999±5.873 mm2). The diameter of the dentin tubules was not different for cervical (3.50±0.08 µm), middle (3.45±0.30 µm) and apical thirds (3.42±0.33 µm) and substrate (H-3.29±0.14 µm; B-3.63±0.06 µm). It could be concluded that: (1) the radicular dentin structure of human and bovine primary teeth and root thirds differ in terms of the tubule density; (2) the radicular dentin morphology of human and bovine primary teeth and root thirds are similar in terms of the diameter of the dentin tubules.

Asunto(s)

Dentina/ultraestructura , Raíz del Diente/ultraestructura , Diente Primario/ultraestructura , Animales , Bovinos , Humanos , Incisivo/ultraestructura , Microscopía Electrónica de Rastreo

RESUMEN

INTRODUCTION: The aim of this study was to evaluate the surface roughness and morphology of enamel with a surface roughness tester and scanning electron microscopy after the removal of metal brackets and polishing. METHODS: Ten orthodontic patients were selected for the study. At the conclusion of orthodontic treatment, their metal brackets were removed. For each patient, teeth on one side of the mouth were randomly chosen for finishing and polishing with aluminum oxide discs (n = 10). Teeth on the other side were finished with multilaminated carbide burs (n = 10). Dental replicas (before and after tooth polishing) were obtained with epoxy resin. Three surface roughness measurements were made in different directions with an angle of 120° among them, and a mean for each dental replica was calculated. The roughness data were statistically evaluated by repeated-measurements analysis of variance. Three specimens from each group were also used for scanning electron microscopy analysis. RESULTS: After resin removal, the average roughness in the carbide bur group (0.31 µm) was significantly greater than that in the aluminum oxide disc group (0.25 µm). CONCLUSIONS: The aluminum oxide disc polishing system resulted in less enamel roughness than did the multilaminated carbide bur system.

Asunto(s)

Desconsolidación Dental/métodos , Esmalte Dental/ultraestructura , Profilaxis Dental/métodos , Incisivo/ultraestructura , Soportes Ortodóncicos , Grabado Ácido Dental/métodos , Adhesividad , Adolescente , Óxido de Aluminio/química , Carbono/química , Resinas Compuestas/química , Aleaciones Dentales/química , Recubrimiento Dental Adhesivo/métodos , Cementos Dentales/química , Desconsolidación Dental/instrumentación , Profilaxis Dental/instrumentación , Resinas Epoxi/química , Femenino , Humanos , Curación por Luz de Adhesivos Dentales , Masculino , Microscopía Electrónica de Rastreo/métodos , Ácidos Fosfóricos/química , Técnicas de Réplica , Dióxido de Silicio/química , Acero Inoxidable/química , Propiedades de Superficie , Adulto Joven , Circonio/química

RESUMEN

AIM: The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. MATERIALS AND METHODS: The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). RESULTS: Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. CONCLUSION: The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

Asunto(s)

Esmalte Dental/ultraestructura , Diente Primario/ultraestructura , Apatitas/análisis , Calcio/análisis , Cristalografía , Diente Canino/química , Diente Canino/ultraestructura , Esmalte Dental/química , Durapatita/análisis , Humanos , Hidróxidos/análisis , Incisivo/química , Incisivo/ultraestructura , Microscopía Electrónica de Rastreo , Fosfatos/análisis , Fósforo/análisis , Espectroscopía de Fotoelectrones , Porosidad , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Diente Primario/química , Difracción de Rayos X

