composite material. The teeth were randomly divided into two major groups consisting of indocyanine green solution (ICG) and tolonium chloride solution (TCH) ...
ORAL & POSTER PRESENTATIONS Abstracts in order of ID numbers 181423 Biomimetic Synthetic Enamel: A Potential Remineralizing Agent for Enamel Repair H. BAGHERI G1, F. SHAFIEI2, T.S. JAFARZADEH KASHI3, and M. BEHROOZIBAKHSH3, 1 Institue for research in Dental Sciences/School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran, 2Tehran University of Medical Sciences, Tehran, Iran, 3Research Center for Science and Technology in Medicine; Tehran University of Medical Sciences, Tehran, Iran Objectives: Currently, remineralizing agents are being considered as a preventive strategy to stop the mineral loss process and to alter the oral conditions toward remineralization. Up to now, fluoride or calcium phosphate containing systems have been introduced to remineralize the defected enamel tissue. Recently polypeptides have been used for regulation of the mineralization process. The aim of this study was to evaluate the regulatory capacity of leucinerich amelogenin peptide (LRAP) on the calcium phosphate mineralization. Methods: Mineralization solutions were prepared to yield final concentration of 2.5 mM Ca+2, 1.5 mM phosphate, and 2 mg/ml LRAP (GL Biochem China) (pH=7.2). 1 ppm F- was added to the selected solutions to study the effect of fluorine ion. Calcium phosphate or fluorinecontaining (1 ppm) solutions were used as the controls. The solutions were incubated at 37°C for 72 h. Transmission electron microscopy (TEM), atomic force microscopy (AFM), and selected electron area diffraction (SAED) techniques were used to study the mineralization characteristics. Results: SAED analysis revealed diffraction patterns corresponding to the apatite structure in all solutions. TEM analysis showed that in LRAP-containing solutions fibers of hyDr.oxyapatite or fluoroapatite arranged in bundles, while in solutions without LRAP, the crystallization occurred without that arrangement. AFM imaging showed the hierarchical prismatic assembly of HA and FA crystals, similar to the enamel structure. Conclusions: LRAP can regulate the crystallization of calcium phosphate and produce prismatic structures like dental enamel. Therefore, LRAP-CP has the potential to be used as a remineralizing agent for enamel reconstruction.
181508 Adherence of Iranian Dentists to Information Technology S. MOHEBBI, M. BONABI, M.R. EBRAHIMPOUR, M. SAHEBJAMEE, and A.J. ABBASI, Tehran University of Medical Sciences, Tehran, Iran Objectives: In the health field, there have been fast development and expansion of use of information and communication technology (ICT) such as navigation portals, telemedicine and
dentistry, remote medicine and dentistry, and patient data-storing. This study aimed to assess the knowledge and usage of professional IT applications among dentists. Methods: The data were collected by a self-administered validated questionnaire distributed among dentists participating in the 52nd International Congress of Iranian Dental Association and a random sample of dentists working in Tehran. It included 7 questions about knowledge, 8 questions on backgrounds, 10 questions on general usage of IT, and 3 questions on the professional usage of IT. The data were entered into SPSS version 18 and the statistical analyses were performed by ANOVA, NPAR test, and regression modeling. Results: From the total of 303 general practitioners, 30.4% were male and 11 dentists (3.6%) indicated that they had no access to a personal computer. Some of the most popular sites used by dentists were Google (94.3%) and social network of Facebook (69.8%). Those with higher scores in general usage of IT had more consulted with their patients through the Internet. The practice of professional IT was more in men and among those with higher general usage of IT. Conclusions: This study was a preliminary evaluation of the topic among oral health professions indicating IT to be almost available to most but not all dentists in Iran. Dentists participating in the study had insufficient knowledge and their professional IT usage is defective and weak, needing more consideration and training.
