Page 214 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

CHAPTER 9
surface roughness, the two implants were identical. After 36 months, 21 patients were available for follow-up.
The implant survival rate was 100% after 36 months. No differences were observed in crestal bone remodeling between the hybrid and moderately rough implant. However, initial bone remodeling was affected by initial soft tissue thickness because the equicrestal implants had implant threads exposed above bone level. Anticipating the biological width re-establishment by adapting the vertical position of the implant in relation to the available soft tissue thickness may prevent that implant threads are not fully covered by peri-implant bone. However, long-term follow-up of the study is necessary to determine the influence of early implant surface exposure and implant surface roughness on crestal bone loss, biological parameters, and implant survival.
Study III also included Oral Health-Related Quality of Life for edentulous patients restored with a two-implant-supported mandibular overdenture. This patient- centred outcome was assessed with the Oral Health Impact Profile-14 (OHIP-14). The study concluded that a two-implant-supported mandibular overdenture in comparison with a conventional removable denture yields a significant improvement in the quality of life.
Chapter 6 (Study IV) presented the five-year follow-up of the first part of study III, determining the effect of soft tissue thickness on crestal bone remodeling and peri- implant health. Twenty-four patients were available for the five-year follow-up. The survival rate was 100%, and only one implant showed a mean bone level higher than 2 mm. During initial bone remodeling equicrestal placement yielded 0.68 mm additional surface exposure compared to subcrestal placement. Afterwards, bone level and peri-implant health were comparable in both treatment conditions and stable up to five years. Hence, Study IV concluded that adapting the vertical position of the implant concerning the soft tissue thickness prevents early implant surface exposure caused by initial bone remodeling. However, in a well-maintained population, this has no impact on long-term prognosis. In addition, the Oral Health-Related Quality of Life was assessed using the Oral Health Impact Profile-14 (OHIP-14), concluding a stable Oral Health-Related Quality of Life over time.
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