Soft and hard tissue changes after immediate implant placement with or without a sub-epithelial connective tissue graft: Results from a 6-month pilot randomized controlled clinical trial.

Abstract

The present pilot RCT aimed to investigate the influence of a connective tissue graft (CTG) in combination with the immediate implant placement (IIP) on hard and soft tissue healing, without a bone replacement graft in the gap between the implant and the socket walls. Thirty patients requiring extraction of one anterior tooth (from premolar to premolar) were randomly assigned to one of the two treatment groups (test: IIP + CTG; control: IIP). Cone-beam computed tomography and optically scans were performed before tooth extraction and at 6-month follow-up. Then, DICOM files were superimposed in order to allow the evaluation of osseous ridge and buccal bone changes, while the superimposition of DICOM and Standard Tessellation Language files allowed for evaluating of soft tissue contour. For testing the differences between the two groups, the non-parametric test as Wilcoxon rank-sum test, was used. Twenty-six of the 30 enrolled patients attended the 6-month follow-up visit. The four patients of the control group that were lost to follow-up were analysed under the intention-to-treat principle. No statistically significant differences between the groups were observed for the vertical buccal bone resorption (p=.90), as well as for the horizontal buccal bone resorption at all measured levels. Significant differences were found between the test and control groups in the horizontal dimensional changes of osseous ridge at the most coronal aspect (p=.0003 and p=.02). Changes in tissue contour were between -0.32 and -0.04 mm in the test group and between -1.94 and -1.08 mm in the control group, while changes in soft tissue thickness varied between 1.33 and 2.42 mm in the test group and between -0.16 and 0.88 mm in the control group, with statistically significant differences for both variables at all measured levels. At 6months, the mean volume increase was 6.76 ± 8.94 mm3 and 0.16 ± 0.42 mm3 in the test and control groups, respectively, with a statistically significant difference. The findings of the present study indicate that the adjunct of a CTG at the time of IIP, without bone grafting, does not influence vertical bone resorption. Within the limits of this study, it can be suggested that the adjunct of a CTG at the time of IIP, without bone grafting, reduces the horizontal changes of the alveolar ridge. Moreover, it allows maintenance of the tissue contour due to an increase in soft tissue thickness.