The Efficacy of FlexMaster’s IntroFile, PreRaCe and Gates Glidden Drills in Straight-Line Access: A CBCT Assessment

Introduction: An overlooked but important part of successful root canal treatment is a straight-line access (SLA). The purpose of this in vitro study was to compare the efficacy of IntroFile and PreRaCe rotary instruments with Gates Glidden (GG) drills in gaining SLA by cone-beam computed tomography (CBCT). Methods and Materials: A total of forty five extracted mandibular first molars were selected and mounted in dental like arches. Subsequently, they were randomly classified into three groups (n=15). After preparation of a standard access cavity, orifices of the mesiobuccal canal was reached and a #10 file was inserted to explore the canals until the file tip was visible at the apex. Then, preoperative CBCT images were taken. SLA was gained in three groups; group 1, FlexMaster’s IntroFile (FM); group 2, PreRaCe (RC) and group 3, GG. Again, the first binding file at the working length (WL) was placed in the canal and postoperative CBCT images in similar positions were taken. The pre/post operative morphology of the canal was evaluated for changes. Data was analyzed using the one-way ANOVA and post-hoc Bonferroni analysis. Results: The average amount of reduction in coronal canal curvature in FM, RC and GG groups was 2.43±1.79, 3.17±2.05 and 8.7±3.45, respectively. This descending trend was statistically significant. The difference between pre/post SLA changes in FM and RC groups was significant compared to GG group, while there were no significant differences between RC and FM. Conclusion: GG drills produced extraordinary results in reducing coronal curvature of the canal and achieving SLA. They are also more effective than nickel-titanium (NiTi) rotary instruments in canals with coronal curvature

Root Morphology and Canal Configuration of First and Second Maxillary Molars in a Selected Iranian Population: A Cone-Beam Computed Tomography Evaluation

Introduction: The aim of this investigation was to evaluate root canal morphology of maxillary first and second molars and also to assess the prevalence and morphology of the second mesiobuccal canal (MB2) in these teeth, using cone-beam computed tomography (CBCT). Methods and Materials: In this cross-sectional study, the total of 470 CBCT images from the archive of Radiology Department of Isfahan University of Medical Sciences (IUMS), Iran, was evaluated and 295 images were selected. The number of roots, and canal configuration were determined based on Vertucci’s classification system. The data was analyzed using SPSS 20, and P-values less than 0.05 were considered significant. Results: A total of 295 images from 295 patients (165 females and 130 males), including 389 maxillary first (197 right and 192 left) and 460 maxillary second (235 right and 225 left) molars were evaluated. The prevalence of MB2 canals were 70.2% and 43.4% in the maxillary first and second molars, respectively. The most common type of Vertucci’s classification was type II (53.1%), followed by type I. Conclusion: The second mesiobuccal canal was present in almost two thirds of first and less than half of second molars. The morphology and canal configuration of a maxillary molar can almost predict the morphology of contralateral molar. However, it does not relate to the ipsilateral molar.Keywords: Cone-Beam Computed Tomography; Maxillary Molar; Mesiobuccal Canal; Root Canal Configuratio

Comparação da precisão de medições lineares em imagens CBCT com diferentes campos de visão

