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Comparison of 2 techniques of subepithelial connective tissue graft in the treatment of gingival recessions.

BACKGROUND
The clinical outcome of connective tissue grafts in the treatment of gingival recessions has been documented in numerous studies. However, no attempt has been made to correlate the postoperative mucogingival changes with the surgical parameters. The present retrospective clinical study was undertaken to 1) evaluate root coverage and mucogingival changes 1 to 1.5 years following treatment of Miller's Class I and II recession defects using 2 variants of the subepithelial connective tissue graft (SCTG) procedure, and 2) assess the effect of the surgical parameters on the postoperative gingival width.


METHODS
Thirty-one recessions in 10 patients treated with the envelope technique (E) and 31 recessions in 11 patients treated with coronally positioned flap combined with connective tissue graft (CP) were retrospectively analyzed to evaluate: 1) percentage of root coverage obtained with the 2 procedures and variations in width of keratinized tissue (KT) 1 to 1.5 years postsurgery, and 2) the effect of the surgical parameters on the postoperative gingival width.


RESULTS
Results showed a mean root coverage percentage of 89.6 +/- 15% for the E group and 94.7 +/- 11.4% for the CP group; the difference between groups was statistically insignificant (P = 0.1388). Mean KT increased significantly from 1.4 +/- 1.1 mm presurgery to 4.5 +/- 1.1 mm postsurgery for the E group while a minor increase in KT was observed in the CP group (2 +/- 1.5 mm presurgery versus 2.7 +/- 1.6 mm postsurgery). For both treatment groups, the mean postsurgical width of keratinized tissue (POSTKT) was found to be mathematically correlated with the mean presurgical width of keratinized tissue (PREKT) and the corono-apical height of the graft that remained exposed (GE) coronal to the flap margin in the recipient site.


CONCLUSIONS
Treatment of human gingival recession defects by the 2 variants of SCTG resulted in significant recession reduction. When SCTG is grafted beneath alveolar mucosa using the combined technique (CP), transformation of the mucosa into keratinized tissue does not seem to occur, at least within 1 to 1.5 years postsurgery. The treatment outcome in terms of keratinized tissue width seems to be correlated with the presurgical gingival dimensions and the height of the graft that remains exposed at the end of the surgical procedure.