Effect of dentin surface treatments on the bond strength of resin-modified glass ionomer cement / 口腔疾病防治

@#Resin-modified glass ionomer cement (RMGIC) has good physical, chemical and biological properties and is suitable for the treatment of deciduous caries, aged root surface caries and wedge-shaped defects. Surface treatment is a common method to improve bonding strength, which can improve physical and chemical retention between different components. This paper mainly introduces the current research status of the influence of different dentin surface treatment methods on the bonding strength of RMGIC. At present, the common dentin surface treatment methods are pretreatment, acid etching, laser treatment, etc. The pretreatment agent can improve the bond strength of RMGIC by increasing the surface area and porosity of dentin. The bond strength of RMGIC could be effectively improved after the dentin was treated by an acid-etching bonding system. The dentin was treated with a laser to obtain a higher bonding strength. However, whether the use of resin adhesives will affect the release of fluoride ions in RMGIC into the deep dentin and thus affect the repair effect also needs further research.

The use of a liner under different bulk-fill resin composites: 3D GAP formation analysis by x-ray microcomputed tomography

Abstract Gap formation of composite resin restorations is a serious shortcoming in clinical practice. Polymerization shrinkage stress exceeds the tooth-restoration bond strength, and it causes bacterial infiltration within gaps between cavity walls and the restorative material. Thus, an intermediate liner application with a low elastic modulus has been advised to minimize polymerization shrinkage as well as gap formation. Objective: The purpose of this in vitro study was to assess gap formation volume in premolars restored with different bulk-fill composites, with and without a resin-modified glass-ionomer cement (RMGIC) liner, using x-ray micro-computed tomography (micro-CT). Methodology: Sixty extracted human maxillary premolars were divided into six groups according to bucco-palatal dimensions (n=10). Standardized Class II mesio-occluso-distal cavities were prepared. G-Premio Bond (GC Corp., Japan) was applied in the selective-etch mode. Teeth were restored with high-viscosity (Filtek Bulk Fill, 3M ESPE, USA)-FB, sonic-activated (SonicFill 2, Kerr, USA)-SF and low viscosity (Estelite Bulk Fill Flow, Tokuyama, Japan)-EB bulk-fill composites, with and without a liner (Ionoseal, Voco GmbH, Germany)-L. The specimens were subjected to 10,000 thermocycles (5-55°C) and 50,000 simulated chewing cycles (100 N). Gap formation based on the volume of black spaces at the tooth-restoration interface was quantified in mm3 using micro-computed tomography (SkyScan, Belgium), and analyses were performed. Data were analyzed using repeated-measures ANOVA and the Bonferroni correction test (p < 0.05). Results: The gap volume of all tested bulk-fill composites demonstrated that Group SF (1.581±0.773) had significantly higher values than Group EB (0.717±0.679). Regarding the use of a liner, a significant reduction in gap formation volume was observed only in Group SFL (0.927±0.630) compared with Group SF (1.581±0.773). Conclusion: It can be concluded that different types of bulk-fill composite resins affected gap formation volume. Low-viscosity bulk-fill composites exhibited better adaptation to cavity walls and less gap formation than did sonic-activated bulk-fill composites. The use of an RMGIC liner produced a significant reduction in gap formation volume for sonic-activated bulk-fill composites.

Effect of Nano-filled Protective Coating on Microhardness and Wear Resistance of Glass-ionomer Cements / 대한소아치과학회지

The purpose of this study was to investigate the effect of adding a protective coating on the microhardness and wear resistance of glass ionomer cements (GICs).Specimens were prepared from GIC and resin-modified GIC (RMGI), and divided into 3 groups based on surface protection: (1) no coating (NC), (2) Equia coat coating (EC), and (3) un-filled adhesive coating (AD). All specimens were then placed in distilled water for 24 h. Surface hardness (n = 10) was evaluated on a Vickers hardness testing machine. Wear resistance (n = 10) was evaluated after subjecting the specimen to thermocycling for 10,000 cycles using a chewing simulator. Data were analyzed using a one-way ANOVA and the Kruskal-Wallis test.Surface hardness was highest in the NC groups, followed by the EC and AD groups. The wear depth of GI + NC was significantly higher than that of all RMGI groups. EC did not significantly lower the wear depth compared to AD.Based on these results, it was concluded that although EC does not increase the surface microhardness of GIC, it can increase the wear resistance.

