One-piece and two-piece dental implant systems appear to have high survival rates over at least a 15-year follow-up period. The study was published on May 13 in Clinical Implant Dentistry and Related Research.
One-piece systems may offer some advantages but were linked to more technical complications, the authors wrote.
“The results of this study demonstrate that both implant systems evaluated provide reliable long-term outcomes with high survival rates,” wrote the authors, led by Dr. Miha Pirc, of the Clinic of Reconstructive Dentistry, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.
To compare the outcomes of one-piece and two-piece dental implant systems after 15–17 years following a previously conducted randomized clinical trial, a study that included 39 patients with 95 implants was conducted. Of the patients, 22 had 45 one-piece implants, and 17 had 50 two-piece implants.
Baseline was set final restoration delivery, and, from there, the patients were entered into structured maintenance programs. At 1, 5, 10, 12, 15, and 17 years, clinical reevaluations were completed and biological, technical, radiographic, and esthetic parameters were assessed.
The study revealed the cumulative implant survival rate was 95%. For one-piece implants, the survival rate was 91.8%, and it was 98% for two-piece implants, the authors wrote.
At 15 – 17 years, marginal bone levels were 0.08 (± 1.15 mm) for one-piece implants and 1.53 (± 0.81 mm) for two-piece implants. Although clinical parameters were stable in both types of implants, bleeding on probing was higher in those with one-piece dental implants.
Furthermore, technical problems occurred in 28 implants. Of those, 23 were one-piece and 5 were two-piece implants. Patients with one-piece dental implants showed a greater complication rate (implant level: 35.4% vs. 5.8%), they wrote.
However, the study had limitations, including that the small sample size limited the statistical power to detect possible differences between the two implant systems, the authors wrote.
To better understand the long-term performance and reliability of implants, more research should be conducted, they wrote.
“Both implant systems demonstrated favorable long-term outcomes with high survival rates,” Pirc and colleagues wrote.
