The effect of chlorhexidine treatment of root surfaces on the attachment of human gingival fibroblasts in vitro.

Chlorhexidine mouthrinse is a widely used adjunct in periodontal therapy due to its bactericidal effects. The effect of this agent on chronic gingivitis and wound healing following surgical therapy in animals and humans has been favorable. The re-establishment of lost connective tissue attachment to the root surface following periodontal therapy is a desirable goal in which the ability of periodontal ligament fibroblasts to reattach to root surfaces of periodontally involved teeth is a critical event. Understanding the effect of chlorhexidine on fibroblast attachment will provide the rationale for its use during the healing phase of periodontal surgery. For this study, impacted third molars were sectioned into 4 pieces. Groups of 10 root pieces were exposed to 0.12% chlorhexidine or saline for 3 minutes followed by a distilled water rinse. The root pieces were incubated with human gingival fibroblasts (HGF) using standard tissue culture techniques for 1, 2, 4, 6, and 8 hours. HGF were prelabeled with 3H-thymidine to a standard specific activity. The surface area of each root piece was determined and the attached cells quantified by using scintillation spectroscopy. The number of cells per unit area was then calculated and the data expressed as cells/mm2. The repeated measures design was statistically analyzed by repeated measures analysis of variance. There was a significant difference between the number of attached cells in the chlorhexidine and the control groups (P less than 0.001). Exposure of root surfaces to chlorhexidine significantly inhibits subsequent fibroblast attachment which may interfere with regeneration of the periodontium. Hence, the data suggest that efforts should be made to minimize chlorhexidine contact with the root surface with physical barriers.