The present invention relates to a periodontal interdental tray and to a periodontal medicament tray syringe that can be used in conjunction with the periodontal interdental tray of the present invention, or can be utilized by itself or in conjunction with other periodontal trays already on the market. The lower reservoir includes a track around the shore thereof so that spectators in the seating area can view the track. If an overcurrent is recognized, the overcurrent indication portion is operated, and the base current of the output transistor circuit is controlled to perform protection of the output circuit from the overcurrent.