A phosphor represented by Formula 1:ZnS:Cu,Cl,Mn,Te. A layer of silicon nitride having a thickness in a range from about 100 to about 150 is conformally deposited over the polysilicon gate. Subsequently, the incised gingival tissue is reflected to form a gingival flap and thereby to expose an alveolar bone underlying the gingival flap. Either side of the first optical waveguide is filled with a filling material, but either side of the second optical waveguide is not filled with the filling material.