Journal of Dentomaxillofacil Radiology, Pathology and Surgery
Volume:9 Issue: 1, Spring 2020

Chemical control of plaque is performed in a variety of pharmacological ways, including the administration of biguanides. Among these bisbiguanides, chlorhexidine is the most common and well-known type of them. The results of different studies on tooth discoloration due to chlorhexidine use are different. The aim of this in vitro study was to compare the effect of concentration and presence of anti-discoloration system in chlorhexidine mouthwashes on tooth discoloration.

This experimental study was performed in-vitro on 32 anterior teeth extracted from patients referred to Guilan University of Dental school, regardless of age and sex. We organized 4 groups including Chlorhexidine group with 0.2% Curasept anti-discoloration system, chlorhexidine 0.12%, chlorhexidine 0.2% and water as negative control. The baseline colors and after treatment colors were recorded by using Vita Easyshade V spectrophotometer and eventually  was calculated.

The mean coloration intensity of chlorhexidine group with ADS, was 2.10 1.43, group of 0.20% chlorhexidine was 2.42  1.09 and 0.12% chlorhexidine was 3.25 1.15 and water was 2.87  1.28. There was no statistically significant difference between all the groups (p = 0.295).

There was no difference between the two concentrations and the presence of anti-discoloration system in chlorhexidine mouthwash. None of the mouthwashes changed the color of the teeth significantly.

In the last month of 2019, the world faced a new and mysterious type of coronavirus disease that sometimes caused pneumonia.In some of the sickened cases, multiple organ damages and Acute respiratory distress syndrome had identified that could arrive to death.To date, despite multiple studies, no vaccine & definitive cure has been discovered Although there has been some efforts for finding proper drugs and treatment plans such as remdesivir.Therefore, disease abatement is still the safest and easiest manner for controlling the virus in public society. Accordingly preventing the disease transmission chain in dental settings and dentistry field is deemed one of the first priorities of healthcare systems due to its high transmissibility in dental practice. This study achieved to review the current knowledge of COVID19 and providing the proper guidelines for all dentistry branches.

To evaluate the ability of dentists in Rasht, Iran, to determine the tooth color by sex, age, and clinical work experience.

A shade tab from the Vita 3D Master shade guide and a questionnaire were sent to each dentist. The questionnaire collected demographic information, namely age, gender, and work experience, so that the results could be examined separately for each variable. At this stage, the dentists answered the questions related to the characteristics of the color samples in terms of value, hue, and chroma, while their knowledge of color evaluation was also examined by certain items. Color evaluation was performed under standard conditions. Finally, the data were statistically analyzed by the chi-squared test at the significance level of 0.05.

The frequency of accurate determination of tooth color was 17.7 %. Generally, no significant difference was found in accurate tooth color identification in terms of sex (p = 0.912), age (p = 0.22), and clinical work experience (p = 0.236).

Dentists had a poor ability in selecting the tooth color, which is affected by a lack of knowledge of the principles of light and color. In addition, dentists should use novel methods for determining color.

Patient dose is the most important concern for any new X-ray system. The dose received by the patients depends on the imaging technique, the optimization of the collimator, filtration and field of view (FOV). The purpose of this study is to evaluate the effect of various imaging parameters on dose received by different organs in a dental CBCT scanners.

In this study, dental CBCT system (Planmeca 3d mid) including the X-ray tube, flat panel detector and a voxelized phantom, was simulated by the GATE Monte-Carlo Code (Version 8). DICOM CBCT images of a person, and Alderson Rando phantom were segmented using MATLAB and 3D slicer software to identify various organs such as bone, bone marrow, soft tissue, brain and thyroid.

The half value layer of the simulated X-ray was found to be 2.6 mm which differed from the experimental value by approximately 6.47%. In some cases, the 3D dose distribution for Rando Phantom was less than that for Voxelized phantom simulated by CT images of a normal person.

The reason of this difference is attributed to the different substances definition. The difference in experimental and simulation data can be due to several reasons i.e. the inaccuracy caused by the use of a limited number of TLDs in experimental measurements, the impossibility of simulating Gentry's actual rotation (hyperbolic's rotation) and the uncertainties caused by converting CT images to e Voxelized phantom.

