Formaldehyde release from root-canal sealers: influence of method.

AIM To examine formaldehyde release from three different root-canal sealers: one phenol resin, one epoxy resin and one paraformaldehyde containing zinc oxide eugenol cement. METHODOLOGY Formaldehyde was measured from freshly mixed material and from specimens allowed to set for 2 days or 2 weeks. Different mixing ratios and sample sizes were tested. Analysis was performed by reacting formaldehyde with acetylacetone and ammonia to form diacetyldihydrolutidine, which was revealed by spectrophotometry. RESULTS Analysis revealed that mixing ratio, time after mixing and surface:weight ratios of specimens had different influences on the formaldehyde release from different materials. CONCLUSIONS From the results of this study it is difficult to define a standardized in-vitro test that can be applied universally for the definitive determination of formaldehyde release from endodontic sealers. Prediction of in-vivo formaldehyde release from endodontic sealers is difficult.