A Prospective, Multicenter, Randomized-controlled 5-year Study of Hybrid and Fully Etched Implants for the Incidence of Peri-implantitis

Background: The dual acid-etched (DAE) implant was commercially introduced in 1996 with a hybrid design incorporating a machined surface in the coronal region from approximately the third thread to the seating surface. This design was intended to reduce the risks of peri-implantitis and other related soft tissue complications that were reported for implants with surface roughness in the coronal region. The objective of this prospective, randomized-controlled clinical trial was to determine the incidence of peri-implantitis for a fully etched implant with the DAE surface extending to the implant platform.

Methods: Patients had implant sites randomly assigned to receive one hybrid control implant and at least one fully etched test implant in support of a short-span fixed restoration to ensure that variables (e.g., demographics, jaw locations, and bone density) were consistent between groups. Prostheses were inserted 2 months after implant placement with follow-up evaluations scheduled annually for 5 years to assess mucosal health based on bleeding on probing, suppuration, and probing depths. Evaluations also included radiographic and mobility assessments.

Results: One hundred twelve patients who were enrolled at seven centers received 139 control and 165 test implants (total: 304 implants). With >5 years of postloading evaluations, there was one declaration of peri-implantitis associated with a control implant that was successfully treated later. Clinical probing and radiographic assessments did not reveal differences between groups in mucosal health outcomes or other signs of peri-implantitis.

Conclusion: Five-year results of this randomized-controlled study showed no increased risk of peri-implantitis for fully etched implants compared to hybrid-designed implants.