Abstract
INTRODUCTION AND AIMS: The histological and morphological differences in soft tissue between natural teeth and peri-implant may result in different clinical effectiveness to free gingival graft (FGG). This research aims to investigate the different efficacy of FGG in augmenting keratinized tissue width (KTW) between tooth and implant sites while evaluating its medium-term stability over a 2- to 5-year follow-up. METHODS: In this study, 29 patients underwent FGG to address insufficient clinical scenarios when KTW <2 mm at the buccal aspect, including 37 implant sites and 33 natural teeth sites both in posterior regions were included. The KTW and gingival margin position (GMP) of these sites was assessed by measuring the intra-oral photographs which were taken at 0 days (T0), 3-month (T1), 6-month (T2), 12-month post-surgery (T3), and 2 to 5 years follow-up (T4). RESULTS: The results revealed that KTW increased significantly in both groups. However, the natural teeth group showed significantly less graft shrinkage (GS) than the implants group. (Teeth: 2.05 ± 0.51 mm and 25.42% ± 6.45%; Implants: 3.18 ± 0.65 mm and 38.92% ± 5.39%, P <.01). From T1 to T4. The gingival margin coronally advanced by 0.47 ± 0.51 mm and 0.18 ± 0.43 mm for the natural teeth and implants group, respectively (P<.05). CONCLUSIONS: A greater KTW reduction after FGG was observed at implants versus natural teeth. And, the graft surrounding implants after crown restoration was stable for up to 2 to 5 years. CLINICAL RELEVANCE: By comparing the changes in KTW around natural teeth and implants following FGG to investigate whether there are differences between them and the degree of differences. Additionally, this allows us to explore whether the restorations impact the effect of FGG. This research can assist clinicians in selecting an appropriate amount of soft tissue during surgery to achieve treatment goals, reduce postoperative discomfort for patients, and enhance predictability in clinicians' ability to increase keratinized tissue. Furthermore, by observing changes in the position of GMP around natural teeth and implants, the effectiveness of FGG in root coverage can be understood, thus improving the predictability of FGG for root coverage.