Effects of carbamide peroxide on dental luting agents

Vital bleaching of natural dentition using a 10% carbamide peroxide in solution may adversely effect restorative materials such as the luting agents. The purpose of this study is to examine surface structure and alterations of atomic weight percentages of elements in (a) zinc phosphate, (b) glass-ionomer, and (c) resin cements after contact with the solution. Dry samples of cement were immersed in a 10% carbamide peroxide solution (pH 4.15) for 1, 6, and 24 h and compared with controls. Observations by light microscopy, energy-dispersive X-ray microanalysis, and scanning electron microscopy were recorded. Scanning electron microscopic analysis indicated an eroded matrix in the ZnPO4 and glass ionomer samples exposed to carbamide peroxide. Energy-dispersive X-ray microanalysis data indicate a definite time-dependent decrease in the aluminum content for both cements. Surface integrity and atomic weight percentage of elements in resin cement were relatively unchanged after treatment with the peroxide solution or water.