Sadao Nakayama

A delayed hypersensitivity reaction to dentine primer in the guinea-pig.

OBJECTIVE This study was undertaken to examine the possibility of a delayed hypersensitivity reaction or contact dermatitis occurring in the guinea-pig in response to methacrylate derivatives used as experimental dentine primers. METHODS The dentine primers 2-HEMA, GM, MA and MMA were tested in a guinea-pig maximization test. RESULTS All the dentine primers tested produced positive delayed hypersensitivity reactions in the guinea-pig. MMA produced the most severe reaction. CONCLUSION It is concluded that in the clinical situation, clinicians and other members of the dental team should be aware of the need for careful handling of the dentine primers tested.

Possibility of Allergic Reaction to Dentin Primer

We studied the allergic reaction of guinea pigs to glyceryl methacrylate (GM), hydroxyethyl methacrylate (HEMA) and meso-erythritol methacrylate (EM), which are used as dentin primers. On the 18th day of the application test, when macroscopic investigation revealed an inflammatory reaction, the methacrylic acid-treated group showed marked eschar formation in comparison with the control group. In each of the dentin primer groups, a slight degree of skin redness was noted, but there were no serious symptoms. On the 25th day, the applications were resumed macroscopic inspection on the 32nd day found eschar in the methacrylic acid group only. Therefore, this experiment with dentin primers suggests a delayed allergic reaction. Local irritability test showed a more severe reaction than the application test. In this test, all experimental dentin primers and methacrylic solution promptly showed inflammation, and the chemical compound, methacrylic acid was a factor in inflammation.