J Oral Maxillofac Surg 70:2070-2079, 2012 Guided Bone Regeneration Using Cyanoacrylate-Combined Calcium Phosphate in a Dehiscence Defect: A Histologic Study in Dogs Jung-Seok Lee, MD,* Seung-Hee Ko, MD,† Young-Taek Kim, PhD,‡ Ui-Won Jung, PhD,§ and Seong-Ho Choi, PhD Purpose: This study evaluated the effects of cyanoacrylate-combined calcium phosphate (CCP) as a candidate for a barrier membrane substitute in guided bone regeneration and the space maintenance capability of CCP placed in a dehiscence defect model. Materials and Methods: Six standardized dehiscence defects (5 3 mm, height width) around dental implants were created on unilateral edentulous ridges in 5 dogs, where each defect was treated with sham surgery, biphasic calcium phosphate (BCP), CCP, barrier membrane (MEM), BCP + MEM, and CCP + MEM. The animals were sacrificed after an 8-week healing interval for histologic and histometric analyses. Results: The BCP and CCP sites showed increased bone formation compared with the control sites, although incomplete defect resolution occurred; bone regeneration heights (area) averaged 3.52 0.69 mm (4.94 2.59 mm 2 ), 3.51 0.16 mm (4.10 1.99 mm 2 ), and 1.53 0.42 mm (1.01 0.74 mm 2 ) for the BCP, CCP, and control sites, respectively. All the MEM sites showed more bone formation compared with the sites that received the same biomaterials without a MEM, and the BCP + MEM and CCP + MEM sites showed extensive bone formation within the defect and on top of the implant; the bone regeneration heights (area) averaged 3.96 2.86 mm (12.46 11.61 mm 2 ), 5.45 0.25 mm (11.63 1.97 mm 2 ), and 2.62 0.27 mm (3.43 0.98 mm 2 ) for the BCP + MEM, CCP + MEM, and MEM sites, respectively. Conclusions: CCP can be a good scaffold for supporting an MEM as opposed to acting as a substitute for the MEM in guided bone regeneration. © 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:2070-2079, 2012 In clinical dentistry, various types of bony defects can occur around or beside a dental implant in an eden- tulous alveolar ridge. In cases where a tooth has been extracted because of severe periodontal destruction owing to periodontitis or endodontic problems, the alveolar bone would be resorbed horizontally or ver- tically. These situations may result in the exposure of an implanted surface and can hamper the ideal place- ment of a dental implant in extreme cases. 1,2 There- fore, such ridge defects should be carefully evaluated and classified and, if indicated, corrected. Seibert 3 classified ridge defects into 3 categories: horizontal, Received from the Department of Periodontology, Research Insti- tute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea. *Clinical Assistant Professor. †PhD Student. ‡Clinical Assistant Professor, Department of Periodontology and Den- tistry, National Health Insurance Company, Ilsan Hospital, Goyang, Korea. §Associate Professor. Professor. Dr Lee and Dr Ko contributed equally to this work. This work was supported by grant 08K1501-01220 from the Center for Nanostructured Materials Technology under the 21st Century Frontier R&D Program of the Ministry of Education, Sci- ence and Technology, Korea. Address correspondence and reprint requests to Dr Choi: Department of Periodontology, Research Institute for Periodon- tal Regeneration, College of Dentistry, Yonsei University, 50 Yonsei- ro, Seodaemoon-gu, Seoul 120-752, Korea; e-mail: shchoi726@ yuhs.ac © 2012 American Association of Oral and Maxillofacial Surgeons 0278-2391/12/7009-0$36.00/0 http://dx.doi.org/10.1016/j.joms.2012.04.044 2070