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- Albrektsson, Tomas, 1945, et al.
(författare)
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An Imbalance of the Immune System Instead of a Disease Behind Marginal Bone Loss Around Oral Implants: Position Paper
- 2020
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Ingår i: The International journal of oral & maxillofacial implants. - : Quintessence Publishing. - 1942-4434 .- 0882-2786. ; 35:3, s. 495-502
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The purpose of this paper is to present evidence that supports the notion that the primary reason behind marginal bone loss and implant failure is immune-based and that bacterial actions in the great majority of problematic cases are of a secondary nature. MATERIALS AND METHODS: The paper is written as a narrative review. RESULTS: Evidence is presented that commercially pure titanium is not biologically inert, but instead activates the innate immune system of the body. For its function, the clinical implant is dependent on an immune/inflammatory defense against bacteria. Biologic models such as ligature studies have incorrectly assumed that the primary response causing marginal bone loss is due to bacterial action. In reality, bacterial actions are secondary to an imbalance of the innate immune system caused by the combination of titanium implants and ligatures, ie, nonself. This immunologic imbalance may lead to marginal bone resorption even in the absence of bacteria. CONCLUSION: Marginal bone loss and imminent oral implant failure cannot be properly analyzed without a clear understanding of immunologically caused tissue responses.
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| 2. |
- Trindade, Ricardo, et al.
(författare)
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Bone Immune Response to Materials, Part II:Copper and Polyetheretherketone (PEEK) Compared to Titanium at 10 and 28 Days in Rabbit Tibia
- 2019
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Ingår i: Journal of Clinical Medicine. - : MDPI AG. - 2077-0383. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Osseointegration is likely the result of an immunologically driven bone reaction to materials such as titanium. Osseointegration has resulted in the clinical possibility to anchor oral implants in jaw bone tissue. However, the mechanisms behind bony anchorage are not fully understood and complications over a longer period of time have been reported. The current study aims at exploring possible differences between copper (Cu) and polyetheretherketone (PEEK) materials that do not osseointegrate, with osseointegrating cp titanium as control. The implants were placed in rabbit tibia and selected immune markers were evaluated at 10 and 28 days of follow-up. Cu and PEEK demonstrated at both time points a higher immune activation than cp titanium. Cu demonstrated distance osteogenesis due to a maintained proinflammatory environment over time, and PEEK failed to osseointegrate due to an immunologically defined preferential adipose tissue formation on its surface. The here presented results suggest the description of two different mechanisms for failed osseointegration, both of which are correlated to the immune system.
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| 3. |
- Trindade, Ricardo, et al.
(författare)
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Osseointegration and foreign body reaction: Titanium implants activate the immune system and suppress bone resorption during the first 4 weeks after implantation
- 2018
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 20:1, s. 82-91
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Wiley Periodicals, Inc. Background: Osseointegration mechanisms are still not entirely understood. Purpose: The present pilot study aims at demonstrating the involvement of the immune system in the process of osseointegration around titanium implants, comparing bone healing in the presence and absence of a titanium implant. Materials and Methods: Fifteen New Zealand White rabbits had one osteotomy performed at each of the distal femurs; on one side, no implant was placed (sham) and on the other side a titanium implant was introduced. Subjects were sacrificed at 10 and 28 days for gene expression analysis (three subjects each time point) and for decalcified qualitative histology (six subjects each time point). At 10 days, the three subjects for gene expression analysis were part of the six subjects for histology. Results: Gene expression analysis: at 10 days, ARG1 was significantly up-regulated around titanium, indicating an activation of M2-macrophages. At 28 days CD11b, ARG1, NCF-1, and C5aR1 were significantly up-regulated, indicating activation of the innate immune system, respectively M1-macrophages, M2-macrophages and group 2-innate lymphoid cells, neutrophils, and the complement system; on the other hand, the bone resorption markers RANKL, OPG, cathepsin K, and TRAP were significantly down-regulated around titanium. Histology: at 10 days new bone formation is seen around both sham and titanium sites, separating bone marrow from the osteotomy/implant site; at 28 days no bone trabeculae is seen on the sham site, which is healing at the original cortical level, whereas around titanium implants, bone continues into organization of more mature cortical-like bone, forming a layer between the implant and the bone marrow. Conclusions: The presence of a titanium implant during bone healing activates the immune system and displays type 2 inflammation, which is likely to guide the host-biomaterial relationship. At the same time, bone resorption is suppressed around titanium sites compared to sham sites after 4 weeks of implantation, suggesting a shift to a more pronounced bone forming environment. This suggests two important steps in osseointegration: identification of the titanium foreign body by the immune system and the development of a bone forming environment, that at tissue level translates into bone build-up on the titanium surface and can be perceived as an attempt to isolate the foreign body from the bone marrow space.
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