Structural and microbiological evaluation of a degradable sustained-release device for use in periodontal therapy.

Degradable protein matrices containing chlorhexidine were tested as intra-pocket drug delivery systems in the treatment of periodontal diseases. The properties of the device were mainly dependent upon the degree of cross linking in the matrix, which could be varied according to the preparative conditions. The degree of cross linking was determined by amino acid analysis based on the amount of free lysine in the protein. The release of chlorhexidine and of the plasticizer used in the preparation of the matrix were determined. The release of chlorhexidine from the matrix was prolonged for a period of 300 hours, and the release of plasticizer ceased after four hours. Limited clinical trials suggest that one of the degradable devices--that containing the highest amount of cross-linking--causes a significant reduction in the amount of perio-pathogenic bacteria following its insertion into the periodontal pockets of patients with periodontal disease.