1.
Acta odontol. latinoam
;
35(1): 10-15, Apr. 2022. graf
Article
in English
|
LILACS-Express
| LILACS
| ID: biblio-1383419
ABSTRACT
ABSTRACT The aim of this study was to determine Vickers microhardness (HV) in bulk fill resins at different depths. Test specimens were prepared with different bulk fill resins: Filtek Bulk-Fill (3M ESPE) [FBF], Surefill SDR flow (Dentsply) [SDR], Fill-UP (COLTENE) [FU] and Surefill (Dentsply) [SF]. Semi-cylindrical test specimens were prepared in a mold 6 mm in diameter and 4 mm thick (n=5). A 1000 mW/cm2 light curing unit was applied (Coltolux LED - Coltene) for 20 seconds. HV was determined with three indentations (Vickers Future Tech FM300, 300 g, 8 s) at four depths: 1, 2, 3 and 4 mm from the top surface to the interior. Data were recorded immediately (t0) and 24 hours later (t24). Results were analyzed with two-way ANOVA (p<0.05), and multiple comparisons were performed using Tukey's test. Mean and SD of HV at t0 for each mm were: [FBF] t0: 49.23(4.65) / 48.32(3.36) / 44.38(2.06) / 40.59(2.58); [FBF] t24: 61.37(3.47) / 62.63(3.03) / 57.27(5.22) / 56.37(5.88); [SDR] t0: 27.81(3.13) / 28.07(2.4) / 27.24(2.94) / 25.71(3.0); [SDR] t24: 35.11(2.16) / 35.17(1.96) / 35.53(1.81) / 33.18(2.08); [FU] t0: 41.43(1.41) / 39.87(0.88) / 38.11(1.81) / 39.09(1.92); [FU] t24: 49.27(1.54) / 48.77(1.77) / 48.65(1.88) / 46.76(4.93); [SF] t0: 71.35(7.09) / 67.39(9.76) / 68.95(6.21) / 64.1(8.35); [SF] t24: 76.06(6.61) / 75.31(9.37) / 75.2(11.57) / 69.81(12.14). ANOVA showed significant effect of material, depth and recording time (p<0.05), and Tukey's test showed that recording sites (depths) differed significantly, giving four homogeneous groups. Under the conditions of this study, it can be concluded that microhardness of bulk-fill resins can be affected by depth and post-curing time.
RESUMEN El objetivo del presente estudio fue determinar la microdureza Vickers (HV) en resinas bulk-fill a diferentes profundidades. Se confeccionaron probetas semicilíndricas de 6 mm de diámetro y 4 mm de profundidad con diferentes composites de aplicación en bloque (Bulk-fill): Filtek Bulk-Fill (3M ESPE) [FBF], Surefill SDR flow (Dentsply) [SDR], Fill-UP (COLTENE) [FU] y Surefill (Dentsply) [SF]. Se polimerizaron con Coltolux LED (Coltene) con 1000 mW/cm2 durante 20s. La HV se determinó realizando 3 indentaciones con 300 g durante 8 s a 1,2 3 y 4 mm desde la superficie de la probeta hacia el interior inmediatamente después de curada y a las 24 h. Se utilizó un microdurómetro Vickers Future Tech FM300. Los resultados se analizaron estadísticamente mediante ANOVA de dos vías y Prueba de Tukey. La media y DS de HV fueron: [FBF] t0: 49,23(4,65) / 48,32(3,36) / 44,38(2,06) / 40,59(2,58); [FBF] t24: 61,37(3,47) / 62,63(3,03) / 57,27(5,22) / 56,37(5,88); [SDR] t0: 27,81(3,13) / 28,07(2,4) / 27,24(2,94) / 25,71(3,0); [SDR] t24: 35,11(2,16) / 35,17(1,96) / 35,53(1,81) / 33,18(2,08); [FU] t0: 41,43(1,41) / 39,87(0,88) / 38,11(1,81) / 39,09(1,92); [FU] t24: 49,27(1,54) / 48,77(1,77) / 48,65(1,88) / 46,76(4,93); [SF] t0: 71,35(7,09) / 67,39(9,76) / 68,95(6,21) / 64,1(8,35); [SF] t24: 76,06(6,61) / 75,31(9,37) / 75,2(11,57) / 69,81(12,14). La evaluación con análisis de varianza mostró el efecto significativo de las variables material, profundidad y momento del registro (p<0,05) y la prueba de Tukey mostró que los sitios de registro (profundidad) fueron estadísticamente significativos, dando cuatro grupos homogéneos. Bajo las condiciones de este estudio podemos concluir que la microdureza de las resinas de inserción en bloque se ve afectada por el nivel de profundidad y el tiempo pos curado.
2.
