this invention is illustrated in the drawing fig1 6 and is generally indicated as 10 referring first to the view of fig1 it can be seen that the tooth isolation device 10 comprises a cup shaped member 12 and a flexible sealing element 14 in a preferred embodiment shown in fig2 the cup shaped member 12 comprises a bottom portion 16 and at least one side 18 that extends outwardly from the bottom portion 16 the side 18 has a first end 20 that is joined to the bottom portion 16 and a second end 22 that is spaced apart from the bottom portion 16 defining an open end of the member 12 in a preferred embodiment the side 18 is formed contiguously with the bottom portion 16 to provide a smooth transition between the side 18 and the bottom portion 16 in a preferred embodiment the member 12 has two apertures 26 formed therethrough the apertures generally opposing one another each aperture is formed through the bottom portion 16 and through side 18 extending along side 18 to a point proximal to the second end 22 each aperture is wide enough and long enough to receive the molars of the person for whom the tooth isolation device 10 is designed for comfort and ease of use tooth isolation devices 10 may be made in any number of sizes between the preferred size for a small child and the preferred size for a large adult in the.