Effect of curing mode on the polymerization characteristics of dual-cured resin cement systems

Arrais, Cesar A.G.; Rueggeberg, Frederick A.; Waller, Jennifer L.; de Goes, Mario F.; Giannini, Marcelo

doi:10.1016/j.jdent.2008.02.014

« Previous Next »Journal of Dentistry
Volume 36, Issue 6 , Pages 418-426, June 2008

Effect of curing mode on the polymerization characteristics of dual-cured resin cement systems

Cesar A.G. Arrais
- Department of Operative Dentistry, School of Dentistry, University of Guarulhos, Guarulhos, SP, Brazil
Frederick A. Rueggeberg
- Department of Dental Materials, School of Dentistry, Medical College of Georgia, Augusta, GA, USA
Jennifer L. Waller
- Department of Biostatistics, Medical College of Georgia, Augusta, GA, USA
Mario F. de Goes
- Department of Restorative Dentistry, Dental Materials Section, Piracicaba School of Dentistry, University of Campinas, SP, Brazil
Marcelo Giannini
- Department of Restorative Dentistry, Operative Dentistry Seciton, Piracicaba School of Dentistry, University of Campinas, SP, Brazil
- Corresponding author at: Department of Restorative Dentistry/Operative Dentistry, Piracicaba School of Dentistry, UNICAMP, Av. Limeira, #901, Piracicaba, SP 13414-900, Brazil. Tel.: +55 1934125340; fax: +55 1934125218.

Received 26 July 2007; received in revised form 20 February 2008; accepted 21 February 2008.

Abstract

Objectives

To evaluate the effects of different curing conditions on the degree of conversion (DC) of dual-cured cementing systems [combination of bonding agent (BA) and resin cement (RC)] using infrared spectroscopy.

Methods

Four fourth generation products [Scotchbond Multipurpose Plus/RelyX (3M ESPE), Optibond/Nexus 2 (Kerr), All Bond2/Duolink (Bisco), and Bond-It!/Lute-It! (Pentron)], and three fifth generation materials [Bond1/Lute-It! (Pentron), Prime&Bond NT Dual-Cure/Calibra (Dentsply), and Optibond Solo Dual Cure/Nexus 2 (Kerr)] were applied to the surface of a horizontal attenuated-total-reflectance unit, and were polymerized using one of four conditions: self-cure (SC), direct light exposure through glass slide (DLE, XL3000/3M ESPE) or through pre-cured resin discs (shades A2;A4/2mm thick/Z250/3M ESPE). Infrared spectra of the uncured cementing systems were recorded immediately after application to the ATR, after the system was light-cured or left to self-cure, and spectra were obtained 5 and 10min later. DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios pre- and post-curing. Data (n=5) were analyzed by two-way repeated measures ANOVA and Tukey's test (p=0.05).

Results

Changes in aliphatic-to-aromatic peak ratios before and after placing RC onto the BA demonstrated that a combined layer was created. All groups exhibited higher DC after 10min than after 5min, except the DLE group of Bond-it!/Lute-it!. No significant differences in DC were observed among light-activated groups regardless of the resin disc shade in three of the four fourth generation cementing systems. The SC groups exhibited lower DC than the DLE groups for both fourth and fifth generation products either after 5 or 10min.

Conclusion

The chemistry of the bonding interface changed when RCs were applied to uncured BAs. The presence of an indirect restoration can decrease the DC of some cementing systems and the self-curing mode leads to lower DC than the light-activating one.

Keywords: Degree of conversion, Dual-cured cementing systems, Indirect restorations, Self-cure