Copyright © 2016 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. Evaluation of the Biocompatibility of New Fiber-Reinforced Composite Materials for Craniofacial Bone Reconstruction Ma˘da˘lina-Anca Lazar, DMD, MD,  Horat ¸iu Rotaru, DMD, PhD, y Ioana Baˆldea, MD, PhD, z Adina B. Bos¸ca, DMD, PhD, § Cristian P. Berce, DVM, PhD, jj Cristina Prejmerean, CSI, PhD, ô Doina Prodan, PhD, CS, ô and Radu S. Caˆmpian, DDS, PhD # Abstract: This study aims to assess the biocompatibility of new advanced fiber-reinforced composites (FRC) to be used for custom- made cranial implants. Four new formulations of FRC were obtained using polymeric matrices (combinations of monomers bisphenol A glycidylmethacrylate [bis-GMA], urethane dimetha- crylate [UDMA], triethylene glycol dimethacrylate [TEGDMA], hydroxyethyl methacrylate [HEMA]) and E-glass fibers (300 g/ mp). Every FRC contains 65% E-glass and 35% polymeric matrix. Composition of polymeric matrices are: bis-GMA (21%), TEGDMA (14%) for FRC1; bis-GMA (21%), HEMA (14%) for FRC2; bis-GMA (3.5%), UDMA (21%), TEGDMA (10.5%) for FRC3, and bis-GMA (3.5%), UDMA (21%), HEMA (10.5%) for FRC4. Cytotoxicity test was performed on both human dental pulp stem cells and dermal fibroblasts. Viability was assessed by tetra- zolium dye colorimetric assay. Subcutaneous implantation test was carried out on 40 male Wistar rats, randomly divided into 4 groups, according to the FRC tested. Each group received subcutaneous dorsal implants. After 30 days, intensity of the inflammatory reaction, tissue repair status, and presence of the capsule were the main criteria assessed. Both cell populations showed no signs of cytotoxicity following the FRC exposures. In terms of cytotoxicity, the best results were obtained by FRC3 followed by FRC2, FRC4, and FRC1. FRC3 showed also the mildest inflammatory reaction and this correlated both with the noncytotoxic behavior and the presence of a well-organized capsule. The composite biomaterials developed may constitute an optimized alternative of the similar materials used for the reconstruction of craniofacial bone defects. According to authors’ studies, the authors conclude that FRC3 is the best formulation regarding the biological behavior. Key Words: Craniofacial bone reconstruction, cytotoxicity, fiber- reinforced composite, implantation test (J Craniofac Surg 2016;27: 1694–1699) R eestablishment of the anatomical continuity and functional reintegration of the bone structures affected by different afflic- tions remains a continuous challenge, despite the recent discoveries in reconstructive surgery. Over time, different materials, such as metal plates, xenografts, allogenic or autologous bone grafts, ceramics, and polymers have been used for bone reconstruction. 1,2 Evolution of materials and techniques used in cranio-maxillofacial bone reconstruction followed the scientific and technical develop- ment. However, there is still a restless pursuit of the perfect reconstruction material. Recently, the biomaterial research is focused also on biodegradable and biocompatible composites. Since mechanical properties of composite materials may be tailored to avoid stress-shielding and bone over-loading, the main concern remains the negative biological reactions that these materials may produce. 3–6 Every foreign material introduced into the structure of a living organism induces local and, sometimes, general reactions. These should be maintained within certain limits, considered physiological. 7 Cytotoxicity studies and implantation tests are most commonly performed to establish the host-to-graft acceptance. This study aims to assess the biocompatibility of 4 new advanced biomaterials based on fiber-reinforced composites (FRC). These materials are intended to be used for reconstruction of large, bicorti- calcalvarial defects. In vitro cytotoxicity testing along with in vivo subcutaneous implantation tests was run comparatively for all the tested materials. The research was focused on the FRC effects on cell viability, local reaction, rejection of the implant, tissue repair. Combining the in vitro with in vivo results provides a better under- standing of the behavior of the tested materials. METHODS The composition of FRCs and preparation method: to produce the FRCs included in the study, following materials were used: bisphe- nol A glycidylmethacrylate (Bis-GMA), UDMA, triethylene glycol dimethacrylate (TEGDMA), hydroxyethyl methacrylate (HEMA), benzoyl peroxide (POB), 2,2-dihydroxyethyl-p-toluidine (DHEPT), butylatedhydroxy toluene, 3-methacryloyloxypropyl-1-trimethoxy- silane (A-174 silane; Sigma Aldrich Chemical Co, Taufkirchen, Germany), biwoven E-glass fibers (Owens Corning, Brussels, Belgium). Two resins (base resin and catalyst resin) were prepared to produce each FRC. The composition of resins in 4 experimental FRCs was shown in Table 1. The resins contained the base mono- mers, bisphenol A-glycidyl methacrylate (Bis-GMA 0 monomer 93 wt%, Bis-GMA 1 dimer 7wt%) and/or urethane dimethacylate From the  Department of Implantology and Maxillofacial Surgery; y Department of Oral and Maxillofacial Surgery; z Department of Physi- ology; § Department of Histology; jj Animal Facility, ‘‘Iuliu Hatieganu’’ University of Medicine and Pharmacy; ô ‘‘Raluca Ripan’’ Institute for Research in Chemistry, ‘‘Babes Bolyai’’ University; and # Department of Oral Rehabilitation, ‘‘Iuliu Hat ¸ieganu’’ University of Medicine and Pharmacy, Cluj-Napoca, Romania. Received August 27, 2015; final revision received March 27, 2016. Accepted for publication May 4, 2016. Address correspondence and reprint requests to Horatiu Rotaru, DMD, PhD, Department of Maxillofacial Surgery and Radiology, ‘‘Iuliu Hat ¸ieganu’’ University of Medicine and Pharmacy, 33 Mot ¸ilor Street, 400001 Cluj-Napoca, Romania; E-mail: hrotaru@yahoo.com The authors report no conflicts of interest. Copyright # 2016 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000002925 ORIGINAL ARTICLE 1694 The Journal of Craniofacial Surgery  Volume 27, Number 7, October 2016