Purpose: To compare the onset of peri-implantitis, incidence of failure, and peri-implant marginal bone level changes between implants with a roughened surface and those with a machined/turned surface.

Materials and methods: All patients needing two dental implants of the same size on the left and right sides of the same arch, and not scheduled for immediate loading, were enrolled between October 2012 and February 2016. The patients were randomly allocated either to Nobel Biocare MKIII or Sweden & Martina Outlink2. Rough-surface implants and machined-surface implants were used from each company. After the preparation of two identical implant sites, each implant (rough or machined of the same group) was randomly allocated to the right and left sides of the same patient, following a split-mouth design. Outcome measures were peri-implantitis onset, incidence of failure, and peri-implant marginal bone level changes. Patients were followed up for 3 years after loading.

Results: One hundred fourteen patients were enrolled and treated; nine patients dropped out. Following an intent-to-treat analysis to avoid overestimation, proportions are given related to the initial number of 114 patients. Peri-implantitis incidence was 4.39% for machined implants (5/114), 0.88% for rough implants (1/114), 1.75% in the Nobel Biocare group (2 cases), and 3.51% in the Sweden & Martina group (4 cases). The failure rate was 1.75% in machined implants (2/114), 0.88% in rough implants (1/114), 0.98% in the Nobel Biocare group (1/114), and 1.85% in the Sweden & Martina group (1/114). No statistically significant differences in marginal bone loss were found comparing different surfaces, while marginal bone loss was significantly lower in Nobel Biocare than in Sweden & Martina implants.

Conclusion: Based on the results of this study, no significant differences can be demonstrated in either peri-implantitis or failure rate or in marginal bone loss between rough and machined implants. Marginal bone loss was significantly worse in machined-surface Sweden & Martina than in rough-surface Nobel Biocare implants.