Journal of Dental Medicine

Background and Aims: As in fissure sealant therapy the tooth surface is mostly enamel, the use of an enamel bonding agent (hydrophobic bonding agent) may be more cost effective than that of newer generations of bonding (hydrophilic bonding agents). The aim of this study was to compare the retention and durability of fissure sealant therapy when applying an enamel bonding agent, a dentin bonding agent and no bonding agent during 4 years.

Materials and Methods: This study was done on the first permanent molars of the upper and lower jaws of 24 students of the first grade of a primary school (6-7 years old). On 36 teeth, a dentin bonding agent (Excite) was applied under the fissure sealant and on 36 teeth an enamel bonding agent (Margin bond) was applied under the fissure sealant. Then, 24 teeth were selected from these two groups and were compared with a group (including 24 teeth) with no bonding agent under the fissure sealant (as control group). All the fissures of the teeth were evaluated annually for 4 years to find out the presence or absence of fissure sealant substance. Data were analyzed using Wilcoxon test.

Results: From the statistical analysis, there was no significant difference in retention and durability of the fissure sealant substance comparing the group with dentin bonding agent (Excite) and the group with enamel bonding agent (Margin bond). Also, using a bonding agent made no significant difference (P>0.05).

Conclusion: According to the results of this study, using a bonding agent made no improvement in the retention and durability of fissure sealant substance.

Background and Aims: With the increasing use of CT (Computed Tomoghraphy) scans in dentistry especially in the implantology, there may be significant increases in the radiation exposure and its risk. During the last year’s ConeBeam Computed Tomoghraphy (CBCT) has been introduced as an imaging modality for dentistry. The aim of this review article was to present comprehensive information have been published, regarding the  radiation dose and image quality of Conventional Multislice Computed Tomography (MSCT), Cone-Beam CT (CBCT) and periapical radiography in dentistry imaging.

Materials and Methods: A review of the literature was carried out in PubMed, Google Scholar, Science Direct and Scopus database using key words (CBCT, MSCT, periapical radiography, radiation dose of dentistry and image quality). These searches were limited to the articles published between the years of 1993 to 2015.

Conclusion: In comparison to MSCT, CBCT had a short scanning times and lower radiation dose, but in comparison to periapical radiography, CBCT had higher radiation dose. In contrast, CBCT with flat panel detector had higher spatial resolution to MSCT. The periapical radiography also had a good image contrast and relatively high resolution. Generally, CBCT was suitable for hard tissue imaging and MSCT was preferred for soft tissue imaging.

Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7) in class 5 composite cavities.

Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan), G Bond (GC, Japan), and Opti Bond Solo Plus (Kerr, USA), according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test.

Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity) in 80% of specimen, and type 4 microleakage (along axial wall) in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity) in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05).

Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.

Background and Aims: The first permanent molar is susceptible to caries, endodontic complications and developmental anomalies. Compromised teeth with poor prognosis could cause the clinician to face dilemmas. The aim of this review article was to assess recent guidelines on the treatment planning of compromised first permanent molars in mixed dentition period.

Materials and Methods: The design of the study was based on review of literature by searching the MEDLINE, Web of science and Google scholar. Key words (permanent first molar, extraction, treatment plan) were used. This search was limited to the English articles published after the year 2000.

Conclusion: A number of factors influenced decision-making process regarding compromised first permanent molars including the restorative status of the tooth, dental age of the patient, degree of crowding and occlusal relationships were assessed. The ideal time for removal of these teeth was 8-9 years of age. However, the current evidence for managing compromised first permanent molars demands clinical trials.

Background and Aims: One of the main disadvantages of light cured composite resin materials is polymerization shrinkage upon curing. This leads to the microleakage of restoration and finally failure of the restoration. The purpose of this study was to investigate the effect of two types of light curing devices with different modes on the microleakage of posterior composite filling in Cl II restorations.
Materials and Methods: In this experimental study, 30 extracted sound molar human teeth were collected. All specimens were randomly divided into 3 groups of ten: Standard LED irradiation, pulse curing LED irradiation and QTH irradiation. All samples were prepared with mesial and distal boxes and composite fillings were done with three different light curing patterns for 20 s. After thermocycling, the specimens were kept in 2% methylene Blue solution for 24 h for microleakage test. After sectioning, the samples were evaluated by a stereomicroscope. For data analysis one-way ANOVA and Kolmogorov-Smirnov were used. P<0.05 was considered statistically significant.
Results: The quantitative tests showed that there were no statistical difference between study groups (P>0.05).
Conclusion: The results showed that both light curing devices were effective and no significant difference between different modes of LED light curing device on microleakage of class II composite restorations was found.

