Bending strength of Fuji® and Ketac® glass ionomers after sonication

Abstract

Glass ionomer cements mixed by conventional methods contain voids that can decrease their overall strength. This study evaluated the effect of sonication on the reduction of air entrapment by measuring the bending strength in glass ionomer cements (Fujj-II and Ketac-fil). Glass ionomer cement was placed in identical-test vials and sonicated for 45s, 10s, or 0s. The bending strengths were measured (0.005 in min-1) after setting times of 1 or 2 weeks. Mean bending strengths (MPa +/- SD) for the 12 treatment both cements (P < 0.001) and sonication times (P < 0.001). The effect of setting time produced minimal increases in bending strength (P < 0.218). The sonication of freshly mixed glass ionomer cements is a possible solution for reducing voids to increase bending strength.

Effect of chlorhexidine gluconate on porosity and compressive strength of a glass ionomer cement

“…The generalised and inherent formation of pores within the GIC reduces its strength to flexion and cohesion 20,11 . These pores are regions of high concentration of stress, which increased the likelihood of fracture of the material 22 .…”

Influences of the insertion method in glass ionomer cement porosity

“…A great number of pores in GIC may result in the reduction of the material resistance and in restoration longevity, in the increase of superficial roughness, which commits the durability and the success of the technique (Arcoria et al, 1992;Covey and Ewoldsen, 2001;Fleming et al, 1999Fleming et al, , 2002Fleming et al, , 2006Nomoto and McCabe, 2001;Nomoto et al, 2004;Raggio et al, 2010;Williams and Billington, 1991). According to Coldebella (2011), it's believed that the no presence of pores is desirable in clinical practice.…”

“…According Coldebella (2011), and Arcoria and Nomoto and Mccabe (2001) this method favors particle agglutination, reduces the air bubble incorporation, and improves mechanical properties (Arcoria et al, 1992;Coldebella et al, 2011;Nomoto and Mccabe, 2001). The consistency of the material is a characteristic that may also be taken into account since it can influence the amount and size of the material pores (Mutal and Gani, 2005).…”

“…These pores represent points of crack propagation and are responsible for failures that reduce the final resistance of restorations (Geirsson et al, 2004;Nomoto and McCabe, 2001;Opdam et al, 2003). Studies (Algera et al, 2005;Arcoria et al, 1992;Coldebella et al, 2011;Nomoto et al, 2004) aim to decrease the incorporation of air bubbles into the material, and improve physical and adhesive properties of GIC.…”

“…The consistency of the material is a characteristic that may also be taken into account since it can influence the amount and size of the material pores (Mutal and Gani, 2005). The more compact the material, the lower is its porosity (Arcoria et al, 1992;Coldebella et al, 2011;Nomoto et al, 2004).…”