Effect of free gingival grafts on naturally-occurring recession in miniature swine.

Miniature swine exhibit naturally-occurring, progressive recession on facial surfaces of the permanent mandibular incisors. The purpose of this study was to determine whether placing a free gingival graft to augment the width of keratinized gingiva of mandibular incisors in miniature swine would prevent or retard recession at the grafted site compared to an untreated contralateral control site. In 8 litter-mate miniature swine, free gingival grafts were placed on the facial surface of the permanent central and lateral incisors on one side of the mandible. The contralateral mandibular incisors did not receive any treatment and served as controls. Clinical measurements, including eruption, recession, pocket depth, attachment level, and keratinized gingival width were obtained preoperatively, 2 to 3 weeks after surgery to assess the success of gingival augmentation, and 3, 6, and 9 months postoperatively. Eight grafted sites were successful and showed significant augmentation of the keratinized gingival width, with a mean increase of 5.8 +/- 0.7 mm, while 6 grafts failed and showed a slight decrease in the mean width of -0.4 +/- 0.5 from the preoperative to postoperative examination. All sites showed significant recession during the experimental period. Successful sites showed no statistically significant or clinically major difference in the rate or amount of recession than contralateral control sites. By 9 months, the average increase in recession from the baseline examination was 2.8 +/- 1.5 mm for successfully grafted sites and 2.6 +/- 1.3 mm for contralateral controls.(ABSTRACT TRUNCATED AT 250 WORDS)