Avaliação das propriedades mecânicas de quatro cimentos de ionômero de vidro convencionais utilizados na cimentação de bandas ortodônticas

Abstract

OBJETIVO: objetivo deste estudo foi comparar a resistência flexural, resistência à compressão e resistência à tração diametral de quatro diferentes cimentos de ionômero de vidro convencionais utilizados para cimentação de bandas ortodônticas (Vidrion C/SS White; Meron/Voco; Ketac Cem/3M ESPE; Vivaglasss/Ivoclar-Vivadent). METODOLOGIA: foram confeccionados 12 corpos-de-prova para cada cimento, em cada teste, seguindo a norma 66 da ADA para resistência à tração diametral e à compressão, e norma 4049 da ISO para resistência flexural. Os testes foram feitos após 24 horas de armazenagem em água destilada a 37ºC, na máquina de testes Universal Instron 4444 sob velocidade de 0,75mm/minuto para resistência flexural e 1mm/min para resistência à tração diametral e à compressão. Os resultados obtidos para o teste de resistência flexural foram: 25,85 ± 5,43MPa (Meron); 21,85 ± 6,96MPa (Vidrion C); 20,85 ± 4,17MPa (Vivaglass); 20,50 ± 4,89MPa (Ketac Cem). Para o teste de compressão os resultados foram (na mesma ordem): 77,72 ± 20,21MPa; 56,49 ± 8,54MPa; 47,84 ± 9,25MPa; 81,93 ± 13,37MPa. RESULTADOS: os resultados para o teste de resistência à tração diametral foram (na mesma ordem): 9,59 ± 2,09MPa; 5,25 ± 1,29MPa; 7,69 ± 2,09MPa; 4,08 ± 1,32MPa. RESULTADOS: os quatro cimentos mostraram-se estatisticamente equivalentes quanto ao teste de resistência flexural. Os cimentos Meron e Ketac Cem foram estatisticamente mais resistentes à compressão que o Vidrion C e o Vivaglass. Em relação ao teste de resistência à tração diametral, o cimento Meron mostrou-se estatisticamente superior aos demais.

Assessment of the mechanical properties of glass ionomer cements for orthodontic cementation

“…The analysis of the compressive strength, diametral tensile strength and microhardness are essential for verification and comparison of mechanical properties of different dental materials, and may infer what material is best suitable to perform clinical functions, resisting to the masticatory forces, wear and application of orthodontic forces. 2,3,17,21,22,28 Furthermore, whenever possible it is interesting to associate a test such as shear bond strength to simulate orthodontic treatment and oral environment for checking the performance of a material under similar conditions. 1,5,9,[11][12][13][14][15] In this context, this study included the analysis of four mechanical properties, aiming to determine which of these three materials is most suitable for the cementation of orthodontic bands.…”

“…Conventional glass ionomer cements (GICs) are widely used in orthodontics and is usually the material of choice for bands and auxiliary appliances cementation. 2,6,[12][13][14][15]19 Several characteristics encourage the use of these materials as biocompatibility, chemical union to enamel and constant release of fluoride. [2][3][4][5][6]16,21,25,27 Specifically in use with orthodontic bands, these features become very important to reduce the incidence of caries and periodontal diseases and provide appropriate union strength between teeth and bands.…”

“…2,6,[12][13][14][15]19 Several characteristics encourage the use of these materials as biocompatibility, chemical union to enamel and constant release of fluoride. [2][3][4][5][6]16,21,25,27 Specifically in use with orthodontic bands, these features become very important to reduce the incidence of caries and periodontal diseases and provide appropriate union strength between teeth and bands. 9,10,13,18,23,24 However, the conventional GICs have disadvantages which can compromise its mechanical performance, such as the susceptibility to moisture during the initial setting reaction, which may extend up to one hour.…”

Can we add chlorhexidine into glass ionomer cements for band cementation?

“…[8][9][10][11] Glass ionomer cements (GICs) remain the most commonly used material for band cementation. 4,12,13 This material exhibits a continuous release and uptake of fluoride, which has certain antibacterial activities. 3,4,[12][13][14][15][16][17] However, conventional GICs have an antibacterial effect against a small spectrum of microorganisms and a low bactericide potential.…”

Orthodontic cements: immediate protection and fluoride release

“…15 Therefore, it is extremely important for orthodontists to know the properties of the material that they use in office, being aware both of their advantages as well as their limitations. 1 During the initial setting stage, glass ionomer cements are more susceptible to hygroscopic alteration of the environment. It may suffer syneresis and imbibition processes, which are the loss or gain of water from the external environment, respectively.…”