J. appl. oral sci
;
27: e20180233, 2019. tab, graf
Article
in English
| LILACS, BBO
| ID: biblio-975899
ABSTRACT
Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initial color, microhardness and chemical composition, the bleaching treatments were performed as G1: Signal Professional White Now POWDER&LIQUID FAST 38% Hydrogen peroxide(S); G2: S+Flor Opal/0.5% fluoride ion(F); G3: S+GC Tooth Mousse/Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) paste(TM); G4: S+UltraEZ/3% potassium nitrate&0.11% fluoride(U); G5: S+Signal Professional SENSITIVE PHASE 1/30% Nano-Hydroxyapatite (n-HAP) suspension(SP); G6: S-F mixture; G7: S-TM mixture; G8: S-U mixture; G9: S-SP mixture. Color, microhardness and chemical composition measurements were repeated after 1 and 14 days. The percentage of microhardness loss (PML) was calculated 1 and 14 days after bleaching. Data were analyzed with ANOVA, Welch ANOVA, Tukey and Dunnett T3 tests (p<0.05). Results: Color change was observed in all groups. The highest ΔE was observed at G7 after 1 day, and ΔE at G8 was the highest after 14 days (p<0.05). A decrease in microhardness was observed in all groups except G6 and G7 after 1 day. The microhardness of all groups increased after 14 days in comparison with 1 day after bleaching (p>0.05). PML was observed in all groups except G6 and G7 after bleaching and none of the groups showed PML after 14 days. No significant changes were observed after bleaching at Ca and P levels and Ca/P ratios at 1 or 14 days after bleaching (p>0.05). F mass increased only in G2 and G6, 1 day after bleaching (p<0.05). Conclusions: The use of desensitizing agents containing fluoride, CPP-ACP, potassium nitrate or n-HAP after in-office bleaching or mixed in bleaching agent did not inhibit the bleaching effect. However, they all recovered microhardness of enamel 14 days after in-office bleaching.
Subject(s)
Humans , Tooth Bleaching/methods , Dental Enamel/drug effects , Dentin Desensitizing Agents/chemistry , Tooth Bleaching Agents/chemistry , Reference Values , Saliva, Artificial/chemistry , Spectrometry, X-Ray Emission , Spectrophotometry , Surface Properties/drug effects , Time Factors , Materials Testing , Calcium Phosphates/chemistry , Microscopy, Electron, Scanning , Caseins/chemistry , Random Allocation , Reproducibility of Results , Analysis of Variance , Potassium Compounds/chemistry , Color , Statistics, Nonparametric , Dental Enamel/chemistry , Hardness Tests , Hydrogen Peroxide/chemistry , Nitrates/chemistry
3.
Braz. oral res. (Online)
;
31: e84, 2017. tab, graf
Article
in English
| LILACS
| ID: biblio-952087
ABSTRACT
Abstract: The study aimed to investigate the effects of bacterial biofilms on changes in the surface microhardness of enamel treated with casein phosphopeptide—amorphous calcium phosphate (CPP-ACP) with and without fluoride. Human enamel blocks with incipient caries-like lesions were divided into four groups of 13: G1: Saliva (Control); G2: fluoride dentifrice (Crest™, 1100 ppm as NaF); G3: CPP-ACP (MI Paste; Recaldent™); and G4: CPP-ACPF (MI Paste Plus; Recaldent™ 900 ppm as NaF). The specimens were soaked in demineralizing solution for 6 h and remineralized in artificial saliva for 18 h alternately for 10 days. The dentifrice was prepared with deionized water in a 1 : 3 ratio (w/w) or applied undiluted in the case of the CPP-ACP group. The surface microhardness (SMH) was evaluated at baseline, after artificial caries, after pH cycling and treatment with dentifrices, and after incubation in media with Streptococcus mutans for biofilm formation. The biofilms were exposed once a day to 2% sucrose and the biofilm viability was measured by MTT reduction. The percentage of change in surface microhardness (%SMHC) was calculated for each block. The data were analyzed by nonparametric test comparisons (α = 0.05). The %SMHC values observed in G2 were different from those of G1, G3, and G4 (p < 0.05). After biofilm formation, %SMHC was positive in G2 and G4 when compared to G1 and G3, but resistance to demineralization after biofilm formation was similar in all groups. In conclusion, the presence of biofilms did not influence the treatment outcomes of anticaries products.
Subject(s)
Humans , Streptococcus mutans/physiology , Cariostatic Agents/chemistry , Caseins/chemistry , Biofilms/growth & development , Dental Enamel/drug effects , Dental Enamel/microbiology , Fluorides/chemistry , Reference Values , Saliva, Artificial/chemistry , Streptococcus mutans/drug effects , Surface Properties , Time Factors , Tooth Remineralization/methods , Materials Testing , Reproducibility of Results , Statistics, Nonparametric , Biofilms/drug effects , Dentifrices/chemistry , Hardness Tests
4.
Fortaleza; s.n; 2016. 44 p. ilus, tab.
