scholarly journals Evaluation of the Surface Hardness and Roughness of a Resin-Modified Glass Ionomer Cement Containing Bacterial Cellulose Nanocrystals

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Maryam Saadat ◽  
Marzieh Moradian ◽  
Babak Mirshekari

The purpose of this study was to evaluate the performance of a resin-modified glass ionomer cement (RMGIC) to which bacterial cellulose nanocrystals (BCNs) were added. BCNs were incorporated into the RMGIC powder in ratios of 0.3%, 0.5%, and 1% (w/w). One control and three experimental groups were enrolled in the study: unmodified RMGIC (control), 0.3% (w/w) BCN-modified RMGIC, 0.5% (w/w) BCN-modified RMGIC, and 1% (w/w) BCN-modified RMGIC. The surface hardness and surface roughness were the parameters assessed. The materials were characterized by scanning electron microscopy (SEM). The data were analyzed using the one-way ANOVA and Kruskal–Wallis tests for surface hardness and roughness, respectively. The addition of BCN resulted in the improvement of surface roughness in all the specimens compared with the control material. The RMGIC modified by 1% (w/w) BCN showed the lowest surface roughness (decreased by 52%) among all tested groups. However, BCN had a negative effect on the surface hardness of RMGIC. The group with 0.3% (w/w) BCN had the least decrease in microhardness (13%). According to the results, the RMGIC group modified by 1% (w/w) BCN had a smoother surface than the other groups. The surface microhardness of the RMGIC decreased after BCNs were added to it.

2021 ◽  
Vol 50 (8) ◽  
pp. 2433-2444
Author(s):  
Fatimah Suhaily Abdul Rahman ◽  
Dasmawati Mohamad ◽  
Habsah Hasan ◽  
Hasnah Osman

The aim of this study was to determine the effects of two types of coumarin derivatives, namely, 3-acetylcoumarin (AC) and coumarin thiosemicarbazone (CT) on surface characteristics such as the roughness, hardness, and morphology of resin-modified glass-ionomer cement (RMGIC). The release of coumarin from the fabricated RMGIC was also investigated. AC and CT at 1.0% (w/w) concentration were added into 0.3 g of RMGIC powder and mixed with 0.1 g of polyacrylic acid. The fabricated RMGIC-AC and RMGIC-CT were evaluated for surface characteristics such as roughness, hardness and topography. The coumarin release of AC and CT from RMGIC was also determined. The RMGIC-CT demonstrated a decreased roughness value among the materials. The surface roughness exhibited by the RMGIC was statistically higher (p < 0.05) than that of fabricated materials. The RMGIC-AC was observed to have the highest hardness value compared to the RMGIC-CT and RMGIC, and this value was significantly higher (p < 0.05). The surface morphologies of the RMGIC-AC and RMGIC-CT showed a number of pores and irregular surfaces. Meanwhile, the surface roughness value of the RMGIC was statistically higher (p < 0.05) than both RMGIC-AC and RMGIC-CT. In conclusion, the large-sized AC particles significantly increased the surface hardness of the fabricated RMGIC. Conversely, the particle size of both coumarins were not influenced the surface roughness value and the coumarin release profile of fabricated RMGICs.


2004 ◽  
Vol 5 (4) ◽  
pp. 42-49 ◽  
Author(s):  
Yusuf Ziya Bayindir ◽  
Mehmet Yildiz

Abstract In this study the top and bottom surface hardness of two polyacid-modified composite resins (PMCRs), one resin-modified glass ionomer cement (RMGIC), and one composite resin were evaluated. The affect of water storage on their hardness was also investigated. The study was conducted using four different groups, each having five specimens obtained from fiberglass die molds with a diameter of 5 mm and a height of 2 mm. Measurements were made on the top and bottom surface of each specimen and recorded after 24 hours and again at 60 days. All tested materials showed different hardness values, and the values of top surfaces of the specimens were found to be higher than the bottom surface in all test groups. There was no statistical difference in the Vickers hardness (HV) values when the test specimens were kept in water storage. In conclusion Hytac displayed microhardness values higher than Vitremer and Dyract. We found the order of HV values to be Surfil > Hytac > Dyract > Vitremer, respectively. Vitremer presented the lowest microhardness level and Surfil the highest. Citation Bayindir YZ, Yildiz M. Surface Hardness Properties of Resin-Modified Glass Ionomer Cements and Polyacid-Modified Composite Resins. J Contemp Dent Pract 2004 November;(5)4:042-049.


2017 ◽  
Vol 15 (3) ◽  
pp. 185
Author(s):  
Dilcele Silva Moreira Dziedzic ◽  
Lucia Helena Ramos da Silva ◽  
Bruna Luiza do Nascimento ◽  
Marina Samara Baechtold ◽  
Gisele Maria Correr ◽  
...  

