A suitable base material for composite resin restorations: zinc oxide eugenol.
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+/-0.05 GPa, respectively. Eugenol from ZOE had detrimental effects on the composite resin only to a distance of less than 100 microm from the ZOE base.


CONCLUSIONS
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.
He
Li-Hong
LH
Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin 9054, New Zealand. lihong.he@otago.ac.nz
Purton
David G
DG
Swain
Michael V
MV
D003188:Composite Resins / Q000737:chemistry*; D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation / Q000145:classification; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D003793:Dental Restoration, Permanent; D055119:Elastic Modulus; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry*
D003188:Composite Resins; D003764:Dental Materials; C474035:Filtek Supreme; D011108:Polymers; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D015035:Zinc Oxide-Eugenol Cement