Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 1 9 EN Sholeh Ghabraei Assistant Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Mohammad Marvi Dentist, Private Practice, Tehran, Iran Behnam Bolhari Associate Professor, Laser Research Center of Dentistry, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Parisa Bagheri Postgraduate Student, Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2017 06 21 2017 08 14 Objectives: Enterococcus faecalis (E. faecalis) is the most commonly isolated microorganism from teeth with postoperative infection. Triple antibiotic paste (TAP) has the ability to eradicate microorganisms from the root canal system when used as an intracanal medicament. The aim of this study was to determine the minimum duration of application of TAP required for elimination of E. faecalis from the root canal system and its minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in an ex-vivo model. Materials and Methods: Root canals of 34 extracted human single canal teeth were inoculated with E. Faecalis after instrumentation, and then 4 g of TAP (ciprofloxacin, metronidazole and doxycycline) was mixed with 4.5 mL of saline and applied as intracanal medicament. The teeth were sectioned longitudinally and dentin chips were collected and evaluated to determine the count of bacterial colonies. Micro-dilution broth test was used to assess the MIC and MBC of TAP. Data were analyzed using SPSS version 22 via the Wilcoxon signed rank test. Results: After seven days of application of TAP as intracanal medicament, E. faecalis was eliminated from the dentinal tubules of the apical half of root canal up to 400 µ depth. The MIC and MBC of TAP in its original concentration were both found to be 16 µg/mL.   Conclusions: The original concentration of TAP was found to be 5×104 times its MIC. Considering the risk of coronal discoloration of teeth following the use of TAP, application of its lower concentrations is recommended. https://fid.tums.ac.ir/index.php/fid/article/view/1996 https://fid.tums.ac.ir/index.php/fid/article/download/1996/985

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 63 68 EN Gholamreza Shirani Assistant Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Mahnaz Arshad Assistant Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran Xaniar Mahmoudi Dentistry Student, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran 2017 08 16 2017 11 05 This case report presents a 16-year-old boy with bilateral temporomandibular joint (TMJ) bony ankylosis due to trauma. The patient had undergone several unsuccessful therapeutic surgeries and was experiencing reduced mouth opening, difficulty in eating and speaking, poor oral hygiene, snoring, and depression. Bilateral gap arthroplasty and distraction osteogenesis (DO) were performed. After the surgery, we were able to move the osteodistractors forward and prevent the upward and backward movement of the proximal mandibular segment with the use of our custom-made Sh-device, which allowed bone growth and soft-tissue matching. The mandibular deficiency was treated, and the patient's sleep quality significantly improved after three months. The physical, orthodontic and speech therapies were continued. The facial asymmetry, difficulty in sleeping, eating and speaking, and low self-esteem were completely resolved. At the 8-year follow-up, the patient's condition was satisfactory. The Sh-device can be used as a contemporary treatment modality for TMJ ankylosis. https://fid.tums.ac.ir/index.php/fid/article/view/2106 https://fid.tums.ac.ir/index.php/fid/article/download/2106/992

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 10 19 EN Farhood Massoumi Assistant Professor, Dental Research Center, Research Institute of Dental Sciences, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mina Taheri Postgraduate Student, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Abolghasem Mohammadi Assistant Professor, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Omid Amelirad PhD Student, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran 2017 08 20 2017 12 04 Objectives: The position of dental implants in the alveolar bone can affect the surrounding bone from biomechanical and biological aspects. The purpose of this study was to evaluate the effect of implant position on stress and strain distribution in the surrounding bone by using finite element analysis (FEA). Materials and Methods: Thirteen computerized models of a 3.8-mm-diameter XiVE implant with the abutment and crown of a mandibular second premolar in a mandibular bone segment were designed. In the reference model, the implant was placed at the center of the alveolar ridge with its crest module located above the alveolar crest. In the other models, the implants were positioned buccally, lingually, coronally or apically by 0.5, 1 or 1.5mm. By using the ANSYS software program, a 100-N load was applied to the buccal cusp parallel to and at a 30-degree angle relative to the longitudinal axis of the fixture. The models were analyzed in terms of the distribution of stress and strain in the bone. Results: The different implant positions induced nonlinear stress and strain changes in the bone. The central, 1.5-mm apical, and 1.5-mm coronal implant positions induced high amounts of stress and strain under off-axial loads. Conclusions: Within the limitations of this study, the results showed that the stress and strain in the bone around the implant undergo small nonlinear changes with buccolingual and apicocoronal shifting of the implant and can be affected by the configuration of the implant in contact with the bone. https://fid.tums.ac.ir/index.php/fid/article/view/2108 https://fid.tums.ac.ir/index.php/fid/article/download/2108/986

