مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال سی و سوم شماره 3 (پیاپی 104، پاییز 1399)

Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.

In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.

In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.

In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.

Dental anxiety and fear can act as a barrier to seek dental care leading to insufficient oral health in people. The aim of this study was to determine the relations between dental fear and anxiety with dental caries status (DMFT) and clinical consequences of untreated dental caries (PUFA) among the adult patients referred to the faculty dental clinic of Tehran University of Medical Sciences.

In this cross-sectional study in 2019, the patients above 18 years old were assessed. Two standard questionnaires, Dental Fear Scale (DFS) and Modified Dental Anxiety Scale (MDAS), were used to assess the scores of dental fear, and dental anxiety, respectively. The demographic data of the patients were recorded. Dental caries status and clinical consequences of untreated dental caries, using DMFT and PUFA, respectively, were measured. Pearson correlation coefficients and multiple linear regression model (Backward method) were used for statistical analysis.

Totally, 283 patients with the mean age of 38.6±11.8 years old participated. The mean scores of MDAS, and DFS were 12.04±4.49, and 41.33±16.87, respectively. Educational level (P=0.03, β=-0.14) and marital status (P=0.01, β=0.17) had significant relationships with MDAS scores. Moreover, a significant relationship was found between marital status and DFS scores (P<0.001, β=0.25). Significant correlations were found between dental anxiety level and D (P<0.001, r=0.36) and M components (P=0.02, r=0.14) of DMFT index. Moreover, there was a significant correlation between dental anxiety and U components of PUFA index (P=0.045, r=-0.12). Furthermore, the correlations between dental fear and D and M component of DMFT were significant (P<0.001, r=0.36; P<0.001, r=0.23; respectively).

Dental anxiety and dental fear were infrequent in the studied population; however, significant relationships were found between dental anxiety and dental fear with dental caries indices. Therefore, it was concluded that the more MDAS and DFS scores, the worse dental caries status.

With increasing age and inability to maintain good oral hygiene, the chances of tooth loss increase and the need for dental implants will increase in the future. It also increases the risk of developing peripheral implants, especially at older ages in the failure of implant treatments. Recently, the high prevalence of cardiovascular disease and peri-implantitis in the elderly has been reported. The aim of this study was to investigate the effect of cardiovascular disease on the peri-implantitis in people with failed dental implants.

In this retrospective study, the files of patients referred to Shahid Montazeri Dental Clinic from 2009 to 2018 whose their failed implants were extracted, were collected. There were a total of 793 people with failed dental implants. The variables of this study were demographic information including age and sex, health status in terms of cardiovascular disease and peri-implantitis, which were identified and then statistically analyzed by examining the files of patients with these two variables. Data were statistically analyzed by SPSS25 statistical software and Chi-square was used to determine the effective variables.

A total of 793 patients had failed dental implants, including 368 women (46.4%) and 425 men (53.6%) with an average age of 50.79 years. 42 patients (5.3%) had heart disease and 44 (5.5%) had peri-implantitis. According to the Chi-squared test, the significance level was less than 0.05 (P=0.011).

The results of this study showed that the cardiovascular disease and peri-implantitis were significantly related.

The chronic blood disorders could have negative effects on various fields of patient’s quality of life. The aim of this study was to evaluate the relationship between the quality of life and oral health in major thalassemia and hemophilia patients.

This cross- sectional study was performed in 1398 on 56 hemophilia patients and 35 thalassemia major patients over 15 years of age. All the subjects were examined clinically to determine DMFT and CPITN, then the subjects completed OHIP-14, xerostomia, SF36 questionnaire. Data was analyzed with T-Test, ANOVA and Chi-square using Stata14.

The mean age of hemophilia and beta-thalassemia patients was 32.3 and 26.2, the mean DMFT index was 8.75 and 7.6, and CPITN index was 2.02 and 2.26, respectively. Analysis of the components of the DMFT index showed a predominance of number of decayed teeth over filled teeth in both groups. According to the CPITN index, 19.6% and 20% of hemophilia and thalassemia patients had gingival healthy, respectively. The mean quality of life total scores in patients with hemophilia and thalassemia was 62.11 and 58.07, respectively. The mean DMFT had a significant negative relationship with the quality of life total scores in both groups. There was a significant relationship between different domains of quality of life and CPITN and OHIP-14 in thalassemia patients. Also patients with dry mouth had lower quality of life.

Hemophilia and thalassemia patients indicated undesirable oral health. It is necessary to improve multidimensional strategies in various fields of health care in patients.

Regarding the need for social accountability in dental education, community-based dental courses has been established to improve the oral health of the community and compensate the shortcomings of the health system. Due to the importance of evaluation, the aim of this study was to determine the dental students’ attitudes and believes in the last year of their study towards the community-based dental education.

