Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 1 10 Hossein Aghili Associate Professor, Department of Orthodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Abbas Ali Jafari Nadoushan Associate Professor, Department of Medical Parasitology and Mycology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Vahid Herandi Dentistry Student, Dentistry School, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. 2015 10 16 Long-term use of orthodontic appliances and fixation ligatures creates a favorable environment for the accumulation of oral normal microflora and increases the risk of enamel demineralization and periodontal disease. The aim of this study was to compare the antimicrobial effects of Zataria Multiflora extract and 0.2% chlorhexidine (CHX) mouthwash on experimentally contaminated orthodontic elastomeric ligatures.In this lab trial study, Iranian and foreign-made elastomeric ligatures were experimentally contaminated in Streptococcus mutans, Enterococcus faecalis and Candida albicans suspensions. Ligatures were then decontaminated using 0.2% CHX as the control, 0.5 mg/ml Zataria multiflora extract mouthwashes as the test and phosphate buffered saline (PBS) as the negative control for one hour. Antimicrobial properties of both solutions were evaluated by comparing the mean viable bacterial cell count on both rings after decontamination, using SPSS version 15 software.The mean viable bacterial cell count on Iranian ligatures was greater than that on foreign-made ligatures before disinfection (P=0.001), however this difference for C. albicans was not statistically significant (P=0.061). Chlorhexidine mouthwash completely eliminated all tested microorganisms attached to both elastomeric rings, but Zataria extract was only capable of completely eliminating C. albicans from both ligatures. Statistically significant differences were found in viable bacterial counts on both ligatures before and after disinfection with Zataria extract (P=0.0001).Zataria multiflora extract has antimicrobial properties and can be used for disinfection of elastomeric ligatures. In vivo studies are required to evaluate the efficacy of the incorporation of this herbal extract in mouthwashes for orthodontic patients. https://fid.tums.ac.ir/index.php/fid/article/view/379 https://fid.tums.ac.ir/index.php/fid/article/download/379/355

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 11 7 Beheshteh Malekafzali Associate Professor, Department of Pediatric, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Maliheh Ekrami Post Graduate Student, Department of Operative, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Armin Mirfasihi Dental Student, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Zahra Abdolazimi Post Graduate Student, Department of Pediatric, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2015 10 16 Although fluoridated toothpastes are among the most accessible fluoride sources for caries prevention, their remineralization potential remains questionable. This study sought to compare the effects of 5 different child formula dentifrices on remineralization of artificial primary enamel caries using a pH cycling model.Twenty sound primary canine teeth were immersed in demineralizing solution for 96 hours to produce 100μm-deep artificial caries. The teeth were then longitudinally sectioned into 100-150 μm-thick slices and randomly divided into 5 groups and treated as follows: group A. Calcium phosphate toothpaste, group B. Pooneh children's toothpaste, group C. Biotin toothpaste, group D. Crest children's toothpaste and group E. Darougar children's toothpaste. The specimens underwent a pH cycling model for 10 days. The degree of demineralization before and after treatment and its changes were evaluated under a polarized light microscope and a stereomicroscope and data were statistically analyzed using repeated measures ANOVA and post-hoc test.Stereomicroscopic analysis showed that only group C had a significant difference with other groups (P0.05). Polarized light microscopic analysis revealed that in addition to group C, a significant difference was detected between groups A and B (P=0.02) and calcium phosphate toothpaste showed higher efficacy.All the understudy toothpastes had remineralizing effect but calcium phosphate children's toothpaste had the highest and biotin toothpaste had the lowest efficacy. https://fid.tums.ac.ir/index.php/fid/article/view/377 https://fid.tums.ac.ir/index.php/fid/article/download/377/353

