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"The adhesive of composite resin has been used for direct bonding of a bracket system of bracket fixed orthodontic treatment by etching. The disanvantage of etching is enamel loss and difficult procedure. Modified glass ionomer cement has been suggested as a bracket bonding system without etching. The chemical bonding without etching can reduce enamel loss and make the procedure more efficient. The purpose of this study was to determine the shear bond strength of modified glass ionomer cement as metal Begg bracket bonding system with and without etching. The subject of this study consisted of two groups which had 15 intact extracted permanent human upper bicuspids for each group. Group I was etched with ortho phosphate acid (37%) for 20 seconds and bonded with modified glass ionomer cement. Group II was untreated and bonded with the same adhesive. The shear bond strength was measured with Pearson Pankee Equipment, and bond failure location was observed under stereo microscope. To differentiate the effects with and without etching, t test was performed, while to observe the location of bond failures, chi-square test was conducted. The results of this study indicated that the shear bond strength of modified glass ionomer cement as bonding system metal Begg Brackets with etching was significantly higher (p<0.001) than without etching. Without etching, bond failure occured between enamel and bonding agent. With etching, the bond failure was mostly found within the adhesive."

"Glass Ionomer Cement (GIC) and Resin Modified Glass Ionomer Cement (RMGIC) are two restorative materials in dentistry that have the capacity of releasing fluoride to saliva, dentino-enamel substance, and the ability to form fluoroapatite crystal. The aim of this study is to compare the amount of fluoride release in saliva and dentino-enamel substance. A total of 48 caries free premolar teeth were prepared to form a cavity with the dimension of 4 X 4 X 2 mm on the buccal surfaces. These teeth were then divided into 3 groups, each containing 16 samples. The first group was determined as the control group, and therefore no restorative material was applied to the teeth in this group; the teeth in the second group were filled with GIC, the third group was filled with RMGIC. These teeth were then soaked in artificial saliva without fluoride content and were incubated at room temperature (37 0Celcius). Each group was divided again into 4 sub groups, each consisting of 4 samples. Each of 4 subgroups received different periods of soaking, namely 1 day, 3 days, 10 days, and 20 days. The fluoride content of saliva was analyzed using ion chromatography, and fluoroapatite on dentino-enamel substance was analyzed using X-Ray Diffraction or XRD. Data obtained from the experiments were analyzed using ANOVA, and the level of significance was set at p ≤ 0,05. There was a significant difference in the analysis of fluoride release in saliva within the 3 groups: GIC, RMGIC, and the control group, and there was no significant difference in the analysis of fluoroapatite formation on dentino-enamel substance within 3 groups. The fluoride content in saliva showed a significant difference within the 3 groups of GIC, RMGIC, and control. No significant difference was found in the fluoroapatite content on dentino-enamel substance."

"The first bone cement developed by Charnley in the 1960s using polymethyl methacrylate (PMMA) remains the most widely used material for fixation of orthopaedic joint replacement. In the field of dentistry, polycarbocylate and glass ionomer cements first came to prominence as dental cements in the late 1960s and early 1970s. Although biocompatible, the zinc component results in the formation of a fibrous collagen capsule around the zinc polycarboxylate cement in vivo, which compromises the strength of the intermediate region between the bone and cement. Glass ionomer cements were anticipated to have potential in orthopaedic applications. The discovery of a well integrated intermediate layer between bone and many bioactive ceramic phases from the calcium-phosphate systems, such as hydroxyapatite (HA), resulted in the development of new cements incorporating such phases. Investigations into bioglass and apatite/wollastonite glass-ceramics prompted the development of off-the-shelf bone graft substitute materials. Synthetic hydroxyapatite is commercially available and serves primarily as a scaffold in order to facilitate the bone regeneration process. Many investigations have ranged from the development of castable bioactive materials to modified bioactive composites. This article attempts to give a broad overview of the different types of cements."

"Penelitian ini bertujuan untuk mengetahui pengaruh lama perendaman dalam berbagai pH saliva buatan terhadap kekerasan permukaan material restoratif glass hybrid (EQUIA® FORTE Glass Hybrid Restorative System, GC Corporation, Japan). Jumlah spesimen 90 buah terbagi dalam sembilan kelompok perlakuan yaitu perendaman dalam saliva buatan dengan pH 4,5; 5,5; dan 7 dengan waktu perendaman masing-masing 1 jam, 24 jam, dan 72 jam pada suhu 37oC. Uji kekerasan permukaan menggunakan Knoop Microhardness Tester (Shimadzu HMV-G Micro Hardness Tester, Japan) dengan beban 50 gram selama 15 detik sebanyak 5 indentasi pada tiap spesimen. Hasil data dianalisis statistik dengan One-way ANOVA (p<0,05). Hasil penelitian menunjukkan terdapat perbedaan bermakna pada setiap kelompok perlakuan yaitu nilai kekerasan pada perendaman dengan larutan saliva buatan pH 4,5 dan lama perendaman 1 jam, 24 jam, dan 72 jam berturut-turut adalah sebesar 69,48 0,57 KHN, 54,76 0,23 KHN, dan 42,90 0,41 KHN. Sementara itu, nilai kekerasan dengan saliva buatan pH 5,5 dan lama perendaman 1 jam, 24 jam, dan 72 jam berturut-turut adalah sebesar 75,34 0,32 KHN, 57,45 0,47 KHN, dan 45,84 0,27 KHN. Dengan larutan saliva buatan pH 7 dan lama perendaman 1 jam, 24 jam, dan 72 jam didapatkan nilai kekerasan berturut-turut adalah 82,89 0,68 KHN, 62,49 0,37 KHN, dan 49,84 0,14 KHN. Disimpulkan bahwa dengan menurunnya pH saliva buatan dan semakin lamanya perendaman dapat menurunkan nilai kekerasan permukaan material restoratif glass hybrid.

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This study aims to determine the effect of immersion time in various pH of artificial saliva on the surface hardness of glass hybrid restorative materials (EQUIA® FORTE Glass Hybrid Restorative System, GC Corporation, Japan). There were 90 specimens (diameter 6mm, thickness 3mm), and the specimens were divided into nine groups immersed in artificial saliva with pH 4,5; 5,5; and 7 for 1 hour, 24 hours, and 72 hours at 37oC respectively. The surface hardness of each specimens were tested using Knoop Microhardness Tester (Shimadzu HMV-G Micro Hardness Tester, Japan) with 50 grams load for 15 seconds, with 5 indentations on each specimens. The statistical analysis using One-way ANOVA (p<0,05) showed that there were significant differences between each groups.

The result showed that the hardness number of the groups immersed in artificial saliva pH 4,5 for 1 hour, 24 hours, and 72 hours respectively are 69,48 0,57 KHN, 54,76 0,23 KHN, and 42,90 0,41 KHN. Meanwhile, the hardness number of the groups immersed in artificial saliva pH 5,5 for 1 hour, 24 hours, and 72 hours respectively are 75,34 0,32 KHN, 57,45 0,47 KHN, and 45,84 0,27 KHN. With artificial saliva of pH 7 for 1 hour, 24 hours, and 72 hours, the hardness number are 82,89 0,68 KHN, 62,49 0,37 KHN, and 49,84 0,14 KHN. It can be concluded that the lower pH value of artificial saliva and prolonged immersion time can reduce the surface hardness value of glass hybrid restorative materials."

"Summary:Comprehensively reviews bonding to enamel, dentin and cementum and analyses relevant adhesion mechanisms. In this book, emphasis is placed on the characterization of material interfaces with dental tissues in situ. It is addressed to both the dental researcher and the clinician."