مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال سی و دوم شماره 2 (پیاپی 99، تابستان 1398)

Diferences whithin shape and size of hand wrenches in diferent systems could affect the torque applied. Therefore, evaluation of wrenches has been emphasized. The aim of the present study was to compare the torque values of the long and short torque wrenches in different implant systems including ITI, Implantium and Nobel Biocare.

In this experimental trial, 5 dentists with at least 5 years of professional experience closed the abutment screw in different implants systems using the long and short manual wrenches while the wrench-induced torque values were calculated by digital torque-meter. Torque application was done for 3 times with 10-minutes resting time between each wrench uses in the habitual closing torque manner. Data were analyzed using two-way analysis of variance test in different implant systems, while the paired comparisons were done using Tukey post hoc test.

The maximum torque values of the long manual wrenches were 27.73±4.57 Ncm, 34.6±8.09 Ncm and 30.6±6.94 Ncm for the ITI, Implantium, and Nobel Biocare systems, respectively. While the values were reported to be 26.4±5.3 Ncm, 35.27±7.94 Ncm and 30.13±5.26 Ncm in the short manual wrenches for the ITI, Implantium and Nobel Biocare systems, respectively. Significant differences were found between ITI and Implantium (P<0.0001), and between Implantium and Nobel Biocare systems (P<0.021). However, no significant differences were observed between ITI and Nobel Biocare systems regarding wrench-induced torque values (P>0.05).

From the results, the torque values obtained by different long and short manual wrenches were specific to different implant systems. These values were less in ITI and Nobel Biocare systems and higher in implantun than those range provided for the implant systems by the companies.

Accurate diagnosis of vertical root fracture (VRF) is a fundamental importance in endodontics. Because of poor prognosis of VRF, digital radiographs with two horizontal angles have limitations in VRF detection. Also, Gutta-percha can produce artifacts that impair CBCT scan accuracy. The aim of this study was to compare accuracy of CBCT and digital radiography system in vertical root fracture in endodentically treated teeth.

In this study, 60 endodentically treated single teeth were selected and randomly coded. The teeth were divided into two groups: 30 with induced root fracture and 30 with no fracture. CBCT scan and digital radiographs with two horizontal angles with a difference of fifteen degrees for all teeth were performed. Two observers assessed the CBCT images and digital radiographies for presence of VRF. The statistical analysis used in this study was Weighted Kappa.

CBCT had the highest sensivity (75.8) and specificity (90). Digital radiography with 68.3 sensitivity and 79.1 specificity were not as efficient as CBCT (P<0.05).

According to this study, the accuracy of CBCT seems to be higher than that of digital radiography in detecting VRF and provides the most reliable data in comparison of digital radiography.

Gypsum products are used for several different purposes. Adaptation and success of casting restorations are dependent on dimensional accuracy, strength, and reproduction of details of dental gypsums. This study was designed to evaluate the dimensional changes and accurate details reproduction of three type IV dental gypsums.

60 samples in 3 groups of dental gypsums of G30,Yeti Rock and FujirockEP were evaluated. The detail reproduction of 50 micron scratched line was analyzed by a microscope at 12× magnification. The samples were assayed for dimensional changes at 2 and 24 hours and 1 week after pouring. Photograph images were taken from samples in fixed distance by a camera (Canon D600) and analyzed in corel draw software. Data were analyzed using ANOVA and chi-square (P<0.05).

There were significant differences in the details reproduction between three gypsums (P≤0.05) and the highest values was for Fujirock EP, Yeti Rock. The G30 did not reconstruct the details. There was no significant difference in the dimensional changes of the evaluated gypsums based on time (P≥0.05).

All three different gypsums evaluated in this study showed the dimensional stability during one week. Fujirock EP and Yeti Rock could reconstruct the details and G30 gypsum could not.

Most children get a lot of anxiety while they visit a dentist. The most important factor in the child's fear at the beginning of treatment is the syringe and needle. Ways to cope with this anxiety include behavioural control techniques such as mental regeneration, distraction, and induction. The purpose of this study was to compare the pain and anxiety in children when using a syringe and toy- shape syringe needle. This study was the first study that used a toy-shape needle cover.

This clinical trial study was conducted on 20 children age from 5 to 8 years. More than half of them were anxious with Cfss-Ds (Dental Subscale of the Children's Fear Survey Schedule) and FIS
(Facial Image Scale) anxiety diagnostic tests, and the rest of them were not anxious. Patients were randomly divided into two groups. The first group received local anesthesia with conventional syringe and the second group, by syringe with toy shape needle cover. Following, the first group received local anesthesia by syringe with toy shape needle cover, and the second group, by a conventional syringe. Heart rate measuring and pain evaluating test was performed. Analysis of heart rate and anxiety data was performed by non-parametric wilcoxonsianed Ranks T-test (P-value was considered significant at 0.001).

