Monomer Conversion in Dual-cured Core Buildup Materials

Abstract

Objectives: To examine the impact of self-curing (SC) and light-curing (LC) mechanisms on the curing efficiency of dual-cured buildup restorative materials (DCB).Methods: The DCB materials tested were: Clearfil DC Core Automix (CD), Cosmecore DC (CM), LuxaCore DC (LX) and MultiCore DC Flow (MC). The SC material Clearfil Core New Bond (CN) and the LC material Clearfil Photo Core (CP) were used as controls. Specimens (Ø=4 mm, d=1 mm, n=4) of DCB materials prepared without light-exposure were tested after 10-, 20-, 30-and 60-minutes of storage in dark and dry conditions (37°C), whereas DCB specimens light-cured immediately after mixing (20 seconds, 850mW/cm 2 ) served as a reference. The amount of remaining C=C bonds (%RDB) was measured on the bottom specimen surfaces using ATR-FTIR spectroscopy. One-way ANOVA and multiple comparison tests were used to evaluate the statistically significant differences (α α=0.05).Results: Polymerization mode had a strong effect on the polymerization efficacy of the DCB materials (p<0.0001). The control materials (CN, CP) performed better than the DCB materials (p<0.0001), except for LX in the LC mode. LX and MC showed better SC conversion during the initial 20-minute period. After 60 minutes, the %RDB values of CM were still above 60%, whereas in CD and LX, they reached the level of LC specimens.Conclusions: The LC initiation mechanism of the DCB materials that were tested resulted in better C=C conversion when compared to their native SC mechanisms. The SC and LC control

Effects of different polymerization protocols on the degree of conversion of two dual‐cured core buildup composites polymerized by light‐emitting diode and halogen light‐curing units

“…Core buildup resin composites have been used in severely damaged teeth to restore the bulk of the coronal portion of the tooth . Despite the long‐term success of large amalgam restorations, resin composites in combination with adequate bonding systems are currently recommended as core materials . The high initial strength of the resin composites expedites the clinical process because the restored teeth may be prepared for indirect restoration at the same appointment …”

“…These effects result in the potential degradation of the extent of monomer conversion of the subsurface levels beyond 2 mm . The dual‐cured version of resin composite buildup restoratives have recently been developed in an attempt to overcome the limitations of both self‐cured and light‐cured resin composite materials by the incorporation of an oxidation–reduction initiator system and photoinitiators . It has an extended working time and is capable of reaching a high degree of monomer conversion in the presence or absence of light .…”

“…4 The dualcured version of resin composite buildup restoratives have recently been developed in an attempt to overcome the limitations of both self-cured and light-cured resin composite materials by the incorporation of an oxidation-reduction initiator system and photoinitiators. 2,4,8 It has an extended working time and is capable of reaching a high degree of monomer conversion in the presence or absence of light. 5,6 The polymerization This article was presented as a poster at the 37th Annual Conference of the European Prosthodontic Association (2013).…”

Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

“…The low consistency of the core material such as MCF and LCZ might be easier to lute the surface of the post, with less air contamination, providing higher bond strength. For TNC and CPC, which use incremental technique, it can be noticed that CPC, which is less consistent, was more translucent and may have allowed less void, promoting more complete polymerization 13 . It seemed that the curing mode did not affect the results, since CPC showed the highest and TNC showed the lowest values of fracture resistance.…”

A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration

“…Moreover, the homogenous distribution and the stable dispersion of the fillers without any sedimentation, demonstrated the stability of the composite mixtures at the different storage periods. The experimental composite was designed as dual-cured resin system with better clinical handling as it allows extended working time and secures polymerisation in deep parts of the canal [32][33][34].…”