RESUMEN

This study analyzed the quality of obturation and physical properties of MTA Fillapex and AH Plus sealer. A sample of 30 human maxillary central incisors were instrumented with Protaper until a F5 (50/05) file. Both sealers were mixed with Rhodamine-B dye to allow visualization on a confocal laser-scanning microscope (CLSM). Next, the canals were filled using the single cone technique. After setting, all samples were sectioned at 2, 4, and 6 mm from the apex. CLSM was used to analyze the gaps and sealer penetration into the dentinal tubules. All samples were scanned 10 µm below the dentin surface and images were recorded at 100× magnification using the fluorescent mode. Additionally, the solubility, flowability and setting time of the sealers were evaluated. All the measured quantities of the examined materials were evaluated for significant differences by means of statistical analysis. The CLSM analysis of the MTA Fillapex showed the highest percentage of gaps at all sections (P = 0.0001). Physical tests revealed adequate properties for both sealers except for a higher solubility of the MTA Fillapex (P = 0.0001). The MTA Fillapex presented flowability and intratubular penetration similar to the AH Plus. Nevertheless, the MTA Fillapex sealer presented a higher solubility and considerable quantity of gaps between the sealer/dentin interface in relation to the AH Plus sealer. Clinicians must take into consideration, the quality of endodontic sealers as it is essential in the outcome of the root canal filling.

Asunto(s)

Incisivo/ultraestructura , Microscopía Confocal , Materiales de Obturación del Conducto Radicular/química , Obturación del Conducto Radicular/métodos , Dentina/ultraestructura , Humanos , Solubilidad , Propiedades de Superficie

RESUMEN

This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal-Wallis, Mann-Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested.

Asunto(s)

Incisivo/ultraestructura , Selladores de Fosas y Fisuras/química , Materiales de Obturación del Conducto Radicular/química , Adhesividad , Humanos , Microscopía Electrónica de Rastreo , Cloruro de Sodio/química , Propiedades de Superficie

RESUMEN

Root canal filling with zinc oxide-eugenol (ZOE) paste following primary tooth pulpectomy is a common practice in pediatric dentistry. This material offers high clinical and radiographic success rates. In some cases, however, it is not resorbed along with the root of the primary tooth. The aim of this study was to describe a case of prolonged retention of a primary maxillary incisor that was subjected to pulpectomy and filled with ZOE paste in order to characterize the aspects of root resorption using scanning electron microscopy.

Asunto(s)

Incisivo/ultraestructura , Pulpectomía/métodos , Tratamiento del Conducto Radicular/métodos , Diente Primario/ultraestructura , Niño , Cemento Dental/ultraestructura , Femenino , Estudios de Seguimiento , Humanos , Microscopía Electrónica de Rastreo , Planificación de Atención al Paciente , Materiales de Obturación del Conducto Radicular/uso terapéutico , Resorción Radicular/fisiopatología , Ápice del Diente/ultraestructura , Exfoliación Dental/fisiopatología , Extracción Dental/métodos , Cemento de Óxido de Zinc-Eugenol/uso terapéutico

RESUMEN

PURPOSE: This evaluation aimed to (1) validate micro-computed tomography (microCT) findings using scanning electron microscopy (SEM) imaging, and (2) quantify the volume of voids and the bonded surface area resulting from fiber-reinforced composite (FRC) dowel cementation technique using microCT scanning technology/3D reconstructing software. MATERIALS AND METHODS: A fiberglass dowel was cemented in a condemned maxillary lateral incisor prior to its extraction. A microCT scan was performed of the extracted tooth creating a large volume of data in DICOM format. This set of images was imported to image-processing software to inspect the internal architecture of structures. RESULTS: The outer surface and the spatial relationship of dentin, FRC dowel, cement layer, and voids were reconstructed. Three-dimensional spatial architecture of structures and volumetric analysis revealed that 9.89% of the resin cement was composed of voids and that the bonded area between root dentin and cement was 60.63% larger than that between cement and FRC dowel. CONCLUSIONS: SEM imaging demonstrated the presence of voids similarly observed using microCT technology (aim 1). MicroCT technology was able to nondestructively measure the volume of voids within the cement layer and the bonded surface area at the root/cement/FRC interfaces (aim 2). CLINICAL SIGNIFICANCE: The interfaces at the root dentin/cement/dowel represent a timely and relevant topic where several efforts have been conducted in the past few years to understand their inherent features. MicroCT technology combined with 3D reconstruction allows for not only inspecting the internal arrangement rendered by fiberglass adhesively bonded to root dentin, but also estimating the volume of voids and contacted bond area between the dentin and cement layer.