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 18 24 Nahid Ramazani Assistant Professor, Children and Adolescent Health Research Center, Department of Pediatric Dentistry, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran. Mina Ranjbar Dentist, Zahedan University of Medical Sciences, Zahedan, Iran. 2015 10 16 Incomplete adaptation of stainless steel crown margins leads to microleakage. The aim of this study was to evaluate the effect of tooth preparation on microleakage of stainless steel crowns (SSCs) placed on mesiodistally reduced primary mandibular first molars.In this In vitro study, 60 primary mandibular first molars with reduced mesiodistal dimension were selected. Pulp cavities were filled with amalgam and occlusal surfaces were reduced. The samples were randomly divided into two groups (groups P and BLP). Standard preparation was done in group P with only proximal reduction. In group BLP, after reducing the proximal undercuts, buccal and lingual surfaces were slightly reduced. Occlusal one-third of the buccal surfaces was beveled in both groups. Then, the SSCs of the primary maxillary and mandibular first molars were fitted and cemented in P and BLP groups, respectively. After immersing the samples into deionized water, thermo-cycling, and immersion in 2% basic fuchsin, the samples were sectioned buccolingually. The mesial halves were evaluated microscopically for microleakage in both buccal and lingual margins. Data were analyzed using Mann-Whitney U test in SPSS 19 at the significant level of 0.05.There was a significant difference in microleakage of the buccal margin (P=0.003); whereas, the difference observed in the lingual margin was not significant (P=0.54).We suggest reduction of buccal and lingual surfaces of mesiodistally reduced primary mandibular first molars and placing lower (mandibular) crowns. https://fid.tums.ac.ir/index.php/fid/article/view/375 https://fid.tums.ac.ir/index.php/fid/article/download/375/351

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 25 30 Sedigheh Khedmat Dental Research Center, Dentistry Research Institute, Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, and Iranian Center for Endodontic Research, Tehran, Iran. Alaleh Hashemi Undergraduate student, School of Dentistry, International Campus of Tehran University of Medical Sciences. Tehran, Iran. Fatemeh Dibaji Department of Endodontics, School of Dentistry, International Campus of Tehran University of Medical Sciences. Tehran, Iran. Mohammad Javad Kharrazifard Statistical Advisor, Dental Research center, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 16 This study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin.Sixty-eight single-rooted single-canal extracted human premolar teeth were used. Tooth crowns were separated from the roots at the cementoenamel junction (CEJ). Roots were buccolingually sectioned into mesial and distal halves. Specimens were randomly divided into 5 groups, with 20 teeth in each solvent group and 4 teeth in each control group. Primary microhardness of specimens was measured using Vickers microhardness tester. Specimens were exposed to solvents for 15 minutes and were subjected to microhardness testing again. Data were recorded and analyzed using repeated measure ANOVA.No significant difference was found in dentin microhardness before and after exposure to solvents in any of the orange oil, eucalyptol, chloroform or saline groups (P=0.727). None of the experimental groups showed any significant difference in terms of dentin microhardness reduction (P=0.99) and had no significant difference with the negative control group.This study showed that chloroform, eucalyptol and orange oil as gutta percha solvents did not decrease the microhardness of root dentin. Thus, none of the mentioned solvents has any superiority over the others in terms of affecting dentin properties. https://fid.tums.ac.ir/index.php/fid/article/view/373 https://fid.tums.ac.ir/index.php/fid/article/download/373/349

