مجله دانشکده دندان پزشکی اصفهان
سال نوزدهم شماره 1 (پیاپی 82، بهار 1402)

The purpose of this study was to compare different methods used for maxillary molars distalization with Temporary Anchorage Devices (TADs) with a Finite Element Analysis (FEM) method.

In this study, three different finite element models were constructed to represent three different methods of distalization. In model 1,a mini screw was inserted in the midpalatal area and used as a skeletal anchorage for the distal movement of the first and second maxillary molars. Model 2 was designed based on the insertion of mini screw in the buccal area. In model 3,a palatal plate was used for molar distalization.

IIn this study, three different finite element models were constructed to represent three different methods of distalization. In model 1,a mini screw was inserted in the midpalatal area and used as a skeletal anchorage for the distal movement of the first and second maxillary molars. Model 2 was designed based on the insertion of mini screw in the buccal area. In model 3,a palatal plate was used for molar distalization.

In model 1 and model 2, distal movement of both molars occurred, but in model 3, some mesial movement was seen in buccal cusp of the first molar and both cusps of the second molar. Maximum distalization of the first and second molar occurred in model 2.

Growth factors and cytokines in the platelet play a major role in the progression of inflammation and healing processes, therefore A-PRF and L-PRF as platelet drive ingredients are widely used in periodontal treatments. The purpose of this study is to compare the effect of A-PRF and L-PRF on the number of gingival fibroblasts adhered to collagen membrane.

In this In-vitro study conducted in winter of 2021 at the Iranian biological resource center, the membrane was cut into five pieces (5x5 mm) and placed at the bottom of a 5 well plate. 1 milliiiter of (A-PRF) was added to two wells in each group. And a similar amount of L-PRF was added to two wells in the other two groups. The last well was left A-PRF or L-PRF free. Gingival fibroblasts were seeded in all the wells. Cell adhesion was evaluated by means of a Field Emission Scanning Electron Microscope after 24 hours of incubation. The Data were analyzed by, one way and two-way ANOVA and Scheffe test (p value < 0.001).

Based on ANOVA there was a statistically significant difference In the A-PRF + group and L-PRF+ group (12.50 and 13.57) compared to the control group (4.67) (p value < 0.001).and Scheffe analysis showed no statistically significant difference between A-PRF+ or L-PRF+ groups (p value = 0.307).

A-PRF and L-PRF are both effective in the adhesion of fibroblasts cells to collagen membranes, although there is no difference between A-PRF and L-PRF in the adhesion of fibroblast cells to collagen membranes.

Oral and dental health is a crucial aspect of overall health and has a great impact on the quality of life. The aim of this study was to evaluate the knowledge, attitude and performance of dental students of Kerman University of Medical Sciences in the field of oral and dental health.

In this cross-sectional study, a questionnaire was completed by 240 dental students of Kerman University of Medical Sciences and information about age, gender, years of education, parents' education, knowledge, attitude and performance of dental students in the field of oral and dental health were collected. To analyze the data, Pearson correlation coefficient and linear regression step by step method using Baron and Kenny test and Chi-square test. The level of significance was set at a p value < 0.05.

48% of students had high knowledge and 42% had a positive attitude towards oral and dental health. There was no significant relationship between the variables of age and type of entry into dentistry and the variables of attitude, knowledge and practice (p value > 0.05). Women and those whose parents were dentists had significantly better oral and dental health performance. There was a significant relationship between knowledge and performance and between attitude and knowledge (p value < 0.05).

The status of students' oral and dental health knowledge, attitude and performance are moderate and It is essential to develop effective programs to improve these variables to enhance the individual and professional performance of students in this field.

Discoloration of resin composite restorations cause patient dissatisfaction. Chlorhexidine mouthwash is an agent that causes significant discoloration of resin composite. The aim of this study was to investigate and compare the effectiveness of two methods of home bleaching and strip bleaching on resin composite samples that are discolored by 0.2% chlorhexidine.

In this in-vitro experimental study number of 24 disc-shaped samples were fabricated from Charisma Diamond resin composite. The initial color of samples was measured by CIE Lab system in spectrophotometer. The samples were immersed in the 0.2% chlorhexidine mouthwash for 2 weeks twice a day for 1 minute each time. The color of the samples was measured again. Samples were divided into 3groups (n = 8). One group was placed in distilled water as the control group. The next two groups were exposed to the effects of home bleaching with 20% carbamide peroxide gel and Crest 3D white luxe white strip. The color of the samples was measured for the last time. Data were analyzed with One-way ANOVA (α = 0.05).

The amount of l, a and b increased by 0.2% chlorhexidine mouthwash in all groups. However, no statistically significant difference was observed between the groups (p value > 0.05). After using bleaching techniques on samples were discolored by 0.2% chlorhexidine mouthwash, l, a and b decreased and the difference between the groups was statistically significant (p value < 0.05).

All of the samples were discolored by 0.2% chlorhexidine mouthwash. After using the bleaching techniques, the rate of color return in home bleaching and strip bleaching was higher than the control group.

 Odontogenic keratocyst (OKC), which is a developmental cyst has aggressive clinical behavior and its recurrence possibility is higher than other odontogenic cysts. The aim of this study was estimate biologic behavior of OKC with p53 immunohistochemistry comparison, as a tumor suppressor between OKC and ameloblastoma.

 In this experimental study, paraffin blocks of 14 OKC and 15 ameloblastoma, were collected from oral pathology department Qazvin University. After confirmation of H&E slides, they were stained immunohistochemically. Then the IHC slides were observed in terms of intensity and staining pattern. Finally, data were analyzed with Wilcoxon and Man-Whitney test (p value < 0.05).

