Evaluation of the relationship between the cost and properties of glass ionomer cements indicated for atraumatic restorative treatment

Abstract

The aim of this study was to evaluate microshear bond strength (μSBS), water sorption and solubility of glass ionomer cements (GIC) indicated for atraumatic restorative treatment (ART). Cylindrical specimens (6x2.4 mm) were used to test the sorption and solubility of each GIC (n = 5). The specimens were weighed before and after immersion in water and desiccation. For the μSBS test, 60 primary molars were ground to obtain flat surfaces from both enamel and dentin. The teeth were then assigned to the tested GIC (n = 10) groups, namely Fuji IX -FIX, Ketac Molar -KM and Maxxion R -MX. The exposed surfaces were pre-treated with GIC liquid. Polyethylene tubes were placed on the pre-treated surface and filled with one of the GIC. After 24 h, the specimens were submitted to the μSBS test. The failure mode was assessed using a stereomicroscope (400x magnification). The powder to liquid ratio and cost of material were also determined (n = 3). The data were analyzed by ANOVA and Tukey's post hoc test. Linear regression was used to determine the relation between cost and the other variables. Overall, MX showed lower μSBS values (enamel: 3.93 ± 0.38; dentin: 5.04 ± 0.70) than FIX (enamel: 5.95 ± 0.85; dentin: 7.01 ± 1.06) and KM (enamel: 5.91 ± 0.78; dentin: 6.88 ± 1.35), as well as higher sorption and solubility. The regression analyses showed a significant and positive correlation between cost and μSBS in enamel (R 2 = 0.62; p < 0.001) and dentin (R 2 = 0.43; p < 0.001); and a negative correlation between cost and water sorption (R 2 = 0.93; p < 0.001) and solubility (R 2 = 0.79; p < 0.001). In conclusion, the materials indicated for ART exhibit distinct physical and mechanical properties; in addition, low-priced materials may interfere with GIC properties.

Surface Hardness of Glass Ionomer Cements used in Atraumatic Restorative Treatment

“…Surface hardness tests may be applied to evaluate the degradation and durability of dental materials, to observe the effect of storage mediums on the surface, as indicative of resistance to wear and durability, and also to monitor the hardening process of cements [5]. From the results of the present study, the Gold Label 9 Group (Fuji IX) presented the best performance among the cements studied, with data similar to those found in the literature [8,11,[24][25][26]. As observed in Table 1, Gold Label 9 obtained the best hardness mean values and alteration in the powder/liquid ratio of Vitro Molar resulted in a significant increase in surface hardness both after one day and after one week.…”

“…After 7 days of storage the microhardness of Vitro Molar increased from 34.7 VH to 56.53 VH, a behavior which has also been observed in other studies [8,25]. The time interval of measurements (after one day and after one week) was chosen because it was the period with the most elevated increase in hardness, as was observed in a previous study [25].…”

“…As Vitro Molar´s performance is worse than Gold Label 9, probably because of the powder to liquid ratio, we decided to test Vitro Molar with 50% more powder than liquid in order to improve its properties [5]. Gold Label 9 was used as the control group in this study, as it was developed for the specific use in ART and because of its good performance [8,11,[24][25][26].…”

“…In Brazil, glass ionomer cements were launched for this purpose, however, these ionomers are very fluid, making it difficult to insert the restorative material in the cavity, in addition to presenting inferior properties [5][6][7]. The lower powder to liquid ratio is probably the responsible for the higher solubility and lower bond strength observed, because it interferes with the ionic bonds between components of the glass ionomer cement and hydroxyapatite from the substrate [8].…”

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).…”