Glass ionomer cement hardness after different materials for surface protection

Abstract

The aim of the present study was to evaluate the Knoop hardness of high viscous glass ionomer cement (GIC) Ketac Molar Easy Mix (3M ESPE, Saint Paul, USA) submitted to different types of compounds for surface protection. Sixty specimens of GIC were made in PVC molds with 7.5 mm diameter and 2.5 mm thickness. Divided in 6 groups: G1, Control (no protection); G2, Cavitine (Copal varnish); G3, Magic bond (Adhesive); G4, Adper Single Bond 2 (Single bottle adhesive); G5, Solid Petroleum Jelly; G6, Nail Varnish. The surface protection was applied after initial setting reaction. The specimens were immersed in deionized water, at 37 degrees C, for 24 h. The surfaces were polished in a rotation machine (Aropol 2V). The hardness test was accomplished in a Digital Microhardness tester HVS-100. In each specimen five indentations were done and repeated after 30 days and 4 months, under the same conditions. The results were submitted to Two-way ANOVA and Tukey Test. The only material that differed from the control group was the nail varnish (p < 0.001), with the other materials showing no significant difference from the control group. It was concluded that the best material for surface protection of GIC was the nail varnish, but because of possible harmful effects, petroleum jelly could be a better option.

Effects of cellulose fibers on the physical and chemical properties of glass ionomer dental restorative materials

“…In the first critical 24 h of setting time of glass ionomer cement there is greater susceptibility to loss and absorption of water. The high solubility and initial syneresis and imbibition are unfavorable properties, which may result in dimensional changes, loss of mechanical properties and formation of cracks [35,36]. Any contamination by water in this phase may cause dissolution of cations and anions in the matrix.…”

“…In addition to having a poor esthetic appearance due to their limited translucency, and technique sensitivity, they have a short working time and prolonged setting period, in which first 24 h are critical, making this material susceptible to hygroscopic change in the medium and solubility [8]. Thus, immediate surface protection of the glass ionomer cement restoration with a waterproofing material is indicated [9][10][11].…”

Microhardness and chemical analysis of high-viscous glass-ionomer cement after 10 years of clinical service as ART restorations

“…The moulds were mounted on top of a glass plate, then covered with acetate strips, compressed with a 0.5 kg weight, and allowed to set for 15 min. Subsequently, cement excesses were removed, the surfaces protected with petroleum jelly, 24 and the specimens were stored in distilled water at 37 8C. After 7 days, the HVGIC specimens were embedded in acrylic moulds, and polished following the same protocol as that described for in vivo specimens.…”

Dureza Knoop de Três Cimentos de Ionômeros de Vidro

“…Um desses cuidados se refere à proteção superfi cial, uma vez que, o material é muito suscetí vel à sinérese e embebição, entre 4 e 8 minutos. Clinicamente esta proteção pode ser realizada com verniz, sistema adesivo ou vaselina sólida, pois esta medida evita evaporação de água que fi ca ionicamente ligada ao redor das cadeias que estão sendo formadas 11,20,21 . Nesta pesquisa, esta proteção ocorreu por meio da armazenagem da amostra em meio líquido oleoso durante todo período do estudo.…”