JOURNAL OF DENTISTRY (SHIRAZ UNIVERSITY OF MEDICAL SCIENCES)
Year:2018 | Volume:19 | Issue:4|Papers Count:12

Statement of the Problem: Central giant cell granuloma of the jaws is comprised of two types namely aggressive and nonaggressive. Controversy exists regarding the histogenesis of this lesion. Up to now, there are no reliable histologic or molecular methods to differentiate aggressive from nonaggressive central giant cell granuloma of the jaw. Moreover, because of different treatment of two groups, correct diagnosis is needed. Purpose: The purpose of this study was to evaluate and compare the expression of cyclin D1 between aggressive and nonaggressive central giant cell granulomas of the jaws. Materials and Method: This retrospective study was performed on 16 paraffin blocks of aggressive central giant cell granuloma, and 16 nonaggressive central giant cell granulomas from Shahid Beheshti Oral Pathology Department and evaluated the expression of cyclin D1 on giant cells and mononuclear cells of the lesions. T-test was used for quantitative evaluation and comparison of cyclin D1 expression be-tween two groups. Results: Overexpression of cyclin D1 in giant cells and mononuclear cells of the lesions of both groups was apparent, but no significant statistical difference was seen. Cyclin D1 positivity was seen predominantly in the nuclei of giant cells. When a giant cell was positive, all the nuclei showed immunoreactivity. In each group mean percentage of the positive giant cells were higher than positive mononuclear cells and significant statistical difference (p= 0. 000) was seen between them. Conclusion: Probably overexpression of cyclin D1 implicates in the pathogenesis of the central giant cell granulomas but it seems that this protein could not be used as a marker for identifying the clinical behavior of these lesions.

Statement of the Problem: Quercetin is a pharmacological flavonoid that can inhibit high mobility group box1 (HMGB1) protein, a non-histone nuclear protein that is implicated in inflammation. Th17 cells are important cells in the pathogene-sis of inflammation. Pulpitis is the inflammation of dental pulp, which usually is accompanied by pain. Quercetin may alleviate this inflammation. Purpose: The current study aimed to compare blocking of HMGB1 function and stimulation of HMGB1 function with quercetin and investigate the effects of the blockage on T helper 17 (Th17) cells and mitogen-activated protein kinase Toll-like receptor 4 (MAPK-TLR4) signaling pathway. Materials and Method: T cells isolated from the pulp involved with pulpitis and the normal pulp were cultured. The cells suspensions were plated in 6-wells culture plates and stimulated with 0. 5 μ g/ml of HMGB1 for 2, 4, 8, and 12 hours. For blocking TLR4, 10 μ g/ml rabbit anti-human TLR4 antibody was added 1 hour before treatment with HMGB1. Results: The level of these cytokines decreased; moreover, western blot data showed that quercetin could decrease MAPK signaling pathway by means of inhi-bition of HMGB1 on T cells. The results showed the reduction of TLR4 pathway and Th17 cell polarization. Conclusion: Our results indicated that the levels of IL-17, IL-33, and IL-6 in su-pernatants from patients’ cultured T cells were increased after stimulation with HMGB-1 following employing quercetin. It also could inhibit MAPK signaling pathway, which subsequently could decrease Th17 production and IL-17. Quercetin could decrease pro-inflammatory cytokines and IL-17 production.

Statement of the Problem: Oral pathological conditions presented in children are various and often different from those of adults. There is considerable variation in the prevalence of these lesions among different regions of the world. Purpose: The aim of this study was to assess the frequency and clinical-pathological features of oral lesions diagnosed in children and adolescents through-out 25 years in an oral pathology department. Materials and Method: This cross-sectional study was conducted in the Depart-ment of Oral and Maxillofacial Pathology at Dental School of Isfahan University of Medical Sciences. All the medical reports and biopsy files of the patients aged <18 years that were diagnosed during January 1990 and December 2015 were retrieved. The data regarding histopathologic diagnosis, site of lesions, and date of diagnosis and demographic characteristics of patients were elicited. The lesions were catego-rized based on their origin and age group of the patients. Descriptive statistics were used as appropriate. The critical level of significance was set at p< 0. 05. Results: 1267 lesions were recorded. The mean age of the samples was 12. 5± 3. 9. Of lesions, (408, 49. 3%) were in posterior area. The most common lesions were odontogenic cysts (416, 32. 9%) and reactive lesions (317, 25. 1%) and the least common lesions were allergic and immunologic disorders (2, 0. 2%). In age groups of 7-12 and 13-18 years, odontogenic cysts [(208, 38. 1%), (198, 31. 4%)] and reac-tive lesions [(143, 26. 3%), (147, 23. 3%)] were the most common lesions, respec-tively. During the 25 years of survey, the prevalence of pulp and periapical disease increased (p< 0. 001), that of bone pathology decreased (p< 0. 05) and trend of other lesions did not significantly change over this time. Conclusion: The most frequent lesions were odontogenic cysts and reactive le-sions. The prevalence of lesions was not changed dramatically during the 25 year. The frequency of oral lesions in Isfahan province (in Iran) is different from other regions in the world and even, to some extent, different from other regions in Iran, which is in agreement with the hypothesis of geographical distribution of these lesions.

