Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Spatial Relationship between Mandibular Third Molars and Inferior Alveolar Nerve using a Volume Rendering Software1514010.22038/jdmt.2013.140ENAli BagherpourDental Research Center, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranMaryam Mohammadzadeh RezaeiMedical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IranShahrokh NasseriMedical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20121005Precise localization of the third molars in relation to the inferior alveolar nerve canal is critical from a clinical point of view and strongly affects the surgical treatment outcome. Recently, by using three-dimensional modeling software, the relationship of third molar root apices and inferior alveolar nerve canal can be better understood. In this study, the spatial relationship of two surgical sites of 19 impacted third molars with close relationship to the inferior alveolar nerve canal is described by using imaging data from a cone beam computed tomography system. This study aimed to investigate the ability of three-dimensional modeling of tooth-nerve relationship using the data imported to Amira 5.2.2 imaging softwareMashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Effect of Chlorhexidine Application on Bond Durability of a
Filled-Adhesive System61014310.22038/jdmt.2013.143ENAlireza BoruziniatDental Research Center, Department of Operative Dentistry, Faculty of Dentistry, Mashhad University of Medical Science, Mashhad, IranMorteza BabazadehGeneral Dentist, Mashhad, IranMahshid GifaniGeneral Dentist, Mashhad, IranJournal Article20121006The aim of this study was to evaluate the effect of chlorhexidine (CHX) application on immediate and two-month bond strength of a filled adhesive system. Methods: Forty eight non-carious human third molars without enamel of occlusal surface were randomly divided into two main groups according to CHX application: control and CHX. Each main group was further subdivided into 2 subgroups depending on storage time: immediate or two-month collagenase storage. In CHX groups, 2% CHX was applied for 30 s. Filled adhesive resin (PQ1) was applied on the etched dentin surfaces and cured in all experimental groups. Composite resin (Amelogen) was placed on the dentin surfaces and shear bond strength (SBS) was evaluated immediately and after two-month storage in collagenase solution. Failure modes were determined by stereomicroscope. Results: There was no significant difference in immediate SBS between groups (P>0.05). After two-month collagenase storage, although SBS was significantly reduced in control group (P<0.05), no significant reduction was observed in CHX group (P>0.05). SBS in CHX group was significantly higher than the control group (P<0.05). Conclusion: The use of CHX had no adverse effect on immediate bond strength of filled adhesive and could preserve the bond strength.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Evaluation of the Occlusion and Arch Dimensions in the Primary Dentition of an Iranian Population111614510.22038/jdmt.2013.145ENMaryam TalebiDental Material Research Center, Department of Pedodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranBehjatolmoluk AjamiDental Research Center, Department of Pedodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranRasoul SahebalamDental Research Center, Department of Pedodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20120909Introduction: The objective of this study was to gather information about normal occlusion and arch dimensions in the primary teeth of the children belonging to an Iranian population. Methods: This descriptive cross-sectional study was performed on 68 children from the city of Mashhad in the 3-5 age range. Dental arch dimensions, interrelationships of primary canine and second molars, overbite and overjet were evaluated. Results: Primate space was observed on both sides of the arch in 82.2% of the subjects. The most prevalent type of primary molar relationship was flush terminal plane (52.1%) followed by distal step (31.3%) and then mesial step (16.7%). The primary canine relationship was ranked in the descending order of prevalence as Class I (77.1%), Class II (13.5%), end-to-end (5.2%) and Class III (4.2%). Normal overbite and normal overjet was observed in 50% and 81.3% of cases, respectively. Conclusion: This study provides an insight into the dental arch dimensions, occlusion, spacing and crowding in primary dentition in Iranian children. In most of the cases, primate space and flush terminal plane were observed.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Hemodynamic Effect of 2% Lidocaine with 1:80,000 Epinephrine Infiltration in Maxillofacial Surgeries under General Anesthesia172014710.22038/jdmt.2013.147ENBaratollah ShabanDepartment of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranElham MoradiDepartment of Oral and Maxillofacial Radiology, Khorasgan Azad University, Isfahan, IranAmir Hossein NejatStudent Research Committee, Mashhad University of Medical Sciences, Mashhad, IranSomayeh Sabzali ZanjanhkhahGeneral DentistTouraj VaeziDepartment of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20121012Introduction: Epinephrine-containing lidocaine is the most used anestheic drug in dentistry. The aim of this study was to investigate the hemodynamic changes following local infiltration of 2%lidocaine with 1:80,000 epinephrine in subjects undergoing orthognatic surgery under general anesthesia. Methods: Twenty five patients without any systemic disease participated. After general anesthesia, two cartridges of 2% lidocaine + 1:80,000 epinephrine were infiltrated around the surgery site. Systolic (SBP) and diastolic (DBP) blood pressure, mean arterial blood pressure (MAP), heart rate (HR), and blood sugar (BS) were measured in three stages: before the injection (M1), at the end of injection (M2), and 10 min after injection (M3). Results: No significant difference observed in SBP, DBP, and MAP at the end of injection and 10 min later. HR was increased significantly after injection and remained significantly higher than baseline after 10 min. BS increased slightly at the end of injection and continued to increase after 10 min. However, changes in BS were not significant. Conclusion: Using two cartridges of epinephrine-containing lidocaine have slight systemic changes in healthy subjects; as a result, this dosage could be used in patients with cardiovascular complications undergoing general anesthesia.