Barrier Membrane Materials for Guided Bone Regeneration (GBR)

1894 words (8 pages) Essay

23rd Sep 2019 Sciences Reference this

Disclaimer: This work has been submitted by a university student. This is not an example of the work produced by our Essay Writing Service. You can view samples of our professional work here.

Any opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of UKEssays.com.

Barrier Membrane Materials for Guided Bone Regeneration (GBR)

Introduction

Guided Bone Regeneration (GBR) is a technique that has been implemented in clinic for almost 30 years. The technique promotes growth of the hard tissue using a space-making barrier membrane which prevents the ingrowth of surrounding soft tissue. Sufficient augmentation of bone on oral sites, namely the alveolar ridge is crucial for implant attachment (figure 1) [2].  Successful GBR is defined by four criteria: epithelium exclusion, space maintenance, fibrin clot stability and the primary wound closure [1].

Get Help With Your Essay

If you need assistance with writing your essay, our professional essay writing service is here to help!

Find out more

Current membrane materials available for commercial use are shown in Table 1 [5]. The barriers may be used with a bone grafting material and can be subdivided into two main categories based on their ability to resorb. Their application is evaluated based on five main design criteria: Biocompatibility, Cell Occlusion, Tissue Integration, space-maintaining ability and ease of handling in a clinical setting [4]. This essay will discuss the success of current materials used for GBR, and their limitations.

Figure 1: (a) sufficient bone width/height, (b) placement of a membrane for GBR (c) subsequent implant [2]

Discussion

Expanded polytetrafluoroethylene (e-PTFE) was the first commercially available membrane, composed of a collar portion with pores allowing connective tissue augmentation and to prevent epithelial intrusions, and an occlusive part to prevent the flap tissues contacting the root surface [6].  The exposure of e-PTFE is problematic as its rough surface induces bacterial colonisation and infection, compromising bone augmentation [3]. High density PTFE (d-PTFE) has subsequently been adopted as a preferred alternative [14]. The smaller pores prevent bacteria invasion and primary soft tissue closure is not required. Additionally, the relatively smooth surface improves the ease of removal [10].

Titanium mesh was introduced as a more stable and better space-making barrier, with small pores to allow interstitial fluid transfer. The metal offers excellent biocompatibility and mechanical properties- combining rigidity, elasticity and plasticity [4]. Titanium-reinforced PTFE membranes show enhanced rigidity and malleability while maintaining sufficient protection for blood clot

Table 1: List of Commercial GBR Membranes [2]

formation [1] However, its stiff structure can lead to exposure of the membranes which can introduce morbidity and provoke premature removal [11].

Resorbable membranes remove the need for a second surgery, offer a better cost-benefit ratio and decrease the risk of patient morbidity, as well as potential tissue damage. There are two main types of resorbable materials utilised for GBR; synthetic polymers, namely polyglycolide (PGA) and polylactide (PLA), and natural collagen-based membranes [4].

Aliphatic polymer-based membranes can be produced on demand, adapted to give required properties due to the wide scope of polymers available and will breakdown to carbon dioxide and water via the Krebs cycle [1].

Collagen is the main component in connective tissues and its inherent biocompatible properties make it a very attractive material option [10]. Collagen- based membranes encourage blood clot formation, enhance cell migration, are well received by patients and can integrate with surrounding connective tissues during degradation, creating an environment which promotes bone formation. Collagen membranes exhibit various structures and degradation rates, depending on their source, extraction and manufacturing method.  Cross-linking of the collagen fibres can improve its relatively low rigidity and prolong the barrier function and has been linked with impeded vascularisation and tissue integration [10]. Thicker collagenous membranes inhibit tissue penetration and promote bone formation; thus, layering is usually advantageous.

The main drawback of bioresorbable membranes is the inflammatory reactions associated with them, which can inhibit bone regeneration [9]. Furthermore, the resorption rate of a polymer and collagen membrane is harder to predict and can vary greatly depending on polymer used or collagen source. When exposed, resorbable membranes break down very quickly due to enzyme action. This can induce healing, but if degradation incomplete bone regeneration is likely [4].

Collagen and synthetic polymeric membranes are much less robust than non-resorbable barriers and require use with a grafting material to prevent collapse [7]. Bone graft materials (table 2) promote bone formation by varying mechanisms. Membrane-graft combinations generally exhibit improved bone regeneration [1].

Table 2: Summary of Bone Graft Materials [15]

Autogenous bone is considered the best grafting material due to its osteogenic (bone generating) abilities [1]. Its high success rate can be attributed to its protein, bone-enhancing substrates, minerals and vital bone cell content. However, its use is limited by the volume of graft available and the morbidity risk during removal [12]. Furthermore, resorption of the graft can occur if it is placed near the roots [1].

Allografts are derived from another individual of the same species, (either frozen, freeze-dried or demineralised freeze-dried bone) and remove the need for a second donor site which is beneficial to the patient [10]. The grafts carry out bone growth by osteo-conductive and inclusive means, due to the presences of bone morphogenic proteins (BMP) thus bone formation is slower, and the volume is less than autografts [1].

Find out how UKEssays.com can help you!

