Warning: mkdir(): Permission denied in /home/virtual/lib/view_data.php on line 81

Warning: fopen(upload/ip_log/ip_log_2024-12.txt): failed to open stream: No such file or directory in /home/virtual/lib/view_data.php on line 83

Warning: fwrite() expects parameter 1 to be resource, boolean given in /home/virtual/lib/view_data.php on line 84
Effect of the exponential curing of composite resin on the microtensile dentin bond strength of adhesives

Effect of the exponential curing of composite resin on the microtensile dentin bond strength of adhesives

Article information

Restor Dent Endod. 2010;35(2):125-133
Publication date (electronic) : 2010 March 31
doi : https://doi.org/10.5395/JKACD.2010.35.2.125
Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul, Korea.
Corresponding Author: Byeong-Hoon Cho. Department of Conservative Dentistry, School of Dentistry, Seoul National University, 275-1 Yeongeon-Dong, Jongno-Gu, Seoul, 110-768, Korea. Tel: 82-2-2072-3514, Fax: 82-2-2072-3859, chobh@snu.ac.kr
Received 2010 March 02; Revised 2010 March 11; Accepted 2010 March 12.

Abstract

Objectives

Rapid polymerization of overlying composite resin causes high polymerization shrinkage stress at the adhesive layer. In order to alleviate the shrinkage stress, increasing the light intensity over the first 5 seconds was suggested as an exponential curing mode by an LED light curing unit (Elipar FreeLight2, 3M ESPE). In this study, the effectiveness of the exponential curing mode on reducing stress was evaluated with measuring microtensile bond strength of three adhesives after the overlying composite resin was polymerized with either continuous or exponential curing mode.

Methods

Scotchbond Multipurpose Plus (MP, 3M ESPE), Single Bond 2 (SB, 3M ESPE), and Adper Prompt (AP, 3M ESPE) were applied onto the flat occlusal dentin of extracted human molar. The overlying hybrid composite (Denfil, Vericom, Korea) was cured under one of two exposing modes of the curing unit. At 48h from bonding, microtensile bond strength was measured at a crosshead speed of 1.0 mm/min. The fractured surfaces were observed under FE-SEM.

Results

There was no statistically significant difference in the microtensile bond strengths of each adhesive between curing methods (Two-way ANOVA, p > 0.05). The microtensile bond strengths of MP and SB were significantly higher than that of AP (p < 0.05). Mixed failures were observed in most of the fractured surfaces, and differences in the failure mode were not observed among groups.

Conclusion

The exponential curing method had no beneficial effect on the microtensile dentin bond strengths of three adhesives compared to continuous curing method.

