مجله تحقیق در علوم دندانپزشکی
سال هفدهم شماره 3 (پیاپی 65، پاییز 1399)

Chitosan has the property of inhibition of the growth of many pathogenic bacteria and fungi. Tissue conditioners are good substances for the growth and colonization of a variety of micro-organisms. The aim of this research was to investigate the antibacterial and antifungal properties of Chitosan, ZnO and Ag nanoparticles added to tissue conditioners.

In this clinical trial study, 42 patients were randomly divided into 7 groups. In first group, the patients received the tissue conditioners (control group) and the second to seventh groups received the tissue conditioners included Chitosan, ZnO and Ag by weight percentage of 0.675, 1.25, 2.5, 5, 10, 20. After 24 and 48 hours using these substances, the microbial culture inside the mouth and denture was done by sterile swap.

  Complete inhibition of growth at 24 h and 48 h occurred in Candida albicans at 2.5 % concentration and in Enterococcus faecalis, Pseudomonas aeruginosa and Streptococcus mutans at 5% concentration of Chitosan, ZnO and Ag nanoparticles. Over time, the growth rate of Candida albicans, Enterococcus faecalis, Pseudomonas aeruginosa and Streptococcus mutans was decreased.

Increasing the concentration of nanoparticles increases the growth inhibition in all studied microorganisms. By increase of growth inhibition, the growth of microorganisms also increases. An enhancement of 5% in the concentration of tissue conditioners results in complete inhibition of the studied microorganisms.

Maintaining the original geometry of canal is an important parameter in successful root canal treatment. The aim of this original study was evaluation of apical root canal transportation and centering ability of SafeSider and K-Flexofile using cone beam computed tomography.

Mesiobuccal root canals of maxillary first molars, with 20-40° curvature, were selected and randomly divided into two groups (n=20). The first group was prepared with K-Flexofile with passive step-back technique and the second group was prepared with SafeSider system. Canal transportation and centering ability was measured using pre- and post-operative CBCT images of the apical 4 mm of the roots taken at 1 mm intervals. Repeated measure ANOVA and Independent T-test were performed to compare data.

The reciprocating SafeSider system transported root canals significantly more than K-Flexofile in the apical 2 mm level and mesiodistal direction (P = 0.006). Centering ability of K-Flexofile in the apical 1 mm level and buccolingual direction was significantly better than SafeSider system (P =0.003).

Manual preparation with K-Flexofile was better capable of maintaining the original geometry of canal and showed better centering ability and less apical root canal transportation than SafeSider system.

Candida albicans play the main role in the onset, preservation and progression of denture stomatitis. Therefore, the present study was conducted with the aim of comparing the anti candidal effect of cinnamon and Querques infectoria extracts with nystatin for treatment of denture stomatitis.

In this experimental study, 43 patients with clinical diagnosis of denture stomatitis were selected and maxillary dentures were taken for 24 hours. Dentures randomly were divided into three groups of 14 tests and one denture was considered as a negative control group for immersion in distilled water. From the tissue surface, all dentures were sampled with swab and the samples were transferred to the laboratory after transfer to the culture medium and the colony count (CFU / mm2) was measured. Then, each of the 14 denture groups were immersed in a hydroalcoholic solution of cinnamon (70%), a hydroalcoholic solution of Querques infectoria (70%) and nystatin suspension for 24 hours. After 24 hours, repeat sampling and colony count was measured and then the colony count before and after immersion was compared. Data was analyzed using SPSS17 statistical software, Chi-square, Fisher exact tests and ANOVA.

There was no significant difference between the three groups obtained colony counts of Candida albicans from dentures (P-value = 0.01).

Both herbal extracts could be effective on treatment of denture stomatitis. It should be more evaluated in future studies.

Oral diseases affect the majority of the population and can affect a person’s overall health. It is reported that punicagranutum contain phytomedicinecapabale  of  suppressing oral pathogens associated with fungal diseases. The aim of this study is the assessement of punicagranutm extract antifungal activity on Candida albicans.

This study was performed in Qazvin University of Medical Sciences in 2019 The70% ethanol extract of punicagranutum was purchased from the Research Institute of Chemical Industry Development and then made in 1- 1/2048 mg/ml concentrations.The antifungal activity of the extractwas examined by determining the MIC (minimum inhibitory concentration) using the Macrobroth dilution method, means macroscopic examination of the test tubes containing serial dilutions of extract and candida albicans to determine the growth or lack of growth of microorganisms through the eye, and MFC (Minimum Fungicidal Concentration) was determined by preparing the subculture of the contents of all of the undeveloped tubes in a MIC experiment in a solid culture. Also, the non-growth aureole diameter with Agar well diffusion method was obtained by preparing wells in a solid culture medium  And pouring different dilutions of the extract into it and measuring the non-growth aurachr('39')s diameter.Data were analyzed using ANOVA, post-hoc tests  (p<0.05).