Asunto(s)

Resinas Compuestas/química , Recubrimiento Dental Adhesivo , Materiales Dentales/química , Vidrio/química , Técnica de Perno Muñón/instrumentación , Cementación/métodos , Cavidad Pulpar/diagnóstico por imagen , Cavidad Pulpar/ultraestructura , Dentina/diagnóstico por imagen , Dentina/ultraestructura , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Incisivo/diagnóstico por imagen , Incisivo/ultraestructura , Microscopía Electrónica de Rastreo , Proyectos Piloto , Cementos de Resina/química , Dióxido de Silicio/química , Propiedades de Superficie , Raíz del Diente/diagnóstico por imagen , Raíz del Diente/ultraestructura , Microtomografía por Rayos X/métodos , Circonio/química

RESUMEN

The presence of residual endodontic sealer in the pulp chamber may cause discoloration of the dental crown and interfere with the adhesion of restorative materials. The aim of this study was to compare the efficacy of different solvents in removing residues of an epoxy resin-based sealer (AH Plus) from the dentin walls of the pulp chamber, by scanning electron microscopy (SEM). Forty-four bovine incisor dental crown fragments were treated with 17% EDTA and 2.5% NaOCl. Specimens received a coating of AH Plus and were left undisturbed for 5 min. Then, specimens were divided in four groups (n = 10) and cleaned with one of the following solutions: isopropyl alcohol, 95% ethanol, acetone solution, or amyl acetate solution. Negative controls (n = 2) did not receive AH Plus, while in positive controls (n = 2) the sealer was not removed. AH Plus removal was evaluated by SEM, and a score system was applied. Data were analyzed by Kruskal-Wallis and Dunn tests. None of the solutions tested was able to completely remove AH Plus from the dentin of the pulp chamber. Amyl acetate performed better than 95% ethanol and isopropyl alcohol (p < 0.05), but not better than acetone (p > 0.05) in removing the sealer from dentin. No significant differences were observed between acetone, 95% ethanol, and isopropyl alcohol (p > 0.05). It was concluded that amyl acetate and acetone may be good options for cleaning the pulp chamber after obturation with AH Plus.

Asunto(s)

Dentina/efectos de los fármacos , Dentina/ultraestructura , Resinas Epoxi/análisis , Resinas Epoxi/metabolismo , Compuestos Orgánicos/farmacología , Materiales de Obturación del Conducto Radicular/análisis , Materiales de Obturación del Conducto Radicular/metabolismo , Solventes/farmacología , Animales , Bovinos , Procesamiento de Imagen Asistido por Computador , Incisivo/efectos de los fármacos , Incisivo/ultraestructura , Microscopía Electrónica de Rastreo , Compuestos Orgánicos/metabolismo , Solventes/metabolismo

RESUMEN

AIM: To evaluate the mechanical behaviour of the dentine/cement/post interface of a maxillary central incisor using the finite element method and to compare the stresses exerted using conventional or customized post cementation techniques. METHODOLOGY: Four models of a maxillary central incisor were created using fibreglass posts cemented with several techniques: FGP1, a 1-mm-diameter conventionally cemented post; CFGP1, a 1-mm-diameter customized composite resin post; FGP2, a 2-mm-diameter conventionally cemented post; CFGP2, a 2-mm-diameter customized composite resin post. A distributed load of 1N was applied to the lingual aspect of the tooth at 45° to its long axis. Additionally, polymerization shrinkage of 1% was simulated for the resin cement. The surface of the periodontal ligament was fixed in the three axes (X =Y = Z = 0). The maximum principal stress (σ(max) ), minimum principal stress (σ(min)), equivalent von Mises stress (σ(vM) ) and shear stress (σ(shear)) were calculated for the dentine/cement/post interface using finite element software. RESULTS: The peak of σ(max) for the cement layer occurred first in CFGP1 (1.77 MPa), followed by CFGP2 (0.99), FGP2 (0.44) and FGP1 (0.2). The shrinkage stress (σ(vM) ) of the cement layer occurred as follows: FGP1 (35 MPa), FGP2 (34), CFGP1 (30.7) and CFGP2 (30.1). CONCLUSIONS: Under incisal loading, the cement layer of customized posts had higher stress concentrations. The conventional posts showed higher stress because of polymerization shrinkage.

