Regeneration of gingiva following surgical excision. A clinical study.

The present clinical trial was carried out in order to analyze whether a zone of keratinized and attached gingiva may regenerate following surgical excision of the gingiva. In addition the alterations occurring in the position of the "soft tissue margin" and the clinical attachment level were assessed. 6 patients, scheduled for periodontal surgery in the canine-premolar regions of both quadrants of the lower jaw, participated in the trial. A Baseline examination performed prior to surgery comprised assessments at the buccal surface of the teeth of dental plaque, gingivitis, probing depth, clinical attachment level, position of the "soft tissue margin" and width of the zones of keratinized and attached gingiva. The entire zone of keratinized and attached gingiva was removed surgically using either a "gingivectomy" or a "flap-excision" procedure. In the "gingivectomy" procedure the wounded area was left to heal by second intention, while in the "flap-excision" procedure the alveolar mucosa was repositioned in a coronal position to achieve complete coverage of the surgically exposed alveolar bone. During healing the patients' oral hygiene status was carefully supervised. All parameters included in the Baseline examination were assessed at reexaminations performed 1, 3, 6 and 9 months following surgery. Already 1 month after surgery all "gingivectomy" units and 9 out of the 14 "flap-excision" units demonstrated presence of a zone of keratinized gingiva. At the final examination (9 months following surgery) all surgically treated buccal areas had regained a zone of keratinized gingiva. However, a zone of attached gingiva reformed less frequently. The examination performed 3 months after surgery revealed that the "soft tissue margin" and the clinical attachment level had become displaced in apical direction, 0.9 and 0.4 mm, respectively. Between the 3-month and the 9-month examinations, however, no further alterations were observed and the gingival units were healthy, independent of the presence or absence of attached gingiva or the width of the zone of keratinized gingiva.