A suitable base material for composite resin restorations: Zinc oxide eugenol
Received 30 September 2009; received in revised form 25 November 2009; accepted 30 November 2009. published online 04 December 2009.
Abstract
Objective
This in vitro study evaluated the effects of a zinc oxide eugenol (ZOE) base on the mechanical properties of a composite resin restoration.
Methods
Class I cavities were prepared on plastic teeth and filled with ZOE plus composite resin, following standard clinical procedures. The samples were sectioned sagittally and the ZOE–resin interface was exposed. After polishing, nanoindentation was performed on the region near the interface, and elastic modulus and hardness were plotted in the form of a color contour map. SEM was employed to observe the interface between composite resin and ZOE base.
Results
In the region close to the ZOE base, the elastic modulus and hardness of composite resin reduced to the values of 9.71±0.54 and 0.51±0.05GPa, respectively. Eugenol from ZOE had detrimental effects on the composite resin only to a distance of less than 100μm from the ZOE base.
Conclusion
Although eugenol suppresses polymerization slightly, by considering the biological advantages of ZOE, together with the results of the current investigation, ZOE may still be considered a suitable base material for composite resin. Bonding is essential for composite resin restorations over ZOE bases to avoid shrinkage detachment.
Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
Corresponding author at: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 647, Dunedin 9054, New Zealand. Tel.: +64 3 479 7084; fax: +64 3 479 5079.
ABSTRACT