Background and Aims: The purpose of this study was to evaluate the sealing ability of MTA and cold ceramic by using bacterial leakage method.
Materials and Methods: In this experimental study, fifty human single root extracted teeth were chosen. In group A, 20 teeth were filled with MTA and in group B, 20 teeth were filled with cold ceramic. Five teeth were used as a positive control (obturated using gutta-percha without sealer), and five teeth were used as negative control (obturated using gutta-percha with AH26 sealer and coated with two layers of nail varnish). A bacterial leakage model utilizing Enterococcus faecalis was used for evaluation of the sealing ability. The teeth were placed in test tubes, so that they formed two upper and lower compartments. The cultured bacteria in the upper chamber were in contact with the coronal area of the tooth. The root end was placed in the lower chamber containing sterile culture media. In this case, the filling of the root canal was only the communication path between the upper and lower chambers. In this method, the presence of turbidity in the lower chamber indicated that bacteria had penetrated through barrier and reached the medium. The leakage was measured. The acquired data was analyzed using Chi-square test.
Results: In group A (MTA), 7 samples and in group B (Cold ceramic), 4 samples should the leakage. In regarding the leakage, there was no statistically significant difference between MTA and cold ceramic. (P=0.288)
Conclusion: The results showed that the sealing ability of MTA and cold ceramic was similar as root filling materials.

Background and Aims: A suitable restorative material must have acceptable mechanical properties. The aim of this study was to evaluate the effect of conventional acidic drinks on the micro-hardness of two dental resins.
Materials and Methods: 48 samples of each of P60 and G-aenial composites were prepared and randomly divided into six groups: Coca-Cola, Fanta, yoghurt drinks, soft beer, Sprites and control groups. The study was in 3 steps: after one day in distilled water and after one day and one week of immersion in beverages per day
(6 hours). The Vickers micro-hardness was then evaluated. Finally, data were analyzed by, t-tests, ANOVA and Tukey tests.
Resultes: Comparing the results between the two groups, a significant difference between the two composite was found. After one day in the water, the average micro-hardness for P60 was of 27.12 (kgf/mm²) and 16.51 (kgf/mm²) for G-aenial amount and these differences were found statistically significant (P=0.0001). For the
6-hour maintenance interval, the average micro-hardness between P60 and G-aenial was statistically significant (P=0.0001). For 42 hours, the average micro-hardness ranged between P60 and G-aenial that were statistically significant (P=0.0004). The stiffness of the P60 composite after 42 hours’ storage in soft beer significantly decreased compared with the control group (P=0.03). G-aenial composite hardness after 42 hours of soaking in the Coca-Cola was reduced significantly compared to yogurt drinks (P=0.02).
Conclusion: As a result, the hardness of P60 composite was higher than that of G-aenial. The hardness of both composites reduced in acidic drinks after one week.

Background and Aims: Microorganisms are the main cause of pulpal and periapical diseases. The most important failure factor is the lack of proper seals for the canal, resulting in microbial leakage. Therefore, the purpose of this study was to evaluate the sealing ability of ProRoot MTA and Bio MTA in canal obturation using fluid infiltration.
Materials and Methods: In this experimental study, 46 extracted mandibular premolar single canal teeth were used. After preparing and disinfecting the teeth with 3% sodium hypochlorite, their crowns were cut off from the cement-enamel junction. The teeth were then randomly divided into four groups: Group 1 (n=20) Bio MTA, Group 2 MTA ProRoot (n=20), negative and positive control groups, each of them contained 3 teeth. The preparation of teeth was performed using the step back method. The filled teeth were then evaluated by fluid filtration for leakage prevention. Data were analyzed by Mann-Whitney test and Tukey test (α=0.05).
Results: The results of statistical analysis showed that there was no significant difference between the MTA ProRoot and Bio MTA in sealing ability (P>0.05). That micro leakage is less in the Bio MTA group than in the ProRoot MTA group, but the difference was not significant.
Conclusion: This study showed that MTA ProRoot and Bio MTA can be used as appropriate canal filling materials.

