Effect of Temperatures on Polymerization Stress and Microleakage of Class V Composite Restorations

Pavinee Padipatvuthikul Didron, Wojciech Chrzanowski, Ayman Ellakwa

.
Department of General Dentistry, Srinakharinwirot University, Bangkok, Thailand.

DOI: 10.4236/ojcm.2013.34011                

Abstract

The loss of interfacial integrity was identified as one of the major causes for replacement of resin composite restorations. Preheating procedure has been proven to enhance flowability and adaptation of resin composites and increase their degree of conversion. The purpose of this study was to investigate polymerization contraction stress produced in resin composites after preheating to 37℃ and 60℃, and measure microleakage of Class V restorations restored with preheated composites. Three resin composites (GC Kalore, Gradia Direct X, Filtek Supreme XT) at room temperature, 37℃, and 60℃ were investigated. Maximum contraction stress of the composites (n = 5) was evaluated in a modified low-compliance device. Samples were light-cured for 40 seconds and the maximum force was recorded during 15 minutes. Calculations were done to adjust for the system’s compliance and obtain linear shrinkage values of composites. Data were analyzed by Multivariated Analysis of Variance (MANOVA) and Tukey’s test for multiple comparisons (α = 0.05). Seventy-two Class V cavities were prepared on the buccal surfaces of extracted premolars and divided into 9 groups. The teeth were restored with composites at 3 temperatures and were thermo-cycled between 5℃ and 55℃ with a one-minute dwell-time for 1000 cycles. The teeth were sealed with wax and nail vanish before placed in 0.5% toluidine blue dye for 24 hours. The teeth were embedded in self-curing resin and sectioned bucco-lingually with a slow-speed diamond saw, providing 3 sections per restoration. Microleakage was rated by two evaluators using a 0 - 4 ordinal scale at the occlusal and cervical margins under light microscope. Microleakage data were analyzed with Kruskal-Wallis ANOVA and Mann-Whitney U test (α = 0.05). Results indicate that preheating composites to 37℃ and 60℃ significantly increased polymerization contraction stress of composites (p < 0.05). A significantly greater amount of leakage was found at the cervical margins (p < 0.05). For all tested materials, preheating composites to 60℃ resulted in significantly less microleakage at the cervical margin.

Keywords

Preheating; Dental Composite; Polymerization Shrinkage; Contraction Stress; Microleakage

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	M. Trujillo, S. M. Newman and J. W. Stansbury, “Use of Near-IR to Monitor the Influence of External Heating on Dental Composite Photopolymerization,” Dental Materials, Vol. 20, No. 8, 2004, pp. 766-777. http://dx.doi.org/10.1016/j.dental.2004.02.003
[2]	M. Daronch, F. A. Rueggeberg and M. F. De Goes, “Monomer Conversion of Pre-Heated Composite,” Journal of Dental Research, Vol. 84, No. 7, 2005, pp. 663-667. http://dx.doi.org/10.1177/154405910508400716
[3]	M. Daronch, F. A. Rueggeberg, L. Moss and M. F. de Goes, “Clinically Relevant Issues Related to Preheating Composites,” Journal of Esthetic and Restorative Dentistry, Vol. 18, No. 6, 2006, pp. 340-350. http://dx.doi.org/10.1111/j.1708-8240.2006.00046.x
[4]	J. L. Ferracane and E. H. Greener, “The Effect of Resin Formulation on the Degree of Conversion and Mechanical Properties of Dental Restorative Resins,” Journal of Biomedical Materials Research, Vol. 20, No. 1, 1986, pp. 121-131. http://dx.doi.org/10.1002/jbm.820200111
[5]	A. A. El Hejazi and D. C. Watts, “Creep and Viscoelastic Recovery of Cured and Secondary-Cured Composites and Resin-Modified Glass-Ionomers,” Dental Materials, Vol. 15, No. 2, 1999, pp. 138-143. http://dx.doi.org/10.1016/S0109-5641(99)00023-8
[6]	R. Walter, E. J. Swift, H. Sheikh and J. L. Ferracane, “Effect of Temperature on Composite Resin Shrinkage,” Quintessence International, Vol. 40, No. 10, 2009, pp. 843-847.
[7]	V. Armengol, A. Jean, B. Enkel, M. Assoumou and H. Hamel, “Microleakage of Class V Composite Restorations Following Er:YAG and Nd:YAG Laser Irradiation Compared to Acid-Etch: An in Vitro Study,” Lasers in Medical Science, Vol. 17, No. 2, 2002, pp. 93-100. http://dx.doi.org/10.1007/s101030200016
[8]	N. Gutknecht, C. Apel, C. Schafer and F. Lampert, “Microleakage of Composite Filling in Er, Cr:YSGG Laser-Prepared Class II Cavities,” Lasers in Surgery and Medicine, Vol. 28, No. 4, 2001, pp. 371-374. http://dx.doi.org/10.1002/lsm.1064
[9]	N. Fróes-Salgado, L. Silva, Y. Kawano, C. Francci, A. Reis and A. Loguercio, “Composite Preheating: Effects on Marginal Adaptation, Degree of Conversion and Mechanical Properties,” Dental Materials, Vol. 26, No. 9, 2010, pp. 908-914. http://dx.doi.org/10.1016/j.dental.2010.03.023
[10]	W. Wagner, M. Aksu, A. Neme, J. Linger, F. Pink and S. Walker, “Effect of Pre-Heating Resin Composite on Restoration Microleakage,” Operative Dentistry, Vol. 33, No. 1, 2008, pp. 72-78. http://dx.doi.org/10.2341/07-41
[11]	U. Lohbauer, S. Zinelis, C. Rahiotis, A. Petschelt and G. Eliades, “The Effect of Resin Composite Pre-Heating on Monomer Conversion and Polymerization Shrinkage,” Dental Materials, Vol. 25, No. 4, 2009, pp. 514-519. http://dx.doi.org/10.1016/j.dental.2008.10.006
[12]	N. Silikas, G. Eliades and D. C. Watts, “Light Intensity Effects on Resin-Composite Degree of Conversion and Shrinkage Strain,” Dental Materials, Vol. 16, No. 4, 2000, pp. 292-296. http://dx.doi.org/10.1016/S0109-5641(00)00020-8
[13]	D. C. Watts, M. Issa, A. Ibrahim, K. Wakiaga, M. Al-Samadini and N. Silikas, “Edge Strength of Resin-Composite Margins,” Dental Materials, Vol. 24, No. 1, 2008, pp. 129-133. http://dx.doi.org/10.1016/j.dental.2007.04.006
[14]	J. L. Ferracane and J. C. Mitchem, “Relationship between Composite Contraction Stress and Leakage in Class V Cavities,” The American Journal of Dentistry, Vol. 16, No. 4, 2003, pp. 239-243.
[15]	F. C. Calheiros, F. T. Sadek, R. R. Braga and P. E. Capel Cardoso, “Polymerization Contraction Stress of Low-Shrinkage Composites and Its Correlation with Microleakage in Class V Restorations,” Journal of Dentistry, Vol. 32, No. 5, 2004, pp. 407-412. http://dx.doi.org/10.1016/j.jdent.2004.01.014
[16]	S. K. Sidhu, T. E. Carrick and J. F. McCabe, “Temperature Mediated Coefficient of Dimensional Change of Dental Tooth-Colored Restorative Materials,” Dental Materials, Vol. 20, No. 5, 2004, pp. 435-440. http://dx.doi.org/10.1016/j.dental.2003.02.001