Page 195 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

similar except the roughness of the implant neck to control confounding factors (Figure 2).
Figure 2: Study implants of study III, moderately rough surface implant (right) and hybrid surface with minimally rough coronal part and moderately rough implant body (left)
Study III concluded that there was no effect of the implant surface roughness on bone level up to three years and, none of the implants was diagnosed with peri-implantitis. A recent systematic review and meta-analysis concluded that implants with a rough surface in patients with a history of periodontal disease showed lower implant survival and higher crestal bone loss than in patients without a history of periodontal disease. 34 However, implants with a minimally rough surface responded similarly irrespective of periodontal history. It is tempting to conclude that a hybrid-implant system may be beneficial in patients with a higher individual risk for implant loss or peri-implantitis.
Study V focussed on macro design features with respect to bone stability and peri- implant health, namely, the effect of microthreaded versus non-microthreaded implant neck. In addition, we investigated the effect of implant-abutment connection, namely internal conical versus external flat-to-flat. For this purpose, a commercially available implant was compared with three specially produced experimental implants. All design features of the implant were similar except one to minimize confounding factors. A split-mouth study design was used to correct for inter-individual variability. After implant placement regular follow-up visits were planned at 3, 6, 12, 24, and 36 months, to ensure that the patients were
GENERAL DISCUSSION
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