Page 54 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

CHAPTER 3
The overall weighted mean implant survival in the selected studies was 96.9% based on remaining implants at the time of evaluation. This shows that dental implant treatment today can be considered predictable. Few papers report on implant failure caused by peri‐implantitis alone. In five treatment groups (Arnhart et al., 2013; Cassetta, Driver, Brandetti & Calasso, 2016; Sener‐Yamaner, Yamaner, Sertgoz, Canakci & Ozcan, 2017), 5%, 1%, 3%, 0%, and 2% of the implants were lost due to peri‐implantitis.85,89,90 Sener‐Yamaner and colleagues reported peri‐ implantitis related failures after 5 years of loading especially in smokers.90 The paper of Arnhart mentioned the loss of two implants after 5 and 10 years because of peri‐implantitis.85 The aforementioned three papers did not report prevalence of peri‐implantitis for the remaining implants and were therefore excluded from the current review. Only two studies reported the prevalence for peri‐implantitis of both lost and functioning implants. Lops described eight of 257 (3.1%) implants with mobility due to severe peri‐implantitis and ten other implants were successfully treated during the 20‐year follow‐up period.91 Chappuis and colleagues reported 19 of 95 implants (20%) with peri‐implantitis whereof six implants were lost and 13 underwent a successful anti‐infectious therapy and were maintained with no further signs of acute infection.14 Both studies included the treated peri‐implantitis implants in the reported prevalence figures despite successful treatment. In the other 36 papers, prevalence of peri‐implantitis was related to surviving implants and dropouts or lost implants prior to the moment of assessment are not taken into account. One can conclude that information of peri‐implantitis in lost implants is scarce, and hence, the reported prevalence may be underestimated in the available literature.
In this review, the prevalence of peri‐implantitis on implant level ranged between 0% and 40%. The case definitions varied considerably between studies, mostly due to heterogeneous thresholds for bone loss, ranging from any detectable bone loss to 3.5 mm. This makes comparisons between studies difficult. Reflecting on the results presented in Table 6, it is obvious that reported prevalence figures are larger when the threshold is low. Using the same implant design, Swedish studies that applied a threshold bone loss of approximately 0.5 mm concluded that 13%–25% of the implants were affected.83,92 Thresholds of bone loss of 2–3 mm yield much lower prevalence in the order of 5%–10%. However, the paper of Meijer, Raghoebar, de Waal and Vissink seems contradictory in this respect.93 With a 2 mm threshold, they detected 20% despite a mean bone loss limited to
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