This study sought to investigate the effect of the field of view (FOV) on linear measurements of cone beam computed tomography (CBCT) images. Methods: In this in vitro study, five dry human skulls were used. After using red wax to simulate soft tissue, the skulls were scanned using Galileos CBCT scanner (Sirona, Bensheim, Germany) with exposure parameters of 85 kVp and 21 mAs and voxel size of 0.280 mm; once with FOV of 15 cm × 8 cm and once again with 15 cm × 15 cm. The measured distances were the distance between the center of the bilateral mental foramen in the axial view (MM), the distance between the alveolar crest and the mandibular inferior border in the sagittal view on the midline (CB), and the depth of the socket of the left mandibular central incisor (L1). Descriptive statistics as well as Pearson’s correlation coefficient were used for statistical analysis (α = 0.05) using SPSS software (v. 25, IBM, NY, USA). Results: The measurements obtained with small and large FOV and with the dry skull were not significantly different (p > 0.05). The measurements obtained in small FOV had excellent correlation coefficient when compared with those obtained with the dry skull, with values of 0.890 for MM, 0.954 for CB, and 0.921 for L1 (p < 0.001). The measurements in large FOV also had excellent correlation coefficient when compared with those on the dry skull, with values of 0.894 for MM, 0.949 for CB, and 0.902 for L1 (p < 0.001). Conclusion: According to our findings, linear measurements obtained by CBCT scans in small and large FOVs were not significantly different than those on dry skulls. Since the linear measurements are accurate regardless of FOV size, selection of FOV must be based on patient factors, such as area of interest and radiation dose.O objetivo do presente estudo é investigar o efeito do campo de visão (field of view – FOV) em imagens de tomografia computadorizada de feixe cônico (CBCT) na medida linear. Métodos: Neste estudo in vitro, foram utilizados cinco crânios humanos secos. Depois de usar cera vermelha para simular tecidos moles, os crânios foram escaneados usando o scanner GALILEOS CBCT (Sirona, Bensheim, Alemanha) usando parâmetros de exposição de 85 kVp e 21 mAs e o tamanho de voxel de 0,280 mm; uma vez com FOV de 15 cm × 8 cm e outra com 15 cm × 15 cm. As medidas usadas foram as distâncias entre o centro dos forames mentuais bilaterais, na visão axial (MM): a distância entre a crista alveolar e a borda inferior da mandíbula, na visão sagital na linha média (CB); e a profundidade do soquete do incisivo central da mandíbula esquerda (L1). Estatística descritiva e o coeficiente de correlação de Pearson foram utilizados para análise estatística (α = 0,05) usando o software SPSS (v. 25, IBM, NY, EUA). Resultado: As medidas obtidas com FOV pequeno e grande e com o crânio seco não foram significativamente diferentes (p > 0,05). As medidas feitas com FOV pequeno apresentaram excelente coeficiente de correlação em relação ao crânio seco, com valores de 0,890 para MM, 0,954 para CB e 0,921 para L1 (p < 0,001). As medidas feitas no FOV grande também apresentaram excelente coeficiente de correlação em relação ao crânio seco, sendo 0,894 para MM, 0,949 para CB e 0,902 para L1 (p < 0,001). Conclusão: De acordo com nossos resultados, as medidas lineares obtidas por CBCT em FOV pequenos e grandes não foram significativamente diferentes das medidas obtidas com crânios secos. Como as medições lineares são precisas, independentemente do tamanho do FOV, a seleção do FOV deve ser baseada de acordo com os fatores do paciente, como área de interesse e dose de radiação

Prevalência de osteosclerose idiopática em ossos da mandíbula: estudo de tomografia computadorizada de feixe cônico

Objective: The aim of this study is to determine the prevalence of idiopathic osteosclerosis (IO) in the mandible in an Iranian subpopulation using cone beam computed tomography (CBCT). Methods: This cross-sectional study was performed on all CBCT images obtained in 2010-2014 from the archive of Oral and Maxillofacial Radiology Department at Isfahan Dental School. Images were evaluated by two observers in identical room and monitoring conditions. IO was defined as homogenous radiopacities with no particular etiology, ranging from 2 mm to 2 cm in size. Demographic information of all patients, as well as the lesion’s number, location, border, shape, and association with adjacent teeth were recorded. Results: From 377 CBCT images, 43 images (11.4%) had at least one IO lesion. Two separate IO lesions were detected in six patients; therefore, 49 IO lesions were found in total. No gender differences were observed in IO prevalence (P = 0.806). Although most common in patients who were in their 30s, IO prevalence was not statistically different among age groups (P = 0.369). IO was most frequent in the molar region, with 63.2% of lesions. Conclusion: IO prevalence was 11.4% in the studied population and was not statistically different between age groups or sexes. Most lesions were found in the mandibular molar region.Objetivo: Este estudo busca determinar a prevalência de osteosclerose idiopática (OI) na mandíbula em uma subpopulação iraniana usando tomografia computadorizada de feixe cônico (TCFC). Métodos: Este estudo transversal foi conduzido em todas as imagens de TCFC obtidas entre 2010 e 2014 do arquivo do Departamento de Radiologia Oral e Maxilo-facial da Isfahan Dental School. As imagens foram avaliadas por dois observadores em condições iguais de ambiente e monitoramento. A OI foi definida como radiopacidades homogêneas sem causa específica, de tamanho entre 2 mm e 2 cm. As informações demográficas de todos os pacientes foram registradas, assim como o número, localização, borda e formato da lesão e sua relação com dentes adjacentes. Resultados: De 377 imagens de TCFC, 43 imagens (11,4%) tiveram pelo menos uma lesão de OI. Duas lesões individuais de OI foram detectadas em seis pacientes; assim, houve 49 lesões no total. A prevalência de OI não demonstrou preferência por gênero (P = 0,806). A OI foi mais comum em pacientes na faixa dos 30 anos de idade, mas sua prevalência não diferiu estatisticamente entre faixas etárias (P = 0,369). A região mais comum para OI foi a do molar, onde ocorreram 63,2% das lesões. Conclusão: A prevalência de OI foi de 11,4% na população estudada e não diferiu estatisticamente entre faixas etárias e sexos. A maioria das lesões foi encontrada na região do molar mandibular