Asunto(s)

Resinas Compuestas/química , Materiales Dentales/química , Diseño de Prótesis Dental , Cavidad Pulpar/ultraestructura , Dentina/ultraestructura , Vidrio/química , Incisivo/ultraestructura , Técnica de Perno Muñón/instrumentación , Cementos de Resina/química , Fenómenos Biomecánicos , Cementación/métodos , Simulación por Computador , Módulo de Elasticidad , Análisis de Elementos Finitos , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Ensayo de Materiales , Modelos Biológicos , Ligamento Periodontal/fisiología , Polimerizacion , Resistencia al Corte , Estrés Mecánico , Propiedades de Superficie , Microtomografía por Rayos X/métodos

RESUMEN

Considering that instrumentation of the apical foramen has been suggested for root canal infection control, this study analyzed the relationship between the files that bind at the apical foramen and the foraminal openings in 50 maxillary central incisors. After preparation of the pulp chamber, access to the canal was obtained with #1 and 2 LA Axxess and K-files with tip cut were inserted up to the apical foramen until binding was felt. The files were fixed with methyl cyanoacrylate and the tooth-file sets were cross-sectioned 10 mm short of the apex. Scanning electron microscopic analysis was carried out and files and foraminal areas were measured using Image Tool software. Statistically significant difference (p<0.0001) was found between files and the apical foraminal areas. The mean foraminal area was 3.8 times larger than the mean file area. The results of this study suggest that it would require 4 files of greater size beyond the one that bound to the foramen in order to allow a better relationship between files and apical openings of maxillary central incisors.

Asunto(s)

Cavidad Pulpar/ultraestructura , Incisivo/ultraestructura , Maxilar/ultraestructura , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/ultraestructura , Cianoacrilatos/química , Diseño de Equipo , Humanos , Microscopía Electrónica de Rastreo , Adhesión en Plástico , Radiografía de Mordida Lateral , Preparación del Conducto Radicular/métodos , Propiedades de Superficie , Fijación del Tejido

RESUMEN

This study evaluated the influence of the cementation system on the regional push-out bond strength and failure pattern of fiber posts to radicular dentin. The roots of 48 extracted human incisors were prepared and divided into 3 groups (n = 16), according to the cementation system: AdperScotchbond Multi-Purpose + resin cement RelyX ARC (SBMP+ARC); Adper SingleBond 2 + RelyX ARC (SB+ARC) and; RelyX U100 self-adhesive resin cement (U100). The posts were cemented as per manufacturer's instructions for each cementation system. After 1 week, the roots were sectioned transversely into 6 discs. Two discs were obtained from the cervical, middle and apical thirds and the push-out test was carried out. The failure pattern was examined on all debonded specimens. The data were analyzed by two-way repeated measures ANOVA and Tukey's test. When U100 was used, no statistically significant difference (p>0.05) was observed among the different root regions. Statistically higher push-out bond strength values were detected in the cervical third for SBMP+ARC and SB+ARC (p<0.05). The U100 showed significantly more mixed failures than SBMP+ARC in the apical third (p<0.05). In conclusion, the self-adhesive cement RelyX U100 was the only cement not sensitive to the root canal region.

