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The Tutodent membrane as a barrier membrane for augmenting horizontal alveolar-ridge defects
Guided Bone for the Treatment of Ridge Defects
Dr Steffen Kistler, Dr Georg Bayer and Dr Frank Kistler, Landsberg am Lech/Germany
In implantological cases with an insufficient bone supply, defect regeneration using bone-replacement materials and barrier membranes is the standard treatment approach today. The buccal bone supply above the implant must be sufficient – or augmented by a suitable method – to stabilize the soft-tissue situation over an extended period, especially in the case of anterior restorations that must meet high aesthetic expectations [1].
Development of a resorbable membrane
Non-resorbable membranes were first used in the early 1980s within the framework of guided tissue regeneration (GTR) as barriers against fast-growing soft tissue and the long junctional epithelium in the treatment of periodontological defects [2,3]. This approach was transferred to dental implantology a few years later, this time within the framework of guided bone regeneration (GBR) [4,5]. The success of guided bone regeneration with membranes depends primarily on factors such as biocompatibility and tissue integration, barrier function, dimensional stability and handling characteristics. In clinical practice, the use of non-resorbable membranes was frequently characterized by handling problems (rigid material, surgical re-entry required for removal) and by frequent membrane exposure during the healing phase, usually necessitating the premature removal of the membrane, which in turn resulted in a less than satisfactory augmentation [6,7]. These issues have since been largely resolved by the development of resorbable membranes. Especially natural collagen membranes appear to be highly suitable for this purpose [8,9]. In combination with bone-replacement materials, collagen membranes additionally exhibit superior wound-healing properties and significantly improved handling (due to better adaptation in the rehydrated state) compared to non-resorbable membranes. One of these collagen membranes is the Tutodent membrane, made of bovine pericardial tissue by means of the Tutoplast process (Tutogen Medical, Ger-
Fig. 1 Rehydrated Tutodent membrane.
many) (Fig. 1). The manufacturers describe the membrane as possessing a native three-dimensional collagen fibre structure, resulting in high multidimensional tear resistance and excellent adaptation to the defect surface. An in-vitro study undertaken to examine biocompatibility showed that the native Tutodent membrane was characterized by the adhesion and proliferation of human fibroblasts from the periodontal ligament as well as by SaOs2 osteoblasts, comparable to other collagen membranes without chemical cross-links [10]. The in-vivo behaviour of the Tutodent membrane was examined histologically and histomorphometrically in a rat model [11]. The membrane exhibited a compact system of interconnecting pores. After approximately two weeks, a full 50 percent of the
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Figs. 2 and 3 Preoperative situation: Horizontal bone deficit at 12 and 22 requiring bone augmentation.
membrane had been vascularized, and after 16 weeks, the membrane had been almost completely reorganized histologically, being replaced by newly formed connective tissue. The absorption time given by the office was eight to 16 weeks. The successful use of this membrane as a barrier in guided bone-regeneration procedures has been shown in combination with various bovine bone-replacement materials [12]. The corresponding study described the treatment of 19 bone defects in eight patients. Depending on the specifics of the defect, the implants were inserted either simultaneously (two patients, seven implants) with the augmentation or in a two-step (staged) procedure (six patients, twelve implants). The mean gain in ridge width six months after augmentation was 3 mm. In another study, 80 patients were treated with a combination of the Tutodent membrane and human cancellous bone tissue (Tutoplast Spongiosa) to improve the deficient bone supply prior to implant treatment [13]. The survival rate of the 310 implants inserted (72 simultaneously, 238 staged) was 93.4 percent (simultaneously) and 95.7 percent (staged), respectively. Unlike the non-resorbable membranes that were strictly designed to fulfil their barrier function, today’s natural collagen membranes such as the Tutodent membrane offer efficient support for overall soft-tissue management. In our surgery, this membrane is also used for augmenting the connective-tissue supply, for instance in the anterior region, which in many cases will save the patient the pain and inconvenience of re-entry surgery [14]. We thus exploit the fact that almost the entire membrane volume is ultimately transformed into connective tissue. Resorbable collagen membranes are usually employed in combination with synthetic or xenogenous bone replacement material, autografts, allografts or a mixture of these.
