ABSTRACT
The use of a narrower-diameter abutment over a larger-diameter implant platform has been shown to decrease peri-implant bone resorption. This technique, known as platform switching, shifts the implant-abutment microgap inward. The aim of this study was to examine whether shifting the microgap further inward by increasing the discrepancy between the implant platform and abutment diameter would result in a decrease in crestal bone loss. Ten patients requiring mandibular or maxillary implant restorations were included in this study. The inclusion criteria called for an alveolar crest thickness of at least 8.0 mm at the implant placement site. Fifteen Certain PREVAIL implants with a body diameter of 5.0 mm, an expanded platform feature with a maximum diameter of 5.8 mm at the collar, and a prosthetic seating surface of 5.0 mm were used in lengths of 8.5, 10.0, 11.5, or 13.0 mm. The implants were connected to 4.1-mm healing abutments in a single-stage protocol. Periapical radiographs taken before and immediately after surgery, 8 weeks after implant placement, immediately after definitive prosthesis insertion, and at 12 and 18 months after loading revealed an average peri-implant bone loss of 0.30 mm. Increasing the discrepancy between the diameter of the implant platform and the restorative abutment may lead to a decrease in the amount of subsequent coronal bone loss.
