Leaching of plasticizers from temporary denture soft lining materials

The loss of the plasticizers dibutylphthalate, butylphthalylbutyl glycolate, benzylbenzoate, methylsalicylate, and benzylsalicylate from four soft lining materials was measured. A 0.1% aqueous solution of triton X-100, reduced was used as immersion medium, since the solubility of plasticizer in this medium was close to that of saliva. The loss of plasticizer was monitored up to 30 d after mixing. For two of the materials, the average amount of leached dibutylphthalate within the first day exceeded the proposed tolerable daily intake (TDI) by about 11 and 32 times, respectively, for an average adult person. Similarly, for these two materials, the average daily amount within the first 30 d of leached dibutylphthalate was 2.2 and 6.6 times larger, respectively, than the TDI limit. The cumulative amount leached over 30 d for each of the four materials was 128-253 mg plasticizer g(-1). The results indicate the need for further biological evaluations of these products.