مجله تحقیق در علوم دندانپزشکی
سال هفدهم شماره 2 (پیاپی 64، تابستان 1399)

Pain during injection of local anesthesia causes fear and anxiety in many patients that could be a reason why patients avoid regular dental treatment. Previous studies have reported the effect of warming anesthetic solutions in various areas such as skin, plastic surgery, and cataract surgery. The purpose of this study was to evaluate the effect of warming anesthetic solution on the control of pain perception during maxillary infiltration in same patient erffering to faculty of Dentistry, Tehran Medical Sciences of Islamic Azad University at 2018.

This research was based on clinical trial,split mouth type. The patients with indication of anesthesia injection for both sides of maxilla which were agreed to participation of this study, considered as study samples.  2 percent Lidocaine (Daroopakhsh-Iran) was heated by (Tommee-Teppee-England) boiler to 40°C and the injection was performed at 37°C in the experimental group, whereas the opposite side, as the control, served 21°C (room temperature) injection. Either side of maxilla was conducted randomly as experimental group (warm injection) and control group (room temperature injection). The intensity of pain perceived during the injection was assessed by 100 mm Visual Analog Scale and statistically analyzed by the MANN-U-WHITNEY test.

Evaluation was made on 16 patients and regarding to type of study, 32 sides. Of samples, 7 male and 13 females were present and age average of them was 36.1±12.98 years old. VAS scores in the control group (room temperature injection) was 38.5±28.5 and in the experimental group (warm injection) was 27.5±20.9. Pain perception was 75% in the control group and 25% in the experimental group (P <0.01).

Warming local anesthetic solution prior to injection can efficiently reduce the pain compared to its use at room temperature.

Nausea reflex during impression-taking is a concern that decreases the patient's ability to accept dental procedures. There are several methods for elimination of nausea reflex, Prescription of Metoclopramide is one of these pharmaceutical methods. The aim of this study is to evaluate effect of Metoclopramide on the elimination of nausea reflex during impression-taking in patients referring to Prosthodontics Department of the Faculty of Dentistry Tehran Medical Sciences, Islamic Azad University in 2018-19.

This research is a clinical trial study (before and after study) which was performed on patients referring to fix Prosthodontics department, faculty of Dentistry. Patients should have no medical problem, without any history of drug or any other type of allergy. Only patients with a nausea reflex VAS benchmark over 5, were included in this study. The patients were asked not to eat since 3 hours before impression-taking. Then the nausea reflex intensity before pharmaceutical treatment recorded. Afterwards, 1 ml (25 drops) of Metoclopramide hydrochloride along with 1 mg of sodium saccharin (as a sweetener) was prescribed. After half an hour, the intensity of the nausea reflex was measured again by the same VAS system, and the amount of change in the nausea reflex intensity was investigated by McNemar's statistical test in SPSS V25 software.

The study was performed on 28 eligible individuals, 46.4% male and 53.7% women, and 25-56 years old, all of whom had a nausea reflex VAS of more than 5, while after using Metoclopramide, all patients (100%) reported nausea reflex score of 5 or less (P <0.0001). The reflex intensity before and after pharmaceutical treatment was 9/7 ± 3/3 and 3.1± 1.4, respectively.

It seems that prescription of Metoclopramide can eliminate nausea reflex intensity during impression-taking in dental patients.

Streptococcus sanguis is known one of the initiating agents of microbial plaque formation. In addition to the physical control of the microbial plaque, the use of mouthwashes as a chemical method to kill microorganisms is effective. Although chlorhexidine is the gold standard for the elimination of oral microorganisms, the unpleasant side effects of its long-term use warrant a more appropriate alternative. The purpose of this study was to compare the antibacterial effect of nanosilver and chlorhexidine mouthwash on Streptococcus sanguis in pediatric department, faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University in 2018-19.

This experimental study was performed on Streptococcus sanguis (in vitro). Experiments were performed on two groups of case (nanosilver mouthwash) and control (chlorhexidine mouthwash) in three parts Initially, antimicrobial potency was measured by Disk diffusion method assay by measuring inhibitory zone diameter. Then, micro and macrodialysis methods were used to measure MIC (minimum inhibitory concentration) and finally to measure MBC (minimum bactericidal concentration) used the Blood agar dilution method.

Statistical analysis showed that the nanosilver mouthwash has no inhibitory zone. Also its MIC and MBC were higher than chlorhexine and this difference was statistically significant (P <0.001)

According to the results of the in vitro study nanosilver mouthwash  has minor bacteriostatic and bactericidal effect compared to chlorhexidine.

