| 0461 Estrogenic Activity of Proprietary Composites Including Photostabilizer, 2-Hydroxy-4-methoxy-benzophenone | ||
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H. TARUMI1, S. IMAZATO1, H. WADA1, M. NARIMATSU1, M. MATSUO2, and S. EBISU1, 1Osaka University Graduate School of Dentistry, Japan, 2Cooperative Research Center for Advanced Science and Technology at Osaka University, Japan Objective: Recently, we have confirmed that a photostabilizer, 2-hydroxy-4-methoxy-benzophenone (HMBP), commonly used for proprietary composites showed an estrogenic activity. We hypothesized that the estrogenic effects may be induced by HMBP eluted from cured composites, as this compound has no functional group. The purposes of this study were to investigate the estrogenic activity of 10 commercially available composites containing HMBP, and to determine the relevance of this chemical to the estrogenicity. Methods: Cured disk specimen of each material was immersed in 2.0 mL of Phenol-red-free D-MEM for 24 hr, and the eluates obtained were incubated with 293T cells, transfected with both human estrogen receptor alpha expression plasmid and firefly luciferase reporter plasmid. The relative luciferase activity to estradiol 17-beta of each sample was calculated, and compared with a negative control (Student-t test). The concentration of HMBP and other components eluted from the specimens was measured by HPLC, and the estrogenic activity of these chemicals was also determined. Results: Among 10 composites tested, five materials (Esthet X, Dentsply/Caulk, EX; Spectrum, Dentsply/Detrey, SP; Revolution, Kerr, RE; Charisma, Heraeus-Kulzer, CH; Flowline, Heraeus-Kulzer, FL) were estrogenic (p<0.05). HMBP was identified in the eluates of all specimens, and the concentrations of HMBP eluted from EX, SP and RE were greater than the minimum concentration (0.23 µg/mL) to show estrogenicity. For CH and FL, elution of HMBP was less than 0.23 µg/mL, but a photoinitiator, 2,2-dimethoxy-2-phenylacetophenone (DMPA), which is also estrogenic, was found to be leached in the greater amount than the minimum estrogenic concentration (0.26 µg/mL). Conclusion: It can be concluded that the estrogenic activity of EX, SP and RE was associated with HMBP eluted, and CH and FL showed the estrogenicity due to the leaching of DMPA. It is suggested that these chemicals need to be replaced by other components with no estrogenic effect. | ||
| Seq #57 - Biocompatibility 11:00 AM-12:15 PM, Thursday, 7 March 2002 San Diego Convention Center Exhibit Hall C | ||
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