Effect of protective coating on microleakage of conventional glass ionomer cement and resin-modified glass ionomer cement in primary molars: An In vitro study

The aim of this in vitro study was to evaluate and compare the effect of protective coating G-Coat Plus on microleakage of conventional glass ionomer cement (CGIC) and resin-modified glass ionomer cement (RMGIC) in primary molars. Materials and Methods: A total of 120 samples were divided into four groups with 30 samples in each group. Group A – teeth restored with CGIC. Group B – teeth restored with CGIC coated with G-Coat Plus. Group C – teeth restored with RMGIC. Group D – teeth restored with RMGIC coated with G-Coat Plus. Microleakage was tested using 2% basic fuschin dye penetration and measured at ×40 original magnification under the stereomicroscope. Results: The results of this in vitro study showed that coating with G-Coat Plus showed a reduction in microleakage in CGIC and complete absence of microleakage in RMGIC when compared to the noncoated groups, which was statistically significant. CGIC without G-Coat Plus showed highest microleakage followed by RMGIC without G-Coat Plus, followed by a relatively less microleakage in CGIC with G-Coat Plus. Conclusion: Significant reduction in microleakage was seen in conventional GIC and RMGIC with G-Coat Plus when compared to conventional GIC and RMGIC without G-Coat Plus.

Effect of hydrogen peroxide application on color and surface roughness of two restorative materials

Aim: This study investigated the effect of an in-office bleaching technique on lightness, color and surface roughness of two commercially available materials: a resin-modified glass-ionomer cement and a nanohybrid resin composite. Methods: Twelve disk-shaped specimens were prepared with both materials. The samples were bleached with 35% hydrogen peroxide. Bleaching was tested initially onto a smooth surface and later onto a polished one of the same specimens. The effect of the treatments on lightness and color was verified with a spectrophotometer. Surface roughness was measured with a digital surface roughness tester. The data were statistically analyzed by repeated measures ANOVA and post hoc Tukey's test (alpha = 0.05). Results: Significant variation in lightness and color was observed on the resin-modified glass-ionomer cement after the first bleaching procedure. Roughness increased significantly only after polishing the resin-modified glass-ionomer cement surface. Composite color variation was evident in the last observation period, but roughness and lightness variation due to bleaching and polishing was not significant. Conclusion: The bleaching treatment caused significant color alterations on the materials tested. This study observed that the application of in-office bleaching onto the glass-ionomer cement promoted clinically observable color alteration, and polishing after bleaching is contraindicated for this material. (AU)

Bond strength of a resin composite and a resin-modified glass-ionomer cement associated or not with chlorhexidine to eroded dentin / Resistência de união de uma resina composta e um cimento de ionômero de vidro modificado por resina com e sem a aplicação de clorexidina à dentina erodida

Objetivo: Apesar da resina composta e o cimento de ionômero de vidro serem amplamente usados para restaurações cervicais, sob condições erosivas estas podem desgastar mais rapidamente. Este estudo objetivou comparar a resistência adesiva ao microcisalhamento de uma resistência de união (RC) e um cimento de ionômero de vidro modificado por resina (RMGIC) à dentina erodida associada à Clorexidina 2% num período de até 6 meses. Material e Métodos: Oitenta terceiros molares humanos foram cortados e uma dentina regular foi obtida, e subsequentemente, foram inclusos com resina acrílica em tubos de PVC. Os dentes foram divididos em dois grupos, de acordo com o tratamento recebido: Adper Single Bond 2 + RC Filtek Z250 (Z) ou RMGIC Vitremer (V). Metade dos corpos de prova foram imersos em saliva artificial (AS) por 24 h (grupo controle) e metade foi erodido artificialmente 3x/1 min diariamente com Coca Cola ®-RC por 5 dias. Metade dos corpos de prova, para cada condição descrita, recebeu água e outra metade a clorexidina 2% por 1 min, antes da restauração. Para todos os grupos, os corpos de prova foram armazenados em saliva artificial renovada semanalmente até os testes. A resistência de união ao microcisalhamento foi avaliado após 1 e 6 meses. Os resultados foram analisados com teste ANOVA 4 critérios e Tukey (p < 0,05). Resultados: Os fatores materiais, substrato e tempo foram estatisticamente significantes, além da interação entre o material e o tempo. O tratamento (água X clorexidina) não foi um fator significante. As restaurações com Z demonstraram resistência de união significantemente maior comparada ao V, em todas as situações. Conclusão: Tanto para a dentina sadia quanto erodida, a resina composta apresentou maior resistência de união comparada ao cimento de ionômero de vidro. O tempo e uso da clorexidina não interferiu na resistência de união. A resina composta demonstrou maior resistência adesiva quando comparada ao cimento de ionomero de vidro.

