A 5-Year Prospective Clinical Study of Submerged and Nonsubmerged Paragon System Implants in the Edentulous Mandible

Purpose: The aim of this investigation was to evaluate the clinical outcome of two different surgical protocols in the edentulous mandible: submerged and nonsubmerged. Further, the Paragon dental implant with a titanium plasma-sprayed surface was evaluated. Materials and Methods: Twenty-nine consecutively treated patients with 168 implants supporting fixed prostheses were included. All but 3 patients were provided 6 implants, placed via nonsubmerged healing on one side and submerged healing on the other. Data were collected from patient records and radiographs. Twenty-four patients participated in the 5-year clinical follow-up examination. Results: After 5 years, all patients still had their mandibular fixed prostheses in function. Cumulative survival rates were 100% for prostheses and 99.4% for implants. However, 3 implants fractured in 1 patient. One submerged implant was lost before loading but no further implants were lost during follow-up. The radiographic bone loss was small for all implants with a mean of 0.14 mm (standard deviation [SD]: 0.37) at 1 year and 0.42 mm (SD: 0.48) at 5 years for nonsubmerged implants and 0.17 mm (SD: 0.32) at 1 year and 0.51 mm (SD: 0.33) at 5 years for submerged implants. Nineteen implants (including the 3 that fractured) presented annual bone loss exceeding 0.2 mm after the first year, yielding a cumulative success rate of 86.2% after 5 years. Conclusion: Single-stage surgery was shown to have the same predictability as two-stage surgery in the anterior edentulous mandible. Paragon implants with a titanium plasma-sprayed surface showed a fracture rate of 2.2% and a success rate of 86.2% after 5 years.