Influences of Different Air-Inhibition Coatings on Monomer Release, Microhardness, and Color Stability of Two Composite Materials.

Luca Marigo,Cinzia Callà,Giulia Fiorenzano,Massimo Cordaro,Gaetano Paolone,Giuseppina Nocca,Salvatore Sauro,Raffaella Castagnola

doi:10.1155/2019/4240264

Abstract

The aim of this study was to evaluate the effect of light-curing protocols on two modern resin composites using different air-inhibition coating strategies. This was accomplished by assessing the amount of monomer elution, surface microhardness, and composite discoloration in different storage conditions. A total of 120 specimens were prepared using Filtek Supreme XTE (3M ESPE, Seefeld, Germany) and CeramX Universal (Dentsply DeTrey, Konstanz, Germany). Specimens were light-cured in air as per manufacturer's instructions or in the absence of oxygen. This latter condition was achieved using three different approaches: (i) transparent polyester strip; (ii) glycerin; (iii) argon gas. Specimens were assessed for release of monomers, Vickers hardness, and discoloration after storage in different solutions. The results were analyzed with ANOVA one-way test followed by Student-Newman-Keuls test. Moreover, multiple comparisons of means were performed using the Student t-test (p<0.05). The amount of monomers released from the tested specimens was very low in all conditions. The presence of oxygen induced some decrease in microhardness. The highest discoloration values, for both materials, were obtained after ageing in red wine. In case finish and polish procedures are awkward to achieve in posteriors composite restoration, light-curing in the absence of oxygen should be considered, especially when performing composite restoration in esthetic areas.

Highlights

Composite resins have been radically improved in the last years in terms of physical properties and aesthetic characteristics [1, 2]
The high-performance liquid chromatography (HPLC) results showed that the amount of monomers released from the composite specimens was very low in all triethylene glycol dimethacrylate (TEGDMA) CeramX Universal (CX) 0.4
Our results showed that the two resin composites (XTE and CX) used in this study had no significant difference in terms of microhardness when light-cured in the presence of glycerin, argon gas, or air (Figure 6)

Summary

Introduction

Composite resins have been radically improved in the last years in terms of physical properties and aesthetic characteristics [1, 2]. Nanohybrid and nanofilled composites are considered universal resin-based restorative materials suitable for the restoration of anterior and posterior teeth due to their excellent aesthetic properties [3] Their polymerization reaction can be inhibited during light-curing procedures due to the presence of oxygen in the atmosphere. This latter acts as scavenger, which tends to convert highly reactive radicals into relatively stable hydroperoxides. The presence of these latter components can alter the quality of the polymerization of the outer layer of resin composites [4].

Objectives

Methods

Discussion

Conclusion