Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 302 308 EN Nasrin Esfahanizadeh Associate Professor, Department of Periodontics, Dental Branch, Islamic Azad University, Tehran, Iran; Member of Dental Implant Research Center, Tehran University of Medical Sciences, Tehran, Iran Niloufar Daneshparvar General Dentist, College Station, USA Farinaz Askarpour Periodontist, Private Practice, Tehran, Iran Nasrin Akhoundi Assistant Professor, Department of Mathematics, South Tehran Branch, Islamic Azad University, Tehran, Iran Mehrdad Panjnoush Assistant Professor, Head of Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2016 01 05 2016 08 12 Objectives: The purpose of this study was to determine buccal bone and soft tissue thicknesses and their correlation in the maxillary anterior region using cone beam computed tomography (CBCT). Materials and Methods: In this cross sectional study, 330 sound maxillary incisors in 60 patients with a mean age of 37.5 years were assessed by CBCT scans. For better visualization of soft tissue, patients were asked to use plastic retractors in order to retract their lips and cheeks away from the gingival tissue before taking the scans. Measurements were made in three different positions: at the crest and at 2 and 5mm apical to the crest. The cementoenamel junction‒crest distance was measured. for data analyses, the Pearson’s correlation coefficient, ANOVA and intraclass correlation coefficient were used. Results: There were mildly significant linear associations between labial soft tissue and bone thickness in the canines and incisors (r<0.40, P<0.05), but no association was found for the lateral incisors. The mean thickness of buccal bone differed significantly in the maxillary anterior teeth, being greater for the lateral incisors (P<0.05). For soft tissue thickness, the results were the same, and the least thickness was recorded for the canines. There was a mild association between labial soft tissue and bone thickness in canines and incisors (r=0.2, P=0.3), but no such linear association was seen for the lateral incisors. Conclusions: The mean thickness of buccal bone and soft tissue in the anterior maxilla was <1mm and there was a mild linear correlation between them.   https://fid.tums.ac.ir/index.php/fid/article/view/1003 https://fid.tums.ac.ir/index.php/fid/article/download/1003/908

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 309 317 EN Neda Moslemi Associate Professor, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Aysan Shahnaz Assistant Professor, Department of Periodontology, School of Dentistry, Ghom University of Medical Sciences, Ghom, Iran Abbas Bahador Associate Professor, Microbiology Department, Tehran University of Medical Sciences, Tehran, Iran Sepehr Torabi Assistant Professor, Department of Periodontology, School of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran Sanaa Jabbari Resident of Endodontics, Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Zahra Alizadeh Oskouei Dentist, Dental Implant Ward, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2016 06 06 2016 09 03 Objectives: With side effects of antibiotics taken into consideration, the necessity of antibiotic therapy after simple implant placement procedures is still a subject of debate and the existing literature on this topic is widely controversial. The aim of this study was to assess the effect of postoperative amoxicillin therapy on early colonization of peri-implant sulcus after implant placement. Materials and Methods: In this randomized controlled clinical trial, 20 patients requiring simple implant placement were randomly allocated to test or control groups and received postoperative amoxicillin or placebo, respectively. Microbiological samples were collected on day 0 and day 7. Mann Whitney and Wilcoxon signed rank tests were utilized to evaluate changes in colony count of identified bacterial species between the test and control groups, and between day 0 and day 7. Results: The decrease in the number of sensitive facultative species and the increase in the number of resistant anaerobes in amoxicillin group were statistically significant as compared to the placebo group (P=0.025 and P=0.005, respectively). The increase in the number of sensitive anaerobes in the placebo group as compared to amoxicillin group, and the decrease in the number of facultative Gram-positive cocci as compared to the placebo group were statistically significant (P=0.011 and P=0.035, respectively). Conclusions: Postoperative administration of amoxicillin resulted in an increase in the number of resistant anaerobes and a decrease in the number of sensitive facultative bacteria and facultative Gram-positive cocci, as compared to the placebo, but with no sign/symptom of infection in any group.   https://fid.tums.ac.ir/index.php/fid/article/view/1285 https://fid.tums.ac.ir/index.php/fid/article/download/1285/918

