Page 215 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

Chapter 7 (Study V) determines the effect of implant neck (microthreaded versus non-microthreaded) as well as the type of connection (internal conical versus external flat-to-flat) on peri-implant bone stability and peri-implant health. According to the literature, peri-implant bone loss is minimized on implants with microthreaded neck design and internal type of abutment connection, albeit that many clinical studies are biased due to confounding factors.
Twenty-five patients were treated with a maxillary implant-supported bar-retained overdenture on four different implant types. Each patient received one implant with an internal connection with microthreads (I MT), one with an internal connection without microthreads (I NMT), one with an external connection with microthreads (E MT), and one with an external connection without microthreads (E NMT). Other design features, as well as surgical and prosthetic protocol, were consistent.
After at least 36 months, the survival rate was 96%. It was concluded that the implant-abutment connection type (internal vs external) and the implant neck design (microthreaded vs non-microthreaded) have no clinical effect on peri- implant bone remodeling, peri-implant bone level after the initial remodeling. Furthermore, it also had no clinical effect on peri-implant health parameters, at least when implants are installed according to soft tissue thickness.
Chapter 8 is the general discussion and includes clinical and future research recommendations. In addition, it highlights the social relevance of the undertaken scientific work in conjunction with a personal reflection. This PhD thesis concludes that:
1. Various peri-implantitis definitions are used in the literature, and reporting of biological parameters is often incomplete. Consistent reporting of peri- implantitis is required for scientific purposes as well as for clinical practice.
2. The peri-implantitis prevalence based on various case definitions did not correlate with the diagnostic parameters ‘mean probing pocket depth’, ‘mean bleeding on probing’, and ‘mean bone loss’. The survival rate showed a substantial correlation with function time, but implant loss over time is low.
3. In the current literature, less than 5% of the implants showed bone loss above 3 mm after at least five years in function. This result was independent
SUMMARY IN ENGLISH
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