Asunto(s)

Cementación/métodos , Recubrimiento Dental Adhesivo , Cavidad Pulpar/ultraestructura , Dentina/ultraestructura , Técnica de Perno Muñón/instrumentación , Cementos de Resina/química , Grabado Ácido Dental/métodos , Bisfenol A Glicidil Metacrilato/química , Materiales Dentales/química , Retención de Prótesis Dentales , Análisis del Estrés Dental/instrumentación , Recubrimientos Dentinarios/química , Vidrio/química , Humanos , Incisivo/ultraestructura , Ensayo de Materiales , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Preparación del Conducto Radicular/métodos , Estrés Mecánico , Propiedades de Superficie , Temperatura , Factores de Tiempo , Ápice del Diente/ultraestructura

RESUMEN

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

Asunto(s)

Filtración Dental/clasificación , Cavidad Pulpar/efectos de la radiación , Dentina/efectos de la radiación , Láseres de Semiconductores/uso terapéutico , Ápice del Diente/efectos de la radiación , Colorantes , Diente Canino/efectos de la radiación , Diente Canino/ultraestructura , Recubrimiento Dental Adhesivo , Cavidad Pulpar/ultraestructura , Dentina/ultraestructura , Ácido Edético/uso terapéutico , Resinas Epoxi/uso terapéutico , Gutapercha/uso terapéutico , Humanos , Incisivo/efectos de la radiación , Incisivo/ultraestructura , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Dosis de Radiación , Materiales de Obturación del Conducto Radicular/uso terapéutico , Irrigantes del Conducto Radicular/uso terapéutico , Preparación del Conducto Radicular/métodos , Capa de Barro Dentinario , Hipoclorito de Sodio/uso terapéutico , Ápice del Diente/ultraestructura , Agua

RESUMEN

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

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Este estudo avaliou o efeito do laser de diodo 980 nm na microinfiltração apical e na morfologia intrarradicular da dentina. Raízes de 110 incisivos inferiores foram utilizadas no estudo: 92 para o teste de microinfiltração e 18 para microscopia eletrônica de varredura (MEV). As raízes foram divididas em 3 grupos de acordo com a solução irrigante (água, NaOCl e NaOCl/EDTA) e subdivididas em 3 de acordo com a irradiação laser (sem irradiação, irradiados com 1,5 W e irradiados com 3,0 W). Duas amostras de cada subgrupo foram preparadas para MEV. As raízes restantes foram preenchidas com AH Plus e guta percha. A infiltração apical foi avaliada nas raízes por meio da penetração do corante e os dados foram analisados por ANOVA e teste de Tukey-Krammer (α=0,05). Os resultados da MEV mostraram intensificação das mudanças quando se aumentou a potência do laser e variações de acordo com a solução irrigadora. Camada de smear modificada foi observada em espécimes tratados com água e irradiados com laser. Raízes irrigadas com NaOCl/EDTA tiveram níveis menores de infiltração (0,17 ± 0,18 mm) estatisticamente diferente (p<0,05) das raízes irrigadas com água (0,34 ± 0,30 mm), mas semelhante (p>0,05) aos irrigados com NaOCl (0,28 ± 0,29 mm). As raízes não irradiadas tiveram níveis menores de infiltração (0,10 ± 0,14 mm), diferente (p<0,05) de 1,5 W (0,32 ± 0,22 mm) e 3.0 W (0,37 ± 0,32 mm). O laser de diodo 980 nm alterou a morfologia da dentina e aumentou a infiltração marginal apical.

