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.
ABSTRACT
BACKGROUND: The distal aspect of the second molar (d-M2) often exhibits infrabony defects due to the adjacent third molar. Although the defects can be treated by guided tissue regeneration (GTR) after removing the third molar, the optimal timing remains uncertain following third molar removal in clinical decision-making. This study aimed to compare delayed and immediate GTR treatments to assist in clinical decision-making. METHODS: D-M2 infrabony defects with a minimum 1-year follow-up were collected and divided into three groups: Immediate GTR group, which underwent third molar extraction and received GTR simultaneously; Delayed GTR group, which underwent delayed GTR at least 3 months after third molar extraction; and Control group, which underwent only scaling and root planing during third molar extraction. The clinical and radiographic parameters related to the infrabony defect before GTR and post-surgery were evaluated using the Kruskal-Wallis test or one-way ANOVA, followed by post-hoc Dunn's test or the Bonferroni test for pairwise comparisons. RESULTS: A total of 109 d-M2 infrabony defects were assessed. No significant differences were found between the two GTR groups, although both of them showed significant reductions in infrabony defect depth: the immediate GTR group (2.77 ± 1.97 mm vs. 0.68 ± 1.03 mm, p < 0.001) and the delayed GTR group (2.98 ± 1.08 mm vs. 0.68 ± 1.03 mm, p < 0.001) compared to the control group. CONCLUSION: GTR can effectively improve d-M2 infrabony defects when the third molar is removed, whether simultaneously or delayed. Patients may experience less discomfort with immediate GTR treatment as it requires only one surgery.