مجله تحقیق در علوم دندانپزشکی
سال نوزدهم شماره 1 (پیاپی 71، بهار 1401)

Surgical extraction of mandibular third molar is the most prevalent oral surgery. Many factors can affect subsequent complications of it. This study aimed to assess radiographic and non-radiographic factors of impacted mandibular third molar and determine the relationship between these factors and surgical complications.

This study has a prospective cohort design and was conducted on 53 patients who had indication of impacted mandibular third molar surgery, in 2020 at Shahid Sadoughi day clinic in Isfahan. the effect of root morphology, Pederson scale, mandibular canal relationship, tooth exposure, and number of operated teeth on surgical complications including pain onset and pain amount, and surgical duration was evaluated. the data was analyzed with Spearman's correlation coefficient, Kruskal–Wallis analysis, Fisher's exact test, and Mann–Whitney test (α<0/05).

The relationship between molar position and surgical duration was statistically significant (p<0/01). the relationship between relative depth, ramus relationship, and root morphology, with surgical duration was also statistically significant (p<0/05). the relationship between age and post-surgical pain scale was also statistically significant (p<0/05). the relationship between Pederson scale, gender, number of extracted teeth, tooth exposure, and mandibular canal relationship with difficulty variables and surgical complications was not meaningful statistically (p>0/05).

Molar position, ramus relationship, relative depth, and root morphology affect surgical duration and could be used in predictive models. Gender doesn’t affect surgical complications and couldn’t be beneficial in predictive models.

Polish and glaze are 2 methods to decrease roughness and bacterial adhesion to the ceramic surfaces. This in vitro study assessed the effect of polish and glaze on the bacterial adhesion of 3 ceramics.

In this in vitro trial, samples of zirconia-reinforced lithium silicate, lithium disilicate and monolithic zirconia ceramic specimens were milled by CAD/CAM device from the blocks and sintered in the oven. The specimens were polished, glazed or remained intact with no preparations as a control group. The specimens' surface roughness were assessed by a profilometer followed by exposing to streptococcus mutans bacterium. The bacterium suspension were inoculated in wells containing tryptic soy broth + 0.2% glucose and ceramic specimens were placed into the wells. The plates were incubated for 48 hours at 37C° to form biofilms on the specimens. After washing, biofilm fix and ethanol removal, 1ml 0.4% crystal violet dye were added. The dye was removed and after washing, 1mm 30% acetic acid was added and 200 µl of the wells containing were transferred to a 96-well plate.The observations of streptococcus mutans adhesion to ceramic specimens were done by SEM.  Two-way analysis of variance was used for evaluation of ceramic type and preparation effects and one-way variance and tukey tests were used for intragroup evaluations.

In the Zolid ceramics, significantly higher bacterial adhesion were noted in the glazed than polished specimens (p=0.005). In the glazed specimens, significantly higher bacterial adhesion were noted in the Zolid ceramic than Suprinity (p=0.01) or IPS.Emax (p=0.009) ceramics.

Then, the surface preparation method showed significant effect on the bacterial adhesion only in Zolid ceramic. Except to polished Zolid ceramics, all ceramics and preparation techniques showed bacterial adhesion.

Chronic periodontitis is caused by a complex of periopathogenic microorganisms, some of which are more closely related to the active phase of the disease. The aim of this study was to investigate the antibacterial effect of two desensitizing agents voco bifluoride 10 and Mi paste on three common periopathogen bacteria

In this experimental laboratory study, samples of three types of bacteria A.a (Aggregatibacter actinomycetemcomitans), Porphyromonas gingivalis (P.g) and P.I (Prevotella intermedia) were used. From each of the compounds of voco bifluoride 10 and MI paste, 3 disks were prepared. After drying and sterilizing the disks, the quality control operations of the disks were performed and cultured in suitable media and exposed to 37 ° C for 48 hours. According to the halo around each disk and its measurement, the growth or non-growth of bacteria was examined. Data were analyzed using t-test and two-way ANOVA

There was no significant difference between the mean diameter of growth inhibition zone of all three types of bacteria A.a, P.g and P.i and the control group under the influence of voco bifluoride 10 and MI (P >0.05). The mean diameter of bacterial growth in the vicinity of MI paste was less than the diameter of bacterial growth in the vicinity of voco bifluoride 10, but this difference was not statistically significant (P >0.05).

