Sandwich Bone Augmentation (SBA) in immediate implant placement post dentoalveolar trauma: a case report
Abstract
Objective: Reporting the application of SBA procedure with titanium mesh as an alternative solution for immediate implant placement in socket with dentoalveolar trauma-induced buccal bone defect.Methods: An 18-year-old female patient visited our department, with a history dentoalveolar trauma and a loss of  tooth 21. Clinical examination during the implant placement procedure exposed  a socket with buccal bone defect. SBA with autogenous chin bone graft combined with DFDBA allograft and stabilized with titanium mesh (Ti-Mesh) for buccal defect on which flap reposition was done with tension free primary closure.Results: Ti-Mesh was removed after 3 months which no sign of inflamation appeared, implant was in a stable condition and new bone formation was observed. Subsequently, healing abutment was placed. A one-year observation suggested a good clinical retention with no luxation observed, along with decent functional and esthetic results. CBCT evaluation showed buccal bone thickness preserved.Conclusion: Sandwich bone augmentation with stabilized titanium mesh provides a satisfying result in treating horizontal buccal bone defect.
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ࡱ > ( ʓ ͓ Ò Ē Œ ƒ ǒ Ȓ ɒ ʒ ˒ ̒ ͒ Β ϒ В ђ Ғ Ӓ Ԓ Ւ ֒ ג ؒ ْ ڒ ے ܒ ݒ ޒ ߒ _! Nr bjbj W b b i , 4 : : $ $ $ $ H H H P l \ H ` . . . n n n a c c c c c c $ J $ n | n n n . . N p p p n ( . $ . a p n a p p l . 0/|W R 4 M 0 ( N h 8 $ U n n p n n n n n 6 : n n n n n n n n n n n n n n n n : Z : ! Sandwich Bone Augmentation in Immediate Implant Placement Post Dentoalveolar Trauma (Case Report) Anton , Poerwati S. Rahajoe, Bambang Dwirahardjo Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Universitas Gadjah Mada email : antonleebm@mail.ugm.ac.id Abstract Background: Dentoalveolar trauma is frequently found in daily practices, and buccal plate loss due to dentoalveolar trauma may complicate the implant placement procedure. Sandwich bone augmentation (SBA) is an alternative technique to augment horizontal buccal bone defect. Objective: Reporting the application of SBA procedure with titanium mesh as an alternative solution for immediate implant placement in socket with dentoalveolar trauma-induced buccal bone defect. Case Report: An 18-year-old female patient visited our department, with a history dentoalveolar trauma and a loss of tooth 21. Clinical examination during the implant placement procedure exposed a socket with buccal bone defect. SBA with autogenous chin bone graft combined with DFDBA allograft and stabilized with titanium mesh (Ti-Mesh) for buccal defect on which flap reposition was done with tension free primary closure. 3 months following the procedure, the Ti-Mesh was removed after which no sign of inflamation appeared, implant was in a stable condition and new bone formation was observed. Subsequently, healing abutment was placed. A one-year observation suggested a good clinical retention with no luxation observed, along with decent functional and esthetic results. CBCT evaluation showed buccal bone thickness preserved. Conclusion: Sandwich bone augmentation with stabilized titanium mesh provides a satisfying result in treating horizontal buccal bone defect. Keywords: Dentoalveolar trauma, horizontal defect, sandwich bone augmentation, titanium mesh Introduction Dentoalveolar fracture often encountered in daily practice and mostly caused by falling, collition, sport, or traffic accident and usually affect anterior part of the face. Dentoalveolar trauma can cause fracture, buccal bone loss, displacement of anterior tooth, and missing tooth that can alter patients quality of life regarding to function, aesthetic, speech, and psychological change.1 Missing tooth associated with dentoalveolar trauma can cause alveolar bone resorbtion 1.5-2 mm vertically and 40-50% horizontally in 6-12 months. Dentoalveolar fracture with buccal bone loss may increase difficulty to obtain initial stability for implant placement.1,2 This article reporting a case of dentoalveolar trauma with missing tooth 21 and buccal bone defect which rehabilitated using immediate implant placement and SBA stabilized with titanium mesh. Case Report A 18-years-old woman came to Emergency Department after traffic accident, collition in anterior part of the face accompanied with tooth loss, no history of head trauma. History of alergy and systemic disease were denied. Physical examination and vital sign were in normal