RESUMO
The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group A- Acid Etching with 37% H3PO4 gel for 15 s; Group B- 5% NaOCl for 60 s + Acid Etching with 37% H3POfor 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by Kolgomorv-Smirnov test and the nonparametric unpaired Mann-Whitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern.
El objetivo del estudio fue evaluar la desproteinización del esmalte primario a través de los tipos de patrones de grabado, con y sin NaOCl 5% utilizado antes del grabado ácido con H3PO4 37%. Quince dientes primarios humanos extraídos se seleccionaron al azar para el presente estudio in vitro, se prepararon bloques de 1mm x 1 mm y se dividieron en dos grupos (n = 21). Estos grupos se trataron de la siguiente manera: Grupo A: Grabado ácido con H3PO4 37% en gel durante 15 segundos; Grupo B: NaOCl 5% durante 60 segundos + Grabado ácido con H3PO4 37% durante 15 segundos. Las muestras se prepararon para el análisis de microscopía electrónica de barrido. Las imágenes obtenidas se evaluaron principalmente por la calidad de los grabados tipo I y II de la superficie del esmalte primario, utilizando el software Image J. Los datos se analizaron en cuanto a su normalidad mediante la prueba de Kolgomorv-Smirnov, se utilizó pruebas no paramétricas: Prueba de Mann-Whitney no pareada. Como resultado, se encontró que el área de superficie media de los valores de patrón de grabado de tipo I y II para el Grupo A era 1922,314 µm2 y el Grupo B era 3840,473 µm2. Finalmente, llegamos a la conclusión de que se puede usar la desproteinización con NaOCl 5% antes del grabado ácido para aumentar el área de adhesión y la calidad del patrón de grabado.
Assuntos
Condicionamento Ácido do Dente/métodos , Colagem Dentária , Proteínas do Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Materiais Dentários/farmacologia , Ácidos Fosfóricos/farmacologia , Hipoclorito de Sódio/farmacologia , Dente Decíduo/efeitos dos fármacos , Colagem Dentária/métodos , Esmalte Dentário/ultraestrutura , Proteínas do Esmalte Dentário/ultraestrutura , Corrosão Dentária , Humanos , Microscopia Eletrônica de Varredura , Desnaturação Proteica , Cimentos de Resina , Propriedades de Superfície , Dente Decíduo/ultraestruturaRESUMO
BACKGROUND: No evidence about damage caused by ball-ended probes on tooth is available. No study compared probing defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth. This exploratory study aimed to compare ultrastructural defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth. METHODS: Forty-nine primary extracted teeth were tactile examined as performed for caries activity assessment. Surfaces were randomly divided into groups based on probe type (ball-ended probe or sharp explorer). Two examiners probed different surfaces using the sharp explorer and the ball-ended probe. The order for examination was randomly determined. Images were captured using environmental scanning electron microscopy (ESEM) before and after probing. Two external examiners evaluated independently the ESEM images and scored them as: 0) no damage, 1) slight marks, 2) distinct marks, 3) marks with discontinuity, 4) enamel break-offs. Multilevel Poisson regression models were used to analyze associations between probing ultrastructural damage and surface type, baseline condition and probe type. Prevalence ratios (PR) were calculated with 95 % confidence interval (CI). RESULTS: The most common defects observed on the dental surfaces were probing marks without discontinuity (scores 1 and 2). Ball-ended probes caused significantly less severe damage than sharp explorers (PR: 0.28; CI: 0.11-0.76, p = 0.01). CONCLUSION: Ball-ended probes cause less damage than sharp explorers when probing gently dental surfaces of primary teeth.
Assuntos
Instrumentos Odontológicos/efeitos adversos , Dente Decíduo/ultraestrutura , Cárie Dentária/diagnóstico , Esmalte Dentário/ultraestrutura , Instrumentos Odontológicos/classificação , Humanos , Distribuição AleatóriaRESUMO
INTRODUCTION: Partial caries removal has been shown to be an effective method to treat deep carious lesions in deciduous teeth. Nevertheless, the possibility of keeping infected dentin in the cavity still requires additional investigation. The objective of this research was to describe changes in primary infected dentin after restoration with glass ionomer cement. METHODS: Dentin from 45 primary molars with deep and active carious lesions was evaluated using clinical and laboratory criteria, before and 60 days after restoration. The clinical analysis evaluated dentin colour (CO), dentin consistency (COS) and laser fluorescence (LF). The laboratory procedures assessed bacterial contamination and mineral content (MC), and evaluated the dentin ultrastructure and collagen content. Data on CO, COS, LF and colony forming units were analysed using the Wilcoxon signed-rank test; MC, bacterial counts and collagen evaluations were evaluated using the Student's t-test. RESULTS: After 60 days, lower values of LF were observed, together with a lower bacterial count, and a higher COS was found, with an increase in calcium, phosphorus and collagen contents. Differences were not detected for CO or for fluorine content. Baseline samples showed enlarged tubules with bacterial invasion; 60-day samples showed better organised tissue, with a more compact intertubular dentin and narrower tubules. CONCLUSION: It is concluded that appropriate cavity sealing can promote beneficial changes in deep carious lesions of primary teeth, even in the presence of infected dentin.