Objective: Although resin composites and glassionomer cements are widely used for dental cervical region restorations, under erosive condition they can wear out quickly. This study aimed to compare, by means of microshear bond strength, the performance of a resin composite (RC) and a resin-modified glassionomer cement (RMGIC) to eroded dentin and its association with 2% chlorhexidine (CHX) up to 6 months. Material and Methods: Eighty sound third molars teeth were cut to obtain flat coronal dentin, which were subsequently embedded in self-curing acrylic resin circular molds. Teeth were divided into two groups, according to the treatment with the Adper Single Bond 2 + RC Filtek Z250 (Z) or the RMGIC Vitremer (V). Half of the specimens were immersed in artificial saliva-AS (control groups) and half subjected to 3x/1 min daily immersion in Regular Coca Cola ®-RC for 5 days. Half of the specimens for each described condition were treated with water and half with 2% chlorhexidine for 1 min prior the restoration. For all groups, the specimens were stored in artificial saliva weekly renewed up to tests. The microshear bond strength was evaluated after 1 month and 6 months. Data, in normal distribution, were analyzed with four-way ANOVA and Tukey (p < 0.05). Results: The factors materials, substrate and time were statistically significant and also the interaction between material and time. Treatment (water x CHX) was not a significant factor. Restorations with Z showed significantly higher bond strength compared to V in all situations. There was a reduction in bond strength values over time for all tested conditions. Conclusion: For both sound and eroded dentin, the resin composite presented higher bond strength compared to resin-modified glassionomer material. The bond strength performance was overall reduced with time and the use of chlorexidine itself did not interfere on bond strength through time...

Effect of light-cured filled sealant on the shear bond strength of metal, ceramic and titanium brackets bonded with resin-modified glass ionomer cement.

Introduction: The purpose of this study was to evaluate the effect of a highly filled light‑cured sealant (HFLCS) on the shear bond strength of metal, ceramic and titanium brackets bonded with resin‑modified glass ionomer cement (RMGIC). Materials and Methods: A total of 60 freshly extracted maxillary premolars were randomly divided into six groups (10 in each group). In all groups, the teeth were etched with 37% phosphoric acid for 20 s and RMGIC (Fuji Ortho LC, GC Europe) was used for bracket bonding. Group 1: Titanium brackets were bonded directly to etched enamel surfaces. Group 2: Titanium brackets were bonded to etched enamel surfaces covered with HFLCS (Pro Seal, Reliance Orthodontic Products, Itasca, IL, USA). Group 3: Metal brackets were bonded directly to etched enamel surfaces. Group 4: Metal brackets were bonded to etched enamel surfaces covered with HFLCS. Group 5: Ceramic brackets were bonded directly to etched enamel surfaces. Group 6: Ceramic brackets were bonded to etched enamel surfaces covered with HFLCS. The specimens were tested in shear mode with a universal testing machine. After debonding, the teeth and the brackets were examined under a scanning electron microscope. Univariate analysis of variance (analysis) was performed to test the main effects of bracket type and HFLCS. Result and Conclusion: The effect of HFLCS on etched enamel surfaces did not affect the bond strength values and bond failure modes of metal, ceramic and Titanium brackets bonded with RMGIC

A ação de sucos de frutas sobre materiais restauradores utilizados em lesões cervicais não cariosas / The action of fruit juices upon restorative materials used in noncarious cervical lesions

