Comparative Study on Microstructure and Mechanical Properties of Four Different Types of Amalgam

Document Type : مقاله‌های پژوهشی

Authors

1 Department of Mechanical Engineering, Tiran Branch, Islamic Azad University, Isfahan, Iran

2 Department of Materials Science and Engineering, Golpayegan University of Technology, Golpayegan, Iran

3 Dentist, Isfahan, Iran

Abstract

Introduction: Amalgam is one of the most commonly used dental restorative material; however, because of its mercury content, risks of mercury release and its low resistance to corrosion, its clinical use is still a matter of debate among researchers. In this research four different commercially available amalgam products in Iran were studied and their mechanical, microstructural and corrosion resistance were studied and compared.
Materials and Methods: In this study, four different samples of commercially available amalgam (Cinalux, Owzan Company, Iran; Honghai Tech., China; ARDENT Amalgam, Sweden; and SDI [GS-80], Australia) were prepared and mixed with mercury in an amalgamator. Then a hardened sample, measuring 6 mm in diameter and height, from each brand was evaluated by scanning electron microscopy (SEM) for ultrastructural characteristics. In addition, 3 samples from each brand undewent a compressive test in a one-axis compression test device. Resistance to corrosion of 3 samples from each brand was tested by polarization method in saline solution. To exactly compare the quantitative data, one-way ANOVA was performed using Graph Pad Prism 6 software program (α = 0.05).
Results: The results showed that although none of the samples had Gama-2 harmful phase, because of differences in the morphology of phases, they exhibited differences in corrosion resistance in the saline solution. Furthermore, their mechanical properties were different due to differences in the morphology of phases and all of them had brittle behavior and their compression strength was >300 MPa.
Conclusion: According to the results, the microstructure of amalgam significantly affects its mechanical properties and corrosion resistance. In addition, all the samples evaluated in the present study formed identical phases.
Key words: Amalgam, Mechanical properties, Microstructure, Phase

1- Bjorklund G, Lindh U, Aaseth J, Chirumbolo S. Mercury in dental amalgams: A great concern for clinical toxicology in developing countries? Journal of Trace Elements in Medicine and Biology 2019; 51: 9–11.
2- Zardiackas LD, Bayne SC. Fatigue characterization of nine dental amalgams. Biomaterials 1985; 6(1): 49-54.
3- Anderson MH, McCoy RB. Dental amalgam. The state of the art and science. Denta Clin North Am 1993; 37(3): 419-31.
4- Acciari HA, Guastaldi AC, Brett CMA. Corrosion of dental amalgams: electrochemical study of Ag–Hg, Ag–Sn and Sn–Hg phases. Ag-Sn and Sn-Hg phases. Electrochimica Acta 2001; 46(24-25): 3887-93.
5- Guerra M, Ferreira C, Carvalho ML, Santos JP, Pessanha S. Distribution of toxic elements in teeth treated with amalgam using μ- energy dispersive X-ray fluorescence, Spectrochimica Acta Part B: Atomic Spectroscopy 2016; 122: 114-7.
6- Al-Saleh I, Al-Sedairi AA. Mercury (Hg) burden in children: The impact of dental amalgam. Sci Total Environ 2011; 409(16): 3003-15.
7- Mitchell M, Warren R, Bellinger D, Browne D. Is dental amalgam toxic to children of color? J Natl Med Assoc 2018; 110(4): 414-6.
8- Dodes JE. The amalgam controversy. An evidence-based analysis. J Am Dent Assoc 2001; 132(3): 348-56.
9- Brett CMA, Ioanitescu I, Trandafir F. Influence of the biological fluid on the corrosion of dental amalgam. Corrosion Science 2004; 46(11): 2803-16.
10- Khodaei M, Amini K, Mahdavian P. Fabrication and evaluation of amalgam/ nano hydroxyapatite composites for dental restoration. Materials Research Express 2018; 5(10): 105403.
11- Darvell BW. Development of strength in dental silver amalgam. Dent Mater 2012; 28(10): e207-17.
12- Chowdhury ND, Ghosh KS. Electrochemical behaviour of dental amalgam in natural, artificial saliva and in 0.90 wt.% NaCl solution. Corrosion Science 2018; 133: 217-30.