The membrane serves as a barrier against the ingrowth of soft tissue into the defect area, protecting particulate material from being lost or dislocated during the healing and integration phase [15]. The following case report shows the aesthetic restoration of the mandibular anterior area in the absence of a sufficient bone supply, by simultaneous implantation and augmentation using a collagen membrane (Tutodent membrane) and suitable bone replacement material (human bone: Tutoplast Spongiosa, Tutogen Medical, Germany).
Clinical case and surgical planning
The 20-year-old patient presented for implant treatment and restoration of teeth 12 and 22, which were congenitally missing. The preoperative clinical examination revealed bilateral horizontal bone defects at both sites (Figs. 2 and 3). Nevertheless, given the bone supply found during the diagnostic stage, implant treatment with simultaneous bone augmentation to manage the horizontal bone defect appeared both reasonable and possible. It was planned to address the hard-tissue defect by way of guided bone regeneration and submerged implant healing. The standard barrier membrane we have been using in our practice for several years now is the Tutodent membrane, which meets all the requirements of a resorbable membrane and has the added benefit of fitting snugly onto the defect surface while offering exceptional tear resistance. The bone was to be augmented using human bone material (Tutoplast Spongiosa), which has been approved in Germany for use in dental surgery for a number of years now. Allogenous bone is an osteoconductive bone material that has been shown to pave the way for the formation of vital autologous bone within only a few weeks or months [16,17,18]. We use Tutoplast Spongiosa particles as bone replacement material for socket preservation [17], horizontal augmentation [13] and sinus lift procedures [18].
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Fig. 4 Close-up of the bone defect at 22. Fig. 5 Situation following implant insertion: Horizontal bone defect, occlusal view. 6 7 Fig. 6 Tutodent membrane secured in place on the palatal side. Fig. 7 Rehydrating the Tutoplast Spongiosa particles with physiological saline solution. 8 9 Fig. 8 Augmentation of the bone defect using human cancellous bone substance. Fig. 9 Covering the defect with the Tutodent membrane followed by apical fixation using two additional titanium pins.
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Surgical approach
Following a palatally shifted incision with vertical reliefs, the alveolar bone defect at site 22 was exposed by preparing a mucoperiosteal flap (Fig. 4). The implant (Dentsply Friadent Xive, 3.8/13 mm) was inserted into the residual bone based on prosthodontic considerations. The occlusal view (Fig. 5) showed the buccal bone deficit above the implant. The Tutodent membrane was adapted to the size of the defect while still dry and secured in place on the palatal side using two titanium pins. Figure 6 shows that the Tutodent membrane stays firmly in place after dry application. The defect itself was augmented using Tutoplast Spongiosa particles previously rehydrated in a sterile physiological saline solution for approximately one minute as per the manufacturer’s instructions (Figs. 7 and 8).
The membrane was pulled over the augmentation material and secured in place on the apical side by two additional titanium pins to prevent dislocation of the cancellous-bone particles (Fig. 9). The implantation and augmentation at site 12 was performed in the same matter (Figs. 10 to 14). Care must always be taken to ensure that the membrane has been sufficiently rehydrated before closing the wound, as this will cause it to cling more closely to the defect margins and make it more efficient in preventing the dislocation of bone particles. If the blood generated within the defect is insufficient for the purpose, physiological saline solution or patient blood may be added (Fig. 15). To ensure a tension-free wound closure, the periosteal incision was performed before the wound was sutured (Ethicon Vicryl 6.0) (Figs. 16 and 17).
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Figs. 10 to 14 Exposure, implantation and augmentation of horizontal bone defect at 12. 16
Fig. 15 Rehydration of the secured Tutodent membrane with blood from the defect. 17
Figs. 16 and 17 Tension-free wound closure.
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Fig. 18 Four months postoperatively. Figs. 19 and 20 Balanced and harmonious gingival profile at the end of the prosthetic treatment phase, approximately one year postoperatively.
Contact Address
Gemeinschaftspraxis Dr Georg Bayer, Dr Steffen Kistler, Dr Frank Kistler, Dr Alexandra Elbertzhagen Von-Kühlmann-Straße 1 86899 Landsberg am Lech GERMANY
Subsequent procedure
After the operation, the patient received a fixed adhesive temporary restoration. The sutures were removed ten days later. Re-entry was performed four months later (Fig. 18). At the end of the prosthetic treatment phase, approximately one year postoperatively, the gingival profile presented harmonious, so that this case can be considered a clinical and aesthetic success (Figs. 19 and 20).
