Caspian Journal of Dental Research
Year:2017 | Volume:6 | Issue:2|Papers Count:8

Introduction: Although recent studies show the association of eosinophils with different tumors including oral malignancies, the role of eosinophils in premalignant conditions of the oral cavity is not known precisely. Therefore, this study aimed to determine the number of eosinophils in premalignant and malignant conditions of the oral cavity and its role in progression to malignancy.Materials & Methods: This cross-sectional study was done on 50 samples with oral squamous cell carcinoma (OSCC), 18 with verrucous carcinoma, 13 with erosive lichen planus, and 10 with leukoplakia with mild dysplasia after confirmation of histopathological diagnosis. The samples were stained with Sirius Red. The total numbers of eosinophils in 10 areas were counted at a magnification of 400x (eosinophil/10HPF). Data are analyzed with Kruskal-Wallis test, Mann-Whitney test, and Spearman’s correlation test.Results: The mean number of eosinophils in OSCC, verrucous carcinoma, erosive lichen planus, and leukoplakia with mild dysplasia was 90.26, 59.72, 11.08 and 0.0 eosinophil/10HPF respectively. The mean number of eosinophils was significantly higher in malignant (OSCC and verrucous carcinoma) than premalignant (erosive lichen planus and leukoplakia with mild dysplasia) lesions of the oral cavity (P=0.0001). No significant correlation was found between the number of eosinophils with histopathologic grade, gender, and age in OSCC samples.Conclusion: The greater number of eosinophils is seen in malignant than premalignant lesions of the oral cavity. It is recommended to consider the high number of eosinophils in premalignant lesions as an indicator for a more potential of preliminary oral lesions to undergo malignant transformation.

Introduction: The aim of this study was to assess the fracture strength of immature single-rooted teeth restored with fiber post and apical plug.Materials & Methods: In this experimental study, fifty mandibular premolars were divided into five groups. The coronal and apical portions were cut to obtain15±1 mm root lengths and cleaning& shaping were performed. Peeso reamer #4 was passed the apex by 1 mm to simulate an immature tooth and the apical portion in group 1 to 5 was filled by lateral compaction of 5 mm of guttapercha; 5 mm of mineral trioxide aggregate (MTA); 5mm of calcium enriched mixture (CEM) cement; 3 mm of MTA and 2 mm of gutta-percha by vertical condensation and 3 mm of CEM cement and 2 mm of gutta-percha, respectively. The remaining portion was restored with glass fiber post and self-etch cement and composite cores were built. Compressive load was applied at a crosshead speed of 1 mm/minute at 90o angle until fracture in a universal testing machine. Data were analyzed using ANOVA in SPSS16.Results: The mean±SD fracture strength was recorded 607.8±162.41 N, 700.48±183.24 N, 595.16±171.77 N, 886.36±382.92N, and 868.87±440.36 N in groups one to five, respectively. No significant difference was observed among the experimental groups (p=0.1).Conclusion: In immature teeth requiring an apical plug, fiber post can be placed directly on the MTA and CEM apical plugs and there is no need for placing gutta-percha on the plug.

Introduction: Incisive foramen in the maxilla is the oral terminus of the nasopalatine canal. This region is important in implantology, Therefore, the aim of this study was to investigate the neurovascular anatomical variations in the maxillary anterior region, observed on cone beam computed tomography (CBCT) images.Materials & Methods: In this cross-sectional study, maxillary CBCT images from 200 patients (100 men, 100 women, average age 45.61±11.01) were evaluated in sagittal, axial and coronal sections and the following parameters were investigated: incisive canal diameter, shapes of canal, presence of accessory canal in the anterior palate and their location, thickness of buccal bone in the sections containing canal, patient's dental and periodontal status in terms of bone loss. Data were collected and analyzed using SPSS, V20. P≤0.05 was considered significant.Results: In sagittal view, the mean diameter of the canal was 2.36±0.69mm.Age and gender did not significantly influence the diameter. Morphological analysis of canal showed that 25% of them were hourglass-like, 23.5% conical, 22%funnel, 27.5% cylindrical, 2% tree branch. Accessory canals were observed in 58 patients (29%) specially near to the canine region. The thickness of buccal bone plate was less in complete edentulous patients than others and also there was a significant relationship between bone loss and canal size in the hourglass and cylindrical shapes.Conclusion: In this study, the prevalence of accessory canals was relatively significant, so it seems essential to carry out cone beam computed tomography in this area for determining the canal morphology and dimensions before implant placement.

