Page 31 - Peri-implant health: the effect of implant design and surgical procedure on bone and soft tissue stability

HOW DO PERI-IMPLANT BIOLOGIC PARAMETERS CORRESPOND WITH IMPLANT SURVIVAL AND PERI-IMPLANTITIS? A CRITICAL REVIEW
and frequently also at implant sites. Furthermore, the PD and the soft tissue thickness were greater at implant than at adjacent tooth sites. Another study confirmed soft tissue thickness ranging between 0.85 mm and 6.85 mm and papilla heights of 7 mm to 9 mm under healthy conditions.48 Kan and colleagues measured an average interproximal thickness of the mucosa of 6 mm with a large range.49 Gallucci, Belser, Bernard and Magne found mesial and distal PD often ranging between 4 and 8 mm depending on how scalloped the mucosa is.50 Animal studies have shown that conditions of mild inflammation already yield deeper pockets around implants compared to teeth and this does not necessarily coincide with actual bone loss.51 A multilevel analysis performed in a group of 52 patients with screw-retained restorations on 92 implants revealed that deeper PD is associated with higher tendency to bleed. This would indicate that an increase in PD in the absence of additional bone loss may be indicative of peri‐implant mucositis.43 Also, Lang and colleagues concluded that the probe penetrates into the connective tissue in situations of mucositis.44 A few studies have looked for correlations between bone loss and clinical parameters among them probing. They concluded that probing depths are of limited value in predicting future peri‐implant bone loss.8,52,53 Long‐term clinical studies have clearly shown that the probing depth of healthy peri‐implant mucosa is not always smaller than 4 mm but very often up to 6 mm.8,54,55 In an 18‐year follow‐up of single turned implants, pockets of up to 9 mm were found despite the absence of bone loss.7 Also, Dierens and colleagues could not demonstrate correlations between PD and marginal bone levels around single implants functional for 16–22 years.8 Deep (>5 mm) and shallow (<4 mm) pockets were found in all bone level groups explaining the poor predictive value of probing in the peri‐implantitis diagnosis when based on bone loss alone.
Probing is hindered by the location of the implant restoration especially in case of partial or full jaw reconstructions. This may be the reason while in some studies patients with multiple implant cases are diagnosed more often with peri‐ implantitis. Dalago and colleagues speculated that this could be attributed to less adequate oral hygiene or possible inclusion of more patients with periodontal history.56 Also, Serino and Strom proved that 65% of the implants with no good accessibility for oral hygiene showed peri‐implantitis compared to 18% when oral hygiene was feasible.22 It is obvious that incorrect probing may lead to iatrogenic bleeding. De Bruyn and colleagues evaluated full jaw patients with
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