In vitro growth of human gingival fibroblasts on root surfaces of endodontically treated teeth

Controversy exists over the potential for new connective tissue attachment to dentin of endodontically-obturated teeth following periodontal therapy. The purpose of this study was to determine whether cultured human gingival fibroblasts would grow in vitro on planed dentin surfaces of endodontically-treated teeth. A model similar to that of Aleo et al. was developed using extracted endodontically-treated human teeth. This model consisted of longitudinally sectioning 10 teeth, root planing one section only, and incubating both sections with a suspension of human gingival fibroblasts. Fibroblast growth was determined by staining with neutral red and trypan blue. The criterion for growth was staining of the complete root surface. All root areas with attached periodontal fibers displayed staining, as well as the complete root surface of all planed sections. Unplaned sections did not stain on root areas formerly exposed to the oral environment owing to periodontal disease, a finding consistent with the results of Aleo et al. Our results indicate that root canal therapy does not interfere with in vitro growth of fibroblasts on planed dentin surfaces of endodontically-treated teeth. Extrapolation to a clinical situation would indicate that normal healing may be expected after periodontal surgery on tissues adjacent to root planed endodontically-treated teeth.