Evaluation of Interproximal Caries with Using of Bitewing Radiography in Dental Student of Islamic Azad University

Statement of Problem: Dental caries is one of the common diseases in the world. It is an infective disease which is caused by loss of minerals and destruction of dental tissues. One of the most effective ways to diagnose the interproximal caries is radiography. Bitewing radiography is the best way for caries diagnosis.Purpose: The aim of this study was to evaluate the prevalence of the interproximal caries in dental students of Islamic Azad University.Materials and Methods: This research was a cross sectional study that was conducted on 89 students of the Azad University consisting of 48 females and 41 males who were selected by random sampling. For each individual student left and right posterior bitewing radiographs were taken with a standard method (the interproximal spaces were between 6-7,5,6 and 4,5). Thus 12 interproximal spaces were examined in each individual. The most proximal cavitation surfaces were detected in the upper Jaw.Results: Results revealed that 6 individuals (6.7%) were totally caries free and 83 individuals (93.3%) showed interproxmal caries. Out of 1068 proximal spaces which had been studied 794 Spaces (73.4%) were caries free and 274 surfaces (25.7%) had caries.Conclusion: The high incidence of proximal caries and the possibility of missing them in the routine examinations make the bitewing radiographs an effective procedure for diagnosis

Evaluation of fibronectin, type I collagen and TGF-ß expression by human periodontal ligament fibroblasts exposed to root end filling materials

Background and Aim: Several materials have been introduced for retrograde fillings, pulp capping and sealing root perforations, but their biological effect on vital tissues and cells is not clear. The purpose of this study was to evaluate the reaction of human periodontal ligament fibroblasts to four root canal filling materials: Pro Root MTA, Root MTA, Portland cement and amalgam. Materials and Methods: In this experimental study, impacted or semi impacted third molar teeth were extracted in aseptic conditions and tissues around the roots were used to obtain fibroblast cell line. After proliferation, cells were cultured in chamber slides and extracts of materials were added to wells. Fibronectin, type I collagen and TGF-  expression were measured by immunocytochemistry method. Data were analyzed by SPSS 11.0 using one way ANOVA and Tukey test. P<0.05 was considered as the limit of significance. Results: Collagen I expression was higher in Pro Root MTA group after 24 hours (p<0.05) and in Portland cement group and positive controls after 48  hours. Portland cement group showed the highest expression of collagen after 1 week. There was no significant difference in fibronectin expression after 24 hours. After 1 week the highest expression of fibronectin was seen in Portland cement, Root MTA and Pro Root MTA groups. TGF-  expression was higher in amalgam, Root MTA and Pro Root MTA specimens after 24 hours and was the highest in Pro Root MTA group after 48 hours. Conclusion: Based on the results of this study, Portland cement and Root MTA are comparable with Pro Root MTA and better than amalgam regarding their effects on human periodontal ligament fibroblasts

Evaluation of linear tomography accuracy in localization of nasal fossa and maxillary sinus

Background and Aim: Accurate measurement of bone height and width is essential prior to dental implant placement. The method of surgery as well as, the type and size of implants are determined according to dimensions of the residual bone. The purpose of this study was to evaluate the accuracy of linear tomography in localization of the floor of nasal fossa and maxillary sinus, and to determine the width of maxillary bone at the designated site for implant placement.Materials and Methods: In this test evaluation study, the vertical distances between the alveolar crest and the floor of nasal fossa and the floor of maxillary sinus was measured by the tomographic slices in 12 sites of three dry human skulls. In addition, the width of maxillary bone was measured at the same slices. The skulls were then sectioned through the marked places. Then the radiographic values were compared with the real values of bone sections.Results: After correction of tomographic values by the magnification factor of the unit, the mean absolute measurement error for vertical values at nasal fossa and maxillary sinus area in tomographic slices were 0.28 mm (SD= 0.24) and 1.1 mm (SD= 0.68) respectively. The mean absolute measurement error for maxillary width at the nasal fossa and maxillary sinus area were 0.65 mm (SD= 0.50) and 0.55 mm (SD= 0.45) respectively. 100 % of vertical values at nasal fossa area and 50 % of vertical values at maxillary sinus area were within ± 1 mm error limit. In addition, 50 % of width measurements at nasal fossa area and 83.3 % at maxillary sinus area were within ± 1 mm error limit.Conclusion: The linear tomography is more accurate in height estimation at nasal fossa area and in width estimation at maxillary sinus area. The accuracy of linear tomography in height and width estimation is within acceptable limits at both nasal fossa and maxillary sinus area

Evaluation of renal osteodystrophy in patients under hemodialysis treatment using digital radiography

Osteodystrophy is one of the most common complications at the last stage of renal disease,"nwhich cause low bone mineral density (BMD) and skeletal deformities in patients. In this study"nevaluation of renal osteodystrophy was evaluated through BMD measurement of 45 under dialysis and"n78 healthy persons by intra-oral digital radiography (RVG). Results Showed that:"n1- The average of BMD in hemodialysis patients was indeed lower than normal population (P^O.OOO)."n2- The mean of BMD of females was lower than males (P=0.021)."n3- There was no correlation between and BMD (P=0.560)."n4- Age and BMD had no significant relationship (P=0.648)."n5- There was negative correlation between alkaline and BMD therefore ALP is a useful predictive factor forBMD(P=0.002)

An evaluation of the subtraction photoshop software accuracy to detect minor changes in optical density by radiovisiography

