Evaluation of the Effects of Two Different Nano-Bioceramics on Improving the Properties of Dental Amalgam

Document Type : مقاله‌های پژوهشی

Authors

1 Department of Materials Science and Engineering, Golpayegan University of Technology, Isfahan, Iran

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

3 Dentist, Isfahan, Iran

Abstract

Introduction: Amalgam is one of the most commonly used dental restorative materials, whose clinical use is still a matter of controversy among researchers. The alloy is criticized due to its mercury content and its dangers and limited resistance to corrosion in the body. In the present study amalgam/nano-hydroxyapatite and amalgam/nano-bioglass composites were produced to eliminate the currently existing limitations and evaluate the effect of the type of reinforcing agent on the mechanical properties and corrosion resistance of amalgam. 
Materials and Methods: In this analytical in vitro study, amalgam/nano-hydroxyapatite and amalgam/nano-bioglass composites with 2 wt% of nano-bioceramic were produced. Nano-bioceramic was added to the amalgam powder before adding mercury, followed by mixing with mercury in an amalgamator and compression in a steel mold. The microstructure of hardened samples was evaluated by scanning electron microscopy (SEM). In addition, the mechanical properties of the composites were evaluated using a universal compression test device. Resistance to corrosion of composites was studied by potentiodynamic polarization method. To compare the quantitative data, one-way ANOVA was performed using Graph Pad Prism 6 software (α = 0.05). 
Results: The results showed that by increasing both bioceramics of hydroxyapatite and bioglass, corrosion resistance of composites increased, with hydroxyapatite exerting a greater impact on corrosion resistance of amalgam in the saline solution. In addition, incorporation of 2 wt% of bioglass and hydroxyapatite resulted in 12 and 15 percentages of improvement in the mechanical properties of the composites.
Conclusion: The developed amalgam basic composites seemed to be good choices for restoration of posterior teeth, with less harmful effects (lower corrosion and higher strength), and hydroxyapatite nanoparticles were more effective than bioglass.
Key words: Amalgam, Bioglass, Hydroxyapatite, Mechanical properties

1. Durnan JR. Esthetic dental amalgam-composite resin restorations for posterior teeth. J Prosthet Dent 1971; 25(3): 175-6.
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. Dent Clin North Am 1993; 37(3): 419-31.
4. Acciari, Guastaldi, Brett. Corrosion of dental amalgams: electrochemical study of Ag-Hg, 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. Barkmeier WW, Cooley RL. Amalgam restoration with a composite resin window. Quintessence Int Dent Dig 1979; 10(4): 31-4.
8. Cardash HS, Bichacho N, Imber S, Liberman R. A combined amalgam and composite resin restoration. J Prosthet Dent 1990; 63(5): 502-5.
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. van Noort R. Introduction to dental materials. 1st ed. St. Louis: Mosby; 1994. p. 74-87.
11. Dodes JE. The amalgam controversy. An evidence-based analysis. J Am Dent Assoc 2001; 132(3): 348-56.
12. Skinner EW, Phillips RW. The science of dental materials. 10th ed. WB Saunders; 1996. p. 361-85.
13. Shojai MS, Khorasani1 MT, Dinpanah Khoshdargi E, Jamshidi A. Synthesis methods for nanosized hydroxyapatite with diverse structures. Acta Biomaterialia 2013; 9(8): 7591-21.
14. Jones JR. Review of bioactive glass: From Hench to hybrids. Acta Biomaterialia 2013; 9(1): 4457-86.
15. Darvell BW. Development of strength in dental silver amalgam. Dent Mater 2012; 28(10): e207-17.
16. 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.
17. Khodaei M, Amini K, Mahdavian P. Fabrication and evaluation of amalgam/nano hydroxyapatite composites for dental restoration. Materials Research Express 2018; 5(10): 105403.