Assuntos
Cárie Dentária/patologia , Cárie Dentária/terapia , Restauração Dentária Permanente/métodos , Dentina/patologia , Dente Decíduo/patologia , Carga Bacteriana , Criança , Pré-Escolar , Colágeno/análise , Cárie Dentária/microbiologia , Dentina/química , Dentina/ultraestrutura , Feminino , Cimentos de Ionômeros de Vidro/uso terapêutico , Humanos , Masculino , Dente Molar/química , Dente Molar/patologia , Dente Molar/ultraestrutura , Fósforo/análise , Dente Decíduo/química , Dente Decíduo/ultraestruturaRESUMO
BACKGROUND: To investigate the influence of chemical and microbiological methods of caries induction on bond degradation of adhesive systems to primary dentin. METHODS: Flat dentin surfaces from 36 primary molars were assigned to three groups (n = 12) according to method to induce caries-affected dentin: (1) control (sound dentin); (2) pH-cycling; and (3) microbiological caries induction model. Teeth were submitted to caries induction for 14 days for both methods, and the sound dentin was stored in distilled water during the same period. Specimens from each experimental group were then randomly reassigned to two subgroups (n = 6) according to the adhesive system tested: two-step etch-and-rinse adhesive (Adper Single Bond 2 - SB) or two-step self-etch system (Clearfil SE Bond - CSEB). Composite buildups were constructed and sectioned to obtain bonded sticks to be subjected to microtensile (µTBS) testing immediately or after 12 months of water aging. The µTBS means were analyzed by three-way repeated measures ANOVA and Tukey's tests (α = 0.05). RESULTS: The µTBS values obtained to artificially-created caries-affected dentin were lower compared with sound dentin, but were not affected by method of caries induction. Water storage for 12 months reduced bond strengths, except to CSEB bonded to sound dentin. CONCLUSION: Chemical and microbiological methods affect similarly the stability of resin-dentin bonds in primary teeth.
Assuntos
Colagem Dentária , Cárie Dentária/etiologia , Dentina/ultraestrutura , Cimentos de Resina/química , Dente Decíduo/ultraestrutura , Condicionamento Ácido do Dente/métodos , Biofilmes , Resinas Compostas/química , Cárie Dentária/microbiologia , Cimentos Dentários/química , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Dentina/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Distribuição Aleatória , Streptococcus mutans/fisiologia , Estresse Mecânico , Resistência à Tração , Fatores de Tempo , Dente Decíduo/microbiologia , Água/químicaRESUMO
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.
Assuntos
Dentina/ultraestrutura , Raiz Dentária/ultraestrutura , Dente Decíduo/ultraestrutura , Animais , Bovinos , Humanos , Incisivo/ultraestrutura , Microscopia Eletrônica de VarreduraRESUMO
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.
Assuntos
Esmalte Dentário/ultraestrutura , Dente Decíduo/ultraestrutura , Apatitas/análise , Cálcio/análise , Cristalografia , Dente Canino/química , Dente Canino/ultraestrutura , Esmalte Dentário/química , Durapatita/análise , Humanos , Hidróxidos/análise , Incisivo/química , Incisivo/ultraestrutura , Microscopia Eletrônica de Varredura , Fosfatos/análise , Fósforo/análise , Espectroscopia Fotoeletrônica , Porosidade , Espectrometria por Raios X , Espectroscopia de Infravermelho com Transformada de Fourier , Dente Decíduo/química , Difração de Raios XRESUMO
PURPOSE: To evaluate the effects of radiation therapy on deciduous teeth. MATERIALS AND METHODS: The enamel and dentin microhardness (n = 12) was evaluated at 3 depths, both before (control) and after each 10 Gy of irradiation and up to a dose of 60 Gy. The morphology was evaluated via scanning electron microscopy (SEM) (n = 8). The data were analyzed using a two-way analysis of variance (ANOVA) and Tukey's test (α = 5%). RESULTS: The enamel microhardness, as a whole, increased (p < 0.05) after a dose of 60 Gy (211.4 KH), mostly in the superficial enamel. There was a significant difference between the values of nonirradiated dentin microhardness (28.9 KH) compared with dentin that was irradiated with doses of 10 Gy (23.8 KH), 20 Gy (25.6 KH), 30 Gy (24.8 KH), and 40 Gy (25.7 KH) (p < 0.05). There was no difference between nonirradiated dentin and dentin irradiated with 60 Gy (p > 0.05). The highest mean value of microhardness (29.9 KH) (p < 0.05) was found in the middle dentin. The groups that were irradiated with doses of 30 and 60 Gy exhibited greater surface changes in their enamel and dentin compared with the nonirradiated groups for all regions, exhibiting an amorphous surface upon increase of the irradiation doses. CONCLUSIONS: The enamel microhardness increased at a dose of 60 Gy, whereas the value of the dentin microhardness did not change. A progressive disruption of enamel and dentin morphology was found with the increased radiation dose.
Assuntos
Esmalte Dentário/efeitos da radiação , Dentina/efeitos da radiação , Radioterapia/efeitos adversos , Dente Decíduo/efeitos da radiação , Esmalte Dentário/citologia , Esmalte Dentário/ultraestrutura , Dentina/citologia , Dentina/ultraestrutura , Dureza/efeitos da radiação , Testes de Dureza , Humanos , Técnicas In Vitro , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura , Dosagem Radioterapêutica , Dente Decíduo/citologia , Dente Decíduo/ultraestruturaRESUMO
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.
Assuntos
Incisivo/ultraestrutura , Pulpectomia/métodos , Tratamento do Canal Radicular/métodos , Dente Decíduo/ultraestrutura , Criança , Cemento Dentário/ultraestrutura , Feminino , Seguimentos , Humanos , Microscopia Eletrônica de Varredura , Planejamento de Assistência ao Paciente , Materiais Restauradores do Canal Radicular/uso terapêutico , Reabsorção da Raiz/fisiopatologia , Ápice Dentário/ultraestrutura , Esfoliação de Dente/fisiopatologia , Extração Dentária/métodos , Cimento de Óxido de Zinco e Eugenol/uso terapêuticoRESUMO
PURPOSE: The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth. METHODS: Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds. CONCLUSIONS: For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.