The mean amount of pain measured after using a syringe with a toy shape needle cover and using conventional syringe had a significant difference of 5.20% between the two groups. The pain was reduced in children who received local anesthesia by syringe with toy shape needle cover (P<0.001).

The physical appearance of the injection device plays an important role in reducing the anxiety and pain of injection in the children.

Due to high mortality rate and cost of smoking, WHO has emphasized on the role of dentists in smoking cessation among patients. The aim of the present study was to investigate the dental students, knowledge toward health consequences of smoking, their attitude towards smoking cessation activities, and their education programs in this field.

In this cross-sectional study, the target group was senior dental students at Tehran and Shahid Beheshti Universities of Medical Sciences, and Azad and Shahed Universities. A questionnaire was used to collect data in addition to background information, on the knowledge, attitudes, and education towards tobacco cessation counseling in dental practice was administered to the students. The sampling method was census. Data were analyzed using oneway Anova followed by Turkey HSD post-hoc test for pairwise comparison.

Overall 138 students participated in this program (The response rate was 100%). Of the maximum achievable knowledge score (28), the average knowledge score in Tehran University was 22.8, in Shahid Beheshti University 20.31, in Azad University 22.31, and in Shahed University 22.16 (P=0.027) with significant statistical differences. However, But the average of attitude and education score of the students did not vary significantly (P>0.05).

Most of the students had sufficient knowledge about the risks of tobacco use and positive attitude toward tobacco cessation counseling. It was concluded that the students would only pay attention to the principals of smoking cessation counselling when they actually believe in them. Therefore, in order to improve the performance of students, training should be given on tobacco cessation techniques at the dental schools, thus, that students could play an effective role in tobacco cessation counseling for patients.

Today, smoking is recognized as a major health problem and an impediment to development in many developing countries. This is the reason of early deaths and disabilities which leads to death of about 4 million people around the globe annually. This study aimed at assessing the awareness and attitude among the students last years dental at Yazd Shahid Sadooghi Medical School in providing consultation for giving up smoking.

This study was a descriptive sectional study that evaluated the awareness and attitudes of students last years dental at school of dentistry. Data was collected through standard questionnaires and were analyzed by T test and Pierson correlation coefficient in SPSS18 software.

A total of 110 students participated in this study. Awareness mean's score of female students was 18.38 and male students 17.66. The attitude mean's score of female students was 31.06 and the male students was 32.45. Based on the correlation coefficient of awareness with age (0.112), with the semester (-0.001) and with a GPA (0.76), it was concluded that awareness with increasing age and GPA increased, and with increasing semester decreases. Also, based on the correlation coefficient of attitude with age (0.013), with the academic semester (0.018) and with a GPA (0.008), it was concluded that attitude with increasing age, semester, and GPA was improved.

Despite the relatively good attitude of dental students about smoking cessation counseling, their awareness was poor. Therefore, the need to revise the education programs and steps in the field of training are required.

Management of an emergency is ultimately the dentist’s responsibility. Therefore, the dentists need to be able to manage an emergency and perform Cardiopulmonary Resuscitation (CPR) if necessary. The present study was undertaken to assess the knowledge of final-year dental students in Tehran regarding CPR.

In a cross-sectional study, 200 final-year dental students (44 males and 156 females) from 4 dental schools in Tehran were randomly selected and surveyed using a multiple choice questionnaire evaluating their knowledge about CPR. The data were analyzed by SPSS16 software using two descriptive and inferential statistical methods via chart drawing of statistical quantities calculation and analysis of variance.

The mean score was 5.43±2.43. A positive correlation was found between receiving practical training and level of knowledge (P=0.001). However, the results showed no statistical differences between sex (P=0.409) or various dental schools (P=0.089).

Since, the level of knowledge about CPR among participants were poor, there is a perceived need for further training in dental schools.

Management of internal root resorption is a challenge to the endodontists. If it is left untreated, it may lead to the destruction of the surrounding dental hard tissues. Despite, routine obturation techniques are often employed without considering the best technique to solve this problem. This study presented a case of internal root resorption and apical periodontitis affecting tooth 12 (FDI) in a 31-year-old female patient, with a history of crown preparation in that region. We managed it with EndosealMTA and gutta-percha. After 12 months follow up, the tooth was still symptomless and in function and healing of bone resorption occurred.