Statement of the Problem: Dental caries is the most common chronic disease among children. Determinants of children’ s oral health behavior should be better understood and known. Purpose: This study aimed to investigate the predictive factors of oral health be-havior among preschool children based on the theory of planned behavior (TPB). Materials and Method: This cross-sectional study included 833 mother-child pairs referring to twenty health centers in Tabriz, North-West Iran, from August 2014 to November 2015. The participants were selected by multi-stage stratified random sampling. Data were collected through self-administered questionnaires completed by the participating mothers. The questionnaire consisted of demograph-ic characteristics, oral health behavior, and TPB structures (attitude, subjective norms, perceived behavioral control, and intention). Results: The mean± standard deviation (SD) of children’ s age was 4. 6± 1. 1 years (ranging 3– 6), and 52% were boys. 20. 3% of mothers had university degrees. The mean (SD) score of children’ s oral health behavior was 5. 8 (± 1. 9) out of 8. Muliple regression analysis revealed a positive relationship between all TPB structures and children’ s oral health behavior F(11, 821)=41. 8, R=0. 6, (p< 0. 001). Furthermore, the TPB structures explained 35% and 29% of the variance in children’ s oral health behavior and maternal intention towards it, respectively. Conclusion: Based on the current finding, TBP is the important predictor of chil-dren’ s oral health behavior. Effective promotion interventions could be designed based on this predictor to help improving the children’ s oral hygiene behavior.

Statement of the Problem: The endodontically treated teeth usually suffer from the discoloration induced by endodontic materials, which can adversely affect the esthetical outcome of a treatment. Purpose: This study aimed to compare the discoloration caused by the silver nano-particles coated with imidazolium as an irrigant, sodium hypochlorite (NaOCl), and chlorhexidine gluconate (CHX). Materials and Method: The root tips of 65 single-rooted human teeth were resect-ed and root canal systems were chemomechanically prepared from the apical as-pect. The specimens were randomly divided into three experimental (n=15) and two control groups (n=10). In the experimental groups, the substance was placed in the root canal for 30 minutes, and then washed with normal saline. Saline or blood alone was used in the control groups. The discoloration was assessed spectropho-tometrically right after substance placement (T1), 1 week (T2), and 1 (T3) and 3 months (T4) after and color change values were calculated. Statistical analysis was performed using multi-sample repeated measures analysis of variance, Tukey's HSD, and Sidak tests. Results: In T1, there was no significant difference in color change between silver nano particle, blood and CHX (p> 0. 05); but these three groups had significantly more Δ E value than NaOCl and Normal Saline (p< 0. 05). NaOCl and normal saline had no significant difference in T1 (p> 0. 05). In T2, T3 and T4 results were the same and showed blood and silver nano particle had significantly higher color change in comparison with NaOCl, CHX and normal saline (p< 0. 05). There was no significant difference between NaOCl, CHX, and normal saline in tooth discol-oration (p> 0. 05). There was no significant difference between silver nano particle and blood in ability of tooth discoloration (p> 0. 05). Conclusion: Within the limitation of this study, silver nano particle material could not be suggested as an intra-canal irrigant regarding its unfavourable tooth discol-oration.