O presente estudo in vitro analisou o efeito de 3 sucos de fruta com baixo pH (suco de cupuaçu, taperebá e laranja), e saliva artificial (controle) sobre materiais restauradores indicados em lesões cervicais não cariosas: resina composta nanoparticulada (Filtek Z350 XT), cimento de ionômero de vidro resino modificado (Vitremer) e um cimento de ionômero de vidro convencional (Fuji II). Os materiais foram avaliados, quantitativamente, quanto à alteração de: peso, rugosidade superficial e microdureza superficial, e qualitativamente, por microscopia eletrônica de varredura (MEV). Foram confeccionados 144 corpos de prova para cada teste quantitativo (n=12) e 45 para o MEV (n=3), de (8mm de diâmetro x 2mm de altura). Os corpos de prova foram preparados, mantidos em saliva artificial por 24 h à 37º C, receberam acabamento em politriz, e em seguida foram realizadas as leituras iniciais. Durante um período de 10 dias consecutivos, os corpos de prova foram submetidos ao desafio erosivo (nos respectivos sucos de frutas) durante 30 minutos três vezes ao dia, totalizando 90 minutos/dia e mantidos em saliva artificial entre os intervalos. Após o período de ciclagem erosiva, foram realizadas as leituras finais...

This in vitro study examined the effects of 3 fruit juices with low pH (cupuaçu, taperebá and orange) and artificial saliva (control) upon restorative materials indicated in noncarious cervical lesions: nanoparticle composite resin (Filtek Z350 XT), resin-modified glass ionomer cement (Vitremer) and a glass ionomer cement (Fuji II). The materials were evaluated quantitatively as for alterations in weight, surface roughness and surface microhardness, and qualitatively by scanning electronic microscopy (SEM). 144 specimens were prepared for each quantitative test (n = 12) and 45 for the SEM (n = 3), of (8mm diameter x 2mm height). The specimens were prepared, stored in artificial saliva for 24 hours at 37º C, were finished in a polishing machine, and then the initial readings were performed. During a period of 10 consecutive days, the specimens were subjected to erosive challenge (in the respective juices) for 30 minutes, three times a day, and totaling 90 minutes/day and kept in artificial saliva between intervals. After the erosive cycling period, the final readings were taken. The data were analyzed using t test, ANOVA and Tukey...

Influence of topical acidulated phosphate fluoride on surface roughness of human enamel and different restorative materials / Influência da aplicação tópica de flúor fosfato acidulado sobre a rugosidade superficial do esmalte humano e de diferentes materiais restauradores

Purpose: The aim of this study was to assess the influence of topical acidulated phosphate fluoride on the surface roughness of both human enamel and different restorative materials. Methods: Resin-modified glass ionomer (Vitremer = V), microhybrid composite resin with fluoride (Tetric Ceram = T), and nanofiller composite resin without fluoride (Z350 = Z) were evaluated. Acidulated phosphate fluoride (APF, 1.23%) was applied to half of the specimens (groups VF, TF, ZF and EF). Ten intact human third molars were used to obtain enamel specimens (E). Six experimental groups (n=10) and two control groups (n=10) were formed. The mean surface roughness (Ra) of both the restorative materials and enamel, with and without fluoride, was evaluated with a profilometer. Data were analyzed with an ANOVA, Tukey's test, Student's t-test, and Dunn-Bonferroni test at the 5% significance level. Results: The mean values of surface roughness, in micrometers, were as follows: Z=0.60; TF=1.00; ZF=1.05; VF=1.18; T=2.10; V=2.70; E=16.99; and EF=21.19. Both E and EF presented significantly higher surface roughness than the other experimental groups. Conclusion: It was concluded that APF increased the surface roughness of enamel and decreased the surface roughness of both resin-modified glass-ionomer cement and microhybrid composite resin with fluoride. The surface roughness of the nanofiller composite resin was not modified by APF.