The use of voco bifluoride 10 and MI paste have no effect on the diameter of the growth inhibition zone of periopathogenic bacteria.

Oral diseases, especially dental caries, are still prevalent in the most developing countries which cost a lot for patients and the health care system. One of the most important ways to reduce costs is to prevent caries. Therefore, the aim of this study was to evaluate the effect of chlorhexidine and fluoride mouthwashes in comparison with Nanosil D1+F combined mouthwash on Streptococcus mutans in vitro.

In this experimental study, well diffusion method was used to evaluate the diameter of the growth inhibition zone of the mouthwashes (chlorhexidine 0.2%, fluoride 0.05%, nanosil D1+F). Then, MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of the mouthwashes were evaluated by the standard microdilution method.

Based on the results of the well diffusion method, the diameter of the growth inhibition zone for fluoride, chlorhexidine, and nanosil mouthwashes was 9, 18 and 32 mm, respectively. MIC values were 125 mg/ml for fluoride mouthwash, 3.9 mg/ml for chlorhexidine mouthwash and 1.95 mg/ml for nanosil D1+F mouthwash. The MIC and MBC values were the same for each mouthwash.

According to the results of the present study, Nanosil D1+F mouthwash had stronger antimicrobial effects on Streptococcus mutans than chlorhexidine 0.2% and fluoride 0.05%.

Nowadays the use of digital technology in dental education hasdramatically increased. The growth and development of educational models shows that it is important to change the approach of education from traditional methods to electronic methods and virtual education. We conducted the present study in aims of investigating the effective factors on the quality of virtual learning from the perspective of dental students of Zahedan University of Medical Sciences.

In this phenomenological qualitative study,a total of 15 semi-structured interviews were conducted until reaching the saturation point. All recorded interviews were transcribed and important phrases were extracted. MAXqda 2018 software was also used to analyze the interviews.

Main themes include "Advantages of face-to-face education", "Limitations of face-to-face education", "Virtual education learning methods", "Advantages of e-learning", and "Disadvantages of e-learning "," E-learning limitations and Suggestions". The main themes of "advantages and disadvantages of e-learning" and "Suggestions for improving E-learning" were emphasized because they had the highest number of sub-themes.

According to the obtained data, the general view of virtual education was positive and despite the mentioned disadvantages, virtual education was considered effective and useful. The students' perspective also showed that the main themes of "advantages and disadvantages of e-learning" and "suggestions for its improvement" were emphasized. Reinforcement of positive point, fixing the defects can improve the virtual education.

Student course is the best time to learn the principles and methods of applying professional ethics, which results in establishing proper communication with patients. However, few studies have been conducted on the level of knowledge of dental students about ethical principles. This study was conducted to investigate the knowledge of last year dental students of the Islamic Azad University of Tehran about the principles of professional ethics in 1399.

This descriptive-analytical cross-sectional study was performed by census method on 150 students of 11th and 12th semesters of dentistry using a valid and reliable questionnaire and according to the ethical principles of ADA. Finally, the data including age, gender, semester, average grade point, and average score of professional ethics were imported into SPSS 24 software and were analyzed using Mann-U- Whitney and multiple regression test. A significance level of 0.05 was considered for all analyzes.

150 students (61 men and 89 women) participated in this study. 71 students (47.4%) were in the 11th semester and 79 students were in the 12th semester (52.7%). The average age of students was 24.68 years and the average grade point of all students was 16.28. After completing the questionnaires, the average score of knowledge of professional ethics was 9.95 (55.2%). The mean score of knowledge of professional ethics in women was slightly higher than men, which was not statistically significant. There was no significant relationship between the ethics score and none of the variables of age, gender, number of credits passed, total grade point average and semester.

The level of knowledge among dental students towards the principles of professional ethics is moderate and this knowledge is not related to demographic characteristics and educational status of the students.

By considering  the relatively high prevalence of systemic diseases, the importance of these diseases in patient management, treatment planning, and treatment outcomes, the controversy in the reported incidence rates, and changes in the frequency of diseases over time, The aim of this study was to determine the frequency of systemic diseases and related factors in patients referred to the Department of Oral and Maxillofacial Diseases, School of Dentistry, Islamic Azad University of Tehran, between 2017 and 2020.

