MBL of immediate and early implants placed in post-extractive sockets affected/not affected by endodontic lesions: a prospective cohort study

Background: The quality of alveolar bone and the presence of infected and contaminated periapical area with fistula, pus and exudate may condition the decision to delay the placement of the implant. On the other hands, the presence of seriously compromised ‘hopeless’ tooth with deeper carious lesions and absence of periapical lesion may represent an indication to the extraction and immediate placement of implant. Aim/Hypothesis: The main purpose of this study was to evaluate the survival rate and marginal bone loss (MBL) at 3 months (pre-load) and 6 months (post-load), 12 and 24 months of implants placed after extraction of ‘hopeless’ molar/premolars (immediate CCL group) and after extraction of teeth affected by acute periapical lesions (early APL group). Implants placed after at least 12 months from the extraction were considered as control group (delayed CG group). Material and methods: A total of 58 zirconium sandblasted acid etched titanium implants were positioned by one experienced operator. Immediate CCL group (n = 20): 20 patients (age male, female) which presented a seriously damaged hopeless tooth free from clinical symptoms (pain, fistula and tenderness) received a gentle stress-free extraction and immediate implant insertion. Early APL group (n = 12): 10 patients (age male, female) which presented a radiographically evident apical bone lesion of < 2 mm or wider and with a seriously damaged root/crown and acute clinical symptoms (pain, fistula and tenderness) were scheduled for tooth extraction according with the ‘Best Practice’ concept. After 3–4 months a flapless implant was placed. Delayed CG group (n = 26): 23 patients (age male, female) received a flapless implant. All implants were loaded after 3 months with a provisionalresin crown for approx. 2–3 weeks and later with a cemented metal/ceramic crown. Mesial and distal MBL was measured with periapical radiographs after 3 months from implant insertion (pre-loading time), 6 months (3 months after loading) and after 12 and 24 months from insertion. Periodontal parameters and survival rate were also measured. A linear generalized model for repeated measures (GLM) was performed to evaluate any statistical differences. Results: The mean follow-up was 24.2 3.4 months. Both immediate and early groups showed statistically lower MBL at 3 month (pre-loading) and 6 months (post-loading time) (TABLE). No differences were observed after 12 and 24 months among the three groups. Conclusions and clinical implications: The study suggest that MBL and survival rate of APL group (infected bone with periapical lesion) is similar to that obtained in immediate implant placed in health bone. The study suggests that both techniques are free from risks of implant failure. Again, both techniques may allow the fast rehabilitation just after 3 months from the implant placement. Interestingly, both