Managing a Mandibular Second Premolar with Three-Canal and Taurodontism: A Case Report

Root canal anatomy diversity and aberrations are common especially in permanent dentition. A thorough understanding of the basic root canal anatomy and its diversities are necessary for successful endodontic treatment. Mandibular second premolars are usually single-rooted and have one root canal. Incidence of three separate root canals in this tooth is quite rare and taurodontism with three separate canals has never been reported in literature so far. The use of cone-beam computed tomography scan in this rare case greatly contributed to making a confirmatory diagnosis and successful nonsurgical endodontic management thereafter

Microbial Contamination of the Outer Surface of X-ray Films

Objectives Infection control is one of the most important aspects of dentistry. Since intraoral radiographic films are directly in contact with the oral environment, microbial contamination may transmit infectious diseases. The purpose of this study was to investigate the frequency of microbial contamination of intraoral radiographic films and compare the probable microbial contamination of two intraoral radiographic film brands available in the Iranian market. Methods in this in vitro, experimental study, 900 radiographic films of two commercial brands, i.e. Intra X-ray and Carestream films were placed in aerobic, anaerobic, and fungal culture media immediately after removal from the packaging in sterile conditions. The samples were transferred to the respective culture media after incubation. The cultured bacteria were Gram-stained, and microscopically observed. The percentage of the contaminated intraoral radiographic films and the type of microbial contamination were reported. Data were analyzed using the Chi-square test. Results Of all, 32.6% of the Carestream films and 44.6% of Intra X-ray films were infected by aerobic microorganisms, mostly Bacillus. In the anaerobic culture, the turbidity of the medium indicated the possible presence of microorganisms. In the fungal culture, no fungal hyphae were observed microscopically. Conclusion The results of this study showed that intraoral films cannot be considered sterile. Intra X-ray radiographic films were significantly more contaminated than Care stream radiographic films

Effect of different conditioning methods on the surface roughness of dental amalgam: SEM analysis

The purpose of this study was incorporation of SEM micrographs for evaluating the effect of different mechanical and chemical treatments on surface roughness of dental amalgam. Amalgam was condensed in 18 plastic molds and the following modification methods were accomplished on samples surface: 1) Chemical solutions (5 groups) on fresh amalgam 2) Chemical solutions (5 groups) on aged amalgam 3) Sandblast on aged amalgam 4) Sandblast on fresh amalgam (2 groups) before & after primary setting. 5) Use of diamond bur (0.10 coarse) on aged amalgam. 6) Acid etch (37% phosphoric acid) on fresh amalgam. 7) Metal etch on fresh amalgam. 8) Varnish solvent in amalgam capsule, trituration &condensation (fresh). 9) Standard sample without any treatment. All groups were analyzed by SEM (×l00, ×500 magnifications were used for roughness quantification and chemical analysis respectively). The numbers of surface peaks were counted in 5 area of each micrograph and consequently the data were assessed by K-S & student T- tests. All groups have statistically significant difference with control except three ones (incorporation of phosphoric acid, EDTA+NH3, and NaOH+I2 on fresh amalgam). Sandblast, diamond bur & metal etch reduced surface roughness and use of chemical solutions showed different reactions

Effect of different conditioning methods on the surface roughness of dental amalgam: SEM analysis

The purpose of this study was incorporation of SEM micrographs for evaluating the effect of different mechanical and chemical treatments on surface roughness of dental amalgam. Amalgam was condensed in 18 plastic molds and the following modification methods were accomplished on samples surface: 1) Chemical solutions (5 groups) on fresh amalgam 2) Chemical solutions (5 groups) on aged amalgam 3) Sandblast on aged amalgam 4) Sandblast on fresh amalgam (2 groups) before & after primary setting. 5) Use of diamond bur (0.10 coarse) on aged amalgam. 6) Acid etch (37% phosphoric acid) on fresh amalgam. 7) Metal etch on fresh amalgam. 8) Varnish solvent in amalgam capsule, trituration &condensation (fresh). 9) Standard sample without any treatment. All groups were analyzed by SEM (×l00, ×500 magnifications were used for roughness quantification and chemical analysis respectively). The numbers of surface peaks were counted in 5 area of each micrograph and consequently the data were assessed by K-S & student T- tests. All groups have statistically significant difference with control except three ones (incorporation of phosphoric acid, EDTA+NH3, and NaOH+I2 on fresh amalgam). Sandblast, diamond bur & metal etch reduced surface roughness and use of chemical solutions showed different reactions