Results showed that the ethanol extract of punicagranutumhad inhibitory effect in concentration of   mg/ml and fungicidal effect in concentration of  mg/ml in which the most of this effect is due to punica granutumbut not theethanol.Also, the mean of maximum non-growth aureole diameter was 21 mm at a concentration of 1 mg / ml.

Comparison of the results of ethanol control group and test group showed that inhibitory and fungicidal effect of hydroalcoholic extract of punicagranutum is not due to Ethanol and the punicagranutum and Ethanol extracts of punicagranutum has antifungal effect on Candida albicans.

Dental caries is a multi-factorial disease Demographic factors, also diet particularly breakfast  which  is an important meal are  factors affecting the level of dental caries. The purpose of this study was investigation  relationship between morning feeding and other demographic factors with  tooth decay in  9 years old Zahedan students

In This descriptive – analytical and cross-sectional study, Zahedan city  divided into four regions based on population table.From each region one public and private school (boy &girl), randomly selected,. for 400 boy& girl students  9 years old was filled the questionnaire about demographic factors, and   breakfast consumption  and oral examination was done for evaluation of  dmft, DMFT and OHI-s criterias by a dentist  . Data  were analyzed  with  soft ware  spss 21  and t-test , ANOVA and Pearson correlation..

The  Mean dmft, DMFT in children served breakfast (5.22±2.5 and 1.34±1.4 ( and in  children  did not consume breakfast (4.5±2.5 and 1.39±1.44) had no significant difference (p>0.05) but  the motherchr('39')s occupation and, father education had significant correlation  with DMFT and  mother  education had significant correlation with  DMFT,,dmft (P <0.05)

breakfast  consumption and its type  was not effective in reducing the level of dental caries. Children with educated mothers had  low permanent and  insidious dental caries and tooth decay  was significantly  lower in children with  employer or teacher  mothers and    educated fathers  .

Drugs have a direct and indirect effect on oral health. Oral problems can affect and impair consumerschr('39') quality of life. Therefore, the present study aimed to evaluate oral health indicators in outpatient addiction treatment centers.

In this descriptive cross-sectional study, 150 addicts referred to three public drug addiction treatment centers in 2019 were studied. The questionnaire consisted of three sections; part 1: demographic information (age, sex, marital status, education, economic status), part 2: information on tobacco use history, types of consumables and methods of consumption, and part 3 Measurement of DMFT indices And Plaque Control Record was used. Data were analyzed using T-test, ANOVA and Spearman correlation coefficients.

In this study, 150 people were included. Of these, 125 were men (92.6%) and 10 were women (7.4%). The mean age±sd addicts was 33.07 ± 10.92 years with a range of 68-13 years. The mean ±sd DMFT was 16.04 ± 9.36 with a range of 32-22 and the mean±sd Plaque Control Record index was 18.92 ± 7.44 with a range of 39.5-5.12.

Drug use increases DMFT and Plaque Control Record indices. It seems that the oral health needs of the drug addict population are widespread and need to be pursued.

Odontogenic cysts are divided into different types of developmental and inflammatory growth.Odontogenic tumors comprise a complex group of lesions.The aim of this study was to evaluate the knowledge of general dentists working in Isfahan of common odontogenic cysts and tumors.

The statistical population of Isfahan general dentists and the number of samples was 199.Standard self-made questionnaires were used to assess the level of knowledge of dentists and paired analytical tests T and T and analysis of variance were used for statistical evaluations.

The mean score of knowledge about cysts (52.9±9.8) and tumors (33.8±21.6) was statistically significant,There was a significant difference between dentistschr('39') knowledge about cysts and tumors,Dentists were moderate for cysts and poor for tumors.Independent t-test showed that dentistschr('39') knowledge score about cysts and tumors was not significantly correlated with gender (P=0.22, P=0.21).One-way ANOVA showed that dentistschr('39') knowledge about cysts and tumors was not significantly correlated with the university of study (P=0.73, P=0.49),The results also showed that the mean score of dentistschr('39') knowledge was significantly correlated with the year of graduation (P = 0.001, P = 0.04)and the highest score was for graduates 69-80years and the lowest score was for graduates 86-90 years.

The results showed that the level of knowledge of most dentists in Isfahan about cysts was moderate and that of tumors was poor. The mean score of dentistschr('39') knowledge about cysts was significantly higher than their knowledge of tumors was significantly correlated with the graduation year so older graduates were more aware about cysts and tumors.

many of systemic diseases are associated with different oral mucosal lesions. One of the most important center for discovery of oral lesions is Internal medicine ward. According to important role of early diagnosis of oral lesions in patients with systemic diseases, this study was designed to evaluate the frequency of oral mucosal lesions among hospitalized patients to internal ward of Yazd Shahid Sadoughi of Medical Science.