range. Excoriation found in lip and right lip commisure. Intraoral examination shows 21 avulsed with open wound and buccal bone loss, tooth 11, 12, 23 fractured class I Ellis, 22 luxated (Figure 1). Injection of human ATS 1500 IU, wound management, maxillary arch arch bar fixation for 3 weeks, and medication administration were done. Immediate dental implant with SBA was planned 2 months after. SHAPE \* MERGEFORMAT Figure 1. Extra oral and intraoral appearance before and after treatment After 2 month follow up, luxation of tooth 22 still occuring and after flap reflection, it can be seen that of buccal alveolar bone was lost (Figure 2) so that extraction of tooth 22 is inevitable and 2 immediate dental implant placement with SBA technique was planned. Figure 2. A. 2 month post trauma, we can see deficit of horizontal alveolar bone and third degree luxation of tooth 22 , B. Post extraction of tooth 22 Trapezium flap was made at distal line angle of tooth 11 and 22. Implan bed preparation was done at ideal 3 dimentional position slightly to palatal, roughened surface dental implant 4x13.5 mm was placed to obtain primary stability (Figure 3), decortication of buccal intramarrow around the implant. SHAPE \* MERGEFORMAT SHAPE \* MERGEFORMAT Figure 3. A-B. Dental implant placement at ideal position and thightened until 30N torque Exposed implant fixture Autogenous cortical cancellous bone graft harvesting from mandibular simphysis (Figure 4B) using auto bone collector drill (Figure 4A) for covering exposed implant fixture (Figure 5A) combined with demineralized freeze dried bone allograft (DFDBA) (Figure 5B). Bone graft stabilization and space maintaining obtained using Ti-Mesh (Figure 5C-D). Flap closure (Figure 5E) was done under tension free condition using periosteal flap release technique, so that primary closure can be achieved and flap was in stable condition to protect Ti-Mesh and graft material bellow. INCLUDEPICTURE "http://static.webshopapp.com/shops/011321/files/003115682/osstem-autobone-collector.jpg" \* MERGEFORMATINET Figure 4. A. Auto Bone Collector Drill B. Autograft harvesting from mandibular symphysis SHAPE \* MERGEFORMAT Figure 5. A-B. Exposed implant fixture covered with autograft+DFDBA, C-D. Ti-Mesh instalment, E. Primary tension-free flap closure Follow up 3 months, clinically result without sign of inflamation. New bone formation around implant fixture can be seen after flap reflection (Figure A) and Ti-Mesh removal, all implant are in stable condition (Figure 6B). Healing abutments were inserted immediately (Figure 6C) for gingival contouring and suturing performed. Figure 6. Ti-Mesh removal, B. 3 months after Sandwich Bone Augmentation revealed new bone formation around implant fixture , C. Healing abutment insertion Follow up 2 month after healing abutment placement, no subjective complain, no sign of inflamation, and estetic gingival emerging profile (Figure 7A). Impression was performed at implant for fabrication of crown (Figure 7B). SHAPE \* MERGEFORMAT Figure 7. 2 month after healing abutment insertion,B-C. Milling Abutment and crown insertion D-E. 1 year Follow up CBCT evaluation showed buccal bone thickness preserved Discussion Dentoalveolar fracture can be defined as damage or loss of hard tissue continuity including tooth and alveolar bone due to trauma or fracture including avulsion, subluxation, or tooth fracture. Dentoalveolar fracture can occur with or without buccal bone loss, and usually caused by small accident such as falling, collition during play, sport, or iatrogenic cause.1,2 In case dentoalveolar fracture accompanied with buccal bone loss and tooth loss, implant placement may need additional GBR procedure to augment alveolar bone and create sufficient foundation for precised and stable implant placement.3,4 GBR procedure is a technique uniquely designed to augment alveolar bone in edentulous area with future prospect of implant placement or augmentation of exposed body implant. GBR principle inspired from GTR (guided tissue regeneration) principle which said that specific external additional cells are required to augment inhabiting cells so that new tissue regeneration can be accelerated. Osteoblast cells, with ability to promote new alveolar bone remodelling, are required for GBR.5,6 GBR success rate and predictability for dental implant application are well known with success rate of more than 95%. Dental implant placement in alveolar bone deficit area can be done directly. Clinical procedure for GBR must follows biological principle known as