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 318 324 EN Aida Saffarpour Assistant Professor, Department of Operative Dentistry, Dental Faculty, Tehran University of Medical Sciences (International Campus), Tehran, Iran Maryam Ghavam Associate Professor, Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Kimiya Sadighi Dentist, Tehran, Iran Tehran University of Medical Sciences, Tehran, Iran Mohammad javad Kharazifard Epidemiologist, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Anna Saffarpour Assistant Professor, Department of Periodontics, Dental Faculty, Tehran University of Medical Sciences (International Campus), Tehran, Iran 2015 11 22 2016 06 30 Objectives: This study aimed to assess the effect of re-etching of desensitized dentin for five and 10 seconds on marginal microleakage of composite restorations. Materials and Methods: Class V cavities (4x2x2mm) were prepared on the buccal surfaces of 64 third molars and randomly divided into four groups of 16. In the control group, Single Bond (SB) adhesive was applied after etching. In BB+SB group, after application of BisBlock (BB) desensitizer agent (which needs etching), SB adhesive was used. In BB+5E+SB group, re-etching of dentin was done for five seconds after application of desensitizer, and then the adhesive was applied. The process in BB+10E+SB was the same as BB+5E+SB group except for re-etching time, which was 10 seconds. The cavities were restored with composite resin. After 24 hours of storage in distilled water and 10,000 thermal cycles, all samples were subjected to dye penetration test. The teeth were sectioned buccolingually in the middle of restorations. A blind examiner observed the sections under a stereomicroscope. Results: At the occlusal margins, no significant difference in microleakage was observed among the groups (P>0.05). Application of BB in combination with SB had no effect in comparison to the control group (P>0.05); while there were significant differences in microleakage scores between BB+10E+SB and control (P=0.002), BB+10E+SB and BB+SB (P<0.001) and BB+5E+SB and BB+SB groups (P=0.009). Conclusions: Dentin re-etching after application of BB desensitizer increased the gingival microleakage of class V composite restorations. Application of BB desensitizer combined with SB adhesive enhanced marginal seal.   https://fid.tums.ac.ir/index.php/fid/article/view/886 https://fid.tums.ac.ir/index.php/fid/article/download/886/909

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 325 332 EN Zainab Kadkhoda Associate Professor, Department of Periodontology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Sahar Chokami Rafiei Postgraduate Student, Department of Periodontology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Bahare Azizi Associate Professor, Department of Periodontology, Dental Faculty, Sanandaj University of Medical Sciences, Kurdistan, Iran Ahad Khoshzaban PHD Student, Dental Biomaterial Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2016 08 27 2016 10 01 Objectives: Periodontal tissue regeneration for treatment of periodontal disease has not yet been mastered in tissue engineering. Stem cells, scaffold, and growth factors are the three main basic components of tissue engineering. Periodontal ligament (PDL) contains stem cells; however, the number, potency and features of these cells have not yet been understood. This study aimed to isolate and characterize the properties of PDL stem cells. Materials and Methods: In this experimental study, samples were isolated from the PDL of extracted teeth of five patients and then stained immunohistochemically for detection of cell surface markers. Cells were then examined by immuno-flow cytometry for mesenchymal markers as well as for osteogenic and adipogenic differentiation. Results: The isolated cell population had fibroblast-like morphology and flow cytometry revealed that the mesenchymal surface markers were (means): CD90 (84.55), CD31 (39.97), CD166 (33.77), CD105 (31.19), CD45 (32/44), CD44 (462.11), CD34 (227.33), CD38 (86.94), CD13 (34.52) and CD73 (50.39). The PDL stem cells also differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively. Conclusions: PDL stem cells expressed mesenchymal stem cell (MSC) markers and differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively.   https://fid.tums.ac.ir/index.php/fid/article/view/1497 https://fid.tums.ac.ir/index.php/fid/article/download/1497/910

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 333 339 Amir Reza Rokn Professor, Dental Implant 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 Kazem Hashemi Postdoc Student, Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Solmaz Akbari Assistant Professor, Dental Implant 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 Mohammad Javad Kharazifard Epidemiologist, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Hamidreza Barikani Researcher, Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Mehrdad Panjnoosh Assistant Professor, Head of Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2016 12 07 Objectives: This study sought to evaluate the accuracy and errors of linear measurements of mesiodistal dimensions of Kennedy Class III edentulous space using cone beam computed tomography (CBCT) in comparison with clinical measurements. Materials and Methods: Nineteen Kennedy Class III dental arches were evaluated. An impression was made of each dental arch and poured with dental stone. The distance was measured on dental cast using a digital Vernier caliper with an accuracy of 0.1mm and on CBCT scans. Finally, the linear mesiodistal measurements were compared and the accuracy of CBCT technique was evaluated by calculating absolute value of errors, intra-class correlation coefficient and simple linear regression model. Results: In comparison with the cast method, estimation of size on CBCT scans had an error of -8.46% (underestimation) to 5.21% (overestimation). In 26.5% of the cases, an accepted error of ±1% was found. The absolute value of errors was found to be in the range of 0.21-8.46mm with an average value of 2.86 ±2.30mm. Conclusions: Although the measurements revealed statistically significant differences, this does not indicate a lower accuracy for the CBCT technique. In fact, CBCT can provide some information as a paraclinical tool and the clinician can combine these data with clinical data and achieve greater accuracy. Undoubtedly, calibration of data collected by clinical and paraclinical techniques and the clinician’s expertise in use of CBCT software programs can increase the accuracy of implant placement.   https://fid.tums.ac.ir/index.php/fid/article/view/1652 https://fid.tums.ac.ir/index.php/fid/article/download/1652/916