In this cross sectional study, two hundres five recently hospitalized patients to internal ward, randomly were investigated for oral mucosal lesions. Age, sex, type & location of lesions, oral hygiene status, smoking and dental prostheses were documented. Data were analyzed by SPSS 19 using Chi square and Fisher exact tests.

80 men and 125 women with the mean age of 52.8 years were examined. Age range of patients was between14 to 97.in this study, Red & white lesions were found to be the most common mucosal lesions (38%), followed by vesicullobullous (12.8%), pigmented (9.8%) & exophitic lesions (6.8%), respectively.

According the high frequency of oral mucosal lesions in hospitalized patients and the importance of early detection, oral medicine specialists beside the physicians can be an important role in early diagnosis and treatment therefore oral examination of hospitalized patients should be considered.

Tobacco products are the cheapest addictive substance available to the community, causing the deaths of six million people a year. In addict persons the amount of oral hygiene and regular referral to dentistry decreases sharply. Considering the fact that young people in many cases they hide cigarette smoking, in this study, we decided to evaluate the state of tobacco abuse status based on oral evidence in males high School Students. 

Material & Methods

This descriptive-analytic study was done by cross-sectional method. Four hundred  shahrbaak male High School Students in 2019 enrolled to the study. The data gathering tool was a pre-prepared questionnaire consisting of two parts: the first part included demographic information and the second part surveied frequency of taking drug use over the past 12 months. Data were analyzed by SPSS 20, T-test ، Chi-Square and Fisher Exact tests. P-vaue less than 0.05 was considered statistically significant.

The frequency of tobacco products abuse based on self- declaration of students was 32.2% and oral evidence was 23.2%. Oral evidence showed 9.5% of the subjects had lips pigmentation, 7.8% had dental color changes and 6% had both. Increasing the number of children, reducing the level of education of parents, having a history of smoking in the family and reducing the academic grade point average, increase the rate of tobacco products abuse in students based on oral evidence and self-declaration.

Factors such as number of children, parentschr('39') education, family history of smoking and academic grade point average, affect the frequency of tobacco products abuse.

  Learning styles are one of the manifestations of individual differences and answer the question of why not all people learn in the usual way and their learning outcomes and academic status are different. The present study examined the relationship between learning styles based on club theory and academic status in resdent of dentistry,faculty  of dentistry, Tehran Medical Sciences, Islamic Azad University.

Methods and Materials:

This research was maded based on cross-sectional method. With the consent of 84 students of dental who were selected by the census method. The kolbchr('39')s standard  Questionnaire and GPA for the entire general course of study were used to collect information. By completing the questionnaire and reviewing the scores obtained by individuals, each personchr('39')s learning style was determined. Data analysis was performed by SPSS software and test (chi square and ANOVA). The study was performed on 84 dental assistants . 64.3%  women and 35.7%  men. The mean and standard deviation of studentschr('39') GPA was16/83 ± 0/239. 81.1% of people had a convergent learning style, 10.7% had an Accommodator style and 7.1% had an Assimilator style. None of the people had a divergent learning style. Examination by statistical tests did not show a significant difference between academic status and different learning styles..  Also, due to the predominance of students with convergent learning style, providing learning environments appropriate to this style, is important for  forcing students to think and scrutinize issues in teaching and learning them for better learning. And acquire or strengthen the necessary capabilities in future educational and work environments.

Background and Aim :

 Today, tissue engineering is considered a significant approach in modern medicine, which is why research in biomaterials has focused on the development of advanced scaffolding for regenerative medicine.  Many natural and synthetic polymers with a variety of origins have been used to make these scaffolds or are recommended by researches. These compositions usually have the properties such as biocompatibility, biodegradability, and some special advantages such as antibacterial properties and wound healing. Other advantages of these polymers and their derivatives are porous structure, sol-to-gel changing ability, ease of chemical modification, high resemblance to biological or intracellular macromolecules, making them valuable candidates for making supporting compositions or scaffolding used in tissue engineering

Methods and Materials:

 To conduct this review, the Science Direct, Google Scholar, PubMed, and Silivica databases were searched by using the following keywords: " pulp"," regeneration"," scaffolding", and "tissue

According to the evaluated researches, a wide range of natural and synthetic compositions can be used as the scaffold for dental pulp regeneration. These materials, that play the role of scaffolding in the three-part tissue engineering, get the best results when create the good conditions for the proliferation of pulp-tissue progenitor cells and good signaling for the invocation and differentiation of these cells into more specific cells. However, in more studies, these scaffolds were used as carriers of precursor cells and growth factors.

Tissue engineering is one of the emerging and successful methods for pulp tissue regeneration. Among the principles of tissue engineering, scaffolds can encourage the regeneration process due to the possibility of independent activity without the presence of precursor cells and independent growth factors. Among the types of scaffolds that were studied, natural based materials have shown the highest level of success.