PASS principle, which area primary wound closure, angiogenesis, space creation/ maintenance, and stability of blood clot and implant fixture. SBA technique was designed following this principle in order to obtain optimal bone regeneratio.7-9 Main principle of SBA technique is application of different layer of bone graft material to mimic alveolar bone layer and then covered with membrane as a barrier (Figure 8). Inner layer filled with easily resorbed cancelous bone graft, outer layer composed by cortical bone graft as a scaffold to facilitate form and maintaining space, and the outermost layer created using membrane barrier.10,11 In this case, SBA technique was used for its advantage such as short treatment time, ideal restoration, less morbidity, more comfortable, and less expensive. In other hand, the main disadvantages of SBA technique is technical difficulty to obtain primary stabilization of implant inserted in horizontal defect.9,11 This becomes important issue because micromovement can cause implant encapsulation which leads to implant failureADDIN CSL_CITATION { "citationItems" : [ { "id" : "ITEM-1", "itemData" : { "DOI" : "10.1016/j.dental.2012.04.022", "ISBN" : "1879-0097 (Electronic)\\r0109-5641 (Linking)", "ISSN" : "01095641", "PMID" : "22592164", "abstract" : "Periodontitis is a major chronic inflammatory disorder that can lead to the destruction of the periodontal tissues and, ultimately, tooth loss. To date, flap debridement and/or flap curettage and periodontal regenerative therapy with membranes and bone grafting materials have been employed with distinct levels of clinical success. Current resorbable and non-resorbable membranes act as a physical barrier to avoid connective and epithelial tissue down-growth into the defect, favoring the regeneration of periodontal tissues. These conventional membranes possess many structural, mechanical, and bio-functional limitations and the \"ideal\" membrane for use in periodontal regenerative therapy has yet to be developed. Based on a graded-biomaterials approach, we have hypothesized that the next-generation of guided tissue and guided bone regeneration (GTR/GBR) membranes for periodontal tissue engineering will be a biologically active, spatially designed and functionally graded nanofibrous biomaterial that closely mimics the native extra-cellular matrix (ECM). Objective: This review is presented in three major parts, including (1) a brief overview of the periodontium and its pathological conditions, (2) currently employed therapeutics used to regenerate the distinct periodontal tissues, and (3) a review of commercially available GTR/GBR membranes as well as the recent advances on the processing and characterization of GTR/GBR membranes from a materials perspective. Significance: Studies of spatially designed and functionally graded membranes (FGM) and in vitro antibacterial/cell-related research are addressed. Finally, as a future outlook, the use of hydrogels in combination with scaffold materials is highlighted as a promising approach for periodontal tissue engineering. \u00a9 2012 Academy of Dental Materials. All rights reserved.", "author" : [ { "dropping-particle" : "", "family" : "Bottino", "given" : "Marco C.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Thomas", "given" : "Vinoy", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Schmidt", "given" : "Gudrun", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Vohra", "given" : "Yogesh K.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Chu", "given" : "Tien Min Gabriel", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Kowolik", "given" : "Michael J.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Janowski", "given" : "Gregg M.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "Dental Materials", "id" : "ITEM-1", "issue" : "7", "issued" : { "date-parts" : [ [ "2012" ] ] }, "page" : "703-721", "title" : "Recent advances in the development of GTR/GBR membranes for periodontal regeneration - A materials perspective", "type" : "article", "volume" : "28" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=51458175-4e79-46eb-ada4-11092031d517" ] }, { "id" : "ITEM-2", "itemData" : { "ISSN" : "08822786", "abstract" : "The biologic principle of guided tissue regeneration was applied to regenerate alveolar bone in conjunction with the placement of titanium dental implants. In one case, complete osseointegration of an implant was achieved by the placement of a Teflon membrane over an implant that had been inserted into an alveolus immediately following tooth extraction. In a second case, the same biologic principle was used to increase the volume (height and width) of a resorbed, edentulous alveolar ridge to provide adequate bone dimensions for implant installation. In both cases, the membranes appear to have prevented the repopulation of the wound area by cells other than those derived from surrounding bone tissue. These two different applications of the principle of guided tissue regeneration open new avenues for reconstructive osseous surgery.", "author" : [ { "dropping-particle" : "", "family" : "Nyman", "given" : "S.