Asunto(s)

Humanos , Filtración Dental/clasificación , Cavidad Pulpar/efectos de la radiación , Dentina/efectos de la radiación , Láseres de Semiconductores/uso terapéutico , Ápice del Diente/efectos de la radiación , Colorantes , Diente Canino/efectos de la radiación , Diente Canino/ultraestructura , Recubrimiento Dental Adhesivo , Cavidad Pulpar/ultraestructura , Dentina/ultraestructura , Ácido Edético/uso terapéutico , Resinas Epoxi/uso terapéutico , Gutapercha/uso terapéutico , Incisivo/efectos de la radiación , Incisivo/ultraestructura , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Dosis de Radiación , Materiales de Obturación del Conducto Radicular/uso terapéutico , Irrigantes del Conducto Radicular/uso terapéutico , Preparación del Conducto Radicular/métodos , Capa de Barro Dentinario , Hipoclorito de Sodio/uso terapéutico , Ápice del Diente/ultraestructura , Agua

RESUMEN

Considering that instrumentation of the apical foramen has been suggested for root canal infection control, this study analyzed the relationship between the files that bind at the apical foramen and the foraminal openings in 50 maxillary central incisors. After preparation of the pulp chamber, access to the canal was obtained with #1 and 2 LA Axxess and K-files with tip cut were inserted up to the apical foramen until binding was felt. The files were fixed with methyl cyanoacrylate and the tooth-file sets were cross-sectioned 10 mm short of the apex. Scanning electron microscopic analysis was carried out and files and foraminal areas were measured using Image Tool software. Statistically significant difference (p<0.0001) was found between files and the apical foraminal areas. The mean foraminal area was 3.8 times larger than the mean file area. The results of this study suggest that it would require 4 files of greater size beyond the one that bound to the foramen in order to allow a better relationship between files and apical openings of maxillary central incisors.

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Uma vez que a instrumentação do forame apical tem sido sugerida para o controle de infecção do canal radicular, este estudo analisou a relação entre as limas que se ajustam no forame apical e a abertura foraminal em cinquenta incisivos centrais superiores. Após o preparo da câmara pulpar, foi feito o acesso radicular com as brocas LA Axxess #1 e 2 e limas K com a ponta cortada foram inseridas até que oferecessem a sensação tátil de ajuste no forame apical. Foram fixadas com cianoacrilato de metila e o conjunto dente-lima foi seccionado a 10 mm aquém do ápice. Foi feita a microscopia eletrônica de varredura e as áreas das limas e dos forames foram medidas por meio do Image Tool software. A análise estatística demonstrou diferença significante entre as áreas das limas e dos forames (p<0,0001). A média da área dos forames apicais foi 3,8 vezes maior que a das limas. Os resultados deste estudo sugerem que seriam necessários 4 instrumentos de calibre maior além do que se ajustou para que haja melhor relação entre as limas e as aberturas foraminais nos incisivos centrais superiores.

Asunto(s)

Humanos , Cavidad Pulpar/ultraestructura , Incisivo/ultraestructura , Maxilar/ultraestructura , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/ultraestructura , Cianoacrilatos/química , Diseño de Equipo , Microscopía Electrónica de Rastreo , Adhesión en Plástico , Radiografía de Mordida Lateral , Preparación del Conducto Radicular/métodos , Propiedades de Superficie , Fijación del Tejido

RESUMEN

This study evaluated the influence of the cementation system on the regional push-out bond strength and failure pattern of fiber posts to radicular dentin. The roots of 48 extracted human incisors were prepared and divided into 3 groups (n=16), according to the cementation system: AdperScotchbond Multi-Purpose + resin cement RelyX ARC (SBMP+ARC); Adper SingleBond 2 + RelyX ARC (SB+ARC) and; RelyX U100 self-adhesive resin cement (U100). The posts were cemented as per manufacturer’s instructions for each cementation system. After 1 week, the roots were sectioned transversely into 6 discs. Two discs were obtained from the cervical, middle and apical thirds and the push-out test was carried out. The failure pattern was examined on all debonded specimens. The data were analyzed by two-way repeated measures ANOVA and Tukey’s test. When U100 was used, no statistically significant difference (p>0.05) was observed among the different root regions. Statistically higher push-out bond strength values were detected in the cervical third for SBMP+ARC and SB+ARC (p<0.05). The U100 showed significantly more mixed failures than SBMP+ARC in the apical third (p<0.05). In conclusion, the self-adhesive cement RelyX U100 was the only cement not sensitive to the root canal region.

