|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1996 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1995 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)
Various dental metals have been used as restrative, prosthetic and endodontic materials, but there have been many case reports of contact allergy associated with dental metals. Then the screening methods to evaluate simply for allergy related to dental metals in humans and experimental animals were investigated and the following results were obtained. *1* 839 normal subjects were patch tested with 16 metal compounds and urushiol. The incidence of positive reaction to each metal was lower than that of urushiol (10.8%). Positive reaction to mercury was 7.7%, which ranked first in dental metals in this study. The order of positivity was Hg>Co>Zn>Sn>Mn>Ni>Au>Pd>In>Cr. Positive reaction to cobalt, nickel and zinc was significantly higher in females than in males. This might be due to the fact that females have more contact with these metals through cosmetics and metal accessories. Positive reaction to metals was high in persons who had experienced allergy to pollen, food or drugs. These findings suggested that persons with allergies were also sensitive to dental metals. *2* Two sesitization tests were compared in guinea-pig. In Maximization method with high sensitivity, Cr, Sn and Ag showed positive reaction. Hg, however, was negative reaction because epidermal necrosis by FCA (Freund's Complete adjuvant) injection perhaps injured immunocyte. On the contrary, Hg exposed positive sensitization reaction in Buehler test, and Cr, Sn and Ag were negative. *3* Mouse ear swelling test (MEST) was simple screening method for detecting sensitization by ear thickness. Hg, Cr and Ni did not show positive reaction by one time induction, and they needed the repeat inductions.
It should be shown in future studies that a simple screening method in vivo and in vitro might be useful for the evaluate of hypersensitivity to dental metals.