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Lang", "given" : "N.P.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Buser", "given" : "D.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Bragger", "given" : "U.", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "The International journal of oral & maxillofacial implants", "id" : "ITEM-2", "issue" : "1", "issued" : { "date-parts" : [ [ "1990" ] ] }, "title" : "Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases.", "type" : "article-journal", "volume" : "5" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=1c239e1e-5d84-4475-99b0-d69ad6c9b48d" ] } ], "mendeley" : { "formattedCitation" : "(13,14)", "plainTextFormattedCitation" : "(13,14)", "previouslyFormattedCitation" : "(13,14)" }, "properties" : { "noteIndex" : 0 }, "schema" : "https://github.com/citation-style-language/schema/raw/master/csl-citation.json" }.12,13 We are using DFDBA as a bone graft with collagen component, which is the most important component of bone tissue, and Bone Morphogenic Protein (BMP) that can trigger new bone formation in the operation area. Contact between DFDBA with bone will create such an ideal environment for osteogenic cell migration and proliferation . Intramarrow decortication around implant was performed using 0.5 mm round bur to increase regional accelerator phenomenon and accelerate angiogenesis.8,9 Figure 8. Sandwich Bone Augmentation technique In this case, flap reflected with periosteal disection to increase flap mobility and reduce tension, that will facilitate stabilization of blood clot and protection of operation site during healing process.8 The most common complication that can occur is wound dehiscence, but in this case its not happening and optimal bone regeneration process can be achieved. Bone volume reduction during bone remodelling process may happen at dehiscence or exposed operation site due to bacterial colonization, vascularization reduction to operation site, and external agent contamination.14 Membrane barrier is a material used for GBR with purpose to prevent migration of epithelial/non osteogenic soft tissue forming cells into the bone graft. Membrane material for GBR technique must qualify following requirement: biocompatible, non toxic, non antigenic, not causing severe inflammatory respon to surrounding tissue.15,16 Non resorbable membrane was used initialy, but, in the recent years, bioresorbable or biodegradable membrane was developed for small defect caseADDIN CSL_CITATION { "citationItems" : [ { "id" : "ITEM-1", "itemData" : { "DOI" : "10.1097/01.ID.0000019547.50849.3B", "ISBN" : "1056-6163", "ISSN" : "1056-6163", "PMID" : "12271567", "abstract" : "Collagen is a versatile material with biological properties that make it useful for the fabrication of implantable devices in medicine and dentistry. In this article we review collagen biosynthesis, structure, and types, as well as the properties that make it compatible with human tissues. (Implant Dent 2002;11: 280\u2013285)", "author" : [ { "dropping-particle" : "", "family" : "Patino", "given" : "Maria G", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Neiders", "given" : "Mirdza E", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Andreana", "given" : "Sebastiano", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Noble", "given" : "Bernice", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Cohen", "given" : "Robert E", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "Implant Dentistry", "id" : "ITEM-1", "issue" : "3", "issued" : { "date-parts" : [ [ "2002" ] ] }, "page" : "280-285", "title" : "Collagen : An Overview", "type" : "article-journal", "volume" : "11" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=0223e5fe-1690-4b48-8cbb-4eb569761a46" ] } ], "mendeley" : { "formattedCitation" : "(17)", "plainTextFormattedCitation" : "(17)", "previouslyFormattedCitation" : "(17)" }, "properties" : { "noteIndex" : 0 }, "schema" : "https://github.com/citation-style-language/schema/raw/master/csl-citation.json" }. Resorbable membrane was available in various form to facilitate various requirement.2,15,16 Polytetrafluoroethylene (PTFE) dan Titanium mesh are the most commonly used non resorbable membrane for treating large alveolar bone defect, which required prolong space maintaining and ability to hold compression force from surrounding tissue until remodelling process was completely doneADDIN CSL_CITATION { "citationItems" : [ { "id" : "ITEM-1", "itemData" : { "author" : [ { "dropping-particle" : "", "family" : "Hitti", "given" : "RA", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Kerns", "given" : "DG", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "Open Pathology Journal", "id" : "ITEM-1", "issued" : { "date-parts" : [ [ "2011" ] ] }, "page" : "33-45", "title" : "Guided Bone Regeneration in the Oral Cavity: A Review.", "type" : "article-journal", "volume" : "5" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=e84a9cc9-f52f-400d-be69-c943571f8513" ] }, { "id" : "ITEM-2", "itemData" : { "DOI" : "10.1016/j.jpor.2012.12.001", "ISBN" : "2212-4632 (Electronic)\\r1883-1958 (Linking)", "ISSN" : "18831958", "PMID" : "23347794", "abstract" : "Research on guided bone regeneration (GBR) is still ongoing, with evidence mainly from preclinical studies. Various current barrier membranes should fulfill the main design criteria for GBR, such as biocompatibility, occlusivity, spaciousness, clinical manageability and the appropriate integration with the surrounding tissue. These GBR characteristics are required to provide the maximum membrane function and mechanical support to the tissue during bone formation. In this review, various commercially available, resorbable and non-resorbable membranes with different characteristics are discussed and summarized for their usefulness in preclinical studies. Membranes offer promising solutions in animal models; however, an ideal membrane has not been established yet for clinical applications. Every membrane type presents both advantages and disadvantages. Titanium mesh membranes offer superb mechanical properties for GBR treatment and its current efficacy in trials will be a focus in this review. A thorough understanding of the benefits and limitations inherent to various materials in specific clinical applications will be of great value and aid in the selection of an optimal membrane for GBR. \u00a9 2013 Japan Prosthodontic Society.", "author" : [ { "dropping-particle" : "", "family" : "Rakhmatia", "given" : "Yunia Dwi", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Ayukawa", "given" : "Yasunori", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Furuhashi", "given" : "Akihiro", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Koyano", "given" : "Kiyoshi", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "Journal of Prosthodontic Research", "id" : "ITEM-2", "issue" : "1", "issued" : { "date-parts" : [ [ "2013" ] ] }, "page" : "3-14", "title" : "Current barrier membranes: Titanium mesh and other membranes for guided bone regeneration in dental applications", "type" : "article", "volume" : "57" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=ba6c12af-e2e8-4e3c-ba98-73a63145d442" ] }, { "id" : "ITEM-3", "itemData" : { "ISBN" : "0198-7569 (Print)\\n0198-7569 (Linking)", "ISSN" : "0198-7569", "PMID" : "7591524", "abstract" : "Advances in bone reconstructive techniques have increased the indications for implant placement in sites previously thought to be unsuitable. This clinical study evaluated a new surgical technique for the treatment of a variety of localized bone defects in four patients utilizing a titanium-reinforced membrane. The membrane material was developed to maintain a large protected space between the membrane and the bone surface without the need for a supportive device. Healing was uneventful in all sites, and the membranes were retrieved after 6 to 12 months. No residual defects were noted, resulting in an average change of implant exposure of 8.2 +/- 2.3 mm for sites with buccal dehiscences and from 5 to 6 mm ridge enlargement in localized bone defects. The quality of the regenerated tissue under the titanium-reinforced membrane appeared as bone structure with a superficial fibrous layer. This fibrous layer was more pronounced in sites treated with a membrane alone but was more than compensated by the quantity of new bone under the soft tissue. The results demonstrated that the use of a reinforced membrane appears to be a viable alternative for the