The Implant-Buccal Plate Distance : A Diagnostic Parameter. A Prospective Cohort Study on Implant Placement in Fresh Extraction Sockets

Aim: The aim of this study was to investigate contour changes around immediate implants in fresh extraction sockets when different grafting procedures are performed based on the distance between the external implant collar and the bony surface on the Buccal Plate (I- BP). A secondary aim was to assess the aesthetic outcome utilizing the Implant Aesthetic Score (IAS). Materials and methods: A prospective cohort study was performed in three centers. Suitable patients to undergo implant placement in fresh extraction sockets were selected. Periodontal biotype, horizontal and vertical peri-implant bone defects and dehiscences were assessed. Depending on the I-BP distance, two types of grafting procedures were performed. In group A (I-BP distance ≥4mm) only the peri-implant gap was grafted during the surgical phase (internal grafting-IG) while group B (I-BP distance <4mm) received both internal and external grafting (IEG). Pre-op (before implant placement) and post-op (after 1- year of loading) master casts of the sites were made and optically scanned. A computerized analysis of the contour changes at the involved sites was performed by superimposing the scanned models. Results: A total of 20 patients (12 females and 8 males) were recruited and 20 non-submerged implants placed in fresh extraction sockets. No implant failed during the observation period. The mean follow-up was 25 months (range 12-37 months). After one year of loading, group A showed a slight decrease in the mean buccal volume, while group B had an increase in volume. Such a difference was statistically significant (P=0.02). Implant Aesthetic Score (IAS) was higher for group B as compared to group A. Conclusion: When implants are placed immediately after tooth extraction, the implant- buccal plate distance (I-BP) may represent a useful diagnostic parameter in choosing the most appropriate grafting procedure (IG vs IEG). In clinical cases in which the distance between implant surface and the buccal plate is < 4 mm the combination of an internal and external grafting (IEG) is recommended to maintain the volume and the contour of the ridge, and to achieve a successful aesthetic outcome.