Aim: This study investigated the effect of an in-office bleaching technique on lightness, color and surface roughness of two commercially available materials: a resin-modified glass-ionomer cement and a nanohybrid resin composite. Methods: Twelve disk-shaped specimens were prepared with both materials. The samples were bleached with 35% hydrogen peroxide. Bleaching was tested initially onto a smooth surface and later onto a polished one of the same specimens. The effect of the treatments on lightness and color was verified with a spectrophotometer. Surface roughness was measured with a digital surface roughness tester. The data were statistically analyzed by repeated measures ANOVA and post hoc Tukey’s test (alpha = 0.05). Results: Significant variation in lightness and color was observed on the resin-modified glass-ionomer cement after the first bleaching procedure. Roughness increased significantly only after polishing the resin-modified glass-ionomer cement surface. Composite color variation was evident in the last observation period, but roughness and lightness variation due to bleaching and polishing was not significant. Conclusion: The bleaching treatment caused significant color alterations on the materials tested. This study observed that the application of in-office bleaching onto the glass-ionomer cement promoted clinically observable color alteration, and polishing after bleaching is contraindicated for this material.


Author(s):  
Farahnaz Sharafeddin ◽  
Somaye Bahrani

Objectives: Glass ionomer cements (GICs) are among the most popular dental restorative materials, but their use is limited due to their clinical disadvantages. Many efforts have been made to improve the properties of these materials by adding various fillers. Incorporation of hydroxyapatite (HA) into the GICs is considered to improve the physical properties of restorations, and may prevent treatment failure. This study aimed to evaluate the surface roughness (Ra) of a conventional glass ionomer cement (CGIC), a resin-modified glass ionomer (RMGI) and a Zirconomer with and without micro-hydroxyapatite (µHA). Materials and Methods: This experimental study was conducted on 6 groups (n=10) including CGIC, CGIC + µHA, RMGI, RMGI + µHA, Zirconomer, and Zirconomer + µHA. A total of 60 disc-shaped samples (6 mm × 2 mm) were prepared in plastic molds and were stored in distilled water for 24 h. After polishing of the specimens, their Ra was measured by a profilometer in micrometers (µm). The data were analyzed using two and one-way ANOVA, Tukey's HSD test, and independent t-test. Results: Incorporation of µHA resulted in statistically significant differences in Ra between the study groups (P<0.05). Following the incorporation of µHA, the Ra significantly decreased in CGIC (P=0.013) and Zirconomer (P=0.003). However, addition of µHA to RMGI resulted in a significant increase in its Ra (P<0.001). Conclusion: Addition of µHA decreased the Ra of Zirconomer and CGIC, and increased the surface roughness of RMGI samples.


2019 ◽  
Vol 22 (1) ◽  
pp. 12-14
Author(s):  
Astrid Yudhit ◽  
Kholidina Imanda Harahap ◽  
Yuli Ratna Dewi

Resin modified glass ionomer cement as restorative material used in dentistry especially in primary teeth. Fresh milk is often consumed by children as daily drink and it contains lactic acid. The aim of this study was to evaluate surface roughness of resin modified glass ionomer cement after immersed in fresh milk for 2, 4, and 6 hours. Samples were disc shape resin modified glass ionomer cement with size 5 mm in diameter and 2 mm in thickness. Totally 24 samples were divided into 3 groups (n=8), group immersed for 2 hours, group immersed for 4 hours, and group immersed for 6 hours. Fresh milk was pure cow’s milk that harvest in the morning by the farmer. Surface roughness measurements was done before and after immersed using a profilometer (Surfcorder SE-300, Laboratory Ltd, Japan). Results showed surface roughness change were 0.0217 ± 0.005 μm for groups A, 0.0366 ± 0.006 μm for groups B, and 0.0555 ± 0.004μm for groups of 6 hours. One Way Anova test showed significant differences between groups (p <0.05). It can be concluded that there was significant increased on surface roughness of modified resin ionomer cement after immersed in fresh milk for 2, 4 and 6 hours.    


2020 ◽  
Author(s):  
Ika Dewi Ana

AbstractHybridization of resin modified- glass ionomer cement (RMGIC) and bioactive glass (BAG) may result higher mechanical strength and resistance to disintegration, while less contain of polyacrylic acid would lead to bioactivity of the cement. In the present study we investigated the effect of BAG from the CaSiO3-Ca3(PO4)2 system addition to the bioactivity of RMGIC. The BAG containing 10, 15, and 20% of P2O5 (denoted as CSP10, 15, and 20) were used in the study to modify the powder of RMGIC, with apatite wollastonite (AWG) was chosen for a comparison. The surface bioactivity was assessed using XRD, FT-IR, and SEM analysis after specimen immersion in the simulated body fluid (SBF). Measurement of Ca, P, F, Sr, and Al was conducted for the remaining SBF. Cells studies were done to evaluate cell attachment, proliferation, and differentiation on the RMGIC containing BAG compared to the one without BAG. Results of Sr and Al analysis lead to the conclusion that addition of BAG may not influence stability of the matrix of the cement. It was also confirmed that addition of bioactive glass was positive factor indicating excellent ions exchange in SBF and spontaneous growth of apatite by consuming the Ca and P ions in the surrounding fluid. The ability of osteoblasts differentiation on the four types of bioactive cements were higher than that of RMGIC without BAG. These results might provide novel insights into the development of a new generation of osteoconductive biomedical materials.


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