References

1. Feilzer AJ, de Gee AJ, Davidson CL. Curing contraction of composites and glass-ionomer cements. J Prosthet Dent 1988. 59297–300.
2. Davidson CL, Feilzer AJ. Polymerization shrinkage and polymerization shrinkage stress in polymer-based restoratives. J Dent 1997. 25(6)435–440.
3. Davidson CL, De Gee AJ, Feilzer A. The competition between the composite-dentin bond strength and the polymerization contraction stress. J Dent Res 1984. 63(12)1396–1399.
4. Feilzer AJ, de Gee AJ, Davidson CL. Setting stress in composite resin in relation to configuration of the restoration. J Dent Res 1987. 66(11)1636–1639.
5. Kemp-Scholte CM, Davidson CL. Marginal integrity related to bond strength and strain capacity of composite resin restorative systems. J Prosthet Dent 1990. 64658–664.
6. Chye CH, Yap AUJ, Laim YC, Soh MS. Post-gel polymerization shrinkage associated with different light curing regimens. Oper Dent 2005. 30(4)474–480.
7. Davidson CL. Resisting the curing contraction with adhesive composites. J Prosthet Dent 1986. 55(4)446–447.
8. Mehl A, Hickel R, Kunzelmann KH. Physical properties and gap formation of light-cured composites with and without 'softstart-polymerization'. J Dent 1997. 25(3-4)321–330.
9. Uno S, Asmussen E. marginal adaptation of a restorative resin polymerized at reduced rate. Scand J Dent Res 1991. 99440–444.
10. Sakaguchi RL, Berge HX. Reduced light energy density decreases post-gel contraction while maintaining degree of conversion in composites. J Dent 1998. 26(8)695–700.
11. Unterbrink GL, Muessner R. Influence of light intensity on two restorative systems. J Dent 1995. 23(3)183–189.
12. Oberholpez G, Botha CT, Preez IC. Advances in light curing units and curing techniques : a literature review. SADJ 2005. 60(10)451–454.
13. Suh BI. Controlling and understanding the polymerization shrinkage-induced stresses in light-cured composites. Compend Contin Educ Dent Suppl 1999. (25)S34–S41.
14. Price RBT, Ehrnford L, Andreou P, Felix CA. Comparison of quartz-tungsten-halogen, light-emitting diode, and plasma arc curing lights. J Adhes Dent 2003. 5193–207.
15. Miyazaki M, Oshida Y, Moore BK, Onose H. Effect of light exposure on fracture toughness and flexural strength of light-cured composites. Dent Mater 1996. 12(6)328–332.
16. Lim MY, Cho KM, Hong CU. Polymerization shrinkage of composite resins cured by variable light intensities. J Korean Acad Conserv Dent 2007. 32(1)28–36.
17. Burgess JO, Walker RS, Porche CJ, rappold AJ. Light curing-an update. Compend Contin Educ Dent 2002. 23(10)889–906.
18. Goracci G, Casa de Martinis L, Mori G. Curing light-intensity and marginal leakage of resin composite restoration. Quintessence Int 1996. 27355–362.
19. Bouschlicher MR, Rueggeberg FA. Effect of ramped light intensity on polymerization force and conversion in a photoactivated composite. J Esthet Dent 2000. 12328–339.
20. Deliperi S, Bardwell DN. An alternative method to reduce polymerization shrinkage in direct posterior composite restorations. J Am Dent Assoc 2002. 1331387–1398.
21. Yap AUJ, Soh MS. Curing efficacy of a new generation high-power LED lamp. Oper Dent 2005. 30(6)758–763.
22. Hofmann N, Hunecke A. Influence of curing methods and matrix type on the marginal seal of class II resin-based composite restorations in vitro. Oper Dent 2006. 31(1)97–105.
23. Koran P, Kurschner R. Effect of sequential versus continuous irradiation of a light-cured resin composite on shrinkage, viscosity, adhesion, and degree of polymerization. Am J Dent 1998. 11(1)17–22.
24. Silikas N, Eliades G, Watts DC. Light intensity effects on resin-composite degree of conversion and shrinkage strain. Dent mater 2000. 16(4)292–296.
25. Friedl KH, Schmalz G, Hiller KA, Markl A. Marginal adaptation of Clss V restorations with and without softstart-polymerization. Oper Dent 2000. 25(1)26–32.
26. Yap AU, Seneviratne C. Influence of light energy density on effectiveness of composite cure. Oper Dent 2001. 26460–466.
27. Van Meerbeek B, Willems G, Celis JP, Roos JR, Braem M, Lambrechts P, Vanherle G. Assessment by nano-indentation of the hardness and elasticity of the resin-dentin bonding area. J Dent Res 1993. 721434–1442.
28. Venz S, Dickens B. Modified surface-active monomers for adhesive bonding to dentin. J Dent Res 1993. 72582–586.
29. Perdigao J, Ramos J, Lambrechts P. In vitro interfacial relationship between human dentin and one-bottle dental adhesives. Dent Mater 1997. 13218–227.
30. Choi KK, Condon JR, Ferracane JL. The effects of adhesive thickness on polymerization contraction stress of composite. J Dent Res 2000. 79812–817.
31. Zheng L, Pereira PNR, Nakajima M, Sano H, Tagami J. Relationship between adhesive thickness and microtensile bond strength. Oper Dent 2001. 2697–104.
32. Cho BH, Dickens SH. Effects of the acetone content of single solution dentin bonding agents on the adhesive layer thickness and the microtensile bond strength. Dent Mater 2004. 20107–115.
33. Dickens SH, Cho BH. Interpretation of bond failure through convesion and residual solvent measurements and Weibull analyses of flexural and microtensile bond strengths of bonding agents. Dent Mater 2005. 21354–364.
34. Scherrer SS, Denry I, Wiskott A, Belser U. Effect of water exposure on the fracture toughness and flexural strength of a dental glass. Dent Mater 2001. 17367–371.
35. Price RB, Bannerman RA, Rizkalla AS, Hall GC. Effect of stepped vs. continuous light curing exposure on bond strengths to dentin. Am J Dent 2000. 13123–128.
36. Caldwell R, Kulkarni G, Titley K. Does single versus stepped curing of composite resins affect their shear bond strength? J Can Dent Assoc 2001. 67(10)588–592.
37. Dauvillier BS, Aarnts MP, Feilzer AJ. Developments in shrinkage control of adhesive restoratives. J Esthet Dent 2000. 12(6)291–299.
38. Dennison JB, Yaman P, Seir R, Hamilton JC. Effect of variable light intensity on composite shrinkage. J Prosthet Dent 2000. 84(5)499–505.
39. Park JG, Cho BH, Lee IB, Kwon HC, Um CM. The effects of various light intensity on the polymerization of resin composites. J Korean Acad Conserv Dent 2001. 26(1)86–94.
40. Yun YH, Park SH. The effect of intermittent composite curing on marginal adaptation. J Korean Acad Conserv Dent 2007. 32(3)248–259.

Article information Continued

Figure 1

SEM micrograph of the bonded interfaces treated with 6 N HCl and 3.5% NaOCl of MP group. No cracks were observed at the junction of the adhesive layer and the hybrid layer or between adhesive layer and composite resin in both continuous curing group (a) and exponential curing group (b).

Figure 2

The failure mode distribution of tested specimens.

C: continuous curing group, E: exponential curing group

MP, Scotchbond Multipurpose Plus; AB, All Bond 2; AP, Adper Prompt.

Figure 3

SEM micrograph of the dentin surface of a debonded specimen in SB-continuous curing group. (a) Low magnification view (× 100). Adhesive failure and brittle failure pattern was observed. (b) High magnification view (× 1000). The dentinal tubules and fractured resin tags indicate failure at the interface between the adhesive layer and dentin.

Figure 4

SEM micrograph of the dentin surface of a debonded specimen in SB-continuous curing group. (a) Low magnification view (× 100). Mixed failure mode was observed through the adhesive layer (A), composite resin (R) and hybid layer (H). (b) High magnification view at the area H (× 1000). The dentinal tubules were covered partially by remnants of adhesive.

Table 1

The composition of the materials used in this study

Table 1

Table 2

The mean microtensile bond strengths (MPa) of tested specimens (Mean ± SD; N, numbers of specimens)

Table 2

MP, Scotchbond Multipurpose Plus; AB, All Bond 2; AP, Adper Prompt

*The same superscripts denote no statistical difference between groups (Tukey test; p > 0.05, uppercase letters = columns; lowercase letters =rows).

Table 3

The failure modes of tested specimens

Table 3

One specimen in MP - continuous curing group was lost before failure mode analysis.

A: adhesive failure, M: mixed failure, Cd: cohesive failure in dentin, Cr: cohesive failure in resin

MP, Scotchbond Multipurpose Plus; AB, All Bond 2; AP, Adper Prompt