Summary
Correct treatment planning, a suitable surgical procedure and the use of the appropriate materials result in more predictable clinical and aesthetic outcomes in cases with defects of the alveolar ridge treated by guided bone regeneration. The use of natural collagen membranes not only simplifies the surgical procedure itself, but it also exerts positive effects on wound healing and the soft-tissue status.
References
[1] Elian N, Ehrlich B, Jalbout ZN, Classi AJ, Cho S-C, Kamer AR, Froum S,Tarnow DP: Advanced Concepts in Implant Dentistry: Creating the “Aesthetic Site Foundation”. Dent Clin N Am 2007; 51: 547-563. [2] Nyman S, Lindhe J, Karring T, Rylander H: New attachment following surgical treatment of human periodontal disease. J Clin Periodontol 1982; 9: 290-296. [3] Gottlow J, Nyman S, Lindhe J, Karring T, Wennström J: New attachment formation in the human periodontium by guided tissue regeneration. Case reports. J Clin Periodontol 1986; 13: 604-616. [4] Dahlin C, Linde A, Gottlow J, Nyman S: Healing of Bone defects by guided tissue regeneration. Plast Reconstr Surg 1988; 81: 672-676. [5] Nyman S, Gottlow J, Karring T, Lindhe J: The regenerative potential of the periodontal ligament: An experimental study in the monkey. Journal of Clinical Periodontology 1982; 9: 257-265. [6] Simion M, Baldoni M, Rossi P, et al.: A Comparative Study on the Effectiveness of e-PTFE Membranes with and without early exposure during the healing period. Int J Periodontics Restorative Dent 1994; 14: 166-180. [7] Tempro PJ, Nalbandian J: Colonization of retrieved polytetrafluoroethylene membranes: morphological and microbiological observations. J Periodontol 1993; 64: 162-168. [8] Zitzmann NU, Naef R, Schärer P: Resorbable versus nonresorbable membranes in combination with Bio-Oss for guided bone regeneration. Int J Oral & Maxillofac Implants 1997; 12: 844-852. [9] Hürzeler MB, Kohal RJ, Naghshbandi J, Mota LF, Conradt J, Hutmacher D, Caffesse RG: Evaluation of a new bioresorbable barrier to facilitate guided bone regeneration around exposed implant threads. Int J Oral & Maxillofac Surg 1998; 27: 315-320. [10] Rothamel D, Schwarz F, Sculean A, Herten M, Scherbaum W, Becker J: Biocompatibility of various collagen membranes in cultures of human PDL fibroblasts and human osteoblast-like cells. Clin Oral Implants Res 2004; 15: 443-449. [11] Rothamel D, Schwarz F, Sager M, Herten M, Sculean A, Becker J: Biodegradation of differently cross-linked collagen membranes: an experimental study in the rat. Clin Oral Implants Res 2005; 16: 369-378. [12] Steigmann M,Pericardium membrane and xenograft particulate grafting materials for horizontal alveolar ridge defects. Implant Dentistry 2006; 15: 186-191. [13] Simsek B, Simsek S, Evaluation of success rates of immediate and delayed implants after tooth extraction. Chinese Medical Journal 2003; 116: 1216-1219. [14] Kistler S, Bayer G, Kistler F: Erfahrungen mit der biologischen Tutodent Membran in der implantologischen Praxis. Implantologie Journal 2004; 5: 47-48. [15] Bartee BK, Nemcovsky CE, Serfaty V: Alveolar ridge preservation following extraction of maxillary anterior teeth. Report on 23 consecutive cases. J Periodontol 1996; 67: 390-395. [16] Tudor C, Srour S, Thorwarth M, Wehrhan F, Stockmann P, Neukam FW, Nkenke E, Schlegel KA, Felzseghy E: Bone regeneration on osseous defects application of particulated human and bovine materials. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008; 105: 430-436. [17] Minichetti JC, D'Amore JC, Hong AY, Cleveland DB: Human histologic analysis of mineralized bone allograft (Puros) placement before implant surgery. J Oral Implantol 2004; 30: 74-82. [18] Froum SJ,Wallace SS, Elian N, Cho SC,Tarnow DP: Comparison of mineralized cancellous bone allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: histomorphometry at 26 to 32 weeks after grafting. Int J Periodontics Restorative Dent 2006; 26: 543-551.