Microhardness of esthetic restorative materials at different depths

Abstract

The aim of this study was to analyze the microhardness of two resin-modified glass ionomer cements (Vitremer; Fuji II LC); two polyacid-modified composite resins (Freedom; F2000) and a hybrid composite resin (Prodigy), at different depths from the upper surface. Six hemi-cylinders (3 mm height; 3 mm radius) per tested material were obtained. Vickers Hardness was determined using a micro-indentation tester. For each hemi-cylinder, three indentations were taken at one of the following depths: 0.4, 1.0, 2.0 and 2.6 mm. For each material, microhardness average was calculated. Statistical analysis was performed using two-way ANOVA and Tukey test Fuji II LC and Vitremer showed no statistically significant difference among hardness means recorded at the four analyzed depths. The hybrid and the polyacid-modified composite resins showed significant decrease microhardness with increasing depth. It may be concluded that for the RMGIC, microhardness was not affected at depths up to 2.6 mm. On the other hand, both hybrid and PMCRs should de better placed in increments not thicker than 2 mm to achieve optimal hardness throughout the restoration

Evaluation of surface roughness and hardness of different glass ionomer cements

“…7 Thus, the reaction may be finished immediately after light exposure, so that operators can have a longer working time. 8 Metal-reinforced glass ionomer cements were introduced to the dental market in 1977. The addition of silver-amalgam alloy powder to conventional materials increase the physical strength of the cement and provide radiopacity.…”

An Evaluation of the Physical Properties of a New Atraumatic Restorative Treatment Material Containing Azadirachta Indica (Neem)

“…[23][24][25] Vicker's hardness has been used to assess the surface hardness of glass ionomer cements; other dental materials have been used elsewhere. [26][27][28][29][30][31][32] Tüzüner T and Ulusu T in their study found that microhardness of one of the marketed ART (Fuji IX) was 53 VHN. [27] In this study, the Vicker's hardness measurement showed highly significant differences for micro-hardness (P <0.0001).…”

Kekerasan permukaan semen ionomer kaca konvensional tipe II akibat lama penyimpanan (The surface hardness of type II conventional glass ionomer cement conventional because of the length of storage)

“…13 Pada penelitian kekerasan permukaan lain menggunakan semen ionomer kaca modifikasi tipe II dengan aktivasi sinar warna A3, didapatkan hasil 50,37 VHN. 4 Adanya perbedaan kekerasan permukaan pada semen ionomer kaca modifikasi tipe II dengan aktivasi sinar tersebut, dapat disebabkan karena ada perbedaan warna powder semen ionomer kaca, perbedaan alat dan metode penelitian yang dipakai. Komposisi semen ionomer kaca tipe II dalam kapsul sama dengan semen ionomer kaca konvensional tipe II.…”

“…1,2 Sifat utama semen ionomer kaca adalah kemampuannya untuk melekat pada enamel dan dentin tanpa ada penyusutan atau panas yang bermakna, mempunyai sifat biokompatibilitas dengan jaringan periodontal dan pulpa, ada pelepasan fluor yang beraksi sebagai anti mikroba dan kariostatik, kontraksi volume pada pengerasan sedikit, koefisien ekspansi termal sama dengan struktur gigi. 3,4 Ada beberapa jenis semen ionomer kaca berdasarkan penggunaannya, tipe I untuk material perekat, tipe II untuk material restorasi dan tipe III untuk basis atau pelapis. 1,5 Semen ionomer kaca tipe II secara umum mempunyai sifat lebih keras dan kuat dibandingkan tipe I, karena mempunyai rasio powder terhadap liquid lebih tinggi.…”