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 13 5 2016 12 31 340 348 EN Farhad Tabatabaian Assistant Professor, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Faeze Masoomi Graduate Student, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mahshid Namdari Assistant Professor of Biostatistics, Department of Community Oral Health, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Minoo Mahshid Professor, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2016 04 20 2016 08 30 Objectives: Masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (ZRC) has not yet been clearly understood in zirconia-based restorations. This study evaluated the effect of three different core materials on masking ability of a ZRC. Materials and Methods: Ten zirconia disc samples, 0.5mm in thickness and 10mm in diameter, were fabricated. A white (W) substrate (control) and three substrates of nickel-chromium alloy (NCA), non-precious gold alloy (NPGA), and ZRC were prepared. The zirconia discs were placed on the four types of substrates for spectrophotometry. The L*, a*, and b* values of the specimens were measured by a spectrophotometer and color change (ΔE) values were calculated to determine color differences between the test and control groups and were then compared with the perceptual threshold. Randomized block ANOVA and Bonferroni test analyzed the data. A significance level of 0.05 was considered. Results: The mean and standard deviation values of ΔE for NCA, NPGA, and ZRC groups were 10.26±2.43, 9.45±1.74, and 6.70±1.91 units, respectively. Significant differences were found in the ΔE values between ZRC and the other two experimental groups (NCA and NPGA; P<0.0001 and P=0.001, respectively). The ΔE values for the groups were more than the predetermined perceptual threshold. Conh>06 15 310 8 Raha Habib Agahi Dentist, Private Practice, Department of Oral Medicine, Kerman Dental School, Kerman University of Medical Sciences. Nader Navabi Assistant Professor, Department of Oral Medicine, Kerman Dental School, Kerman University of Medical Sciences. Arash Shahravan Associated Professor, Kerman Oral and Dental Research Centre, Kerman University of Medical Sciences. Amirreza Ghassemi Dentist, Private Practice, Department of Oral Medicine, Kerman Dental School, Kerman University of Medical Sciences. 2015 10 16 Considering the importance of randomized clinical trials (RCTs) in the evidence-based approach, the objective of this study was critical appraisal of reporting RCTs in Iranian dental journals.After adequate searching, 113 RCT articles published during 2003-2010 were reviewed for quality of reporting with the CONSORT scale. The quality of each paper was assessed on 20.Although statistical analysis was described in 93.8%, acceptable methods for randomization and blinding were found in only 8% and 11.5% of the papers, respectively. Reasons for withdrawal were also given in just 20.4% of the articles.This study revealed that the quality of reporting RCTs in Iranian dental journals does not meet the recommended standards generally and needs to be improved. https://fid.tums.ac.ir/index.php/fid/article/view/452 https://fid.tums.ac.ir/index.php/fid/article/download/452/428

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 3 2014 06 15 319 27 Ali Peimani Assistant Professor, Department of Oral Surgery, Dental School of Rafsanjan University, Rafsanjan, Iran. Farimah Sardary Assistant Professor, Department of Oral Medicine, Dental School of Rafsanjan University, Rafsanjan, Iran. 2015 10 16 Temporomandibular disorders (TMD) are clinical conditions characterized by pain and sounds of the temporomandibular joint (TMJ). This study was designed to assess the effect of low-level laser therapy (LLLT) on healing of osteoarthritis in rats with TMD.Thirty-two male Wistar rats (250-200 g) were housed in standard plastic cages. After injection of Complete Freund's adjuvant into the TMJ, rats were randomly divided into two groups of 16 (case and control) and anesthetized; then osteoarthritis was induced via intraarticular injection of 50 µl of Complete Freund's adjuvant; into the bilateral TMJs. In the case group, LLLT was done transcutaneously for 10 minutes daily, starting the day after the confirmation of osteoarthritis. Exposure was performed for 10 minutes at the right side of the TMJ with 880 nm low-level laser with 100 mW power and a probe diameter of 0.8 mm. Control rats were not treated with laser.After three days of treatment the grade of cartilage defects, number of inflammatory cells, angiogenesis, number of cell layers and arthritis in rats in the case group were not significantly different compared with controls (P>0.05). After seven days, the grade of cartilage defects, number of inflammatory cells, number of cell layers, and arthritis in the case group improved compared to controls (P https://fid.tums.ac.ir/index.php/fid/article/view/450 https://fid.tums.ac.ir/index.php/fid/article/download/450/426