Thesis
in Portuguese
| LILACS
| ID: biblio-971911
ABSTRACT
O plasma de baixa temperatura (PBT) tem tido seu uso investigado na destruição dosbiofilmes orais, no entanto,seu efeito sobre os substratos dentários ainda não estácompletamente esclarecido. O objetivo deste trabalho foi avaliar o efeito do PBT na durezasuperficial, no ângulo de contato, na morfologia das superfícies e composição química doesmalte e dentina bovinos. Para tanto, foram analisados a dureza de superfície Knoop (DS), asalterações nos ângulos de contato (AC), a morfologia de superfície por MicroscopiaEletrônica de Varredura (MEV) e sua composição química através da EspectofotometriaRaman (ER). Inicialmente, foram confeccionados blocos de esmalte e dentina com dimensõesde 4x4x2 mm preparados a partir de dentes bovinos. Todos os blocos foram polidos e dividosem três grupos (n=6): Plasma de Argônio, Gás de Argônio e Controle. A MS foi avaliadaantes e depois de cada tratamento, realizando-se cinco penetrações em cada espécime (50g/5spara esmalte e 25g/5s para dentina). A determinação do AC foi realizada dispersando umagota de água sobre a superfície tratada e observando o ângulo de contato obtido em 1 min e 1hora, utilizando fotografias digitais de alta resolução e o programa Image J. As alteraçõesfísicas na morfologia do esmalte e dentina submetidos ao PBT foram observadas a partir daMEV. Adicionalmente, a proporção relativa do conteúdo orgânico e mineral do esmalte edentina após os tratamentos foram analisados por ER. . Os dados foram avaliados por análisede variância (ANOVA) 1 via para MS e 2 vias (tratamento e tempo) para AC, após Tukeyteste (α < 0,05). Os resultados da MS demostraram não haver diferença significativa noesmalte (p = 0,087) após os tratamentos. No entanto, a MS da dentina diminuiu após otratamento de plasma de argônio (p = 0,005)...
Low-temperature plasma (LTP) is a promising technology with the potential benefit ofdestroying the matrix of the oral biofilm and also produce antimicrobial effect on the bacterialcell. However, the effect of LTP on dental structures is not clear. The objective of this studywas to evaluate the effect of LTP on enamel and dentin substrates. Therefore, we analyzedKnoop microhardness to calculate the percentage of surface hardness (SH), changes in contactangles (CA), the surface topography by Scanning Electron Microscopy (SEM) and also thechemical composition by Raman spectrometry (RS). Initially, 4x4x2 mm enamel and dentinblocks were prepared from bovine incisors. All blocks were polished and divided into threegroups (n = 6); argon plasma, argon flow rate and control. The SH was assessed before andafter each treatment, performing five penetrations in each specimen (50g / 25g and 5s enamel/ dentin 5s). Contact angles changes were performed by dispersing water drop on the treatedsurfaces and observing the contact angle obtained after 1 min and 1 hour. For that, highresolutiondigital photos and the Image J program was used. Physical changes in the structureof enamel and dentin submitted to LTP were observed from the SEM. Additionally, therelative proportion of the organic and mineral content of the enamel and dentin after treatmentwere analyzed by RS. Data were evaluated by analysis of variance (ANOVA) - 2-way(treatment and time) and Tukey test (α <0.05). For the SH the results showed no significantdifference in the enamel (p=0.087), however, the SH of dentin decreased after treatment withargon plasma (p=0.005)...
Subject(s)
Humans , Plasma Gases , Spectrum Analysis, Raman , Microscopy, Electron, Scanning
5.
Rev. odontol. UNESP (Online)
;
44(4): 207-212, jul.-ago. 2015. tab
Article
in Portuguese
| LILACS, BBO
| ID: lil-755990
ABSTRACT
Introdução: O cimento resinoso dual é o principal material para cimentação de cerâmicas. Contudo, fatores, como fonte de luz, podem influenciar no desempenho do cimento. Objetivo: Avaliar a influência de duas fontes de luz de diferentes intensidades sobre a microdureza de um cimento resinoso quando fotoativado sob diferentes cerâmicas. Material e método: Foram fotoativados 40 espécimes de cimento resinoso dual (10 mm × 1,0 mm) por meio de duas fontes de luz LED, com intensidades de 1.000 mW/cm² e 800 mW/cm² durante 40 segundos, sob cerâmicas (15 mm × 2 mm) à base de zircônia, espinélio MgAl2O4 e dissilicato de lítio. No grupo controle, foi utilizada uma placa de vidro de mesma dimensão. As amostras tiveram a superfície regularizada com lixa d`água (600 e 1200). Após armazenagem a seco no escuro (24 h), foram realizadas as medidas de microdureza Vickers (HMV Shimadzu - 50g/10 segundos). Os dados foram submetidos à Anova fatorial e ao teste de Tukey com nível de significância de 5%. Resultado: O cimento polimerizado apresentou valor médio de microdureza e desvio padrão para o grupo controle de 43,9±1,5 e 43,4±1,3, para as intensidades de 1.000 mW/cm2 e 800 mW/cm2, respectivamente. O menor valor de microdureza do cimento foi observado para a cerâmica à base de espinélio MgAl2O4, polimerizado a 800 mW/cm², com valor de 34,3±3,3.