Caspian Journal of Dental Research

69-76

Authors: Mostafa Ebrahimi , Reza Ghorbanipour , Tania Ghasemi , Ali Bijani , Maysam Mirzaie *

Introduction: Metal brackets are the most commonly used brackets in clinical orthodontics, but the sight of color of the metal bracket can be unpleasant for some patients. Ceramic brackets offer the desired beauty but they have higher frictional resistance. Considering that in vitro studies suggest that CO2 laser reduces the friction between the wire and slot of the bracket in the sliding mechanics, the aim of this study was to evaluate the clinical effect of CO2 laser on the speed of tooth movement using the sliding mechanics. Materials & Methods: This randomized double-blind clinical trial was performed on 7 patients and a total of 13 half jaws in each group. These patients were candidates for bilateral extraction of the first premolars due to lack of space or dentoalveolar protrusion. After alignment and leveling, the ceramic brackets were passively bonded. The ceramic brackets of the experimental group irradiated with the CO2 laser and the brackets of the control group were bonded unchanged. The brackets were examined with an atomic force microscope (AFM) before and after irradiation. Statistical data were analyzed paired t-test to compare the rate of gap closure between the two groups at one-month intervals. ANOVA was used to examine the reduction in spacing at three-month intervals. A value of p<0.05 was considered statistically significant. Results: The rate of gap closure between the two groups was compared at one-month intervals, which was not statistically significant in either month. Furthermore, in the comparison between the study and control groups, the decrease in the distance between the canine and second premolars was not statistically significant after a total of three months (p=0.0918). Conclusion: According to the results of this study, CO2 laser irradiation of the bracket surface has no effect on the speed of movement of the canine when sliding on the wire.

85-90

Authors: Arezoo Yadollahzade , Taghi Amiriani , Elham Fakhari *

Introduction: The oral cavity has been suggested as a potential reservoir for Helicobacter pylori (H. pylori), which could be a major cause of reinfection after standard systemic therapy. The aim of this study was to evaluate the effect of full-mouth disinfection (FMD) on the recurrence of H. pylori infection. Materials & Methods: This randomized clinical trial was conducted on 40 patients with chronic periodontitis and H. pylori infection. Of these, 20 patients received quadruple anti-H. pylori therapy only (group A) and the other 20 patients received quadruple therapy plus FMD (group B). The presence of H. pylori was detected by a 14C-urea breath test (UBT) after 1 and 6 months. Data were analyzed with SPSS 16 using the chi-square test. A value of p<0.05 was considered statistically significant. Results: Of 40 dyspeptic patients, 15(75%) and 18(90%) of 20 in groups A and B, respectively, had a negative UBT after 4 weeks. Of the patients with successful eradication of H. pylori after 1 month, 8(53.3%) and 6(33.3%) of 15 in group A and 18 in group B, respectively had a positive UBT after 6 months. There were no statistically significant differences between the two groups in the follow-up periods (p>0.05). Conclusion: Implementation of quadruple therapy plus FMD may reduce recurrence of the infection although further studies are recommended to confirm the results.

98-105

Authors: Zahra Shokri , Maryam Seyedmajidi , Mahdi Pouramir , Ali Bijani , Raheleh Ahmadian , Mina Motallebnejad *

Introduction: Oral lichen planus (OLP) is a chronic mucocutaneous inflammatory disorder with an unknown etiology. Although a considerable body of evidence suggests that immunologic factors are involved in the etiology of OLP, the involvement of cytokines in the pathogenesis of the disease is not fully understood yet. The aim of the present study was to assess interleukin-6 (IL-6) levels as a proinflammatory cytokine in the saliva of OLP patients compared to healthy controls. Materials & Methods: This case-control study was conducted on 30 OLP patients (12 males and 18 females) and 30 healthy control subjects, selected from individuals who were referred to the Department of Oral and Maxillofacial Diseases in Faculty of Dentistry, Babol University of Medical Sciences. Samples of unstimulated saliva were collected. Salivary IL-6 levels were measured using an ELISA kit and compared between OLP patients and healthy controls. The collected data were analyzed by Chi-square, independent t-test, and receiver operating characteristic (ROC) curve using SPSS 18 Sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) ​​were calculated. A value of p<0.05 was considered significant. Results: Mean salivary IL-6 values in OLP patients and healthy controls were 24.68±9.90 ng/L and 13.76±9.27 ng/L, respectively. The difference was statistically significant (P<0.001). The mean IL-6 values in reticular and erosive forms of OLP clinically were 24.35±9.26 ng/L and 24.91±10.64 ng/L, respectively. This difference was not statistically significant (P=0.87). Conclusions: Higher levels of IL-6 in saliva of OLP patients compared with healthy controls support the role of IL-6 in the pathogenesis of the disease.

115-123

Authors: Narges Mirzania , Elham Zajkani , Armaghan Naghili *

Introduction: Recently, a new category of dental bonding agents called universal adhesives has been introduced to the market, which are claimed to be able to create a strong bond between composite resins and teeth, metal surfaces and all types of ceramics alone and without the use of other primers. The aim of this study was to evaluate the performance of universal adhesives in the repair of amalgam restorations with composite resins in comparison with the conventional method. Material & Methods: In this experimental in vitro study, 80 amalgam blocks were prepared and after abrading the surface with an intraoral sandblaster and performing the aging process, the specimens were divided into 4 groups of 20 each, depending on how each surface was prepared by different bonding in the following order: Single Bond2 (S), Alloy Primer and Single Bond (AS), G-Premio Bond (G) and Alloy Primer and G-Premio Bond (AG). The composite blocks were then cured on the surface of the specimens. Finally, the specimens were tested for micro-shear bond strength (µSBS) using a micro-tensile tester and their cross-section was examined for fracture pattern under a stereomicroscope. Data were analyzed using Kruskal-Wallis, Man Whitney, and chi-square tests. A value of P<0.05 was considered significant. Results: The highest and lowest bond strengths belonged to the AG and S groups, respectively. The mean difference of µSBS in the four groups was significant, except in the AS and G groups. Conclusion: G-Premio universal bond is able to create sufficient bond strength between composite and amalgam. However, it is recommended to use a combination of Alloy Primer with all bonding systems to improve bond strength.

130-135

Authors: Pegah Mosannen Mozafari , Nooshin Mohtasham , Mehrzad Khorshid * , Mostafa Alizadeh Abkooh , Shohreh Taherimoghadam

Peripheral ameloblastoma (PA) is a rare subtype of ameloblastoma that occurs in soft tissue. It most commonly affects the mandible and is more common in males. It most commonly occurs in the sixth decade of life. This case report represented a 19-year-old girl with a 10-mm lesion on the lingual gingiva of the mandible. The surface was papillary and no pain or bleeding was noted. Histopathologic examination revealed neoplastic proliferation of odontogenic epithelial cells nested in a connective tissue context. Unlike many other PA cases, these nests appeared to originate from the basal cell layer of the epithelium. Cone-beam computed tomography and orthopantomogram did not reveal severe bone involvement and aggression. The patient is planned to be followed-up for 10 years. The prognosis of patients with PA is generally good, but cases of lesion recurrence have been reported. Due to the rarity of PA, further studies are needed on its development and treatment outcome.