Journal of Dental Research, Vol 63, 901-905, Copyright © 1984 by International & American Associations for Dental Research Online Journals
Lipid peroxidation as a possible cause of benzoyl peroxide toxicity in rabbit dental pulp--a microsomal lipid peroxidation in vitro
M. Terakado, M. Yamazaki, Y. Tsujimoto, T. Kawashima, K. Nagashima, J. Ogawa, Y. Fujita, H. Sugiya, T. Sakai and S. Furuyama
The toxicity of composite resin on rabbit dental pulp was investigated
biochemically. A microsomal fraction of rabbit dental pulp was incubated
with each of the components of composite resins, and the formation of
peroxide was determined by the thiobarbituric acid reaction. Benzoyl
peroxide (BPO), the most widely used catalyst, was the most effective on
peroxidation, but monomers were not. Cations such as Cu2+ or Fe2+ were
required for acceleration of this reaction. Authentic polyunsaturated fatty
acids and phospholipids were extensively converted into their peroxides by
BPO, but amino acids and carbohydrates were not. Among the active oxygens,
hydroxyl radicals were thought to be responsible for BPO-dependent
peroxidation. The results presented in this paper indicate that the lipid
portion of the cells may be attacked by hydroxyl radicals produced by BPO
and copper or iron. Therefore, BPO is considered to be the major factor
responsible for the toxicity of composite resins.