Objetivo: Este estudo avaliou a influência da aplicação tópica de flúor fosfato acidulado sobre a rugosidade do esmalte e de diferentes materiais restauradores. Metodologia: Amostras de cimento de ionômero de vidro modificado por resina (Vitremer - V), resina composta microhíbrida com flúor (Tetric Ceram - T) e resina nanopartículada sem flúor em sua composição (Z350 - Z) foram confeccionadas. Metade das amostras recebeu aplicação tópica de flúor fosfato acidulado a 1,23% (FFA) (grupos VF, TF, ZF e EF) e a outra metade não, totalizando 6 grupos experimentais (n=10). Dez terceiros molares humanos hígidos foram utilizados para confecção de amostras de esmalte (E), constituindo os grupos controles (n=10). A rugosidade média superficial (Ra) dos materiais restauradores e do esmalte, com e sem flúor, foi analisada pelo rugosímetro. Os dados foram submetidos à análise de variância, testes de Tukey, t-Student e de Dunn-Bonferroni (5 % de significância). Resultados: Os valores médios de rugosidade, em micrômetros, foram: Z=0,60; TF=1,00; ZF=1,05; VF=1,18; T=2,10; V=2,70; E=16,99 e EF=21,19. E e EF apresentaram Ra significativamente superior aos grupos experimentais. Conclusão: Concluiu-se que o FFA aumentou a rugosidade do esmalte, diminuiu a do cimento de ionômero de vidro e da resina microhíbrida com flúor e não alterou a rugosidade da resina nanoparticulada sem flúor.

Effect of etching and light-curing time on the shear bond strength of a resin-modified glass ionomer cement

The aim of this study was to assess the influence of etching and light-curing time on the shear bond strength (SBS) and adhesive remnant index (ARI) of a resin-modified glass ionomer cement (RMGIC) upon debonding of orthodontic brackets. Sixty-eight bovine permanent incisors were obtained and embedded in acrylic resin. Edgewise metallic brackets were bonded to the teeth with Fuji Ortho LC RMGIC. The specimens were randomly assigned to 4 groups, using the following etching and light-curing times: G1: 10 percent polyacrylic acid and 40 s (control); G2: 37 percent phosphoric acid and 40 s; G3: 10 percent polyacrylic acid and 50 s; and G4: 37 percent phosphoric acid and 50 s. Shear test was performed at 0.5 mm/min and the ARI was assessed. G2 (3.6 ± 0.98 MPa) presented significantly higher (p<0.05) SBS than G1 (2.76 ± 0.86 MPa) and G4 (2.86 ± 0.68 MPa), and there was no statistically significant difference (p>0.05) between G2 and G3 (2.94 ± 0.67 MPa). ARI presented prevalence of scores 2 and 3 in all groups. RMGIC SBS enhanced with 37 percent phosphoric acid etching and 40 s light-curing time, but this did not occur when the light-curing time was increased, regardless of the acid used. RMGIC presented prevalence of failures at the adhesive/bracket interface.

O objetivo desta pesquisa foi avaliar a influência do condicionamento ácido e do tempo de fotopolimerização na Resistência Adesiva (RA) e no Índice de Adesivo Remanescente (IAR) do Cimento Ionômero de Vidro Modificado por Resina (CIVMR). Sessenta e oito incisivos permanentes de bovinos foram obtidos e incluídos em resina acrílica. Bráquetes metálicos edgewise foram colados nesses corpos de prova com o CIVMR Fuji Ortho. A amostra foi dividida em 4 grupos, utilizando os seguintes condicionamentos ácidos e tempos de fotopolimerização: G1- Ácido poliacrílico a 10 por cento e 40 s (controle); G2- Ácido fosfórico a 37 por cento e 40 s; G3- Ácido poliacrílico a 10 por cento e 50 s; e G4- Ácido fosfórico a 37 por cento e 50 s. O teste de cisalhamento foi realizado a 0,5 mm/min e o IAR avaliado. O G2 (3,6 ± 0,98 MPa) apresentou RA estatisticamente maior que o G1 (2,76 ± 0,86 MPa) e o G4 (2,86 ± 0,68 MPa) (p<0,05), e não houve diferença estatística entre G2 e G3 (2,94 ± 0,67 MPa) (p>0,05). O IAR apresentou prevalência dos escores 2 e 3 em todos os grupos. A RA do CIVMR aumenta com condicionamento com ácido fosfórico a 37 por cento e 40 s de fotopolimerização, mas isto não ocorre quando o tempo de fotopolimerização é aumentado, independente do tipo de ácido utilizado; e o CIVMR apresenta prevalência de fratura na interface adesivo/bráquete.

