Glass Ionomer Cement Formulations: I. The Preparation of Novel Fluoroaluminosilicate Glasses High in Fluorine

Tang

J. Zhejiang Univ. Sci. B

et al. 2013

Abstract:Objective: This study deals with the effect of phosphoric acid etching and conditioning on enamel micro-tensile bond strengths (μTBSs) of conventional and resin-modified glass ionomer cements (GICs/RMGICs). Methods: Forty-eight bovine incisors were prepared into rectangular blocks. Highly-polished labial enamel surfaces were either acid-etched, conditioned with liquids of cements, or not further treated (control). Subsequently, two matching pre-treated enamel surfaces were cemented together with one of four cements [two GICs: Fuji I (GC), Ketac Cem Easymix (3M ESPE); two RMGICs: Fuji Plus (GC), RelyX Luting (3M ESPE)] in preparation for μTBS tests. Pre-treated enamel surfaces and cement-enamel interfaces were analyzed by scanning electron microscopy (SEM). Results: Phosphoric acid etching significantly increased the enamel μTBS of GICs/RMGICs. Conditioning with the liquids of the cements produced significantly weaker or equivalent enamel μTBS compared to the control. Regardless of etching, RMGICs yielded stronger enamel μTBS than GICs. A visible hybrid layer was found at certain enamelcement interfaces of the etched enamels. Conclusions: Phosphoric acid etching significantly increased the enamel μTBSs of GICs/RMGICs. Phosphoric acid etching should be recommended to etch the enamel margins before the cementation of the prostheses such as inlays and onlays, using GICs/RMGICs to improve the bond strengths. RMGICs provided stronger enamel bond strength than GICs and conditioning did not increase enamel bond strength.

Section: Introductionmentioning

confidence: 99%

Improvement of enamel bond strengths for conventional and resin-modified glass ionomers: acid-etching vs. conditioning

Tang

J. Zhejiang Univ. Sci. B

et al. 2013

“…It also adheres to compact and cancellous bone. Similar adhesive properties to metals and plastics are well known [28,33].…”

Section: Ionomer Cement Chemical and Mechanical Propertiesmentioning

confidence: 63%

The interface between ionomer cement and bone in the porcine cervical spine

et al. 1996

The interface between bone and ionomer cement has been studied in twelve young adult pigs 1-6 months after anterior cervical discectomy, removal of adjacent end plates and grafting of the bone defect with ionomer cement. Methods used to study the interface were fluorescence microscopy, scanning electron microscopy, electron microprobe analysis and radiological investigation. The interface in all animals consisted of collagenous tissue. The amount of collagenous fibres was related to the amount of residual movement within the motion segment: animals undergoing anterior plating after reconstruction of the bone defect presented with more or less compactly organized collagenous tissue. Sequential fluorochromic marking of osteoid formation revealed a vital bone bed around the interface but no signs of direct bone apposition to the ionomer cement plug. No signs of toxicity or graft rejection were noted. Ionomer bone cement contrary to experimental and clinical experience induces the formation of a connective tissue layer of different density in the porcine cervical spine.

Bol. Soc. Esp. Ceram. Vidr.

“…In order to optimize the compression strength of glass-polyalkenoate cements, future work could be oriented toward the improvement of the glass reactivity, toward the optimization of the polymer/glass ratio and toward the use of nanometric glass particles. (3)(4)(5)(6)(7). El vidrio también permite controlar la velocidad de endurecimiento, la resistencia mecánica e imparte la propiedad de translucidez a los CPAV.…”

Section: Effect Of Polyacrylic Acid Molecular Weight and Sio 2 /Al 2 mentioning

confidence: 99%

Efecto del peso molecular del ácido poliacrílico y de la relación SiO2/Al2O3 en el vidrio sobre la resistencia mecánica de cementos de polialqueonato vítreo

Vargas‐Gutiérrez¹,

Rivera²,

López³

et al. 2002

Los cementos de polialquenoato vítreo son ampliamente utilizados para aplicaciones dentales. Con el propósito de entender mejor los procesos involucrados en las reacciones de formación de este tipo de cementos y de explorar su uso en aplicaciones ortopédicas, en el presente trabajo se realizó un estudio para analizar el efecto del peso molecular del ácido poliacrílico y de la proporción síli-ce/alúmina sobre la resistencia a la compresión y las características microestructurales de cementos de polialquenoato vítreo. Las probetas obtenidas fueron sometidas a pruebas de compresión y al análisis por microscopía electrónica de barrido (MEB) y por espectroscopía infrarroja por transformada de Fourier (IRTF). En una primera serie de experimentos se consideraron pesos moleculares promedio del ácido poliacrílico de 2000, 9700, 15268 y 64000, manteniéndose constante la relación SiO 2 /Al 2 O 3 en un valor de 2,5. En una segunda serie de experimentos se consideraron relaciones SiO 2 /Al 2 O 3 de 2,1; 1,67; 1,25; 0,95 y 0,8; utilizando ácido poliacrílico con peso molecular constante de 64000. Los máximos valores de resistencia mecánica (82,5 MPa) se alcanzaron cuando el peso molecular del ácido poliacrílico fue de 64000 y la relación SiO 2 /Al 2 O 3 en el vidrio fue de 1. Estos valores de resistencia a compresión de los cementos de polialquenoato vítreo son similares a los reportados para cementos a base de polimetilmetacrilato, lo cual sugiere su uso potencial en aplicaciones ortopédicas. Finalmente, se evaluó cualitativamente la reactividad de los vidrios y la presencia de grupos funcionales -COOH sin reaccionar utilizando IRTF, así como la separación de fases en vidrios con relaciones SiO 2 /Al 2 O 3 > 1 y la reactividad superficial de las partículas de vidrio empleando espectroscopia de dispersión de rayos X (DERX) en el MEB. A fin de optimizar la resistencia a compresión de los cementos de polialquenoato vítreo, trabajos futuros pueden ser orientados a mejorar la reactividad de los vidrios, a optimizar la relación polímero / vidrio y a utilizar partículas de vidrio de tamaño submicrónico. Palabras clave: cementos de ionómero vítreo, cementos de polialquenoato vítreo, biomateriales, cementos dentales, materiales dentales. Effect of polyacrylic acid molecular weight and SiO 2 /Al 2 O 3 ratio on the mechanical strength of glass-polyalkenoate cementsGlass-polyalkenoate cements are widely used for dental applications. To better understand the processes involved in the formation reactions of this kind of cements and in order to explore their use in orthopedic applications, in the present work a study was carried out to analyze the effect of polyacrylic acid molecular weight and that of the SiO 2 /Al 2 O 3 ratio in the glass on the compression strength and microstructural characteristics of glass-polyalkenoate cements. The produced samples were subjected to compression tests as well as to scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) analyses. An initial experimental series considered mean polyacrylic a...