Electron beam effect on biomaterials I: focusing on bone graft materials.
BACKGROUND
To develop biocompatible bony regeneration materials, allogenic, xenogenic and synthetic bones have been irradiated by an electron beam to change the basic structures of their inorganic materials. The optimal electron beam energy and individual dose have not been established for maximizing the bony regeneration capacity in electron beam irradiated bone.


RESULTS
Commercial products consisting of four allogenic bones, six xenogenic bones, and six synthetic bones were used in this study. We used 1.0-MeV and 2.0 MeV linear accelerators (power: 100 KW, pressure; 115 kPa, temperature; -30 to 120°C, sensor sensitivity: 0.1-1.2 mV/kPa, generating power sensitivity: 44.75 mV/kPa, supply voltage: 50.25 V), and a microtrone with different individual irradiation doses such as 60 kGy and 120 kGy. Additional in vitro analyses were performed by elementary analysis using field emission scanning electron microscopy (FE-SEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and confocal laser scanning microscopy (CLSM). In vivo clinical, radiographic, and micro-computed tomography (Micro-CT) with bone marrow density (BMD) analysis was performed in 8- and 16-week-old Spraque-Dawley rats with calvarial defect grafts.


CONCLUSIONS
Electron beam irradiation of bony substitutes has four main effects: the cross-linking of biphasic calcium phosphate bony apatite, chain-scissioning, the induction of rheological changes, and microbiological sterilization. These novel results and conclusions are the effects of electron beam irradiation.
Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, 62-1 Changgyeonggungno, Jongno-gu, Seoul 110-768 South Korea.
Soung Min
SM
Kim
Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, 62-1 Changgyeonggungno, Jongno-gu, Seoul 110-768 South Korea.
Huan
H
Fan
Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, 62-1 Changgyeonggungno, Jongno-gu, Seoul 110-768 South Korea.
Yun Ju
YJ
Cho
Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, 62-1 Changgyeonggungno, Jongno-gu, Seoul 110-768 South Korea.
Mi Young
MY
Eo
Quantum Optics Research Division, Korea Atomic Energy Research Institute, Daejeon, South Korea.
Ji Hyun
JH
Park
Radiation Instrumentation Research Division, Korea Atomic Energy Research Institute, Daejeon, South Korea.
Byung Nam
BN
Kim
Quantum Optics Research Division, Korea Atomic Energy Research Institute, Daejeon, South Korea.
Byung Cheol
BC
Lee
Department of Oral Pathology, College of Dentistry, Gangneung-Wonju National University, 123 Chibyon-dong, Gangneung, 210-702 South Korea.
Suk Keun
SK
Lee
Allogenic bone; Bony regeneration; Electron beam irradiation; Synthetic bone; Xenogenic bone