Avaliação da solubilidade e desintegração de cimentos de ionômero de vidro modificado por resina e compômeros em função de proteção superficial / Evaluation of the solubility and disintegration of resin modified glass ionomer cements and compomers using surface protection

O cimento de ionômero de vidro foi desenvolvido a partir da união de dois outros materiais, o cimento de silicato e o cimento policarboxilato de zinco. Mesmo com a evolução desses materiais, a propriedade solubilidade/desintegração ainda está pouco clara na literatura. O objetivo deste trabalho foi avaliar comparativamente a solubilidade e desintegração de cimentos de ionômero de vidro modificados por resina e de compômeros, bem como, a necessidade ou não de aplicação de agentes de proteção sobre suas superfícies. Os materiais utilizados foram: M1-Vitremer (3M Co.); M2-Fuji II LC (GCAmerica Inc.); M3-Dyract (Dentsply); e M4-Compoglass (Vivadent). Os agentes de proteção superficial utilizados foram: P1-Fluroshield (Dentsply) e P2-FinishingGloss (3M Co.). Estes materiais foram submetidos a testes de solubilidade e desintegração de acordo com a norma ISO 7489 de 1986. Aos resultados foram aplicadas transformações angulares e submetidos à análise de variância (p < 0,05) a dois critérios fixos e teste de homogeneidade. Os cimentos de ionômero de vidro modificados por resina e os compômeros apresentaram diferentes valores de solubilidade e desintegração. O menor valor foi obtido pelo Dyract, seguido pelo Fuji II LC e Compoglass com valores intermediários e Vitremer com o maior valor. Concluiu-se que os materiais submetidos à proteção superficial apresentaram menores valores de solubilidade e desintegração que os não protegidos; os agentes protetores, Finishing Gloss e Fluroshield mostraram-se eficazes para proteção superficial dos cimentos de ionômero de vidro modificados por resina e compômeros

The glass ionomer cement was developed from two other materials, the silicate cement and the zinc policarboxilate cement. Even though these materials have been enhanced since their creation, the solubility/disintegration properties are still not clear in the specific literature. This study main purpose was to evaluate the solubility and disintegration of resin modified glass ionomer cements as well as the necessity of using coating materials over their surface. M1-Vitremer (3M ESPE); M2-Fuji II LC (GCAmerica Inc.); M3-Dyract (Dentsply); and M4-Compoglass(Vivadent) were used in this study. The coating materials used were P1- Fluroshield (Dentsply) and P2-Finishing Gloss (3M ESPE). These materials underwent solubility and disintegration tests according to ISO 7489 policies from 1986. The results were submitted to angular transformations and variance analysis and homogeneity test suggesting: the resin modified glass ionomer cements and compomers showed different solubility and disintegration rates, Dyract < Fuji II LC = Compoglass < Vitremer; the resin modified glass ionomer cements and compomers submitted to the surface protection showed lower solubility and disintegration rates contrasted to the non-protected specimens; Finishing Gloss and Fluroshield demonstrated effective surface protection for resin modified glass ionomer cements and compomers

The effects of salivary contamination on tensile bond strength of resin modified glass ionomer cements in bonding brackets / 대한치과교정학회지

The purposes of this study were to evaluate applicability of resin modified glass ionomer cements and to determine the effect of salivary contamination on the tensile bond strength. Fourty extracted human permanent premolars were prepared for bonding and standard edgewise brackets were bonded with Ortho-One, Fuji Ortho LC, Vitremer and Advance. Fourty extracted human permanent premolars were contaminated with saliva, dried and bonded with same materials above. The tensile bond strength was tested by Instron testing device after storage in normal saline at 37degrees C for 24 hours from bonding. The results were as follow : 1. The tensile bond strength of Ortho-one group was 7.68 1.76, Advance group was 7.87 2.80, Fuji Ortho LC group was 4.99 +/-2.53, Vitremer group was 2.80 0.88 MPa. The tensile bond strength in contaminated condition of Ortho-One group was 4.12 1.67, Advance group was 5.37 0.68, Fuji Ortho LC group was 4.41 1.61, Vitremer group was 2.60 1.10 MPa.. 2. Salivary contamination did not affect the tensile bond strength when compared with the uncontaminated enamel group in Fuji Ortho LC and Vitremer (p>0.05) and there was great significant difference in the tensile bond strength of Ortho-One and Advance. 3. Advance, Ortho-One and Fuji Ortho LC seemed to have clinically a proper bond strength.