Evaluation of the Flexural Strength and Color Stability of Two Injection Acrylic Resins and a Heat-cure Acrylic Resin

Document Type : Original Articles

Authors

1 Dental Material Research Center, Department of Prosthodontics, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran

2 Graduate, Student Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Introduction: An important consideration in newly introduced acrylic resins is to determine the flexural strength and color stability of dentures fabricated using these materials. The general aim of this study was to evaluate and compare the flexural strength and color stability of two injectable acrylic resins (IvoBase High-Impact and Vertex Castavaria) and a heat-cured acrylic resin (Meliodent).
Method and Materials: In this study, 30 cuboid samples were fabricated (10 specimens from each group), measuring 3 mm in thickness and 67×15 mm in dimension. The flexural strengths of the samples were determined using 3-point flexural strength test and their color changes were evaluated by immersion in tea using spectrophotometry technique. Data were analyzed with SPSS 22, using one-way ANOVA and HSD Tukey tests (α = 0.05).
Results: The mean flexural strength values of the IvoBase, Vertex Castavaria and Meliodent samples were 58.16, 66.01 and 77.38 MPa, respectively. In relation to color changes, the ∆E values of IvoBase, Vertex Castavaria and Meliodent samples were 6.56, 3.59 and 6.23, respectively.
Conclusion: Meliodent heat-cured acrylic resin which uses the conventional system showed the best flexural strength, and Vertex Castavaria showed the best color stability.
Key words: Acrylic resins, Color, Denture bases, Flexural strength, Immersion.

1. Zarb G, Hobkirk J, Eckert S, Jacob R. Prosthodontic treatment for edentulous patients. Complete dentures and implant-supported prostheses. 13th ed. St. Louis: Mosby Inc.; 2013. p. 133-9.
2. Pfeiffer P, Rosenbauer EU. Residual methyl methacrylate monomer, water sorption, and water solubility of hypoallergenic denture base materials. J Prosthet Dent 2004; 92(1): 72-8.
3. Craig R, Powers JM, Wataha JC. Dental materials, properties and manipulation. 8th Ed. St. Louis: Mosby Inc.; 2003. p. 121.
4. Tandon R, Gupta S, Agarwal SK. Denture base materials: from past to future. Ind J Dent Sci 2010; 2(2): 33-9.
5. Negrutiu M, Sinescu C, Romanu M, Pop D, Lakatos S. Thermoplastic resins for flexible framework removable partial dentures. Timisoara Med J 2005; 55(3): 295-99.
6. Ajaj-ALKordy NM, Alsaadi MH. Elastic modulus and flexural strength comparisons of high-impact and traditional denture base acrylic resins. The Saudi Dental Journal 2014; 26(1):15-8.
7. Gurbuz O, Unalan F, Dikbas I. Comparison of the transverse strength of six acrylic denture resins. OHDMBSC 2010; 9(1): 21-4.
8. Morweng RPN, Essop ARM, Motloba D. Effect of denture cleansers on flexural strength of heat-polymerized and auto-polymerized acrylic resins. S Afr Dent J 2016; 71(10): 518-21.
9. Uzun G, Hersek N. Comparison of the fracture resistance of six denture base acrylic resins. J Biomater Appl 2002; 17(1): 19-29.
10. Memon MS, Yunus N, Razak AA. Some mechanical properties of a highly cross-linked, microwave-polymerized, injection-molded denture base polymer. Int J Prosthodont 2001; 14(3): 214-8.
11. Golbidi F, Jalali O. An evaluation of the Flexural Properties of Meliodent and Acropars Heat Polymerized Acrylic Resins. J Dent Med Tehran Univ Med Sci 2007; 4(2): 68-71.
12. Grajower R, Goultschin J. The transverse strength of acrylic resin strips and of repaired acrylic samples. J Oral Rehabil 1984; 11(3): 237-47.
13. Harrison A, Hugget R. Effect of the curing cycle on residual monomer levels of acrylic resin denture base polymers. J Dent 1992; 20(6): 370-4.
14. Jagger RG. Effect of the curing cycle on some properties of a polymethylmethacrylate denture base material. J Oral Rehabil 1978; 5(2): 51-7.
15. Barbosa DB, de Souza RF, Pero AC, Marra J, Compagnoni MA. Flexural strength of acrylic resins polymerized by different cycles. J Appl Oral Sci 2007; 15(5): 424-8.
16. Mirzaei S. The comparison of water sorption and dimensional stability of two injection acrylic resins with a traditional acrylic resin. [Thesis]. Isfahan, Iran: Isfahan University of Medical Sciences; 2017. [In Persian].
17. Haghi HR, Asadzadeh N, Sahebalam R, Nakhaei M, Amir JZ. Effect of denture cleansers on color stability and surface roughness of denture base acrylic resin. Indian J Dent Res 2015; 26(2): 163-6.
18. Safa’a AA, Fahmy MM, Abdulla SM. Chromatic stability of light-activated resin and heat-cure acrylic resin submitted to accelerated aging. The Saudi Journal for Dental Research 2015; 6(1): 41-7.
19. Sagsoz NP, Yanıkoglu N, Ulu H, Bayındır F. Color changes of polyamid and polymetyhl methacrylate denture base materials. Open Journal of Stomatology 2014; 4: 489-96.
20. Turker SB, Sener ID, Akkus E, Bugurman B. Effect of staining solutions on the colour stability and surface properties of denture base material. Balk J Stom 2012; 16: 49-56.
21. Imirzalioglu P, Karacaer O, Yilmaz B, Ozmen MSc I. Color stability of denture acrylic resins and a soft lining material against tea, coffee, and nicotine. J Prosthodont 2010; 19(2): 118-24.