Page 58 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

CHAPTER 3
This critical review revealed mean BoP ranging from 4.7%–95%. Gerber and colleagues concluded that BoP is highly dependent on the probing pressure, which strengthens the difficulty of interpreting probing assessments.102 When the probing pressure increased from 0.15N to 0.25N, BoP increased with 14% at implant sites. This increase was found to be significantly higher when compared to tooth sites (6.6%). A low probing force of 0.15N resulted in similar findings at implants and tooth sites. None of the selected papers gave detailed information on probing force. Only the paper by Chappuis used the sulcus bleeding index instead of BoP.14 By doing so, there is no de‐attachment of the mucosa around the implant as it is carried out without using a high force. This could explain the low bleeding score.
Merli and colleagues evaluated the peri‐implant BoP together with PD scoring. They observed a 39% BoP and an increase in odds ratio by 1.8 for each 1 mm increment of PD.103 For pockets of 3 mm, 30%–40% were BoP‐positive. Over 80% of the pockets of 7 mm were bleeding. Also, the paper of Farina confirmed an odds ratio for BoP of 1.6 for each 1 mm increment of PD.63 In both studies, also similar proportion of BoP‐positive sites was detected for pockets of 4 mm (27%) and 7 mm (60%). It is therefore obvious that deeper pockets have a higher tendency to bleed. A recent large retrospective cohort study of nearly 5,000 Straumann implants placed in 2,060 patients with up to 10‐year follow‐up concluded that time alone and minimal bleeding did not correlate with bone loss but that care should be taken for implants with profuse bleeding or suppuration.67 They found the highest mean bone loss around implants with suppuration and minor changes for implants with minimal to moderate or profuse bleeding. They concluded that BoP around implants is a weak indicator of ongoing or future loss of crestal bone. The fact that BoP is a binary analysis of bleeding (bleeding or no bleeding) may possibly explain high false‐positive bleeding scores. They suggested the use of an ordinal scale assessment to overcome this issue. In our review, only three of the 41 included papers used an ordinal scale, which may explain why the review could not find a significant correlation between reported prevalence and mean BoP and mean bone loss.
Suppuration is an unequivocal sign of inflammation that may be indicative of bone loss. In most clinical papers, suppuration as a diagnostic parameter is grouped together with bleeding and denoted as “BoP and/or suppuration.” Only
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