Comparative evaluation of root canal morphology of mandibular premolars using clearing and cone beam computed tomography

Background: Different techniques are used to evaluate the anatomy of root canal system. The present study was aimed to evaluate the root canal morphology of mandibular premolars using clearing and cone beam computed tomography (CBCT) techniques. Materials and Methods: A total of 182 mandibular first and second premolars were evaluated in vitro using 100 μm CBCT cross sections. The root canal morphology of the teeth was determined based on Vertucci classification in relation to the prevalence of C-shaped canals, lateral canals, and furcation location. Having removed the pulp tissue with NaOCl solution and staining the root canals with India ink, the samples were decalcified with 5% nitric acid and dehydrated with isopropyl alcohol. Finally, the samples were cleared with methyl salicylate. Data were analyzed by SPSS 16 software using McNamara, t-test, and Kappa coefficient. Results: After Type I, the most frequent morphologies in both first and second premolars were Type V followed by Type IV. The prevalence rates of C-shaped morphology in first premolars using clearing and CBCT were 4.4% and 6.6%, respectively. However, no C-shaped morphology was found in second premolars. The maximum and minimum levels of agreement between the two techniques were observed in Type IV and Type V root canal morphologies, respectively. Extra root canals were identified in 25% and 13% of the first and second premolars, respectively. Conclusion: CBCT showed a higher accuracy in determining C-shaped root canal morphology than the clearing technique. It also showed the least accuracy in diagnosing lateral root canals

Effect of SnO2, ZrO2, and CaCO3 nanoparticles on water transport and durability properties of self-compacting mortar containing fly ash: experimental observations and ANFIS predictions

This paper investigates the influence of the addition of nanoparticles, namely SnO2, ZrO2 and CaCO3, at different doses on the durability and the microstructure of self-compacting mortar (SCM). Rheological characteristics were observed through mini slump flow diameter and mini V-funnel flow time. Transport properties were studied by the water absorption and capillary absorption tests. Mechanical properties were determined by the compression tests. Durability properties were examined by the electrical resistivity and rapid chloride permeability tests. Microstructure of SCMs was investigated through scanning electron microscopy (SEM). The mixtures containing nanoparticles exhibit improved transport properties, with increased compressive strengths and resistance to water and chloride ion penetration. These improvements are attributed to the compact microstructures, as the micro pore system was refined in the presence of nanoparticles. Based on fresh and hardened mortar properties, it is found that 5 wt% SnO2, 4 wt% ZrO2, and 3 wt% CaCO3 would serve as suitable replacement levels in optimizing the overall performance. An adaptive neuro-fuzzy inference system (ANFIS) was employed to predict the SCM properties. The numerical results show that the metamodels provide accurate estimates of experimental results

Using Of Educational Movie In Teaching Preapical Bisecting Technique In Dental Students’ Isfahan University Medical Sciences

Introduction: Parallel with the progress in the educational technology, teaching methods have shifted from traditional methods to new methods. One of these methods and educational tools, in the electronic education, is educational movies. This study was done to review the effect of educational bisecting periapical radiograph technique video clip on dentistry students’ learning at Isfahan University of Medical Sciences. Methods: In this quasi-experimental study, 54 students of the 6th semester of the dentistry school of Isfahan University of Medical Sciences, who studied the course of dental radiology in the academic years 2017-2018, were included in the study. These students were randomly divided into two groups; in the first group, method of taking radiographs were taught in the field. In the second group, the teaching method was both in the field and by movie. Scores of two groups were compared for evaluate learning of the students. Data analysis was performed using descriptive statistics and independent test. Results: The mean score of dental radiography in the traditional group was 41±9/06 and in the other group was 105±16.05. The difference between the means of the two groups was significant )p>0/001,t 32.1). The average score of students' satisfaction with the quality of the educational video was 40/3±5/2. Conclusion: The results showed that educational movie with traditional methods could be an effective strategy for better learning in students