181684 Fracture Resistance of Posts in Full-Coverage Restorations of Primary Incisors A. BAGHALIAN1, M. RANJPOUR2, T. HOOSHMAND3, and A. EBRAHIMI2, 1Qazvin University of Medical Sciences, Tehran, Iran, 2Qazvin University of Medical Sciences, Qazvin, Iran, 3School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran Objectives: The purpose of this study was to evaluate the fracture resistance of 4 different posts in full-coverage restorations of severely decayed primary incisors. Methods: 50 primary incisors were selected for this study and all the teeth were sectioned 1 mm above the CEJ. After filing and irrigation of root canal space, the canals were obturated with metapex and 3 mm of post space was prepared inside the canals. Intact glass fiber post, splitended glass fiber post, composite resin post, and orthodontic wire γ post were used as intracanal posts. The final composite resin restoration was done by using pedodontic strip crown. After thermocycling the specimens, the fracture resistance was measured using a universal testing machine. Results: The mean fracture resistance of split-ended glass fiber posts was higher than that of other posts; however, there was no significant difference between any of the groups (P>0.05). Conclusions: Split-ended glass fiber posts seem to be a more appropriate option for fullcoverage restorations in primary incisors.
182551 Human and Animal Bone Substitutes for Augmentation before Implant Placement A. KESHVAD, Shahed University, School of Clinical Dentistry, Tehran, Iran, and T. HOOSHMAND, School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran Objectives: The aim of this study was to compare 2 commercially available human and animal derived bone grafts to augment partially edentulous human bone prior to implant placement for those volunteers with insufficient host bone. Methods: According to the exclusion and inclusion criteria, 12 healthy volunteers (6 in each group) who accepted our protocol and consented for the study were selected. Similar or identical bone particle sizes were selected from the two products, namely Bio-Oss™ (as an animal derived bone) and Faraz-Kish™ (as a human derived bone), in each surgical approach to augment the partially edentulous areas that had insufficient width or height for placing implants of 10 mm or more. The decision of bone quantity was based on the cone beam computerized tomography (CBCT) obtained in one center by only one radiologist. One edentulous area for each patient on the same jaw was left non-grafted to act as a control group and one edentulous area was grafted with one material for comparison. Xenograft and allograft groups were compared with each other and with their corresponding control groups using before and after values reported on the digital CBCTs. Results: To obtain post grafting results, 6 months laps' period was considered as a proper time before the grafted area was subjected to control CBCT. This and the number of subjects necessary to Dr.aw a conclusion took 3 years for the study to complete. Data were analyzed using Kruskal-Walis test and the level of significance was set at P0.05) among the materials in the subcutaneous tissues but it was significant on day 15. The initial setting time for MTA and Biodentine regarding the method of mixing (40, 32 min) were (28, 12min) for MTA and biodentine respectively. Conclusions: All the cements represent good histocompatibility but it seems that the method of mixing may improve this initial setting time so may have influenced the release of some ingredients of cements like Ca+ and physiological characteristics.
183101 Endodontic Cements Influence on Odontogenic Differentiation of Pulp Stem Cells M.A. SAGHIRI1, A. ZIADLOU2, and A. AHADI2, 1Kamal Asgar Reserch Center, Encino, CA, 2 private practice, Tehran, Iran Objectives: The regeneration of pulp is a major problem in endodontics. Therefore, it is desirable to develop new cement to provide infrastructure for pulp regeneration. Dental pulp stem cells (DPSCs) are appropriate cells for evaluating the ability of Odontogenic differentiation of endodontic cements. The current investigation evaluated the ability of Odontogenic differentiation of mineral trioxide aggregated (MTA) and Biodentine.
Methods: In the present study, isolated pulp stem cells from human molars were cultured and expanded. The cells from passage 3 were then loaded onto (MTA) and Biodentine cement plugs and treated with odontogenic supplements (OSs) that included vitamin D3 for a period of 7 days. DPSCs cultivated on cement plugs and normal pulp tissue were the controls. These groups were compared in terms of odontogenic differentiation markers. Results: The activity of Alkaline phosphatase (ALP) and the levels of dentine sialophosphoprotein (DSPP) expression and dentine matrix acidic phosphoprotein 1 (DMP1) genes tended to be significantly higher in the MTA and control (P