Statement of the Problem: Oral squamous cell carcinoma (OSCC) is one of the most widely occurring cancers worldwide. Early diagnosis of primary tumors is the key to improve treatment outcome. Detecting cancer, determining prognosis, and monitoring disease progression or treatment response can be done based on molecu-lar markers. CA19-9 is an isolated form of Lewis antigen. It is widely used for detect-ing pancreatic cancer in the clinical setting. P57 (KiP2) is a tumor suppressor gene. It is a positive regulator of cell proliferation, regulating proliferation through G1 phase by inhibiting cyclin dependent kinases. Its expression decreases in most malignan-cies. OSCC has variable differentiation grades and local invasion potential. Purpose: The aim of this study was to evaluate and assess the correlation of CA19-9 and P57 expression with invasive front and grade of OSCC. Materials and Method: This cross-sectional study was performed on forty paraffin blocks in three histologic grades; well, moderate, and poorly differentiated SCC. The two markers were assessed by immunohistochemistry methods (En vision). Propor-tional and total scores and staining intensity were measured for all samples. Results: CA19-9 staining was low in all three grades. The Kruskal Wallis test showed no significant correlation between tumor grade and CA19-9 expression; however, there was a significant difference between tumor intensity and margin in-tensity (p= 0. 003). P57 staining was high in all three grades. The Kruskal Wallis test showed no significant correlation between tumor grade and P57 expression. There were no significant differences in total intensity of staining in margins of tumor (p= 0. 85). Conclusion: Within the limitations of this study, it may be concluded that expression of CA19-9 and P57 cannot be used as determinants of tumor grade. Higher expres-sion of CA19-9 in invasive front of SCC can be representative of local invasion and higher activity of tumor cells in the margins.

Statement of the Problem: Recurrent aphthous stomatitis (RAS) is the most prevalent ulcerative condition of the oral mucosa. Many studies have emphasized on immunologic factors as the reason of inducing RAS; however, the exact etio-logic cause of RAS has not been identified yet. Vitamin D has an endocrine func-tion and regulatory effects on the immune system. It has potential therapeutic effects on autoimmune diseases, psoriasis, and neoplasms. Vitamin D deficiency has been detected in some autoimmune diseases such as rheumatoid arteritis. Purpose: The aim of the present study was to compare the serum and salivary levels of vitamin D in patients with RAS and healthy individuals. Materials and Method: In this cross sectional study, patients with RAS, refer-ring to the Department of Oral Medicine, Tabriz Faculty of Dentistry, were eval-uated after taking medical history, clinical examinations, and completing an in-formed consent form. The serum and salivary vitamin D levels were compared between case (n=26) and control (n=26) groups. Results: The mean serum vitamin D levels in the case and control groups were 33. 0. 7± 12. 41 and 50. 89± 9. 30 (ng/dL), respectively, with a statistically significant difference (p< 0. 001). On the other hand, the mean salivary vitamin D levels in the case and control groups were 17. 36± 8. 01 and 20. 79± 6. 31 (ng/dL), respec-tively, with no statistically significant difference (p= 0. 09). In addition, the corre-lation between the serum and salivary levels of vitamin D was 56%, being statis-tically significant (p< 0. 001). Conclusion: The serum levels of vitamin D in patients with RAS were signifi-cantly less than that in healthy individuals; however, there were no significant differences in salivary vitamin D levels between patients with RAS and healthy individuals. In addition, there was a significant and positive correlation between serum and salivary levels of vitamin D in all patients.

Statement of the Problem: Dental caries is a common chronic disease. Mouth-washes and other preventive approaches play an important role in caries preven-tion. Finding the most efficient mouthwash in the market is always a concern for dentists and patients. Purpose: This study aimed to assess the effect of chlorhexidine (Behsa, Iran) and xylitol plus 920 ppm fluoride (FX) (Fuchs, Germany) mouthwash on salivary Streptococcus mutans (S. mutans), which is the main microorganism responsible for dental caries. Materials and Method: This single-blind randomized clinical trial was conduct-ed on 30 dental students, divided into two groups. The salivary count of S. mu-tans was measured at the beginning of the study. Group 1 students used chlorhex-idine mouthwash while group 2 used FX mouthwash for two weeks. Saliva sam-ples were collected again and salivary count of S. mutans was determined. Data were analyzed using Mann Whitney and Wilcoxon signed rank tests Results: Salivary count of S. mutans significantly decreased in the two groups after using the mouthwashes (p< 0. 05) and no significant difference was noted in the mean colony count between the two groups after the use of mouthwashes (p> 0. 05). Conclusion: Within the limitations of this study, the results showed that both mouthwashes could decrease S. mutans count.