Accuracy of Cone-Beam Computed Tomography in Determining the Root Canal Morphology of Mandibular First Molars

Introduction: The aim of the present in vitro study was to compare the accuracy of cone-beam computed tomography (CBCT) in determining root canal morphology of mandibular first molars in comparison with staining and clearing technique. Methods and Materials: CBCT images were taken from 96 extracted human mandibular first molars and the teeth were then evaluated based on Vertucci’s classification to determine the root canal morphology. Afterwards, access cavities were prepared and India ink was injected into the canals with an insulin syringe. The teeth were demineralized with 5% nitric acid. Finally, the cleared teeth were evaluated under a magnifying glass at 5× magnification to determine the root canal morphology. Data were analyzed using the SPSS software. The Fisher’s exact test assessed the differences between the mesial and distal canals and the Cohen’s kappa test was used to assess the level of agreement between the methods. Statistical significance was defined at 0.05. Results: The Kappa coefficient for agreement between the two methods evaluating canal types was 0.346 (95% CI: 0.247-0.445), which is considered a fair level of agreement based on classification of Koch and Landis. The agreement between CBCT and Vertucci’s classification was 52.6% (95% CI: 45.54-59.66%), with a significantly higher agreement rate in the mesial canals (28.1%) compared to the distal canals (77.1%) (P<0.001). Conclusion: Under the limitations of this study, clearing technique was more accurate than CBCT in providing accurate picture of the root canal anatomy of mandibular first molars.Keywords: Cone-Beam Computed Tomography; Root Canal Morphology; Root Clearin

Cone-Beam Computed Tomography Comparison of Canal Transportation after Preparation with BioRaCe and Mtwo Rotary Instruments and Hand K-Flexofiles

Introduction: The aim of this in vitro study was to evaluate the transportation of mesiobuccal canals of mandibular first molars prepared with either BioRaCe or Mtwo rotary instruments or hand K-Flexofile, by means of cone-beam computed tomography (CBCT). Methods and Materials: Forty-five mandibular molars were selected and randomly divided into three groups (n=15). Mesiobuccal roots of these teeth were prepared by BioRaCe, Mtwo, or hand K-Flexofile. Transportation was measured by pre- and post-operative CBCT images. Two-way ANOVA analysis was applied to detect any differences between the groups followed by the post hoc Tukey’s tests. The level of significance was set at 0.05. Results: The non-parametric Friedman test was used to compare the behavior of each file at 3-, 6- and 9-mm levels. There were no significant differences between different levels in Mtwo group (P=0.15); however, the differences in K-Flexofile and BioRaCe groups were significant (P>0.05). Post hoc Tukey’s test revealed significant differences between BioRaCe and K-Flexofile and also between Mtwo and K-Flexofile, both in the 3-mm depths (P<0.05). Conclusion: Under the limitations of the present study, BioRaCe and Mtwo rotary instruments are considered suitable for canal preparation to greater apical sizes provided that the recommended sequences are observed

Benign Cementoblastoma Involving Deciduous and Permanent Mandibular Molars: A Case Report

Cementoblastomas are rare benign odontogenic tumors. Diagnosis of these lesions must be made by an association of clinical, radiographic, and histopathological findings. Cementoblastomas rarely occur in both primary and permanent dentitions. We describe the sixth case of cementoblastoma in the literature with the involvement of both deciduous and permanent teeth. The aim of this case report is to present the clinicoradiopathologic features of a cementoblastoma in a 4.5-year-old boy with an unusual recurrence. The first clinical and radiographic features appeared on the deciduous mandibular second molar. The second lesion occurred 1 year after treatment at 5.5 years old, involving the permanent mandibular first molar, and a subsequent lesion was seen at age 8 years in the edentulous region of the extracted mandibular first molar. After the last surgery, there was no recurrence of the lesion at 6 months’ follow-up. Follow-ups of patients with cementoblastomas are highly recommended for an early detection of recurrence

The effect of education on knowledge and attitude towards the harmful effects of smoking among students of Shahid Beheshti University of Medical Sciences, Tehran

