The effect of ultrasound on the uptake of fluoride by glass ionomer cements

Abstract

Ultrasound has been shown to improve the set of glass ionomer cements (GICs) and also other cement properties. In particular, the release of fluoride is enhanced. These cements also can take up fluoride ion from liquids. The aim of this study is to investigate the effect of ultrasound on this cement property. Two commercial dental restorative GICs were used together with a modified commercial material and an experimental material based on a F-free glass. All three commercial materials came in capsules which were mixed as makers directed, the experimental material was mixed as in previous papers. Mixed cement was placed polyethylene moulds to create 3 × 2 mm thick discs. These were either allowed to standard set for 6 min or set with ultrasound for 55 s. 18 samples were made for each material/set. Three samples were placed in 4 ml of 0.2% NaF solution for 24 h at 37°C. The cylinders were removed and the F concentration of the solutions measured by ISE using TISAB decomplexant. F uptake was determined by difference from the original NaF concentration. The two conventional GICs showed reductions of 17.4 and 8.5% for ultrasound compared to standard set whereas the modified material increased by 32.3% and the experimental one by 20.6%. It is suggested that the effect of ultrasound may increase the surface area of the residual glass particles in the GIC which would increase F uptake. In GICs where considerable F ion is released into the cement matrix by the enhanced reaction caused by ultrasound this may be sufficient to reverse the former effect producing the reduced uptake observed.

In-vitro Study on Temperature Changes in the Pulp Chamber Due to Thermo-Curing of Glass Ionomer Cements

“…The acid base neutralization reaction of Glass Ionomer Cements can be accelerated through the use of external energy such as ultrasound (2,3,4) and heat (5,6,7). This is particularly useful in overcoming the moisture sensitivity which Stakleni ionomer grijan je (thermo-cure) 90 sekunda i pritom su zabilježene promjene temperature u pulpnoj komori.…”

“…The uses of external energy such as ultrasound and radiant heat have been reported to provide acceleration of the setting chemistry of GICs. (3,4). Both are reported to enhance physical properties (5,6).…”

“…No dodatak smole štetno je djelovao na otpornost na abraziju, dimenzijsku stabilnost, stabilnost boje i, naravno, na biokompatibilnost. Istraživanja su pokazala da korištenje eksterne energije, poput ultrazvuka i radijacije, toplinom ubrzava kemijske reakcije stvrdnjavanja staklenoionomernih cemenata (3,4). Također je dokazano da oboje poboljšava fizikalna svojstva (5,6).…”

Influência da aceleração de presa por meio de ultrassom, luz halógena e diodo emissor de luz nas propriedades e resistência de união à dentina de cimentos de iônomero de vidro

“…O CIV é um material que possui vantagens como habilidade de união química aos substratos dentários (Raggio et al, 2010;Glasspoole et al, 2002;Yiu et al, 2004a;Pacifici et al, 2014), adesão direta à estrutura dental (Xie et al, 2008;Talal et al, 2009;O'Brien et al, 2010), selamento marginal, capacidade de remineralizar tecidos dentários (Fabián Molina et al, 2013), capacidade de liberação de flúor assegurando seu efeito anticariogênico (Talal et al, 2009;Shahid et al, 2011;Selimović-Dragaš et al, 2013;Pacifici et al, 2014;Calvo et al, 2016;Pupo et al, 2015), bem como biocompatibilidade e coeficiente de expansão térmica similar a estrutura dental (Hse et al, 1999;Xie et al, 2000;Azevedo et al, 2010;Arita et al, 2011;Pacifici et al, 2014) minimizando a microinfiltração na interface dente-esmalte (Xie et al, 2008) e apresenta baixa citotoxidade (Xie et al, 2000;Azevedo et al, 2010).…”

“…O uso de ultrassom também tem sido associado com a melhoria da captação de flúor pelo CIV (Shahid et al, 2011) acredita-se que a alta frequência de vibração do material pode diminuir em volume e número os espaços vazios geralmente presentes no CIV, aumentando a longevidade da restauração (Kleverlaan et al, 2004;Talal et al, 2009;Azevedo et al, 2011), melhorando a dureza do material durante as primeiras 24 h após a aceleração (Kleverlaan et al, 2004) e permite um melhor escoamento e adaptação do CIV na cavidade (Talal et al, 2009).…”