Volumetric buccal bone alterations at immediate implant sites with or without soft tissue augmentation: A 6-month assessment.

Abstract

<h4>Background</h4>This study is part of a randomized controlled trial investigating the impact of soft tissue augmentation (STA) using subepithelial connective tissue graft (SCTG) (immediate implant with subepithelial connective tissue graft [ICT] group) or acellular dermal matrix (ADM) (immediate implant with acellular dermal matrix [IAD] group) versus no STA (control) on the clinical outcomes following immediate implant placement (IIP). This study aimed to investigate volumetric buccal bone dimensional changes at immediate implant sites 6 months after the surgery.<h4>Methods</h4>Forty-five patients requiring extraction of a maxillary anterior tooth or premolar and randomly assigned to one of the three groups were included. Cone-beam computed tomography (CBCT) images were obtained prior to tooth extraction and 6 months after IIP and then superimposed to evaluate 3D (volumetric) and 2D (linear) changes in buccal bone dimensions around the implant. Measurements included three regions of interest (coronal, middle, and apical segments). The associations between clinical factors and 3D buccal bone dimensional changes were analyzed using linear regression analysis. The correlations between 3D and 2D measurements were analyzed using Pearson's correlation coefficient. Statistical significance was assessed using an alpha level of 0.05.<h4>Results</h4>Volumetric bone dimensional changes were not significantly different between the groups. The greatest amount of bone loss occurred in the coronal segment (ICT: -14.99 ± 4.29 mm³; IAD: -13.60 ± 3.97 mm³; Control: -12.58 ± 4.09 mm³; p = 0.286). The thick bone morphotype was significantly associated with increased absolute volumetric bone loss (p = 0.001, 0.041, and 0.013 for coronal, middle, and apical segments, respectively). Measurements of 3D and 2D bone dimensional changes had low to high correlations (range 0.39-0.95) in different segments.<h4>Conclusion</h4>STA did not significantly affect bone dimensional loss at 6 months. Linear measurements may not fully represent volumetric bone dimensional changes at immediate implant sites.<h4>Clinical trial registration</h4>This study is part of a randomized controlled trial (RCT) registered with ClinicalTrials.gov (ID NCT02864862). The title of the trial is Esthetic Outcomes Following Immediate Implant Combined with Soft Tissue Augmentation.<h4>Plain language summary</h4>This study investigated how soft tissue augmentation (STA) affected the changes in bone around dental implants placed immediately after tooth extraction. Specifically, it compared the use of a connective tissue graft and an acellular dermal matrix against no STA. Forty-five patients who needed a maxillary anterior tooth or premolar extraction and a dental implant were included. Before the extraction and 6 months after implant placement, cone-beam computed tomography (CBCT) scans were taken to measure changes in the bone dimensions around the implants. The analysis included three sections of the bone: the coronal, middle, and apical sections. The results showed no significant differences in bone changes between the different treatment groups. The greatest bone loss was found in the coronal section. Measurements taken in three dimensions (3D) and two dimensions (2D) showed varying degrees of correlation. Overall, the findings suggested that STA did not affect bone loss around dental implants, and 2D measurements may not accurately reflect the 3D changes in bone.