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 31 8 Mojgan Paknejad Associtate Professor, Dental Research Center Dentistry Research Institute, Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran ; Dental Implant Research Center, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. AmirReza Rokn Dental Implant Research Center, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran ; Professor, Department of Periodontoics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Nina Rouzmeh Assistant Professor, Department of Periodontics, School of Dentistry, Qom University of Medical Sciences, Qom, Iran. Mohadeseh Heidari Assistant Professor, Department of Periodontics, School of Dentistry, Mazandaran University of Medical Sciences, Mazandaran, Iran. Azadehzeinab Titidej Assistant Professor, Department of Oral and Maxillofacial Pathology, School of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran. Mohammad Javad Kharazifard Statistical Advisor, Dental Research center, Tehran University of Medical Sciences, Tehran, Iran. Ali Mehrfard Student, Islamic Azad University. 2015 10 16 Considering the importance of bone augmentation prior to implant placement in order to obtain adequate bone quality and quantity, many studies have been conducted to evaluate different techniques and materials regarding new bone formation. In this study, we investigated the bone healing capacity of two different materials deproteinized bovine bone mineral (DBBM with the trade name of Bio-Oss) and demineralized freeze-dried bone allograft (DFDBA with the trade name of DynaGraft).This randomized blinded prospective study was conducted on twelve New Zealand white rabbits. Three cranial defects with an equal diameter were created on their calvarium. Subsequently, they were distributed into three groups: 1. The control group without any treatment; 2. The Bio-Oss group; 3. The DynaGraft group. After 30 days, the animals were sacrificed for histologic and histomorphometric analysis.Substantial new bone formation was observed in both groups. DynaGraft: 56/1 % ± 15/1 and Bio-Oss: 53/55 % ± 13/5 compared to the control group: 28/6 % ± 11/2. All groups showed slight inflammation and a small amount of residual biomaterial was observed.Considerable new bone formation was demonstrated in both DynaGraft and Bio-Oss groups in comparison with the control group. Both materials are considered biocompatible regarding the negligible foreign body reaction. https://fid.tums.ac.ir/index.php/fid/article/view/371 https://fid.tums.ac.ir/index.php/fid/article/download/371/347

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 39 48 Nasrin Farhadian Associate Professor, Department of Orthodontics, Faculty of dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Amirfarhang Miresmaeili Associate Professor, Department of Orthodontics, Faculty of dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Ramin Azar Assistant Professor, Department of Orthodontics, Faculty of dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Massoumeh Zargaran Assistant Professor, Dental Research Center, Department of Oral and Maxillofacial Pathology, Faculty of dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Abbas Moghimbeigi Associate Professor, Modeling of Noncommunicable Disease Research Center, Department of Biostatistics and Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran. Sanaz Soheilifar Assistant Professor, Department of Orthodontics, Faculty of dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. 2015 10 16 After maxillary expansion, a long period of retention is necessary to prevent early relapse. Therefore, it is beneficial to accelerate bone formation in the expanding midpalatal suture to reduce relapse. This study was designed to evaluate the effect of dietary vitamin C on osteogenesis of rat midpalatal suture during expansion.Fifty-four male Wistar rats were randomly divided into three groups, each with a control and an experimental subgroup. An open-loop spring was bonded to maxillary incisors of each animal to expand the premaxillary suture. Experimental groups received dietary vitamin C in their water. The rats in the three groups were sacrificed at three, nine or 17-day intervals after bonding the spring. Then, the premaxilla was dissected and sections were made and stained with hematoxylin and eosin and osteopontin marker. Osteoblasts and osteoclasts were counted in the suture. Two-way ANOVA and the Mann-Whitney-U test were used for analyzing the data.After three days, the number of osteoblasts was significantly higher in the vitamin C group but after nine days it was significantly higher in the control group and after seventeen days there were no significant differences between the groups. Osteoclast counts were not significantly different between vitamin C and control groups.Vitamin C had a positive effect on osteogenesis at the beginning of bone formation in the expanding suture, but after nine days it had a negative effect on suture osteogenesis in rats. https://fid.tums.ac.ir/index.php/fid/article/view/369 https://fid.tums.ac.ir/index.php/fid/article/download/369/345

