It is proposed that poly-L-glutamate (molecular weight approximately 50,000) and proteinaceous material from supernatant salivary fluid that has been modified by attaching homosulfonamide to the side-chain carboxyls via amide bonds be tested for adsorption onto the coronal surfaces of extracted, human teeth. If these peptide materials carrying covalently attached homosulfonamide can be adsorbed onto extracted teeth, the effectiveness of these agents in preventing or inhibiting in vitro bacterial colonization of treated teeth will be evaluated. It also is proposed that tooth-attached poly-L-glutamate and salivary proteins be tested for chemical modification by attachment of homosulfonamide via amide bonds. If these peptide materials can be modified by homosulfonamide attachment after adsorption of the peptide material onto extracted teeth, these coated teeth will be subjected to in vitro bacterial colonization and examined for prevention of colonization. BIBLIOGRAPHIC REFERENCES: Grigsby, W.R., Sabiston, C.B., Jr., and Grigsby, T.A. 1976. Covalent Binding of 1-14C Ethylglycinate to Salivary Protein. Journal of Dental Research 55, B92, abstract 122. Grigsby, W.R., Parrish, J.M., and Sabiston, C.B., Jr. Adsorption of Dansylated Salivary Proteins on Extracted, Etched, Human Teeth. 1976. Journal of Dental Research 55, B92, abstract 121.