زمینه و اهداف: نظر به شیوع نسبتا بالای مصرف سیگار در دانشجویان و نقش آگاهی و نگرش در پیشگیری از مصرف سیگار، پژوهش حاضر با هدف تعیین تاثیر آموزش بر آگاهی و نگرش نسبت به مضرات مصرف سیگار میان دانشجویان اجرا گردید.   مواد و روش‌ها: این مطالعه مداخله‌ای از نوع نیمه ‌تجربی در سال 1395 و در میان 130 نفر از دانشجویان خوابگاهی دانشگاه علوم پزشکی شهید بهشتی تهران (65 نفر در هر یک از دو گروه مداخله و کنترل) انجام شد. ابزار گردآوری اطلاعات، پرسشنامه مشخصات جمعیتی و زمینه‌ای و پرسشنامه روا و پایای موجود جهت سنجش آگاهی و نگرش نسبت به مضرات مصرف سیگار بود که در دو مرحله قبل و سه ماه پس از مداخله تکمیل گردید. آموزش در این مطالعه در قالب شبکه‌های اجتماعی اجرا و پیام‌های آموزشی طی 6 نوبت به دانشجویان گروه مداخله ارسال گردید. داده‌های گردآوری شده با استفاده از آزمون‌های متناسب و نرم‌افزار SPSS  نسخه 16 تحلیل شدند. تمامی مراحل مطالعه حاضر طبق موازین اخلاقی اجرا گردید. یافته‌ها: قبل از مداخله، بین متغیرهای جمعیتی و زمینه‌ای، میانگین نمرات آگاهی و نگرش نسبت به مضرات مصرف سیگار در دو گروه، تفاوت معنادار وجود نداشت (p>0.05). پس از مداخله، مقایسه دو گروه نشان داد که میانگین نمرات آگاهی و نگرش نسبت به مضرات مصرف سیگار در گروه مداخله به طور معناداری نسبت به گروه کنترل، تغییر داشته است (p<0.05).  نتیجه‌گیری: در مداخلات آموزشی جهت ارتقای آگاهی و نگرش نسبت به مضرات مصرف سیگار در دانشجویان، می‌توان از شبکه‌های اجتماعی استفاده کرد.Background and Aims: Considering the relatively high prevalence of smoking among students and the role of knowledge and attitude in smoking prevention, the present study aimed to determine the effect of education on knowledge and attitude towards the harmful effects of smoking among students.Materials and Methods: This was a quasi-experimental interventional study conducted in 2016 among 130 dormitory students of Shahid Beheshti University of Medical Sciences in Tehran (65 students in each intervention and control groups). Data gathering tool was a demographic and background characteristics questionnaire. A valid and reliable questionnaire was used to assess the knowledge and attitude towards the harmfulness of smoking that was completed in two stages before and three months after the intervention. In this study, education was performed using Social Networks and educational messages were sent to the students of the intervention group in 6 sessions.The collected data were analyzed through the proportional tests and SPSS software version 16. All stages of the study were conducted according to moral standards.Results: There was no significant difference between demographic and background variables before the intervention and also the mean scores of knowledge and attitude towards the harmfulness of smoking in both groups (p > 0.05). Comparing two groups after the intervention showed that the mean scores of knowledge and attitude towards the harmfulness of smoking have changed significantly in experimental group compared to control group (p < 0.05).Conclusion: Social networking can be used in educational interventions to promote knowledge and attitude towards the harmful effects of smoking in students

Investigating the health literacy influencing ways on the adoption of smoking preventive behaviors in Health Belief Model developed by health literacy

زمینه و اهداف: ادغام سواد سلامت به الگوی اعتقاد بهداشتی، به تقویت عملکرد این الگو در پیش‌بینی رفتارهای پیشگیرانه از مصرف سیگار یاری می‌رساند، اما نوع این تاثیر و نحوه عملکرد سواد سلامت در این الگوی ترکیبی، تاکنون مشخص نشده است. لذا این مطالعه با هدف تعیین راه‌های تاثیر سواد سلامت بر اتخاذ رفتارهای پیشگیرانه از مصرف سیگار در الگوی اعتقاد بهداشتی تلفیقی با سواد سلامت انجام شد.  مواد و روش‌ها: در این مطالعه مقطعی-تحلیلی، 340 نفر از دانشجویان خوابگاهی دانشگاه علوم پزشکی شهید بهشتی تهران با روش نمونه‌گیری خوشه‌ای یک مرحله‌ای وارد مطالعه شدند. ابزار گردآوری داده‌ها شامل پرسشنامه روا و پایای مبتنی بر الگوی اعتقاد بهداشتی درباره پیشگیری از مصرف سیگار و پرسشنامه سنجش سواد سلامت (HELIA) بود. داده‌ها با نرم‌افزار SPSS نسخه 16 و روش تحلیل مسیر مبتنی بر رگرسیون تک متغیره و چندگانه، تحلیل شدند. تمامی مراحل مطالعه حاضر طبق موازین اخلاقی اجرا گردید.    یافته‌ها: سواد سلامت تاثیری مستقیم و معنادار بر تمامی سازه‌های الگو و اتخاذ رفتار داشت. همچنین از طریق تاثیر بر سازه‌های الگو، به‌طور غیرمستقیم بر اتخاذ رفتار تاثیر داشت و از بین این تاثیرات، فقط تاثیر آن از طریق متغیرهای حساسیت‌درک ‌شده و خودکارآمدی بر روی اتخاذ رفتار، معنادار بود. ضمنا تاثیر غیرمستقیم سواد سلامت بر اتخاذ رفتار بیشتر از تاثیر مستقیم آن بود. نتیجه‌گیری: با استفاده از الگوی اعتقاد بهداشتی تلفیقی با سواد سلامت و تاکید بر متغیرهای حساسیت‌درک ‌شده و خودکارآمدی، می‌توان تا حدودی سواد سلامت و در نتیجه اتخاذ رفتارهای پیشگیرانه از مصرف سیگار را در دانشجویان ارتقا داد.Background and Aims: Incorporation of health literacy (HL) into health belief model (HBM) assist in strengthening the performance of this model in predicting smoking preventive behavior. However, the type of such an effect and the way in which the HL works in this hybrid model has not yet been determined. Therefore, this study was aimed to determine the influencing ways of HL on adoption of smoking preventive behavior in HBM incorporated with HL. Materials and Methods: In this cross-sectional study, 340 dormitory students of Shahid Beheshti University of Medical Sciences in Tehran were enrolled using single-stage cluster sampling. The data collection tool was a valid and reliable questionnaire based on HBM on smoking prevention and HL questionnaire (HELIA). Data were analyzed using SPSS version 16 and path analysis method based on single-variable and multiple regressions. All stages of the study were conducted ethically. Results: HL had a direct and statistically significant effect on all structures of the model and adoption of behavior. Also, it indirectly influenced adoption of behavior by influencing the structures of the model. Only perceived susceptibility and self-efficacy variables significantly affect adoption of behavior. In addition, the indirect effect of HL on the adoption of behavior was greater than its direct effect. Conclusion: It is possible to improve the degree of HL and, therefore, the adoption of smoking preventive behavior among students through the use of HBM incorporated with HL, which emphasizes on perceived susceptibility and self-efficacy variables

Evaluation of the Prevalence of Mucous Retention Pseudocyst and its Correlation with the Associated Risk Factors Using Panoramic Radiography and Cone-Beam Computed Tomography

Objectives: Mucous retention pseudocyst (MRP) of the maxillary sinus is an incidental finding on radiographs. The radiographs taken for dental purposes provide an opportunity for dentists to recognize asymptomatic maxillary sinus anomalies. The purpose of this study was to determine the prevalence of MRP on panoramic and cone-beam computed tomography (CBCT) views and to evaluate the associated risk factors. Materials and Methods: In this study, 710 panoramic radiographs and 90 CBCT scans were examined with regard to the presence of MRP in the maxillary sinus during 2014-15. The MRP prevalence and some associated risk factors such as age, gender, season, smoking, allergy, asthma, chronic sinusitis, nasal polyp, mucosal thickening, and post-nasal drip (PND) were evaluated. Results: The frequency of MRP was 2.4% on the 710 evaluated panoramic images and 43.3% on the 90 evaluated CBCT views. The frequency of MRP on the panoramic and CBCT views was higher in males than in females. There was a significant association between smoking and MRP on panoramic images (P=0.02) and CBCT views (P<0.001). There was a significant association between PND and MRP on CBCT views (P=0.02). The highest frequency of MRP was seen in spring (P=0.04) according to panoramic radiographs and in spring and summer (P=0.001) according to CBCT views. Conclusions: The occurrence of MRP had a significant association with smoking and PND, and the highest frequency of MRP was detected in spring and summer. Also, CBCT scanning detects MRP more accurately than panoramic radiography