Our academic experts are ready and waiting to assist with any writing project you may have. From simple essay plans, through to full dissertations, you can guarantee we have a service perfectly matched to your needs.

View our services

Xenografts originate from the tissue of another species and are widely used in GBR [13]. They are usually stripped of their organic components to eliminate immune-reaction, giving a brittle calcium rich matrix structure material. Common xenograft materials include natural hydroxyapatite (HA) from animal bones and de-organified bovine bone (anorganic bone matrix, ABM); both possess properties that mimic bone minerals in humans and thus promote bone augmentation [1].

Alloplasts consist of either natural or synthetic materials, usually bioactive glass polymers, calcium sulphates or ceramics such as synthetic HA or tricalcium phosphate (TCP) [13]. Their use removes the threat of disease transmission and their design and production can be controlled to a molecular level, allowing optimisation of the size and connections of macropores for vascular growth, the phase distribution and the morphology of the blocks and granules. However, a lack of knowledge of optimal surface characteristics to promote tissue interaction with the material limits this advantage [12].

Selection of a suitable graft material will depend on the recipient and the nature of defect, but a combination of graft materials usually creates an optimal environment by combining favourable mechanical and biological properties [1]. When utilized with a barrier membrane, these graft composites are associated with superior GBR results.

Conclusion

The materials available for GBR span a wide range of properties and the ideal choice will depend on the bone defect. Non-resorbable membranes have been shown to promote bone augmentation. Resorbable membranes offer a more comfortable treatment option for the patient but must be used in conjunction with a supporting graft material to achieve comparable results.

References

[1] Liu J, Kerns DG. Suppl 1: Mechanisms of Guided Bone Regeneration: A Review. The open dentistry journal. 2014;8:56.

[2] Rakhmatia YD, Ayukawa Y, Furuhashi A, Koyano K. Current barrier membranes: titanium mesh and other membranes for guided bone regeneration in dental applications. Journal of prosthodontic research. 2013;57(1):3-14. Figure.1, Table 2. Typical Commercially Available Membranes

[3] Hutmacher D, Hürzeler MB, Schliephake H. A review of material properties of biodegradable and bioresorbable polymers and devices for GTR and GBR applications. International Journal of Oral & Maxillofacial Implants. 1996 Sep 1;11(5).

[4] Rakhmatia YD, Ayukawa Y, Furuhashi A, Koyano K. Current barrier membranes: titanium mesh and other membranes for guided bone regeneration in dental applications. Journal of prosthodontic research. 2013;57(1):3-14. Fig.1

[5] Elgali I, Omar O, Dahlin C, Thomsen P. Guided bone regeneration: materials and biological mechanisms revisited. European journal of oral sciences. 2017 Oct;125(5):315-37.

[6] Scantlebury TV. 1982‐1992: A decade of technology development for guided tissue regeneration. Journal of periodontology. 1993 Nov; 64:1129-37.

[7] Hämmerle CH, Jung RE. Bone augmentation by means of barrier membranes. Periodontology 2000. 2003 Oct;33(1):36-53.

[8] Von Arx T, Buser D. Horizontal ridge augmentation using autogenous block grafts and the guided bone regeneration technique with collagen membranes: a clinical study with 42 patients. Clinical oral implants research. 2006 Aug;17(4):359-66.

[9] Von Arx T, Broggini N, Jensen SS, Bornstein MM, Schenk RK, Buser D. Membrane durability and tissue response of different bioresorbable barrier membranes: a histologic study in the rabbit calvarium. International Journal of Oral & Maxillofacial Implants. 2005 Nov 1;20(6).

[10] Farzad M, Mohammadi M. Guided bone regeneration: A literature review. Journal of Oral Health and Oral Epidemiology. 2012 Jul 4;1(1):3-18.

[11] Watzinger F, Luksch J, Millesi W, Schopper C, Neugebauer J, Moser D, Ewers R. Guided bone regeneration with titanium membranes: a clinical study. British Journal of Oral and Maxillofacial Surgery. 2000 Aug 1;38(4):312-5.

[12] Buser D, editor. 20 years of guided bone regeneration in implant dentistry. Quintessence Publishing Company; 2009.

[13] Sheikh Z, Hamdan N, Ikeda Y, Grynpas M, Ganss B, Glogauer M. Natural graft tissues and synthetic biomaterials for periodontal and alveolar bone reconstructive applications: a review. Biomaterials research. 2017 Dec;21(1):9.

[14] Hoffmann O, Bartee BK, Beaumont C, Kasaj A, Deli G, Zafiropoulos GG. Alveolar bone preservation in extraction sockets using non-resorbable dPTFE membranes: a retrospective non-randomized study. Journal of periodontology. 2008 Aug;79(8):1355-69.

[15] Sheikh Z, Sima C, Glogauer M. Bone replacement materials and techniques used for achieving vertical alveolar bone augmentation. Materials. 2015 May 27;8(6):2953-93. Table 1, Bone replacement graft tissues and materials.

Cite This Work

To export a reference to this article please select a referencing stye below:

Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.
Reference Copied to Clipboard.

Related Services

View all

DMCA / Removal Request

If you are the original writer of this essay and no longer wish to have your work published on the UKDiss.com website then please: