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.

8-14

Authors: Pouya Abedi , Zahra Mohyadin , Sara Hosseini , Mehdi Abbasi *

Introduction: Residual oxygen-free radicals of bleaching agents before composite restorations can increase microleakage in enamel and dentin margins, and also various bleaching techniques are being developed using light sources. The present study was conducted to compare the effect of diode laser bleaching and LED activated bleaching on the microleakage of composite restorations. Materials & Methods: This in-vitro study was conducted on 84 extracted human premolars in three groups: In group one, class-V cavities were prepared and the teeth (n=12) were restored with composite ten days after bleaching with 35% hydrogen peroxide with no activator. In groups two and three (n=36 each), the teeth were bleached with a Diode laser activator and LED, respectively. Thereafter, each group was divided into three subgroups (n=12), cavities were prepared and restored with composite three, five, and ten days after bleaching. Digital photographs were used to assess microleakage in the enamel and dentin margins. Data were analyzed using Friedman and Wilcoxon Signed Ranks tests (p<0.05). Results: The lowest amount of microleakage in the enamel margin pertained to the diode laser ten-day subgroup (0.17±0.38) and the diode laser ten-day subgroup in the dentin margin (0.50±1.03). Also, the highest amount of microleakage in the LED group was in the three-day subgroup of the dentin margin (2.78±0.42). Five-day subgroup of diode laser-activated bleaching had a lower amount of microleakage compared to the control group (P=0.042). Conclusion: It may be concluded that diode laser-activated bleaching with 35% hydrogen peroxide has a better effect on reducing microleakage with an interval of five to ten days, compared to the control and LED activated bleaching group.

21-29

Authors: Farzaneh Mohammadi , Fatemeh Koohpeima , Mohammad Javad Mokhtari *

Introduction: Metal nanoparticles may apply to the cavity walls as acceptable antibacterial agents. The present work was conducted to assess the effect of silver nanoparticles (NPs) on the resin cements Shear Bond Strength (SBS) using one self-etch and one etch and rinse resin cement. Materials & Methods: Sixty intact noncarious extracted, human third molars were selected. All teeth were cut out in the middle of dentin thickness. Resin cement samples were randomly assigned to five groups: (A) Duolink cement without any further surface treatment; (B) Duolink cement with silver NPs (0.5%) dentin surface treatment after acid etching and before the One Step Plus (OSP) adhesive system; (C) Duolink cement with silver NPs (0.5%) dentin surface treatment before acid etching and OSP; (D) Panavia F2.0 cement without any further surface treatment; and (E) Panavia F2.0 cement with silver NPs (0.5%) dentin surface treatment. SBS was assessed by using universal testing machine. Then, human gingival fibroblasts (HGF) cells were treated with tested materials. The biocompatibility of resin cement was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The maximum and minimum of the SBS at the presence of silver NPs were observed in group E (15.81±0.91, P-value<0.01) and group B (12.01±0.15, P-value <0.05), respectively. In comparison with the controls, the resin cements incorporated with 0, 0.2% and 0.5% silver NPs, 20.34%, 22.00% and 22.67% for Panavia F2.0 and 36.84%, 37.34% and 38.17% for Duolink flow - decreased in total cell number, respectively (P-value<0.01). Conclusion: These findings demonstrated that Panavia F2.0 cement with silver NPs dentin surface treatment showed satisfactory result in the SBS compared to Panavia F2.0 cement without any further surface treatment.

38-45

Authors: Yasin Baghban , Imaneh Asgari *

Introduction: Demanding qualitative dental services calls for hiring competent staff in dental offices. This study was designed to evaluate dental assistants' educational status and ability to perform tasks. Materials & Methods: In this cross-sectional study, 200 dental assistants working in the offices and clinics of Isfahan, Iran during 2020 were selected using random systematic sampling. The researcher-made evaluation tool with a content validity index of 0.77 was used. Tasks were evaluated by 13 items in 6 sub-scales including communication skills, preparation, radiography, cooperation with dentists, health promotion through prevention and infection control. Moreover, information was requested about the education and training course of the dental assistant. The score of ability was achieved at the range of 0 to 20. The relationship between gender and training course as well as between age and experience level was evaluated with Mann-Whitney test and Spearman correlation. Results: The most frequent major of the study was accounting. The mean total ability score of the dental assistants was 19.1±6.5, ranging from 17.7 to 20. The highest and lowest ability scores were related to the cooperation with dentists and health promotion through prevention, respectively. The mean ability score had a weak relationship with age but had no significant relationship with experience. The mean ability score only in the area of radiography had a significant relationship with the training course and gender (P=0.012). Conclusion: Despite the diversity in the degree and field of study, the ability and task status of the assistants was desirable. In the area of health promotion through prevention, there is a need for training and monitoring its implementation.

56-63

Authors: Azadeh Zakariaee Jubari , Azadeh Torkzadeh *

Introduction: The maxillary sinuses are the largest paranasal sinuses adjacent to the teeth. Due to anatomical variations in different people, knowledge of these variations is essential for rhinoplasty and sinusitis. The aim of the present study was to determine the relationship between maxillary sinus volume with nasal septal deviation, concha bullosa and infundibulum size using cone-beam computed tomography (CBCT). Materials & Methods: In this descriptive -analytical study, CBCT images of 135 patients who underwent maxillofacial imaging were evaluated. In order to measure the volume of maxillary sinuses, CBCT images of axial sections were used with a thickness of 2 mm and Digimizer image analysis software. In the coronary section of nasal septum deviation, types of concha bullosa and infundibulum size were determined. Data were analyzed using one-way ANOVA, paired t-test, Pearson correlation test and regression. A value of P<0.05 was considered significant. Results: There was a significant inverse relationship between the mean of volume of the right sinus (p=0.012, r=-0.216) and left sinus (p<0.001, r=-0.303) with the deviation of the nasal septum. A significant inverse relationship was found between the mean volume of right maxillary sinus (p<0.012, r=-0.357) and left maxillary sinus (p=0.006, r=-0.357) with infundibulum size. The mean volume of right and left sinues from coronal view was not significantly different in the presence or absence of concha bullosa. There was no significant difference between male and female in the mean volume of the right and left sinuses. Conclusion: The present findings suggest that maxillary sinus volume is smaller the deviation in moderate and severe septal deviation cases and that the maxillary and with increasing size of infandibulum, the volume of maxillary sinus was larger.