The purpose of this clinical trial was to evaluate the effect of tetracycline root preparation on guided tissue regeneration in the treatment of Class II furcation defects. Nine pairs of defects with horizontal clinical attachment level value ≥5 mm comprised the study group. Measurements were made to determine presence of plaque, gingival condition, probing depth, and vertical and horizontal clinical attachment level. Defects from each pair were randomly assigned for treatment with an expanded polytetrafluoroethylene membrane (e‐PTFE) and tetracycline root conditioning (100 mg/ml) or the membrane alone. The membranes were removed 4 to 6 weeks postsurgery. Patients were then seen monthly for the duration of the study. Six months postsurgery, all clinical measurements were repeated. Following either treatment, improvement was observed in all clinical parameters, particularly in horizontal clinical attachment level. However, there was not a statistically significant difference in the improvement observed between sites treated with guided tissue regeneration in conjunction with tetracycline as compared to membrane placement alone. Further studies are needed to fully evaluate tetracycline root preparation in conjunction with regenerative therapy. J Periodontol 1993; 64:133–136.

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The present study examined the orientation of gingival fibroblasts in simulated periodontal spaces in vitro. Extracted human teeth were root planed followed by root resection and root canal instrumentation. The middle and cervical thirds of each root were cut transversely to create 600-micron thick sections. Cortical bovine bone was cut, sectioned and contoured to create bone rings 600 micron thick with an internal diameter large enough to accommodate a root slice leaving a circumferential space varying from approximately 0.1 to 1.0 mm. Root slices and bone rings were incubated in a solution of collagenase and hyaluronidase to remove all remaining soft tissue and partially demineralized in EDTA (18%) for 30 minutes. Human gingival fibroblasts (HGF) were plated to confluency in tissue culture dishes. The dentin slices were then gently placed over the HGF monolayer along with bone rings around them to create simulated periodontal spaces. Control root slices were placed without bone rings around them. Cultures were maintained under standard tissue culture conditions. Representative specimens were obtained after 2, 3 and 4 weeks of culture and processed for scanning electron microscopy (SEM). At 2 weeks, the HGF had formed sheets of cells attached to the periphery of the root slices at one end and to the inner surface of bone rings at the other end. The orientation of cell sheets varied from being perpendicular to the periphery of the slice to oblique. At 3 and 4 weeks, the density and size of cell sheets increased and the orientation was maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

The present study examined the orientation of cultured human gingival fibroblasts in simulated periodontal spaces in vitro containing three dimensional hydrated collagen gels. Extracted human teeth were root planed followed by root resection and root canal instrumentation. The middle and cervical thirds of each root were cut transversely to create 600-micron thick sections. Cortical bovine bone was cut, sectioned, and contoured to create bone rings 600 micron thick with an internal diameter large enough to accommodate a root slice leaving a circumferential space varying from approximately 0.1 to 1.0 mm. Root slices and bone rings were incubated in an enzyme solution to remove all remaining soft tissues and then completely demineralized in EDTA (18%) for 72 hours. Human gingival fibroblasts (HGF) were plated to confluency in tissue culture dishes. The dentin slices were then gently placed over the HGF monolayer along with bone rings around them to create simulated periodontal spaces. Five days later, when initial cell attachment to the dentin and root slices had occurred, a collagen gel was poured in the space. The cultures were maintained for six weeks and were then processed for transmission electron microscopy. The HGF appeared to have formed multilayered cell sheets extending from the periphery of the root slices to the inner surface of bone rings. The HGF had apparently attached to both the bone and root surfaces. There was a close interaction of cells with the matrix fibrils of the gel. The cells and matrix fibrils were oriented parallel to each other.(ABSTRACT TRUNCATED AT 250 WORDS)