This cross-sectional study was performed on 159 dental students in the sixth year (October and February, 2018) of Isfahan dental school by census. These students took the relevant questionnaire, which was developed by researchers in three sections of “attitudes toward field activities”, “lessons and experiences of field activities during dentistry training” and “barriers and problems of field activities”. Its content and face validity was confirmed. They completed it on their own and after collecting information and descriptive analyzes, the relationship between the gender and entry group with attitude scores was analyzed by Mann-Whitney U test.

Out of a total of 102 questionnaires which were answered (response rate of 64%), half of the students believed in the need to provide dental services in the form of mobile/outreach services for the community. 90% of the students agreed with the combination of field education with routine education in the dental schools. They also considered these services as an opportunity to use their experiences and knowledge to promote oral health in the community. 84% of them believed that their self confidence improved while providing services outside the faculty. In many of the propositions in the field of attitude to provide service in the field, a significant percentage (50 to 60%) did not have an opinion.

There was a good and positive aspects in many areas of attitude toward providing services in social fields as well as attitude towards the lessons learned from community-based dental education. However, we should consider the attitude-emotional aspects of educational objectives in the community-based courses in dental schools.

Radiography is one of the most important para-clinical methods in diagnosing and selecting treatment in dentistry. Due to the potential dangers of X-rays for patients, the professional responsibility of the dentist requires that unnecessary radiographs to be avoided. The aim of this study was to investigate the awareness of dentists in Zanjan about the principles of radiation protection in 2019.

This cross-sectional study was performed on 107 general dentists and specialists working in Zanjan and the questionnaires were distributed among them. The level of awareness of dentists in 27 questions of radiographic prescribing questionnaire was evaluated and in each of the mentioned questions, their gender, age, work experience, participation in retraining, having X-ray machine in the field of dentistry and type of activity were evaluated. Data were analyzed by Chi-square test, Independent T-test, and ANOVA using SPSS software version 22.

The results showed that the level of knowledge of general dentists about the principles of radiation protection (14.35±3.08) was lower than that of specialized dentists (17.19±2.35). Those who participated in retraining workshops (13.85±2.99) had less knowledge than those who did not (15.97±3.97), which was statistically significant (P<0.05); However, there was no significant difference in the dentistschr('39') knowledge about the principles of radiation protection based on gender, age, type of activity, having an X-ray machine at the place of treatment, and history of clinical experience (P≥0.05).

Awareness of dentists at various levels was moderate. Therefore, designing and holding more purposeful retraining courses to maintain and improve the level of awareness of dentists according to the guidelines provided by the authorities, still seems to be necessary.

A significant percentage of children with dental caries require, hospital dentistry and their parents do not have much information in this regard. The aim of this study was to determine the knowledge, attitude and practice of pediatricians in hospital dentistry in Isfahan Province.

This cross-sectional study was performed on 100 pediatricians working in Isfahan. The self-administered questionnaire included demographics of doctors and 19 questions for assessing the knowledge, attitude and practice of pediatric practitioners about hospital dentistry under general anesthesia. Raw data were analyzed by Chi-square test using SPSS software version 23.

100 pediatricians with an average age of 44.1±5.7 years (57% male) completed the questionnaire. 53% of the pediatricians had a high level of awareness about hospital dentistry and 42% about its related guides. 66% practitioners had a favorable attitude toward general anesthesia and costs, while 71% considered the parentschr('39') awareness were poor about hospital dentistry. Only 43% of pediatricians performed oral examinations in their daily visits, and 17% had a referral for hospital dentistry. Male pediatricians aged from 35 to 45 had a higher level of knowledge about hospital dentistry. The attitude and practice of pediatricians did not have a significant relationship with their age. Meanwhile, male pediatricians had better performance in oral and dental examination and referral for hospital dentistry (P=0.15).

From the results of this study, there is a need for a serious improvement in the level of knowledge, attitude, and practice of pediatricians in the field of hospital dentistry.

Removable partial denture (RPD) is a common treatment to restore partially edentulous areas; however, a limited number of studies have been made on oral hygiene habits among patients with RPD. The aim of this study was to evaluate the patients’ knowledge about various cleaning methods of RPD to consciously improve hygienic habits of the patients.

This study was a cross-sectional study performed on 96 RPD patients referred to Jundishapur faculty of dentistry from 1395 to 1396. Demographic data namely age, sex, level of education, and other information about general health status, duration of dentures usage, and denture cleaning frequency were taken by the census through questionnaires. The descriptive statistics, chi-square, and T-test were used for statistical analysisof data (P<0.05).

The patient age, sex, and smoking habits had significant effects on the prosthesis maintenance habits (P<0.05). The patients over 50 years of age, females, and nonsmokers significantly preferred dipping method over other RPD storage methods (P<0.05). The frequency of denture cleaning was significantly greater in males (53.3%) compared to females (23.9%) (P<0.05).

According to the results of this study, most RPD patients did not clean their dentures appropriately and have little knowledge on how to maintain and clean them. Regular and periodic recall and written instructions might be helpful to improve patientschr('39') awareness on proper cleaning and maintenance of partial dentures.