Published online Sep 30, 2008.
https://doi.org/10.5395/JKACD.2008.33.5.457
Comparison of the residual stress of the nanofilled composites
Abstract
"Residual stress" can be developed during polymerization of the dental composite and it can be remained after this process was completed. The total amount of the force which applied to the composite restoration can be calculated by the sum of external and internal force. For the complete understanding of the restoration failure behavior, these two factors should be considered. In this experiment, I compared the residual stress of the recently developed nanofilled dental composite by ring slitting methods.
The composites used in this study can be categorized in two groups, one is microhybrid type-Z250, as control group, and nanofilled type-Grandio, Filtek Supreme, Ceram-X, as experimental ones. Composite ring was made and marked two reference points on the surface. Then measure the change of the distance between these two points before and after ring slitting. From the distance change, average circumferential residual stress (σθ) was calculated. In 10 minutes and 1 hour measurement groups, Filtek Supreme showed higher residual stress than Z250 and Ceram-X. In 24 hour group, Filtek showed higher stress than the other groups.
Following the result of this experiment, nanofilled composite showed similar or higher residual stress than Z250, and when comparing the Z250 and Filtek Supreme, which have quite similar matrix components, Filtek Supreme groups showed higher residual stress.
Figure 1
Geometry of the expermental ring before and after slitting.
Table 1
Characterization of the resin composites tested
Table 2
Measured circumferential residual stress (σθave) value and elastic modulus of test materials
References
-
Toschi F, Melandri C, Pinasco P, Roncari E, Guicciardi S, de Portu G. Influence of residual stresses on the wear behavior of alumina/alumina-zirconia laminated composites. J Am Ceram Soc 2003;86:1547–1553.
-
-
Whittle AJ, Burford RP, Hoffman MJ. Influence of Residual Stress on the Relationship Between Pipe Pressure and C-Ring Tests. Polym Eng Sci 2000;40:2311–2316.
-
-
Choi KK, Ryu GJ, Choi SM, Lee MJ, Park SJ, Ferracane JL. Effects of cavity configuration on composite restoration. Oper Dent 2004;29:462–469.
-
-
Eick JD, Welch FH. Polymerization shrinkage of posterior composite resins and its possible influence on postoperative sensitivity. Quintessence Int 1986;17:103–111.
-
-
Ferracane JL, Mitchem JC. Relationship between composite contraction stress and leakage in Class V cavities. Am J Dent 2003;16:239–243.
-
-
Uno S, Asmussen E. Marginal adaptation of a restorative resin polymerized at reduced rate. Scand J Dent Res 1991;99:440–444.
-
-
Yoshikawa T, Burrow MF, Tagami J. The effects of bonding system and light curing method on reducing stress of different C-factor cavities. J Adhes Dent 2001;3:177–183.
-
-
Braga RR, Hilton TJ, Ferracane JL. Contraction stress of flowable composite materials and their efficacy as stress-relieving layers. J Am Dent Assoc 2003;134:721–728.
-
-
Lu J. Introduction. In: Lu J, editor. Handbook of measurement of residual stress. Lilburn, GA: The Fairmont press Inc; 1996. pp. 1-4.
-
-
Seif MA, Kishawy HA, Hassan MA. Residual stresses in plastic pipes by laser speckle technique. J Test Eval 1997;25:465–470.
-
-
Seif MA, Short SR. Determination of residual stresses in thin-walled composite cylinders. Exp Tech 2002;26:43–46.
-