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 20 29 EN Amir Ali Reza Rasouli Ghahroudi Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Afshin Khorsand Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran; Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Sanaz Mahmoodi Pharmacist, Private Practice, Tehran, Iran Sahar Chokami Rafiei Postgraduate Student, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2017 06 20 2017 08 10 Objectives: The aim of this study was to compare the efficacy of bovine bone substitute (Compact Bone B. ®) alone versus bovine bone substitute and simvastatin for human maxillary sinus augmentation. Materials and Methods: This study was conducted on 16 sinuses in eight patients. Radiographic assessments were done preoperatively (T0), immediately (T1) and at nine months after sinus grafting (T2). Alveolar bone height and density were assessed on cone beam computed tomography (CBCT) scans using Planmeca Romexis™ Imaging Software 2.2. Results: The change in alveolar bone height and density between T0, T1 and T2 was significant in both groups. Alveolar bone height (h0, h1, h2) and vertical height of the grafted bone (g1, g2) in three lines (anterior, middle and posterior) were not significantly different between groups. The grafted bone height shrinkage (%) in the anterior, middle and posterior limits of the augmented area were not significantly different between groups. The existing alveolar and grafted bone density increased significantly in both groups between T1 and T2, except for the existing alveolar bone density in the control group. There were no statistically significant differences between the alveolar bone density values obtained in TI and T2 between groups, except for the existing alveolar bone density at T1. Conclusions: This study did not show any significant positive effect for simvastatin in maxillary sinus augmentation based on radiographic examination. https://fid.tums.ac.ir/index.php/fid/article/view/1997 https://fid.tums.ac.ir/index.php/fid/article/download/1997/987

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 30 40 EN Elham Khoshbin Assistant Professor, Department of Endodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran Zakiyeh Donyavi Assistant Professor, Department of Endodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran Erfan Abbasi Atibeh Assistant Professor, Department of Periodontics, School of Dentistry, Alborz University of Medical Sciences, Karaj, Iran Shahin kasraei Professor, Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Rasoul Yousefimashouf Associate Professor, Department of Microbiology, Hamadan University of Medical Sciences, Hamadan, Iran Ghodratollah Roshanaei Associate Professor, Modeling of Noncommunicable Diseases Research Center, Department of Biostatistics and Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran Faranak Amani Assistant Professor, Department of Endodontics, School of Dentistry, Alborz University of Medical Sciences, Karaj, Iran 2017 06 13 2017 08 22 Objectives: Laser irradiation, as an adjunct to root canal preparation, may increase the success rate of endodontic treatments. This study aimed to assess the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) and diode lasers on the apical seal of the root canals filled with AH Plus® and mineral trioxide aggregate (MTA)-based sealers. Materials and Methods: This in-vitro experimental study was conducted on 96 single-rooted, single-canal extracted human teeth with closed apices. The root canals were prepared by using ProTaper® rotary instruments and were randomly divided into six groups (n=16): 940-nm diode laser and AH Plus® sealer (group 1), Nd:YAG laser and AH Plus® sealer (group 2), AH Plus® sealer (group 3), 940-nm diode laser and MTA-based sealer (group 4), Nd:YAG laser and MTA-based sealer (group 5), MTA-based sealer (group 6), as well as positive and negative control groups. A bacterial leakage model was used for microleakage assessment. Qualitative assessment was done by using a scanning electron microscope (SEM). Data were analyzed by two-way analysis of variance (ANOVA) at the significance level of 0.05. Results: There were statistically significant differences between the experimental and control groups (P=0.002). The laser-treated groups showed a lower apical microleakage compared to the non-laser-treated groups, although the difference was not statistically significant (P>0.05). No significant differences were noted between the two lasers in terms of the apical microleakage, irrespective of the type of sealer (P>0.05). Conclusions: Laser irradiation, as an adjunct to root canal preparation, has no significant effect on the level of apical microleakage. https://fid.tums.ac.ir/index.php/fid/article/view/1958 https://fid.tums.ac.ir/index.php/fid/article/download/1958/988