 In 86.7 % of ameloblastoma with positive expression p53 marker, 77% were weak expression and 33% were moderate expression. Among positive staining samples 84.6% were focally and 15.4% were scattered. In the case of OKC 11.4% indicated p53 marker that 80% showed weak expression and 20% showed moderate expression. 50% were focally and 50% were scattered. These findings support was not significially different between intensity and pattern of p53 marker between ameloblastoma and OKC (p value > 0.05).

 Expression of p53 was similar in ameloblastoma and OKC. Probably, high expression of p53 in odontogenic epithelial cells was one of the reasons for the OKC aggressive behavior. This findings vindicate biologic behavior of OKC.

The aim of this study was to evaluate the educational environment of the School of Dentistry from the perspective of Ardabil dental students based on the DSLES model.

In this descriptive cross-sectional study, 197 pre-clinical and clinical students participated who studied in Ardabil Dentistry School in 2022. A 48-item DSLES questionnaire was used to collect data. Data analysis was performed using descriptive statistics and T-test.

The results of the analysis of 7 components of the educational environment based on the DSLES questionnaire showed the results as followings: the mean and standard deviation of student-student (2.18 ± 0.50), the organization of the educational program (2.16 ± 0.49), meaningful experience (1.81 ± 0.46), supportiveness (1.70 ± 0.49), breadth-interest (1.66 ± 0.47), flexibility (1.61 ± 0.43) and emotional climate (1.54 ± 0.41). Also, the mean and standard deviation in the whole questionnaire (educational environment) were estimated to be (1.82 ± 0.30). The results also showed that there is no significant difference in the educational environment of Ardabil Dental School from the perspective of Ardabil dentistry students based on gender (p value > 0.05); But there was a significant difference based on pre-clinic and clinic training course (p value < 0.05).

Based on the results, it is suggested that more attention should be paid to flexibility in the content of the curriculum and also to more communication channels between students and faculty officials to respond to their concerns.

Since 2019, the coronavirus has become a global problem and Iran has a high mortality rate in this regard. Dentistry and medicine are considered to be high-risk jobs during the pandemic, and it is essential that dentists and general practitioners have sufficient information to deal with the virus. The aim of this study was to evaluate and compare the knowledge and attitude of dentists and general practitioners in Isfahan regarding COVID-19 disease. Materials &

This descriptive-analytical cross-sectional study was performed on 200 dentists and general practitioners working in Isfahan. The data was collected by questionnaire and the prepared data were statistically analyzed by, independent t-test, ANOVA and calculating the mean.

The mean scores of general knowledges of dentists and general practitioners were 4.19 ± 1.24 and 4.35 ± 1.36, respectively, and their mean scores of specialized knowledges were 3.71 ± 1.49 and 1.32 ± 4.46 out of 7, respectively. The relationship between specialized knowledge score and degree was significant (p value = 0.001). The mean score of attitude with the subject of "concern about corona" in dentists and general practitioners were 3.39 ± 12.3 and 20.86 ± 2.68 and the mean score of attitude with the subject of "personal protection and preventive measures" in both Group was calculated 26.32 out of 35.

In the present study, dentists and general practitioners had sufficient knowledge about most aspects of COVID-19 disease, but they did not have sufficient knowledge about the incubation period of Corona virus and personal protection protocols and there is an urgent need for training in this regard. They also had a positive attitude towards the use of personal protective equipment.

 The most important goal behind preparing root canal is to clean the root canal. Using rotary instruments facilitate the preparation of root canal, and also it helps a better cleaning of the canal. The present study aimed to evaluate the attitude and performance of pediatric dentists about using rotary files in primary dental pulpectomy in Iran.

Methods and Materials: 

The present study is a cross-sectional and descriptive study conducted in 150 Iranian pediatric dentists in 2020. The questionnaires were completed by 148 dentists. The demographic data and the practice and attitude of Iranian pediatric dentists to using rotary files in the pulpectomy of primary teeth were collected. Data were analyzed using Chi-square test with significant level less than 0.05.

In the present study 45.6% of the participants used rotary files. While 55.8% of dentists reported that the most important advantage of rotary files compared to manual files is the reduction of working time, 62.2% of dentists reported that the most significant disadvantage of using rotary files compared to manual files in deciduous teeth is the high price of rotary files and necessary equipment. In this study 85% of the dentists reported using rotary files for both E and D deciduous teeth.

 Overall, based on the findings of the present study, the total prevalence of using rotary files in the pulpectomy of primary teeth among Iranian pediatric dentists is 45.6%.

 The use of photodynamic therapy is a relatively new approach in medical science with an old background. In this method, it is possible to use light to inactivate and destroy cells and microorganisms. In dental treatments, it can be effective in many aspects of treatment, such as the treatment of gum diseases, oral and premalignant lesions, and root canal treatment. Initially introduced as an anti-infective treatment, photodynamic therapy has become a promising treatment method due to various advances in this field.

Description: 

According to the various findings of this study, photodynamic therapy can be useful as an adjuvant treatment of gum diseases and root canal treatment as as it is a minimally invasive process and can improve the treatment outcomes. Additionally, it can be used in the treatment of premalignant and superficial lesions in the head and neck region, as well as for early diagnosis of premalignant lesions with the potential to become malignant.

 According to the recent advances regarding the use of photodynamic therapy in dental managements, today this method can be used as an adjuvant treatment in many dental procedures. In addition, further studies are needed to show the use of photodynamic therapy as an independent treatment in dental managements.