Marginal adaptation of full ceramic zirconia restorations are one of the important factors in their long-term success and one of the factors affecting marginal adaptation and their strength is the finish line design.This study was conducted to compare the effect of finishline design on the adaptation of monolithic zirconia crowns.

In this in-vitro study, 3 standard PEEK dies with 7 mm height and 5 mm diameter (in cervical) with convergence angle of 10°  in the walls was prepared by Ceramill motion 2 (Amann Girrbach, Austria) in three groups with chamfer,sloped shoulder and shoulder design. After pouring the molds made from PEEK dies with epoxy resin,30 dies(10 samples per group) were made.The construction of zirconia crowns (zolid preshades,Amann Girrbach, Austria) was performed using the Ceramill map extraoral scanner (Amann Girrbach, Austria) and the CAD / CAM method Ceramill motion 2 (Amann Girrbach, Austria). After cementing the crowns with Panavia F2,they were cut in the Buccolingual direction and the gap was measured at 7 points by the SEM (TESCAN S8000, China) at 500x magnification. In this study, one-way Anova statistical methods were used to show the effect of preparation design on marginal matching and Tukey HSD test to compare groups with each other.

Marginal gap values of the samples evaluated by the mean of AMO and MO,for Chamfer, Sloped shoulder and shoulder groups were (60.37±11.78/57.29±12.63),(73.37±14.79/68.08±14.21) and (95.42±9.60/92.59±10.83) microns and the internal gap values measured by Axial and Occlussal averages were (49.60 ± 10.37/120.37 ± 33.61),(46±9.37/124.41±32.10) and (69.43±9.73/163.49±27.79) microns respectively. There was a significant difference between Chamfer and sloped shoulder groups with shoulder group (P <0.05) but there was no significant difference between Chamfer and sloped shoulder group (P> 0.05).

From the results,it may be concluded that chamfer and sloped shoulder showed better marginal adaptation than that of shoulder,although the chamfer group had the better adaptation among all groups.

Information technology (IT) can make a powerful contribution to dental education and practice. The aim of the present study was to determine access, knowledge and usage of IT among dental students of Islamic Azad University of Esfahan in 2015.

We conducted a cross-sectional study using a stratified random sampling method in 2016. A validated self-administered questionnaire requested information from 150 dental students. Mann-Whitney U, Spearman correlation coefficient and Linear Regression Model served for statistical analyses.

Among dental students, 58.9 % were women and 41.1% were man.Only 1.3% indicated that they had no access to a computer, and 4% did not have a personal email. Most students reported their access to computer (67.1%) and internet (70%) as good. Mean score of IT knowledge was 11(SD 1.7; range 7-14). However, most were not familiar with any general (78.6%) and professional dental websites (72.6%). Regarding general use of IT, most students reported daily use of social networks (87.8%) but just 10.3% had checked their emails on a daily basis. Professional use of IT among students was poor (only 11.3% reported daily use of professional dental websites and 12.7% had downloaded educational materials on a daily basis). Students with higher knowledge of IT and those who had reported more general IT usage, showed higher level of professional use (P-value<0.05).

Dental students’ access to IT was good, however, their professional performance was poor. Regarding the importance of IT in dentistry, it’s essential to inform students about dental informatics and its professional performance.

Compare with Dentigerous cyst, Odontogenic Keratocyst is one of exclusive developmental cyst with unique clinical and histopathologic features. Considering the determining role of epidermal growth factor receptor (EGFR) in cell proliferation and survival, and the controversial results of previous studies regarding the expression of this marker by the odontogenic cysts, this study aimed to compare the expression of EGFR marker by Dentigerous cyst (DC) and odontogenic Keratocyst (OKC) as two lesions with more common neoplastic transformation.  

In this experimental study, 49 specimens (23 DCs and 26 OKCs) were evaluated. Immunohistochemical staining was performed using EGFR antibody. Evaluation of EGFR expression was made regarding to Tie-JUN Li et al. So, The location of EGFR expression in the epithelial cells ( Basal layers, Suprabasal & basal , All layeres) were assessed through histopathologic sections.. Data were analyzed using the Mann-Whitney test, t-test and chi-square test.

In The present Study, of 49 evaluated cases, the mean percentage of EGFR expression was 58.20±17.97% in the 23 DC and 78.05±19.27% in the 26 OKC specimens. The EGFR expression of OKC was significantly higher than DC (P=0.001). However, the Mann-Whitney test showed no significant difference regarding EGFR score (P=0.144). The chi-square test revealed no significant difference in expression of EGFR in the basal layer, basal and suprabasal layers and all layers (P=0.524).