Introduction: Soft tissue has a prominent role in diagnosis and treatment plan in orthodontics.Facial proportions are measurable on lateral cephalograms. The purpose of this study was to compare the means of the normal soft tissue proportions of babol people with the norms of Caucasians.Materials & Methods: In this cross-sectional study, 100 cases with normal occlusion and proportional facial profile were participated from babol. After taking radiographs and tracing, the soft tissue variables were analyzed to find means and standard deviations. The data were compared with Caucasian's norms using T-test.Results: The norms of following variables in babol people were significantly different from those of Caucasians: facial convexity, nasolabial angle, upper lip thickness, chin soft tissue thickness and protrusion of lower lip.Conclusion: In babol, people have a more convex profile, more prominent nose and lower lip than caucasians.

Introduction: Increased consumption of energy drinks has raised concerns about their effects on dental restorations. This study assessed the effects of two energy drinks on the surface microhardness of methacrylate and silorane-based composites after 1-week and 1-month periods.Materials & Methods: In this in-vitro study, 90 cubic samples were prepared from Filtek P90, Filtek Z250 and Filtek Z350 XT composite resins. Vickers hardness test was performed to measure the baseline surface microhardness for each specimen. Ten randomly selected samples from each composite material were then immersed in one of the two sports drinks (Red Bull and Hype) or artificial saliva (control). Surface microhardness was re-evaluated after 1 week and 1 month of immersion. The data were evaluated using ANOVA via post-hoc Tukey tests and repeatedmeasure test (α=0.05).Results: Surface microhardness of all composites were significantly decreased in energy drinks in both evaluation periods (P<0.001). In artificial saliva, microhardness was significantly increased after 1 week and decreased after 1 month of immersion (P<0.001). After 1 month, the lowest microhardness changes were observed in Filtek Z350 XT composite. (18% and 14% reduction in Hype and Redbull respectively). Differences between energy drinks were significant for Z350 XT composite only after 1 week (P=0.01) and for Z250 composite after 1 week and 1 month (P=0.020 and P<0.001 respectively).Conclusion: Hype and Red Bull energy drinks can affect the surface hardness of composite resins depending on their characteristics and exposure time.

Introduction: Mental foramen is an important landmark in mandible and knowledge regarding the actual location of mental foramen is important in dentistry.Materials & Methods: A total of 1172 digital panoramic radiographs were evaluated for assessment of the location of the mental foramen. The location was classified into six groups in relation to the apices of the premolars and first molar.Results: In 957 of panoramic radiographs, fulfilling the inclusion criteria, the most common location of the mental foramen was at the apex of the mandibular second premolar. In 837 cases (87.5%), the mental foramen was located symmetrically on both sides of the mandible. Therefore, the apex of the second premolar was the most common symmetric location in both genders.Conclusion: The results showed that the most common location of the mental foramen in population of southeast Iran was at the apex of the second premolar.

Introduction: Oral cancer is the most common malignancy in head and neck region. Primary diagnosis is critical and low knowledge of dentists can lead to improper or delayed diagnosis. The aim of this study was to evaluate the knowledge of general dentists regarding oral cancer and the complications of its treatment in Babol, Iran.Materials & Methods: This cross-sectional study was performed on all general dentists working in Babol. Seventy-six dentists entered into the study and filled out the questionnaire. Data were analyzed bySPSS software.Results: Mean score of knowledge in the group with more than 21-years-experience was significantly higher than the group with less than 10-years-experience (p=0.017). There was a positive correlation between total knowledge and years of experience (p=0.001).There was no significant relationship between other criteria with total score of knowledge (p.0.05).Conclusion: It seems that knowledge the babol dentists’ regarding oral cancer and cancer treatment complications is not sufficient.

Full mouth rehabilitation with fixed implant supported prostheses is one of the challenging treatments, because important factors in aesthetic and function should be considered. Implants' alignments and locations should be planned before the insertion unless the improper inclination and location of implants would lead to difficulties in patient's comfort, oral hygiene problem and inability to reconstruct the acceptable functional and aesthetical prosthesis.This clinical report described the step by step prosthetic treatment procedure of full mouth rehabilitation and 1-year follow-up of a patient who underwent 10 and 8 implants in upper and lower jaw respectively, which were unaligned and malpositioned. In the cases of improper alignment and position of implants, modified prosthetic design with consideration of biomechanical principles should be incorporated to overcome the limitations.