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Introduction: It has been demonstrated that cytokines are important factors in the progression of periodontitis and some of them have an important role in the pathogenesis of periodontal disease. The aim of this study was to compare IL-23 levels in gingival crevicular fluid of patients with chronic periodontitis and healthy subjects. In addition, the relationship between IL-23 levels and probing pocket depths was assessed. Materials & Methods: In this in vitro study, samples were collected from the gingival crevicular fluid of 19 patients with chronic periodontitis and 19 healthy subjects, using paper points. The samples were transferred to the laboratory in transfer vials. IL-23 levels were determined using ELISA reader. The relation between IL-23 levels and probing depths was assessed. Data were analyzed with SPSS 20 using independent t-test and Pearson’s correlation coefficient (α = 0.05). Results: The results showed statistically significant differences in IL-23 levels in GCF between healthy subjects and patients with chronic periodontitis, with higher IL-23 levels in patients with chronic periodontitis (p value < 0.001). In addition, there was a significant and direct correlation between IL-23 levels and pocket depths in patients with chronic periodontitis (p value < 0.001, r = 0.811) and healthy subjects (p value < 0.001, r = 0.858). Conclusion: Based on the results of the present study, IL-23 levels in gingival crevicular fluid can be used for the diagnosis of chronic periodontitis. [ABSTRACT FROM AUTHOR]

Introduction: A standardized questionnaire is the principal tool for assessing individuals' knowledge. Since no standard questionnaire is available for assessing elementary school hygiene instructors' knowledge about dental taumas the aim of this study was to design and standardize such a questionnaire with acceptable validity and reliability. Materials and methods: In the present descriptive study in order to design a standard questionnaire, existing questions about individuals' knowledge on dental trauma were evaluated from papers published in English and 42 questions were selected. The English questions were translated into Persian in a linguistic style. The validity of the questions was fully evaluated by experts in epidemiology, Persian language, pedodontists and endodontics, considering the target group and a Persian questionnaire was prepared. In order to evaluate the reliability of the designed questionnaire, 30 hygiene instructors from Shiraz elementary schools were asked to answer the questionnaire. Inter-item correlation, Cronbach's alpha and alpha when the item was deleted, were used along with intra-class correlation test with SPSS 18. All the necessary changes were made and validity and reliability tests were repeated until appropriate results were achieved. Results: Assessment of the reliability of the questionnaire was carried out twice, which resulted in a questionnaire with 19 multiple choice questions. Cronbach's alpha of the final questionnaire was 0.887 and ICC was 0.716. No significant change was observed after deleting each question. Conclusion: Under the limitations of the present study, it can be concluded that a standardized Persian questionnaire, including 19 questions with acceptable validity and reliability is now available to evaluate school hygiene instructors' knowledge about dental trauma and can be used in other similar studies in Iran. [ABSTRACT FROM AUTHOR]

Introduction: Accurate estimation of remaining alveolar bone using conventional tomography is essential in implant treatment. The purpose of the present study was to evaluate the accuracy of conventional spiral tomography in determination of alveolar bone height in posterior mandibular region. Materials and Methods: Thirty edentulous regions were selected in the mandible and assessed by conventional tomography. Residual bone height was measured on tomograms. Panoramic radiography was performed on patients after implant placement. The remaining bone height was measured on panoramic images. The magnification coefficient was determined by comparing the real and radiographic implant lengths. The effect of magnification was eliminated and the resultant data were used as the gold standard. Data were analyzed with SPSS 15 using paired t-test and the measurements on tomograms were compared with the gold standard (α=0.05). Results: There was a significant difference between the accuracy of radiographic measurements using the conventional spiral tomography (0.37±0.89) and the gold standard (0.29±0.81) (p value = 0.03). Conclusion: Under the limitations of the present study, the accuracy of conventional spiral tomographic images was less than the real dimensions. [ABSTRACT FROM AUTHOR]

