Now, Guided Tissue Regeneration (GTR) membranes which used biodegradable polymer were used in dental clinics. However, these membranes did not have any biological function such as the promotion of cell adhesion. In this study, GTR membrane surface was hydrolyzed with alkaline solution and collagen or fibronectin which was cell-adhesive protein was immobilized on GTR membrane surface using water-soluble carbodiimide. Afterwards, the attachment and proliferation of human gingival fibroblasts was investigated. It revealed that collagen immobilization onto GTR membrane by alkaline hydrolysis for 10min enhanced cell attachment, but the degradation of GTR membrane was occurred. The development of another method for immobilization cell adhesive protein onto GTR membrane instead of alkaline hydrolysis was necessary.
The supragingival dental calculi of the twenties of youth and the past forty of adult were compared concerning the change of structure and composition. The dental calculi were examined using a stereoscopy, a SEM, and the SEM-EDS. The granular crystals were observed in the calculi of youth. The calculi of adult showed a lamellar pattern. The granular, fibrous, and flake-like crystals were observed in the calculi of adult. SEM-EDS analysis showed that Ca and P were major elements, and Na and Mg were the trace elements. It was suggested that the difference may be cause in the content of Na and Mg related with aging. The Ca/P molar ratio was 1.19 on average in the youth. The Ca/P molar ratio was 1.46 on average in the adult. The possibility that the difference is in the crystal of dental calculus because of the aging was suggested.