The peripheral giant cell granuloma(PGCG) or the so-called “giant cell epulis “ is one of the most common oral giant cell lesions. It occurs in response to chronic local irritation, and originates from mucoperiosteum or the periodontal ligament.This article presents the clinical and histopathological findings of PGCG in the esthetic zone in a 26 years old female patient. The treatment plan consisted of an excisional biopsy with immediate soft tissue grafting by placement of a free gingival graft in order to prevent esthetic complications. The six-month clinical follow-up showed no recurrence of the lesion and soft issue healing.Proper management of a PGCG lesion requires eliminating other pathologies prior to planning for surgery. Correct diagnosis of such lesions is essential to optimize the treatment and prevent recurrence. Clinical examination alone may not give a correct picture, thereby requiring histopathological confirmation.Immediate soft tissue augmentation using free gingival graft has been suggested as a surgical solution after removal of PGCG when soft tissues and the whole attached gingiva is lost.

The aim of this study was to evaluate the knowledge of senior dental students about Hepatitis B, Hepatitis C and Human immunodeficiency viruses (HIV).

This was a cross-sectional, descriptive, questionnaire-based study. In the study, a researcher-made questionnaire was used. The questionnaire had 2 sections. First section recorded demographic data of participants (age, gender), the type of faculty (Guilan University of Medical Sciences or the International Campus branch) and students’ semester (11th or 12th). The second section included 13 questions. Validity and reliability were determined. For each correct answer, score one was considered and for each wrong answer, score zero was determined. Their knowledge was categorized as poor (0-4), moderate (5-9), and good (10-13) Data obtained from research questionnaires was analyzed by SPSS software version 21 using chi-square, kruskal-wallis test and Mann Whitney. Significant value was set as p< 0.05.

showed that, the effects of age, gender, type of faculty and semester on the knowledge of students in dental faculty of GUMS and International Campus faculty were not significant. The mean score of students’ knowledges was 5.47±1.63.

Students’ knowledge was moderate in the current study. Efficacious training programs should be prepared for dental students to increase their knowledge, regarding hepatitis B, hepatitis C and HIV.

A few studies have investigated the effect of saliva contamination of cured or uncured adhesive systems. The aim of this study was to evaluate the effect of salivary contamination and different decontamination methods on microleakage of composite restorations. 

Class V cavities (2 mm wide, 1.5 mm deep, and 4 mm long) were prepared on buccal and lingual surfaces of 135 extracted human premolars. The specimens were randomly divided into 9 groups, 30 cavities in each. The materials used consisted of single bond (3M) and Z250 (3M). Except group 1 (Control), in Groups 2-5, uncured adhesive, and in groups 6-9 cured adhesive was contaminated with saliva (30 s). Decontaminating procedures were: blot-drying, rebonding (Groups 3 and 6), rinsing, air-drying, rebonding (Groups 4 and 7), rinsing, blot-drying, rebonding (Groups 8 and5). In groups 2and 9 no decontamination procedure was done. After restoring the cavities, thermo-cycling and dye penetration, they were sectioned buccolingually and analyzed by stereomicroscope. Data were analyzed by Kruskal-Wallis and Dunn tests (P<0.05).

In occlusal margins; there were no significant differences in the microleakage between groups 3,4,5 with group 1(P>0.05) but in gingival margin, there were significant differences in the microleakage between all of the groups with group1(P= 0.0001).

None of the methods in this study could reduce the micro leakage in the cavities with both enamel and dentin margins.

 Due to the important role of imaging in the diagnosis and treatment plan in orthodontics, CBCT (Cone Beam Computed Tomography) images because of their three-dimensional nature, can minimize the disadvantages of two-dimensional images such as magnification, distortion, or superimposition. The purpose of this study was to evaluate the accuracy of conventional cephalograms and CBCT scan measurements in linear orthodontic diagnostic measurements.

In the first part, the distances between the 14 anatomical landmarks on the 5 dried human skulls (reference models) identified by metal spheres were measured by a digital caliper. In the next step, CBCT images were scanned from the same reference models. In the second part, radiographic images were taken from 26 patients enrolled according to inclusion and exclusion criteria in three stages, scanning CBCT images, digital LC (Lateral Cephalometric) images from the same CBCT images, manual tracing of digital LC images. Finally, using the obtained data, the accuracy of measurements performed directly on the reference models with CBCT images as well as the CBCT images, digital LC and traced digital LC images of the patients were evaluated together.

The mean of direct measurements on the reference models was not significantly different from the measured values on CBCT images (ρ-value> 0.05). In other words, the measurement of the CBCT images was the same as the reference models. Also, in most cases, linear measurements between the traced LC image with digital LC images and the CBCT of patients were different (ρ-value > 0.05). Meaning traced LC images and digital LC in 8 cases, CBCT and digital LC in 4 cases and finally traced digital LC and CBCT in 5 cases were different.

The present study showed that the accuracy of CBCT image measurements was similar to the direct measurements obtained from the reference models. Also, the accuracy of linear measurements of CBCT images is higher and more reliable than that of digital LC images as well as traced digital LC images.