Statement of the Problem: Due to the close contact with patients during dental treatments, dentists and those affiliated to the dental profession are at higher risk for various infections. Infection prevention in dentistry is an important topic that has gained more interest in recent years. Purpose: We aimed to evaluate the protective role of front-closed and front-open gowns against staphylococcus aureus contamination of dental students before and after restorative treatments. Materials and Method: Sixty male dental students performed the restorative treat-ments on the teeth of the patients in the front-closed and front-open gowns groups. Before and after the treatment, the wet sterile swab samples were collected from the students’ neck and anterior part of the chest. The samples simultaneously cultured on the blood agar and the Staphylococcus-specific medium using spread plate method. Finally, the colonies were counted within 24-48 hours. Results: The mean of the total colony count increased in both groups of front-open (787. 8 ± 88. 91) and front-closed gowns (630 ± 122. 7), but the changes were signifi-cant only in the front-open gown group (p≤ 0. 001). Compared to the front-closed gown group (430± 71. 08), the total colony count of staphylococcus aureus in the front-open gown group (490. 3± 62. 5) was increased significantly (p≤ 0. 001). Conclusion: We confirmed that dental students occupationally exposed to the bacte-rial agents and even simple minor changes in gown could considerably decrease the contamination. Education about bacterial transmission, as well as infection preven-tion and control measures is necessary for dental students, especially when they par-ticipate in clinical practice.

Statement of the Problem: There is not enough information available about the effect of thickness reduction and the coloring method on the color of new mono-lithic zirconia ceramic system. Purpose: This study aimed to evaluate the effect of varying thickness reductions and number of coloring liquid applications on the final color of anatomic contour monolithic zirconia ceramics. Materials and Method: In this experimental in-vitro study, 48 disk-shaped mono-lithic zirconia specimens (10×2mm) were divided into three groups (Group I to III) according to the number of A2-coloring liquid applications (n=16). Each group was then divided into 4 subgroups (n=4) by reducing the thickness of 2 to 0. 5 mm in increments of 0. 5 mm on the colored surface. Color measurement was done through CIELab (l*, a*, b*) on a reflection spectrophotometer on five differ-ent areas of each specimen. Color differences (Δ E) were calculated. Data were analyzed by using two-way ANOVA and Tukey’ s HSD test (α =0. 05). Results: The number of coloring liquid applications and reducing the thickness of monolithic zirconia disks had significant effects on CIE L* a* and b* values. The CIEL*, a* and b* values increased as the thickness decreased (p< 0. 05), whereas, increasing the number of coloring liquid applications resulted in decreased CIE L* value and increased CIE a* and b* values (p< 0. 05). Conclusion: Decreasing the thickness of monolithic zirconia increases the light-ness and reddish, yellowish appearance. Meanwhile, increasing the number of coloring liquid applications reduces the lightness and makes it seem more reddish and yellowish.

Microbial infection is common in patients with leukemia. However, aspergillosis is a rare complication of oral region. Attention to early diagnosis and multidiscipli-nary treatment can reduce the wide range of complications of the infection in these patients. This article reports 4-year history of a child with leukemia, who suffered from a rare aspergillosis infection in the palatal region of oral cavity during chemotherapy. Early diagnosis and treatment of bacterial and fungal infections, especially rare types such as aspergillosis, in patients with leukemia is important for reducing widespread complications. However, prosthetic treatment and attention to psycho-logical complications of orofacial defects would also improve their quality of life significantly. These improvements can be seen more clearly in children.

Osteochondroma (osteocartilaginous exostosis) is one of the most common benign tumors of bone but is rare in the craniofacial region. Only a few cases of osteochon-droma of the coronoid process have been reported in the literature, since the time of its discovery (osteochondroma of a coronoid process) by Jacob in 1899. We present a case of osteochondroma of the left coronoid process in a 16-year-old female pa-tient. Contrary to the literature, our patient had no limited mouth opening despite a close approximation of left hyperplastic coronoid process with zygomatic arch, making it a unique case among similar cases. Plain radiography can be used for this hyperplastic condition but due to its inherent distortion and being only two-dimensional (2D) it has a limited diagnostic advantage. Cone beam computed to-mography (CBCT) was employed for necessary diagnostic information. We man-aged our patient with an intraoral coronoidectomy.