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Esse estudo avaliou a influência do sistema de cimentação na resistência de união regional e os padrões de fratura de pinos de fibra à dentina radicular. As raízes de 48 incisivos humanos extraídos foram preparadas e divididas em 3 grupos (n=16) de acordo com o sistema de cimentação: AdperScotchbond Multi-Purpose + cimento resinoso RelyX ARC (SBMP+ARC); AdperSingle Bond 2 + RelyX ARC (SB+ARC) e cimento resinoso autoadesivo RelyX U100 (U100). Os pinos foram cimentados conforme as recomendações dos fabricantes para cada sistema de cimentação. Após uma semana, as raízes foram seccionadas transversalmente em 6 discos. Dois discos foram obtidos para os terços coronário, médio e apical e o teste de push-out foi realizado. O padrão de fratura foi avaliado em todos os espécimes. Os dados obtidos foram analisados através dos testes ANOVA dois fatores e Tukey. Quando o cimento U100 foi testado, não foram observadas diferenças significativas (p>0,05) entre as diferentes regiões radiculares. Valores de resistência de união significativamente superiores foram encontrados no terço coronário para SBMP+ARC e SB+ARC (p<0,05). O U100 apresentou significativamente mais fraturas mistas que o SBMP+ARC no terço apical (p<0,05). Conclui-se que o cimento resinoso autoadesivo RelyX U100 foi o único cimento não afetado pela região do canal radicular.

Asunto(s)

Humanos , Cementación/métodos , Recubrimiento Dental Adhesivo , Cavidad Pulpar/ultraestructura , Dentina/ultraestructura , Técnica de Perno Muñón/instrumentación , Cementos de Resina/química , Grabado Ácido Dental/métodos , Bisfenol A Glicidil Metacrilato/química , Retención de Prótesis Dentales , Materiales Dentales/química , Análisis del Estrés Dental/instrumentación , Recubrimientos Dentinarios/química , Vidrio/química , Incisivo/ultraestructura , Ensayo de Materiales , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Preparación del Conducto Radicular/métodos , Estrés Mecánico , Propiedades de Superficie , Temperatura , Factores de Tiempo , Ápice del Diente/ultraestructura

RESUMEN

OBJECTIVE: Although the general mechanisms of dentinogenesis are understood, several aspects regarding tertiary dentine formation still deserve investigation, especially regarding the presence and distribution of some noncollagenous matrix proteins. As dentine matrix protein 1 (DMP 1) is present in primary dentine, it is possible that this protein may also be present in the dentine matrix secreted after injury, but there are no immunocytochemical studies attempting its detection in tertiary dentine. The aim of this study was to examine the ultrastructural immunolocalization of DMP 1 in the tertiary dentine after extrusion of the rat incisor. STUDY DESIGN: Upper incisors were extruded 3mm and then repositioned into their sockets. After several periods, the incisors were fixed and processed for transmission electron microscopy and for immunocytochemistry for DMP 1. RESULTS: Extrusion yielded both types of tertiary dentine, which varied in aspect and related cells. DMP 1 was found in the mineralized matrix of all types of dentine, presenting high affinity for collagen, but rare colloidal gold particles over predentine. DMP 1 was evident in the supranuclear region and inside the nucleus of some odontoblast-like cells. CONCLUSION: The observed association between DMP 1 and collagen seem to be essential for reactionary and reparative dentine formation.