In this descriptive cross-sectional and retrospective study, 1699 records of patients referred to the Department of Oral and Maxillofacial Diseases department  between 2017-2020, which were in the archives of the faculty, were reviewed. Data were recorded in Information forms included :age, sex, place of birth, marital status, occupation, pregnancy, smoking , drug use, history of hospitalization , history of specific illness in first-degree relatives , history and type of systemic diseases. Patients were classified according to the mentioned variables and the frequency of each class was calculated. Data were analyzed by spss11 and statistical tests were used are: chi2- Anova- Binary logestic regression.

Among 1699 patients, Systemic diseases were reported in 717 patients (42.2%). The most common systemic diseases are hypertension (19.1%), diabetes (14.4%), gastrointestinal diseases (10.7%) and the least common systemic diseases are rheumatic fever, history of chemotherapy and radiotherapy and endocarditis.The relationship  Between age, marital status, drug use, smoking, history of hospitalization were significant and having first-degree relatives with a history of underlying diseases with systemic diseases was statistically significant. (P=0.003)

 The results of the present study showed that relatively remarkebale percentag of our sample sizes which reffered to dental school, sufferd from systemic diseases.this mater emphasis on exact and correct history taking to achive the best and low risk patient's treatment.

  Various factors cause damage to the eyes of dentists, staff and patients during dental procedures. Due to the presence of microbial agents in saliva, it is necessary to pay attention to eye protection. However, according to studies, only 62-52% of dentists use personal protective equipment. Therefore, this study aimed to evaluate the knowledge and practice of dentists regarding the use of goggles to prevent eye injuries in dentists, office staff and patients.

The present cross-sectional study was designed and performed on 114 general and specialist dentists in Zanjan in 1399. The questions were designed in two areas of knowledge and practice, and after reviewing the reliability and validity of the questionnaire were provided to the participants. Related to statistrial analyzing fo data, Mann-U-Whitney and kolmogoro-smirnov tests were approached.

Frequency of dentist’s knowledge and theire performance were 60.37±28.92 and 40.26±48.93, respectively Statistical analysis showed that despite the high knowledge and practice of specialists in all cases compared to general dentists; there was no significant difference between the two groups in the use of goggles to prevent eye injuries of dentists, office staff, patients (p> 0.05 ).

In general, the knowledge of specialist dentists about the use of protective glasses and their performance is better than general dentists and there is a need for further education in the field of eye injuries and the use of protective glasses.

Due to their occupational nature, dentists may be prone to musculoskeletal disorders in the upper body. The aim of the present study was to study of musculoskeletal disorders of the cervical spine and upper extremity in dentists with a review approach.

In this review article, an attempt was made to collect studies conducted on the subject of research from 2000 to June 2021. The websites Google Scholar, PubMed, Science Direct, SID, ISC and Magiran were used and keywords related to the topic were used to search for articles. 

According to the search method, 140 articles were found, which were finalized, according to the inclusion and exclusion criteria abstract of 45 articles. Finally, 29 articles were reported based on the full text and compliance with inclusion and exclusion criteria in the present study. Most studies have reported the cervical spine as the most common area. Other results were included more than half of Dentists experience musculoskeletal disorders, more among women than men, at least one disorder in the last 12 months, as well as temporary disability and lack of daily activities due to pain and musculoskeletal disorders.

In general, the knowledge of specialist dentists about the use of protective glasses and their performance is better than general dentists and there is a need for further education in the field of eye injuries and the use of protective glasses.

Epulis Fissuratum (EF) is a hyperplasia of mucosal fibrosis and its main cause is the use of improper prosthesis. Treatment of these lesions is necessary because any change in the natural tissue of the oral mucosa causes the accumulation of opportunistic microflora, such as Candida albicans. Therefore, this study aimed to report an interesting observation about the EF response to drug therapy.

A 62-year-old female patient referred to the Dental Clinic of Semnan University of Medical Sciences (SUMS) while suffering from a long-term mouth ulcer.Diagnosis of EF was suggested based on the clinical appearance as well as the association of the prosthesis with the lesion. Therefore, gargling a suspension of 100,000 units of nystatin four times a day was also prescribed, and oral hygiene by removing the prosthesis was recommended, in unnecessary times and at night.Subsequently, in follow-up sessions, a gradual improvement was observed unitl the disease was completely eliminated .

It seems,  Regarding the relationship between EF and the accumulation of microorganisms, a cours of drug treatment might be notable effect on reduction size of EF.