Hydrolytic stability of dental composites: one-year aging effect on surface roughness and surface/subsurface hardness
Estabilidade hidrolítica de compósitos odontológicos: efeito de um ano de armazenamento sobre a rugosidade da superfície e dureza da superfície e subsuperfície.
Moraes, R.R.; Marimon, J.L.M.; Schneider, L.F.J.; Brandt, W.C.; Correr Sobrinho, L.; Bueno, M.
Rev. odontol. UNESP, vol.36, n4, p.383-387, 2007
Abstract
The effect of one-year aging on roughness and hardness of microhybrid composites was investigated. Z250 (3M ESPE) and Charisma (Heraeus Kulzer) were tested. Specimens were stored in distilled water at 37 °C for 24 hours, 6 months or 1 year. Knoop hardness indentations were performed on surface and subsurface (1 mm deep). Data were submitted to three-way ANOVA and Tukey’s test (p ≤ 0.05). Surface roughness (Ra, μm) was measured at 24 hours, 6 months and 1 year. Data were submitted to Repeated Measures ANOVA and Tukey’s test (p ≤ 0.05). Surface hardness ranged from 55.0 to 48.6 and 44.0 for Z250, and from 49.8 to 40.7 and 39.5 for Charisma, at 24 hours, 6 months and 1 year, respectively. Subsurface hardness ranged from 57.8 to 60.9 and 54.2 for Z250, and from 50.4 to 54.3 and 50.7 for Charisma, at 24 hours, 6 months and 1 year. After 6 months, both composites presented softer surfaces (p < 0.01). When comparing 6-month and 1-year, only Z250 showed a decrease in hardness (p < 0.05). For the subsurface, a decrease in hardness after 1 year was observed (p < 0.05). Generally, hardness at the subsurface was higher than surface hardness (p < 0.01), and Z250 was harder than Charisma (p < 0.01). Roughness ranged from 0.53 to 0.52 and 0.52 for Z250, and from 0.52 to 0.56 and 0.56 for Charisma, at 24 hours, 6 months and 1 year, with no significant differences among the materials (p = 0.231).
Keywords
Aging, composite resins, hardness, inorganic particles, surface properties
Resumo
O efeito do envelhecimento por um ano na rugosidade e dureza de compósitos micro-híbridos foi investigado. Z250 (3M ESPE) e Charisma (Heraeus Kulzer) foram testados. Espécimes foram armazenados em água destilada a 37 °C por 24 horas, 6 meses ou 1 ano. Endentações de dureza Knoop foram feitas na superfície e subsuperfície (1 mm). Os dados foram submetidos à ANOVA e teste de Tukey (p ≤ 0,05). A rugosidade da superfície (Ra, μm) foi mensurada em 24 horas, 6 meses e 1 ano. Os dados foram submetidos à ANOVA de Medidas Repetidas e teste de Tukey (p ≤ 0,05). A dureza superficial variou de 55,0 para 48,6 e 44,0 para Z250, e de 49,8 para 40,7 e 39,5 para Charisma, em 24 horas, 6 meses e 1 ano, respectivamente. A dureza da subsuperfície variou de 57,8 para 60,9 e de 54,2 para Z250, e de 50,4 para 54,3 e 50,7 para Charisma. Depois de 6 meses, os compósitos apresentaram menor dureza superficial (p < 0,01). Comparando 6 meses e 1 ano, apenas Z250 mostrou menor dureza (p < 0,05). Para a subsuperfície, foi observada diminuição na dureza após 1 ano (p < 0,05). Em geral, a dureza na subsuperfície foi maior que na superfície (p < 0,01), e Z250 foi mais dura que Charisma (p < 0,01). A rugosidade variou de 0,53 para 0,52 e 0,52 para Z250, e de 0,52 para 0,56 e 0,56 para Charisma, em 24 horas, 6 meses e 1 ano, sem diferenças significativas entre os materiais (p = 0,231).
Palavras-chave
Envelhecimento, resinas compostas, dureza, partículas inorgânicas, propriedades de superfície
References
1. Ferracane JL. Hygroscopic and hydrolytic effects in dental polymer networks. Dent Mater. 2006;22:211-22.
2. Finer Y, Santerre JP. The influence of resin chemistry on a dental composite’s biodegradation. J Biomed Mater Res A. 2004;69:233-46.
3. Ferracane JL, Berge HX, Condon JR. In vitro aging of dental composites in water--effect of degree of conversion, filler volume, and filler/matrix coupling. J Biomed Mater Res. 1998;42:465-72.
4. Turssi CP, Hara AT, Serra MC, Rodrigues AL Jr. Effect of storage media upon the surface micromorphology of resin-based restorative materials. J Oral Rehabil. 2002;29:864-71.
5. Yap AU, Tan SH, Wee SS, Lee CW, Lim EL, Zeng KY. Chemical degradation of composite restoratives. J Oral Rehabil. 2001;28:1015-21.
6. Soderholm KJ. Degradation of glass filler in experimental composites. J Dent Res. 1981;60:1867-75.
7. Soderholm KJ, Zigan M, Ragan M, Fischlschweiger W, Bergman M. Hydrolytic degradation of dental composites. J Dent Res. 1984;63:1248-54.
8. Say EC, Civelek A, Nobecourt A, Ersoy M, Guleryuz C. Wear and microhardness of different resin composite materials. Oper Dent. 2003;28:628-34.
9. Kawai K, Iwami Y, Ebisu S. Effect of resin monomer composition on toothbrush wear resistance. J Oral Rehabil. 1998;25:264-8.
10. Bollen CM, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater. 1997;13:258-69.
11. Lloyd CH. The fracture toughness of dental composites. III. The effect of environment upon the stress intensification factor (KIC) after extended storage. J Oral Rehabil. 1984;11:393-8.
12. Munack J, Haubert H, Dogan S, Geurtsen W. Effects of various storage media on surface hardness and structure of four polyacid-modified composite resins (“compomers”). Clin Oral Investig. 2001;5:254-9.
13. Watts DC, McNaughton V, Grant AA. The development of surface hardness in visible light-cured posterior composites. J Dent. 1986;14:169-74.
14. Reinhardt KJ. Unconverted double bonds and interface phenomena in composite materials. Dtsch Zahnarztl Z. 1991;46:204-8.
15. Asmussen E, Peutzfeldt A. Influence of specimen diameter on the relationship between subsurface depth and hardness of a light-cured resin composite. Eur J Oral Sci. 2003;111:543-6.
16. Soderholm KJ, Lambrechts P, Sarrett D, Abe Y, Yang MC, Labella R, et al. Clinical wear performance of eight experimental dental composites over three years determined by two measuring methods. Eur J Oral Sci. 2001;109:273-81.
17 Yamaga T, Sato Y, Akagawa Y, Taira M, Wakasa K, Yamaki M. Hardness and fracture toughness of four commercial visible light-cured composite resin veneering materials. J Oral Rehabil. 1995;22:857-63.
18. Kim KH, Ong JL, Okuno O. The effect of filler loading and morphology on the mechanical properties of contemporary composites. J Prosthet Dent. 2002;87:642-9.
19. Moraes RR, Lima FG, Bueno M, Demarco FF. Influência do tempo de armazenamento sobre o selamento de restaurações de amálgama utilizando diferentes forradores. Rev Odontol UNESP. 2005;34:135-40.
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email