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 3 2014 06 15 328 34 Nahid Ramazani Assistant Professor, Children and Adolescent Health Research Center, Department of Pediatric Dentistry, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran. Rahil Ahmadi Assistant Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Shahed University, Tehran, Iran. Mansure Darijani Dentist, Zahedan University of Medical Sciences, Zahedan, Iran. 2015 10 16 Adverse effects of dental materials, especially metals, have been an important issue in recent decades.The purpose of this study was to determine the amount of nickel released from stainless steel crowns in artificial saliva.In this in-vitro study, 270 stainless steel crowns were divided into five groups, each with nine subgroups. Each group (I to V) was comprised of four, five, six, seven and eight crowns, respectively. Each subgroup was placed in a polyethylene jar containing artificial saliva and held in an incubator at 37°C for four weeks. The amount of released nickel was determined on days 1, 7, 14, 21 and 28, using an atomic absorption spectrophotometer. Wilcoxon Signed-Rank and Kruskal-Wallis with Dunn's post hoc tests (SPSS software, v. 18) were used for statistical analysis at a significance level of 0.05.The mean level of nickel on day 1 was more than that of day 7; this difference was statistically significant for all groups (P < 0.05), except for group II (P = 0.086). Also, the mean difference of released nickel between the groups was significant on day 1 (P = 0.006) and was insignificant on day 7 (P = 0.620). The nickel levels were zero on days 14, 21, and 28.The amount of nickel was below the toxic level and did not exceed the dietary intake. https://fid.tums.ac.ir/index.php/fid/article/view/448 https://fid.tums.ac.ir/index.php/fid/article/download/448/424

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 3 2014 06 15 335 42 Minoo Mahshid Associate Professor, Prosthodontics Department, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Allahyar Geramy Professor, Dental Research Center Dentistry Research Institute & Department of Orthodontics, Tehran University of Medical Sciences, Tehran, Iran. Massoud Ejlali Assistant Professor, Prosthodontics Department, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Majid Sedaghat Monfared Assistant Professor, Prosthodontics Department, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Shirin Rezvani Habib Abadi Assistant Professor, Prosthodontics Department, Dental School,Qazvin University of Medical Sciences, Qazvin, Iran. 2015 10 16 The main goal of this study was to evaluate differences in stress distribution relevant to the number of implants under an anterior bridge when combined with a removable partial denture in the posterior region.Four three-dimensional finite element models (3D FEM) were designed from a mandible containing an implant-supported bridge extending between canines, and a bilateral distal extension removable partial denture. A nonrigid connection was selected as the attachment method between the partial denture and the anterior implant-supported fixed prosthesis; 2, 3, 4 and 5 implants supporting the bridge all with 10mm length and 3.8 mm diameter were assessed. With the aid of the finite element program ANSYS 8.0, the models were loaded and von Mises stresses were evaluated.In spongy bone, stress forces showed a decrease from 2 implants to 4 implants but showed an increase in the 5-implant model. Stresses on cortical bone of terminal implants were in similar range in the 2-, 3- and 4-implant models. While, in the 5-implant model the amount of stresses on terminal implants increased dramatically. The stresses on implants were nearly similar in all models, with the greatest amount on terminal implants.Within the limitations of this study, 2-, 3- and 4-implant models showed less stress on cortical and spongy bone in comparison with the 5-implant model. The stresses transferred to implants were nearly similar. https://fid.tums.ac.ir/index.php/fid/article/view/446 https://fid.tums.ac.ir/index.php/fid/article/download/446/422

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 3 2014 06 15 343 54 Habib Ollah Ghanbari Associate Professor, Department of Periodontics, Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Morteza Taheri Associate Professor, Department of Periodontics, Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Salman Abolfazli Assistant Professor, Department of Periodontics, Dental Research Center, School of Dentistry, Ahvaz University of Medical Sciences, Ahvaz, Iran. Saeed Asgary Professor, Department of Endodontics, Iranian Center for Endodontic Research, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Maryam Gharechahi Assistant Professor, Department of Endodontics, Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. 2015 10 16 This study aimed to compare the efficacy of MTA and CEM cement in Class II furcation defects in human mandibular molars.Forty furcation defects were treated in 16 patients with chronic periodontitis. The clinical parameters of probing depth (PD), vertical and horizontal clinical attachment levels (VCAL and HCAL), open vertical and horizontal furcation depths (OVFD and OHFD), and gingival margin level (GML) were measured at baseline and at 3- and 6-month (re-entry surgery) pos