clinical treatment of non-space-maintaining implant/bone defects. Further clinical and experimental investigations are recommended.", "author" : [ { "dropping-particle" : "", "family" : "Jovanovic", "given" : "S A", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" }, { "dropping-particle" : "", "family" : "Nevins", "given" : "M", "non-dropping-particle" : "", "parse-names" : false, "suffix" : "" } ], "container-title" : "International journal of periodontics & restorative dentistry", "id" : "ITEM-3", "issue" : "1", "issued" : { "date-parts" : [ [ "1995" ] ] }, "page" : "56-69", "title" : "Bone formation utilizing titanium-reinforced barrier membranes.", "type" : "article-journal", "volume" : "15" }, "uris" : [ "http://www.mendeley.com/documents/?uuid=6cea3e53-dbdc-4af6-84e8-20f58da66867" ] } ], "mendeley" : { "formattedCitation" : "(6,18,19)", "manualFormatting" : "(6,18)", "plainTextFormattedCitation" : "(6,18,19)", "previouslyFormattedCitation" : "(6,18,19)" }, "properties" : { "noteIndex" : 0 }, "schema" : "https://github.com/citation-style-language/schema/raw/master/csl-citation.json" }.2,6,16 In this case, titanium mesh was used based on its advantage, such as flexible, easily formed, and its porosity which can facilitate direct blood supply from periosteum to tissue and bone graft bellow it. The main disadvantages of using non resorbable membrane is the necessity of second surgical procedure to remove the membrane that can decrease patient comfortability, increasing cost, and causing little resorbtion at crestal area due to new flap opening.2,16 Conclusion Implant placement in dentoalveolar fracture case with horizontal bone defect using sandwich bone augmentation technique and titanium mesh stabilization can provide satisfying result in management of horizontal buccal bone defect for immediate implant placement and extensive bone defect. References ADDIN Mendeley Bibliography CSL_BIBLIOGRAPHY 1. Turkistani J, Hanno A. Recent trends in the management of dentoalveolar traumatic injuries to primary and young permanent teeth. Dental Traumatology 2011:4654. 2. Addo ME, Andreasen JO, Andreasen FM AL. Textbook and color atlas of traumatic injuries to the teeth (4th edition)2007;203(10):615615. 3. Liu J, Kerns DG. Mechanisms of Guided Bone Regeneration: A Review. Open Dent J 2014;8(1):5665. 4. Lee A, Brown D, Wang H-L. Sandwich Bone Augmentation for Predictable Horizontal Bone Augmentation. Implant Dent 2009;18(4):28290. 5. Hwang D, Sonick M. Guided Bone Regeneration: Concepts and Materials. Implant Site Dev 2015;15378. 6. Hitti R, Kerns D. Guided Bone Regeneration in the Oral Cavity: A Review. Open Pathol J 2011;5:3345 7. Fu JH, Oh TJ, Benavides E,et al. A randomized clinical trial evaluating the efficacy of the sandwich bone augmentation technique in increasing buccal bone thickness during implant placement surgery: I. Clinical and radiographic parameters. Clin Oral Implants Res 2014;25(4):45867. 8. Wang HL, Boyapati L. PASS Principles for Predictable Bone Regeneration. Implant Dent 2006;15(1):817. 9. Wang H-L, Misch C, Neiva RF. Sandwich bone augmentation technique: rationale and report of pilot cases. Int J Periodontics Restorative Dent 2004;24(3):23245. 10. Fu J, Wang HL. Horizontal bone augmentation: the decision tree. Int J Periodontics Restorative Dent 2011;31(4):42936. 11. Fu J, Wang H. The Sandwich Bone Augmentation Technique. Clin Adv Periodontics 2012;2(3):1727. 12. Bottino MC, Thomas V, Schmidt G, et al. Recent advances in the development of GTR/GBR membranes for periodontal regeneration - A materials perspective., Dental Materials 2012;28:70321. 13. Nyman S, Lang NP, Buser D, Bragger U. Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases. Int J oral Maxillofac Implant 1990;5(1):9-14. 14. Pellegrini G, Pagni G, Rasperini G. Surgical approaches based on biological objectives: GTR vs GBR techniques. Int J Dent 2013;1-13. 15. Khan R, Khan MH, Bey A. Use of collagen as an implantable material in the reconstructive procedures - an overview. Biology and Medicine 2011;3: 2532. 16. 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;57:314. PAGE \* MERGEFORMAT 10 A B C B A B A C A B E D B C A D E S T a b g h i j ~ Ʃo\?o Ah#* h#* B*CJ OJ QJ ]aJ fH mH!ph333 q sH!9h#* h#* B*CJ OJ QJ ]aJ fH ph333 q $h#* h CJ OJ QJ aJ mH!sH! 9h#* h#* B*CJ OJ PJ QJ aJ mH!nH!ph sH!tH!9h#* h B*CJ OJ PJ QJ aJ mH!nH!ph sH!tH!9h#* hY{ B*CJ OJ PJ QJ aJ mH!nH!ph sH!tH!0h7/) hY{ CJ OJ PJ QJ aJ mH!nH!sH!tH! ?h7/) hY{ 5B*CJ OJ PJ QJ \aJ mH!nH!ph sH!tH! T b & ' ( ) * + , - . ; $dh a$gdB dh gdq d gd/<