Background: This study evaluated the safety and effectiveness of a tissue-engineered skin product composed of viable neonatal keratinocytes and fibroblasts and compared it to a free gingival graft (FGG) in a procedure to enhance keratinized tissue (KT) and wound healing around teeth that do not require root coverage.
Methods: Twenty-five subjects were enrolled who had at least two non-adjacent teeth in contralateral quadrants exhibiting an insufficient zone of attached gingiva requiring soft tissue grafting where root coverage was not desired. One tooth was randomized to receive an FGG, and the other was randomized to receive bilayered cell therapy (BCT). The amount of KT was measured at baseline and 3 and 6 months, and the texture and color of the grafted tissue were compared to the surrounding tissue at months 1, 3, and 6. A questionnaire was used to determine subject preference at 6 months. Biopsies and persistence studies were performed on a subset of the subjects.
Results: The FGG generated statistically significantly (P <0.001) more KT than the test device (BCT) (4.5 +/- 0.80 mm versus 2.4 +/- 1.02 mm); no significant difference in recession or clinical attachment level was detected between treatment groups (P = 0.212 and P = 0.448, respectively); and no significant differences were detected at any time point for bleeding on probing (BOP), resistance to muscle pull, or inflammation. The BCT group had significantly better color and texture match with surrounding tissue (P <0.001), and subject preference was significantly greater for the BCT group (P = 0.041). No device-related adverse events or safety issues occurred during the course of the study.
Conclusions: The tissue-engineered graft BCT was safe and capable of generating de novo KT without the morbidity and potential clinical difficulties associated with donor-site surgery. The amount of KT generated with FGG was greater than generated with BCT; however, 24 of 25 test sites demonstrated an increase in KT at 6 months, with more than three-quarters of the sites yielding > or =2 mm bands of KT.