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 06 41 46 EN Seyed Hossein Mohseni Salehi Assistant Professor, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Afshin Khorsand Associate Professor, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Sahar Chokami Rafiei Assistant Professor, Department of Periodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Faris Yousif Mirkhan Postgraduate Student, Department of Periodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran 2017 07 23 2017 10 29 Objectives: This study sought to assess the efficacy of modified pedicle grafting as a noninvasive technique for soft tissue augmentation around maxillary dental implants. Materials and Methods: This descriptive study was conducted on eight patients who met the inclusion criteria. Prior to the second-stage surgery for exposing the implants, the buccal keratinized mucosa width, vestibular depth, and mucosal thickness around the implants were measured. The same parameters were measured six months after the second-stage surgery and were compared with the baseline values. Also, the color match of the graft with the adjacent gingival and mucosal tissues was evaluated. Results: Forty-seven maxillary implants were evaluated. The minimum and maximum gains of keratinized mucosal width were respectively equal to 0mm and 7mm, with a mean of 4.31±1.19mm. The mean vestibular depth around the implants was 9.47±1.75mm (ranging from 5mm to 12mm) six months after the surgery. At the beginning of the study, a thin mucosa surrounded the implants, but after six months, the peri-implant keratinized mucosa width increased. The color match of the graft with the adjacent gingival and mucosal tissues was excellent based on the periodontists' opinion. Conclusions: Modified pedicle grafting is a safe and predictable technique for soft tissue augmentation around maxillary implants. This technique is reliable for increasing the width of keratinized mucosa in fully and partially edentulous patients with a shallow vestibular depth. The stability of the pedicle flap is achieved by fixing the flap to the tissue around the healing abutment. https://fid.tums.ac.ir/index.php/fid/article/view/2069 https://fid.tums.ac.ir/index.php/fid/article/download/2069/989

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 15 1 2018 01 ycetemcomitans and can be used as an adjunct to routine treatments for successful periodontal therapy in vivo. https://fid.tums.ac.ir/index.php/fid/article/view/2752 https://fid.tums.ac.ir/index.php/fid/article/download/2752/1757

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 16 3 2019 05 29 194 205 EN Marziyeh Alikhasi Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Narges Ameri Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran Hakimeh Siadat Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. AND Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Ahmad Reza Shamshiri Department of Epidemiology and Statistics, School of Health, Tehran University of Medical Sciences, Tehran, Iran MohammadReza Nejati Nano Robotics Laboratory, Department of mechanical Engineering, Sharif University of Technology, Tehran, Iran 2018 09 06 2018 11 03 Objectives: Internal fit of implant frameworks is an important factor determining the long-term success of dental implant restorations. This in-vitro study aimed to evaluate dimensional changes of implant-supported zirconia frameworks fabricated by two computer-aided design/computer-aided manufacturing (CAD/CAM) systems from scanning to sintering. Materials and Methods: A master model of a three-unit fixed partial denture was fabricated with two implant abutments. In each CAD/CAM system (AmannGirrbach and Zirkonzahn), the master model was scanned 12 times, and data were saved as Standard Transformation Language files (scanning groups). Using semi-sintered zirconia, 12 real-size frameworks (milling groups) and 12 enlarged frameworks, were sintered (sintering groups) and made by each system. Dimensions of the master model and frameworks in each phase were measured. Dimensional changes (compared to the master model) were calculated. Data were analyzed using repeated measures analysis of variance, independent t-test, and paired sample t-test (α=0.05). Results: Comparison of the two CAD/CAM systems revealed that although dimensional changes were greater in the Zirkonzahn system in the milling phase, they were greater in the AmannGirrbach system in the sintering phase. Evaluation of fabrication phases in each system revealed greater dimensional changes in the milling phase compared to other phases in the Zirkonzahn system (P<0.05). However, in the AmannGirrbach system, the values were not significantly different between the milling and sintering phases (P>0.05). Conclusion: Within the limitations of this study, the results showed that fabrication phases, type of CAD/CAM system, and abutment size had significant effects on dimensional changes. https://fid.tums.ac.ir/index.php/fid/article/view/2811 https://fid.tums.ac.ir/index.php/fid/article/download/2811/1758

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 16 3 2019 05 29 206 213 Abdolaziz Haghnegahdar Department of Oral and Maxillofacial Radiology, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran Aisa Zamani Student Research Committee, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran Mehrdad Vossoughi Oral and Dental Disease Research Center, Department of Dental Public Health, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran 2018 09 18 2018 11 25 Objectives: Temporomandibular disorder (TMD), as a prevalent condition, has been reported to be related to changes in sleep quality. This study aims to assess the association between TMD severities and sleep quality in a selected Iranian population by the application of the Helkimo index and the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Materials and Methods: This study comprised 50 non-TMD subjects and 150 TMD patients, which were equally selected from each TMD severity category. The study was conducted at the School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. The patients were first examined and categorized into four TMD severity groups according to the Helkimo index: Non-TMD, mild, moderate, and severe. Then, the patients completed the PSQI questionnaire, which was a standard version translated into Persian and adjusted for Iranian patients. Results: Comparison of mean PSQI scores of the four groups revealed a significant difference (P<0.001). Pairwise comparisons showed that the severe, moderate, and mild TMD groups and the control received the highest to the lowest PSQI scores (12.26±2.35, 8.20±1.92, 6.88±1.89, and 5.28±1.32, respectively). Similarly, regression analysis indicated that by controlling the effect of demographic variables, the mean PSQI significantly increased as TMD severity increased. Conclusion: According to the results, all three categori