Silk Suture in Parodontal Operation. We have studied in vivo the different reactions of the organism after the apposition of two different types of silk suture during the same parodontal operation, putting the two types of threads at alternate stitchs in the same patient. Successively we have assessed under the optic and electron microscope the bacterial component adhesed to the filament after its removal. As it has already been observed in the previous works done in vivo there is a different reactiveness depending on the fact that the sutures present a different bacterial or tissutal adhesion.