The expression of EGFR marker in OKC was significantly higher than in DC, which may justify the progressive growth potential of OKC.

The new coronavirus - 2 is known to be a major threat to public health around the world. Common ways of transmitting the virus include direct transmission (sneezing, coughing and inhaling infected droplets and aerosols) and contact transmission (oral mucosa, nose and conjunctiva). When dental services are provided, large amounts of aerosols are produced during working with equipment. Iran was one of the main centers for the spread of the disease at the beginning of the epidemic, so this study evaluates the extent and severity of COVID-19 in the pre- and post-quarantine period.

The study was conducted through an online questionnaire, in which 1,100 member of dental association volunteered to participate in the study.

Since past 3 months, 74 (28.1%) reported Covid-19 symptoms, while totally, 18(2.2%) had definite infection. Ceramists had the highest incidence (50%) and dental students had the lowest incidence (19.3%) of symptoms. Among dental treatment staff, definitive rate of COVID-19 was higher in ceramists and dental students compare to dentists and dental specialists. In this study, 11.8% of the participants knew one of the members of the medical staff who died of COVID-19. The mean age of definite patients was 35.24 ± 12.24 yarrs old.

The low rate of definitive infection of dental treatment staff in this study shows that disinfection of the environment and sterilization and use of protective devices can normally be effective and useful in preventing the spread of disease and infection.

 The purpose of this study was to evaluate the referral rate for dental services and it's preventing Factors and oral Health related behavior in people with history of drug abuse referred to drug rehabilitation centers in the city of Sari.

This was a cross-sectional study. 120 people with history of drug abuse referred to drug rehabilitation centers in the city of Sari were participated in this study. Data collection was done with standardized questionnaire about demographic data and interview based on the questionnaire about addiction history, oral health related behavior, referral rate for dental services and it's preventing Factors. SPSS V:16 and Chi-square test were used for statistical analysis. SPSS V16 and Chi-square test were used for statistical analysis.

The most common barrier to dental services was “little priority of dental care in life" which was mentioned in 89.2%of people and then "the inability to pay for dental costs"in 68.3% and "fear of dentist and pain during treatment" in about half of them. “Improper access to dental services” was mentioned in more than a quarter of people. Oral health care behavior was poor in people with history of addiction. 52% of them never brush their teeth or brush rarely. 90% of them never floss their teeth or floss rarely. 82% eat sugery food in more than two times a day and the last dental visit was more than a year ago in 68% of them.

  According to the poor oral health related behavior and and the problems that these people are involved with and due to the reasons for less dental visits, appropriate educational, preventive and therapeutic actions seem necessary to improve  the quality of life in people who are being treated for addiction.

 In this study, a brief but accurate evaluation of the role of graphene oxide in dentistry and interaction with all soft and hard tissues, the study of studies conducted in vitro or in vivo and new approaches in the field of tissue engineering has been investigated

Reviewed articles using Medline, Google scholar, Scopus, Science Citation Index and Magiran Embase databases and the keywords of graphene oxide, antibacterial material, tissue engineering and dentistry from 2015 to 2020 which includes 28 complete articles and 6 abstracts were gathered. 

The addition of graphene oxide to dental fillers or bone tissue regenerating membranes has provided acceptable results in many cases. In discussing mechanical properties, the addition of graphene oxide increases the mechanical strength and also improves the physical stability of the structure. Graphene and graphene based materials have shown toxic effects on hard and soft tissue cells, which are necessary for clinical applications, the optimal concentration of this oxide.

  Adding graphene to dental materials was developed to increase their resistance to corrosion and improve their mechanical properties, but there was conflicting information about the cytotoxicity of graphene.

  Adenomatoid Odontogenic Tumor (AOT) accounts for less than 3% of all odontogenic tumors. It commonly occurs in anterior region of maxilla associated with an impacted tooth. Multifocal odontogenic lesions are uncommon and have only been observed in conditions associated with known genetic mutations. To the best of our knowledge, only three cases of multifocal adenomatoid odontogenic tumors (AOT) have previously been reported in the literature.

In this study, we report the second case of a bilateral, separate AOT in the maxilla in the midline in a 13-years old male. The patient presented with bilateral masses in the maxilla on either side of the midline which had been developed in 1 month.

It seems, bilateral occurance of AOT in anterior region of maxilla can be correlated with faster growth and genetic susebtibility.