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 12 1 2015 02 15 49 59 Farzin Heravi Department of Orthodontics, School of Dentistry Mashad University of Medical Sciences, Mashhad, Iran. Mohamad Hadi Moayed Department of Materials and Metallurgical Engineering, Ferdowsy University, Mashhad, Iran. Nima Mokhber Department of Orthodontics, Academic Center of Education, Culture and Research (ACECR), Mashhad, Iran. 2015 10 16 The commonly used Nickel-Titanium (NiTi) archwires in orthodontic treatment are often exposed to fluoride-containing mouthwashes. The aim of this in-vitro study was to evaluate and combStatus="received"> 2015 10 16 In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope.Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p https://fid.tums.ac.ir/index.php/fid/article/view/422 https://fid.tums.ac.ir/index.php/fid/article/download/422/398

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 4 2014 08 15 433 9 N Velmurugan Professor, Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Chennai, Tamil Nadu, India. C Sooriaprakas Post Graduate Student, Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Chennai, Tamil Nadu, India. Preetham Jain Post Graduate Student, Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Chennai, Tamil Nadu, India. 2015 10 16 Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation.Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20): EndoVac Microcannula (group I), EndoVac Macrocannula (group II), NaviTip irrigation needle (group III) and Max-i-Probe Irrigating needle (group IV); 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically.Group I, group III and group IV showed 100% extrusion (20/20) but group II showed only 40% extrusion (8/20). The difference in this respect between group II and other groups was statistically significant (P https://fid.tums.ac.ir/index.php/fid/article/view/420 https://fid.tums.ac.ir/index.php/fid/article/download/420/396

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 4 2014 08 15 440 6 Kiamars Honardar Assistant Professor, Department of Endodontics, School of Dentistry, Shahed University, Tehran, Iran. Hadi Assadian Assistant Professor, Department of Endodontics, School of Dentistry, Shahed University, Tehran, Iran. Shahriar Shahab Assistant Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Shahed University, Tehran, Iran. Zahra Jafari Postgraduate Student, Department of Endodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Ali Kazemi Associate Professor, Department of Endodontics, School of Dentistry, Shahed University, Tehran, Iran. Kiumars Nazarimoghaddam Assistant Professor, Department of Endodontics, School of Dentistry, Shahed University, Tehran, Iran. Mohammad Javad Kharrazifard Epidemiologist, Dental Research Center Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Hossein Labbaf Assistant Professor, Department of Endodontics, School of Dentistry, Shahed University, Tehran, Iran. 2015 10 16 Use of rotary Nickel-Titanium (NiTi) instruments for endodontic preparation has introduced a new era in endodontic practice, but this issue has undergone dramatic modifications in order to achieve improved shaping abilities. Cone-beam computed tomography (CBCT) has made it possible to accurately evaluate geometrical changes following canal preparation. This study was carried out to compare canal centering ability and transportation of Twisted File and BioRaCe rotary systems by means of cone-beam computed tomography.Thirty root canals from freshly extracted mandibular and maxillary teeth were selected. Teeth were mounted and scanned before and after preparation by CBCT at different apical levels. Specimens were divided into 2 groups of 15. In the first group Twisted File and in the second, BioRaCe was used for canal preparation. Canal transportation and centering ability after preparation were assessed by NNT Viewer and Photoshop CS4 software. Statistical analysis was performed using t-test and two-way ANOVA.All samples showed deviations from the original axes of the canals. No significant differences were detected between the two rotary NiTi instruments for canal centering ability in all sections. Regarding canal transportation however, a significant difference was seen in the BioRaCe group at 7.5mm from the apex.Under the conditions of this in vitro study, Twisted File and BioRaCe rotary NiTi files retained original canal geometry. https://fid.tums.ac.ir/index.php/fid/article/view/418 https://fid.tums.ac.ir/index.php/fid/article/download/418/394

Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 11 4 2014 08 15 447 54 Saeed Moradi Professor, Department of Endodontics, Dental Materials Research Center, School of Dentistry, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran. Reza Disfani Assistant Professor, Department of Endodontics, Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences (MUMS), Mashhad, Iran. Mahdi Lomee Assistant Professor, Department of Endodontics, School of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.