Patient V. came to the clinic with complaints of burning, swelling and pain of the buccal mucosa in the area of a bridge made four months ago for teeth 2.3, 2.5 made of stainless steel, coated with titanium nitride.

Objectively: a bridge on teeth 2.3, 2.5 made of stainless steel coated with titanium nitride, a discoloration of the metal in the area of adhesions of the bridge, tooth 2.6 is covered with a gold alloy crown, on tooth 2.7 there is a stainless steel crown.

Additional research methods: skin tests for haptens: Ni, Cr, Co - positive, potential difference> 50 mV

What diagnosis can be made in the presence of these complaints and an objective study?