Asunto(s)

Dentina Secundaria/ultraestructura , Proteínas de la Matriz Extracelular/análisis , Incisivo/ultraestructura , Fosfoproteínas/análisis , Animales , Núcleo Celular/ultraestructura , Colágeno/ultraestructura , Esmalte Dental/ultraestructura , Pulpa Dental/ultraestructura , Oro Coloide , Inmunohistoquímica , Incisivo/lesiones , Masculino , Microscopía Electrónica de Transmisión , Odontoblastos/ultraestructura , Ratas , Ratas Wistar , Avulsión de Diente/patología , Reimplante Dental

RESUMEN

OBJECTIVE: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. MATERIAL AND METHODS: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging from 20x to 1000x. Group I: 10 primary molars exfoliated due to physiologic root resorption; Group II: 10 permanent teeth with periapical granulomas showing signs of resorption; Group III:10 permanent teeth therapeutically extracted during the course of orthodontic therapy with evidence of resorption, and Group IV: 10 permanent teeth associated with odontogenic tumors that showed evidence of resorption. RESULTS: In Group I, the primary teeth undergoing resorption showed smooth extensive and predominantly regular areas reflecting the slow ongoing physiologic process. In Group II, the teeth with periapical granulomas showed the resorption was localized to apex with a funnel shaped appearance in most cases. Teeth in Group III, which had been subjected to a short period of light orthodontic force, showed the presence of numerous resorption craters with adjoining areas of cemental repair in some cases. Teeth associated with odontogenic tumors in Group IV showed many variations in the patterns of resorption with extensive loss of root length and a sharp cut appearance of the root in most cases. CONCLUSION: Differences were observed in the patterns of external root resorption among the studied groups of primary and permanent teeth under physiologic and pathological conditions.

Asunto(s)

Microscopía Electrónica de Rastreo , Resorción Radicular/patología , Raíz del Diente/ultraestructura , Ameloblastoma/patología , Diente Premolar/ultraestructura , Cemento Dental/ultraestructura , Pulpa Dental/ultraestructura , Dentina/ultraestructura , Humanos , Incisivo/ultraestructura , Diente Molar/ultraestructura , Ortodoncia Correctiva , Granuloma Periapical/patología , Tejido Periapical/ultraestructura , Ápice del Diente/ultraestructura , Exfoliación Dental/patología , Diente Primario/ultraestructura

RESUMEN

OBJECTIVE: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. MATERIAL AND METHODS: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging from 20x to 1000x. Group I: 10 primary molars exfoliated due to physiologic root resorption; Group II: 10 permanent teeth with periapical granulomas showing signs of resorption; Group III:10 permanent teeth therapeutically extracted during the course of orthodontic therapy with evidence of resorption, and Group IV: 10 permanent teeth associated with odontogenic tumors that showed evidence of resorption. RESULTS: In Group I, the primary teeth undergoing resorption showed smooth extensive and predominantly regular areas reflecting the slow ongoing physiologic process. In Group II, the teeth with periapical granulomas showed the resorption was localized to apex with a funnel shaped appearance in most cases. Teeth in Group III, which had been subjected to a short period of light orthodontic force, showed the presence of numerous resorption craters with adjoining areas of cemental repair in some cases. Teeth associated with odontogenic tumors in Group IV showed many variations in the patterns of resorption with extensive loss of root length and a sharp cut appearance of the root in most cases. CONCLUSION: Differences were observed in the patterns of external root resorption among the studied groups of primary and permanent teeth under physiologic and pathological conditions.

Asunto(s)

Humanos , Microscopía Electrónica de Rastreo , Resorción Radicular/patología , Raíz del Diente/ultraestructura , Ameloblastoma/patología , Diente Premolar/ultraestructura , Cemento Dental/ultraestructura , Pulpa Dental/ultraestructura , Dentina/ultraestructura , Incisivo/ultraestructura , Diente Molar/ultraestructura , Ortodoncia Correctiva , Granuloma Periapical/patología , Tejido Periapical/ultraestructura , Ápice del Diente/ultraestructura , Exfoliación Dental/patología , Diente Primario/ultraestructura