Introduction: Many factors may cause distortion of panoramic radiographs, of which patient's head position can be mentioned. The aim of this study was to determine the effect of changing the head position in sagittal plane on magnification in different zones of the jaws and to compare it with the normal position. Materials and methods: In this in vitro descriptive-analytical and cross-sectional study seven human dry mandibles were used. The skulls were marked in different dental areas at specific horizontal and vertical distances by radiopaque markers. Panoramic radiographs were taken from each skull tilted and rotated 1‒2, 2‒4 and 4‒6 degrees to left. Magnification in each area was calculated. Data were analyzed with SPSS 18, using t-test and ICC (α ≤ 0.05). Results: The results suggested that changing the position of head in the sagittal plane resulted in greatest changes in the horizontal dimension. The majority of statistically significant changes were observed in values higher than 4 degrees in the third to sixth left mandibular teeth (p values of 0.044, 0.005, 0.044 and 0.006, respectively). Changes in the second premolar and first molar were observed in lower degrees (higher than 2 degree). During tilting and rotation of skulls, the maximum changes were observed in horizontal plane from maxillary lateral incisors to second molars (with p values of 0.013, 0.026, 0.011, 0.016, 0.007 and 0.012, respectively) and in the mandibular lateral incisors to the first molars (with p values of 0.033, 0.002, 0.026, 0.017 and 0.052, respectively). Significant changes were observed in rotations higher than 2 degrees on the left side. Conclusion: Changing head position (rotation and tilting) to a maximum of 6 degrees around the sagittal plane will cause statistically significant changes in horizontal dimensions, but these changes are clinically negligible. [ABSTRACT FROM AUTHOR]

Introduction: Use of digital radiography in dentistry, as a new imaging technique, continues to increase. A digital system has numerous advantages. The aim of this study was to determine the frequency of the use of digital radiography and the reasons for using or not using digital imaging systems among dentists in Esfahan in 2012. Materials and methods: In the present descriptive/analytical survey, 140 dentists who participated in continuing education courses in 2012 were randomly included. The participants received a questionnaire consisting of 18 questions and filled it on the spot. Data was analyzed by SPSS 16 using chi-squared test and t-test (α=0.05). Results: Ten responders (7.2%) had digital equipment in their office; 104 dentists (74.8%) prescribed digital radiographs for referring patients to radiology centers. The most important reasons for using digital systems by the respondents were no need for film processing steps, absence of artifacts due to film processing procedures and low radiation doses. There were no significant differences between the users and non-users of digital systems in relation to educational degree (general practitioner or specialist) and years in dentistry (p value = 0.619, years in dentistry; p value = 0.45, educational degree). Conclusion: Under the limitations of the present study, although the frequency of the use of digital radiographic systems is low in dental offices in Esfahan, it is advisable top order digital radiographs when referring patients to radiology centers. Lack of need for film processing steps and high costs are the reasons for using and not using digital systems, respectively. [ABSTRACT FROM AUTHOR]

Introduction: Considering the diverse uses of panoramic radiographs in dentistry, precise measurement of dimensional changes in each region of the radiograph can be effective in their clinical application. The aim of the present study was to examine the horizontal and vertical magnification of different areas of the jaws on analog panoramic radiographs. Materials and Methods: In this descriptive analytical study, 10 dry human skulls were marked by gutta-percha in different horizontal and vertical dental areas (central, lateral, canine, first and second premolar and first and second molar areas) and radiographs were then prepared from each skull using two analog panoramic machines (Planmeca XC and Soredex Cranex-Tome). Measurement on the skulls and radiographs were independently carried out by two observers. Data were analyzed by SPSS 18 software. Horizontal and vertical magnifications were computed in each region and compared with the values reported by the manufacturer at a significance level of 95%. Inter-class correlation coefficients (ICC) were calculated for each observer and between observers. Results: The magnification means in transverse and vertical dimensions with Planmeca XC were 1.04 ± 0.15 and 1.15 ± 0.08, respectively, yielding differences of -0.046 and -0.15 from the values reported by the manufacturer. The magnification means in transverse and vertical dimensions with Soredex Cranex-Tome were 1.05 ± 0.15 and 1.17 ± 0.08, respectively, yielding differences of -0.12 and -0.24 from the values reported by the manufacturer. The intra-observer and inter-observer ICCs were 98% and 95%, respectively. Conclusion: Under the limitations of the present study, the magnification means in vertical and horizontal dimensions in various regions of the jaws, reported by manufactures, are reliable. [ABSTRACT FROM AUTHOR]