Immediate implant, alveolar ridge preservation and Sealing Socket Abutment: 3D radiographic analysis

Abstract

Background : Immediate implant placement in combination with alveolar ridge preservation (ARP) is one of the therapeutic modalities to counteract post-extraction bone resorption in molar sites. However, the achievement of primary closure following this procedure remains invasive and challenging. To tackle this limitation, a sealing socket abutment (SSA) has been introduced. Aim/Hypothesis : The aim of this retrospective study was to provide a 3D-radiographic evaluation of horizontal and vertical bone dimensional changes following immediate implant placement in molar sites with simultaneous ARP technique and installation of a sealing socket abutment (SSA). Materials and Methods : The radiographic data (cone beam computed tomography-CBCT scans) of 80 consecutive patients treated with the SSA technique were examined for potential inclusion. Only patients for whom both a preoperative and a postoperative CBCT (minimum 1 year after implant placement) could be retrieved were included in the study. Preoperative and postoperative scans were superimposed and all measurements were performed by two independent examiners. Horizontal bone changes were measured in the middle of the implant at the reference line (RL) and at-2 mm,-5 mm and-7 mm below the RL (Fig. 1a). Vertical bone changes were measured buccally, at the middle of the implant, and proximally (Fig. 1b, 1c). Additional vertical bone changes at the middle of the alveolar crest proximally were evaluated (Fig. 1c). Paired student t-test and Wilcoxon signed rank test were conducted to compare measurements between baseline and 1 year after. Results : A total of 27 patients and 28 implants were included. Radiographic analyses showed no significant differences in horizontal and vertical bone dimensional changes between baseline and 1-year post-surgical values. Horizontal hard tissue change at the RL was 0.37 ± 1.27 mm (P = 0.13) and it decreased towards-7 mm level (0.004 ± 0.37 mm, P = 0.95). Vertical bone changes of the buccal plate showed at each side no statistically significant differences between the two time points. Similar results were observed at the middle of the alveolar crest, with the bone loss of-0.36 ± 1.66 mm mesially (P = 0.36) and-0.10 ± 1.34 mm distally (P = 0.70). Conclusions and Clinical Implications : Based on the present findings, and within the limits of a retrospective study, immediate implant placement in molar sites with simultaneous ARP technique and installation of SSA leads to minimal bone dimensional changes in the first year postoperatively. The stability of the hard tissue dimensions can be beneficial for long-term implant success.