Statement of Problem: Subtraction is a newly presented radiography technique to detect minor density"nchanges that are not visible by conventional radiography."nPurpose: The aim of this In-vitro study was to evaluate the efficacy of photoshop subtraction software for"ndetecting minor density changes between two dental images."nMaterials and Methods: In this research, five dried human mandibles were held in fixed position while thin"naluminium sheets were superimposed on each mandible on the 1th and 2nd molar teeth regions."nA reference image, without aluminium sheet placement, was obtained from each mandible subsequently series"nconsist of 20 images with aluminium sheets, ranging from 50p. to "5Q0"x were recorded by radiovisiography"n(RVG) system. Initial images were subtracted from subsequent ones by Photoshop subtraction software. The"ndifference in density between the two images at the 1st and 2nd molar sites was related to the aluminium"nsheets. The optical density of aluminium sheets was determined by densitometer."nResults: In the present study, 6.6% of the optical density changes of the minimum aluminium thickness as"n300u. could be detected by photoshop software software."nConclusion: The findings of this study showed that the accuracy of photoshop subtraction software was equal"nto that of the conventional subtraction softwares. Additionally, the accuracy of this software was proved to be"nsuitable for clinical investigations of small localized changes in alveolar bone

Variations among dentists in visual and radiographic diagnosis of occlusal caries

"nBackground and Aim: Diagnosis of occlusal caries in early stages is more difficult than other types, and  needs practical proficiency and accuracy as well as application of advanced and modern equipments. The aim of this study was to evaluate the variations among dentists in diagnosis of occlusal caries. "nMaterials and Methods: In this descriptive cross-sectional study, 6 permanent first molar teeth of 8-10 years old children with occlusal caries of 1, 2 and 3 degrees were selected (Espelid method). Color photographs and bitewing radiographs of teeth were displayed on computer monitor and 157 general dentists were asked to determine the existence and depth of caries. Data were analyzed using SPSS software and chi-square test. P<0.05 was considered as the level of significance. "nResults: 94% of dentists did not diagnose any lesion in grade I caries.3.8% reported enamel caries (correct diagnosis) and 1.9% reported dentin caries. In grade II caries, 15.7% of dentists could not diagnose any caries, 60.7% recognized the caries at the level of enamel (correct diagnosis), and 22.31% reported the dentin level, and 1.3% reported pulp exposures.7% of dentists could not diagnose any caries in grade III, while 27.2% recognized lesions at enamel and 58.9% at dentin level (correct diagnosis), 6.1% of dentists reported pulp exposures and 0.3% did not respond. Female dentists showed significantly higher correct diagnosis compared to males (p=0.013). "nConclusion: Based on the results of this study, despite considerable variations among general dentists in diagnosis of occlusal caries, the total accuracy was acceptable

Centering Ability of F6 SkyTaper and RaCe Rotary Files: A Cone-Beam Computed Tomography Study

Background and Aim: Maintaining the original shape and path of the canal is among the most important criteria for optimal root canal preparation. The aim of this study was to compare the centering ability of F6 SkyTaper and RaCe rotary files in mesiobuccal canals of mandibular molars.   Materials and Methods: In this experimental study, 30 mesiobuccal canals of extracted human mandibular molars with 25-30-degree curvature were randomly divided into two experimental groups (n=15) of RaCe and F6 SkyTaper. After mounting of the teeth in a putty mold, the distance between the canal walls and the outer surface of the roots in mesial and distal aspects was measured. The measurements were made at 1, 3 and 7 mm from the apex. Initial glide path in the canals was achieved using a # 15 K-file. Then, the canals in group A were prepared by RaCe rotary file #25/6% while the canals in group B were prepared by F6 Sky Taper rotary file #25/6%. Measurements were repeated and the difference between the two measurements was calculated and compared with the Mann-Whitney U test. Results: The mean centering ability was 0.72 ± 0.62 in the RaCe group and 0.95 ± 1.39 in F6 SkyTaper group. the centrality was better in F6 SkyTaper group (it was closer to 1) but the difference was not statistically significant (P=0.4). Conclusion: Both RaCe and F6 SkyTaper rotary systems partially offset the centrality of the root canal system

In Vivo Diagnostic Accuracy of Digital Radiography in the Detection of Secondary Caries in Anterior Teeth

Background and Aim: Secondary caries are a common challenge for dentists. Many researchers have evaluated the accuracy of digital radiographic systems in the detection of secondary caries and have reported controversial results. Therefore, the aim of this in vivo study was to determine the diagnostic accuracy of digital radiography in the detection of secondary caries in anterior teeth. Materials and Methods: In this diagnostic in vivo study, 34 patients were selected from among the individuals who wished to replace their anterior teeth restorations. The restorations in need of replacement were class III or class IV composite resin restorations which were at least 5 years aged with either a crack in the restoration body or with more than 0.5mm marginal maladaptation or marginal discoloration. Digital radiographs were obtained and were observed randomly by four oral and maxillofacial radiologists. Caries detection was classified using a 5-point Likert scale. Statistics were computed to assess Kappa coefficients. Results: According to the data, observer reliability for PSP sensor was between 0.79 and 0.88 which is an indicator of the high accuracy of PSP sensor. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 90, 77, 86, 85 and 86 % respectively. Conclusion: The results suggest that in vivo digital radiography with PSP sensors is sufficiently accurate in the detection of secondary caries