Immediate versus delayed loading of post-extraction implants in the aesthetic zone: a prospective longitudinal study with 4-year follow-up.

The aim of this randomized clinical trial was to compare the outcome of immediate versus delayedloading protocol using a new conical connection implant in post-extractive sockets with 4-year followup. Patients requiring single-tooth extraction for root fractures or periodontal disease in the maxillary or mandibular anterior or premolar areas were selected for the present study. After extraction, implants were placed immediately in fresh sockets. After randomization process, in group A immediate loading was performed while in group B a delayed loading protocol was followed. In both groups mean marginal bone loss was measured through intraoral digital radiographs at 3, 6, 12, 24, 36 and 48 months from loading. After a 48-month follow-up period, a success and survival rate of 96.55% was found in both groups. At 48-month follow-up, for group A a mean marginal bone loss of 0.14 ± 0.15mm was found, while for group B a value of 0.12 ± 0.12 mm was measured. No statistically significant differences between groups were found at each time point (P>0.05). When used in post-extractive immediate and delayed loading implant rehabilitations, the new conical connection implant showed a predictable outcome at 48-month follow-up. However, further clinical studies are needed to evaluate soft tissues adaptation, patient satisfaction, and long-term follow-up.