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Microleakage under Orthodontic Metal Brackets Bonded with Three Different Bonding Techniques with/without Thermocycling212815110.22038/jdmt.2013.151ENBerahman SabzevariDepartment of Orthodontics, Faculty of Dentistry, Rafsanjan University of Medical Sciences, Rafsanjan, IranBarat Ali RamazanzadehDepartment of Orthodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranSaied Mostafa MoazzamiDepartment of Operative and Aesthetic Dentistry, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranArmin SharifiDentist, Private Practice, Mashhad, IranJournal Article20120905Introduction: The aim of this study was to compare the microleakage of beneath the orthodontic brackets bonded with 3 different bonding techniques and evaluate the effect of thermocycling. Methods: One hundred and twenty premolars were randomly divided into 6 groups, received the following treatment: group 1: 37% phosphoric acid gel+Unite primer+Unite adhesive, group 2: 37% phosphoric acid gel+ Transbond XT primer+Transbond XT adhesive, group 3: Transbond plus Self Etching Primer (TSEP)+Transbond XT adhesive. Groups 4, 5, and 6 were similar to groups 1, 2, and 3, respectively. Evaluation of microleakage was done following to thermocycling test. After bonding, the specimens were sealed with nail varnish except for 1 mm around the brackets and then stained with 0.5% basic fuchsine. The specimens were sectioned at buccolingual direction in 2 parallel planes and evaluated under a stereomicroscope to determine the amount of microleakage at bracket-adhesive and adhesive-enamel interfaces from gingival and occlusal margins. Results: Microleakage was observed in all groups, and increased significantly after thermocycling at some interfaces of Unite adhesive group and conventional etching+Transbond XT adhesive group, but the increase was not significant in any interface of TSEP group. With or without thermocycling, TSEP displayed more microleakage than other groups. In most groups, microleakage at gingival margin was significantly higher than occlusal margin. Conclusion: Thermocycling and type of bonding technique significantly affect the amount of microleakage.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301The Effect of Full Crown Preparation on Normal and Inflamed Pulp Tissue: An Animal Study293316010.22038/jdmt.2013.160ENMaryam BidarDental Research Center, Department of Endodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranAzam Sadat MadaniDental Material Research Center, Department of Prosthodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranNooshin MohtashamDepartment of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranMandana VardkarEndodontist in Private Practice, Tehran, IranHamid JafarzadehDental Research Center, Department of Endodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran0000-0001-5318-7129Journal Article20121001Introduction: Full crown preparation may have adverse effects on pulp tissue. In this study, the effect of full-crown preparation on intact versus inflamed pulp tissue was studied. Methods: Fifteen healthy mature cats were randomly selected for this study. The study was performed on four canine teeth of each cat. Cats were anesthetized and then radiographs were taken from the canine teeth. Class V cavities were prepared in cat canine teeth. Soft decayed dentin was placed on the floor of cavities and sealed. After 1 month, all of the samples prepared for crown fabrication. Before crown preparation, an impression was taken in a custom tray. During crown preparation, the remnants of carious dentin were removed and undercuts were sealed by glass-ionomer. After preparation, self-cured acrylic temporary crowns were fabricated in a direct procedure and cemented permanently by glass-ionomer. One week later, teeth of the opposite jaw were prepared in a similar procedure. After 2 months, vital perfusion performed and the pulp tissue was histologically examined. Results: There was no significant difference between 4 groups, regarding to histologic status of the pulp. In healthy lower jaw, inflammation was the most frequent but in the other groups, necrosis was most frequent. Also, there was no significant difference between the upper jaw and the lower jaw groups regarding to the frequency of necrosis and inflammation. Conclusion: There is no significant difference between intact and inflamed groups regarding the frequency of necrosis and inflammationMashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41502120130301Malignant Peripheral Nerve Sheath Tumor in the Maxilla: Report of a Rare Case343716210.22038/jdmt.2013.162ENJahanshah SalehinejadDental Research Center, Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranAtefeh NassehDental Research Center, Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranAmir Hossein JafarianDepartment of Pathology, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, IranNazanin BashardoustDepartment of Oral and Maxillofacial Pathology, Faculty of Dentistry, Gilan University of Medical Sciences, Rasht, IranJournal Article20120128Malignant peripheral nerve sheath tumor (MPNST) is a rare malignant tumor that develops either from a preexisting neurofibroma or <em>de novo.</em> The cell of origin is believed to be the Schwann cell and possibly other nerve sheath cells. In this report, we describe a rare case of MPNST that arise from the socket of second left maxillary molar that has been already extracted in a young man. He was referred to a dentist’s office with a tumor-like mass of soft tissue on his left maxillary gingiva. Biopsy and histopathologic examination was performed and based on histologic and immuno-histochemical findings, the diagnosis of MPNST was made. MPNST is a rare malignant tumor in the oral cavity. Dentists must be careful and conscious because this rare malignancy can occur in gingiva and can mimic the clinical feature of any benign gingival enlargements.