Background and Aims: The aim of the present study was to evaluate the effect of applying hydrophobic resin after use of different generation of the bonding systems on nanoleakage.
Materials and Methods: 20 third molar teeth were selected. The teeth were randomly divided into 4 groups of 5, each was treated using the fourth, fifth, sixth, and seven generation of dentin bonding. Then, the crown of teeth was sectioned from the CEJ region and each specimen was divided into two halves with mesiodistal cut, one half for the application of dentin bonding without the addition of a hydrophobic resin, and the other for the same dentin bonding by the addition of a hydrophobic resin. Afterwards, the specimens were restotred by composites. After placement of specimens in silver nitrate, the amount of nanoleakage was evaluated by SEM. Data were analyzed using a repeated measurement statistical analysis (α=0.05).
Results: The use of hydrophobic resins decreased nanoleakage and range of variations in all groups (P<0.05). This reduction was greater for total-etch dentin bonding. Higher degree of nanoleakage occurred in total-etch dentin bonding in most evaluated areas. In general, Clearfil S³ bond showed the least percent of the nanoleakage.
Conclusion: All dentin bonding systems showed some degree of reduction in nanoleakage after hydrophobic layer application and the reduction was greater in Total-etch adhesives systems.

Background and Aims: The self-adhering composites were introduced to reduce the chair time and minimizing handling errors. They can be bonded micromechanically to the dental structure without the need for separate adhesive application. Since there is limited information about bonding performance of this type of composite, the aim of this study was to evaluate the microleakage of enamel and dentin margins compared to the conventional adhesive systems.
Materials and Methods: 30 intact premolars were selected and on their buccal and lingual surfaces, standardized class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared. Then according to the materials used, the specimens were randomly divided into three groups including: 1) Vertise flow, 2) SE bond + ValuxTM Plus, and 3) Single bond + ValuxTM Plus. After final polishing of the restorations, the specimens were subjected to 1000 thermal cycles of 5±2 and 55±2°C and after that dye penetration was examined by stereomicroscope. The collected data were statistically analyzed using Kruskal-Wallis test and Mann-Whitney test
Results: The lowest rate of the occlosal microleakage was related to group 2 (P<0.05) and there was no significant difference between groups 1and 3 (P=0.58). Also, no significant difference was found in the gingival microleakage among the three groups (P=0.23). On the other hand, in each group, the gingival microleakage was significantly higher than occlosal margins (P<0.05).
Conclusion: According to the results, sealing ability of self-adhering composite is comparable with that of the conventional adhesives.

Background and Aims: 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.
Materials and Methods: 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.
Results: 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.
Conclusion: 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.

Background and Aims: This study aimed to collect reports and HIS in a web-based system due to the problems of paper recording of student activities in practical courses, as well as the lack of computers in the departments for observing graphs and treatment plans.
Materials and Methods: The initial graphic design of the website was done after the assessment of needs and the necessary planning for designing the website. The main template of the website was designed after consulting with the faculty and the designer company. A combination of HTML, CSS, JQuery, and Java script was used for static coding and what the user sees or interacts with. Then, the basic information entered the website and the content designer put the website in the designed layout. In the end, a sample hosting space was prepared and the website was fully provided to the professors and faculty officials to work with as an administrator and a user. They conveyed all their opinions and the corrections were made based on the feedback given.
Results: The use of the internet and software with a central database played a significant role in monitoring and evaluating the long-term information of the student and the evaluation of the entire department, universities, and patients in each region up to macro-national evaluations. This could give the expansion and advancement of science in addition to the central registration of documents and radiographs, as well as their ease to access.
Conclusion: The designed website was well received among the students and the attending staff. Introducing a web based logbook and HIS system can optimize the clinical teaching. These logbooks could help both students and staff saving time and resources, and to facilitate providing better personalized care for patients.

Background and Aims: Supporting the preventive approach is important in training future dentists. The purpose of the present study was to evaluate the knowledge, attitude and practice of senior dental students regarding non-invasive management of dental caries.
Materials and Methods: A cross-sectional study was conducted in 2019 using total sampling method and a valid and reliable questionnaire. Knowledge, attitude and self-reported practice of senior dental students regarding caries risk assessment (CRA) and management of lesions in two paper patients were assessed. The data analysis was performed using SPSS20 and the descriptive and analytical statistics were reported.
Results: In overall, 86 students (response rate=91%) were responded. In the knowledge section, caries history in the previous year, having frequent fermentable carbohydrate, xerostomia, and low socio-economic status were considered by more than half of students as factor for caries risk assessment. More than 90% of students had a positive attitude towards CRA in children. Nearly 50% of students tend to restore enamel lesions in proximal and occlusal surfaces in high-risk scenarios. There was significant association between the OHI instruction and debris index improvement (P=0.04) in the integrated comprehensive care clinic (TUMS). The linear regression analysis showed that there was no significant association between the demographic characteristics, place of education, previous course on the level of knowledge and attitude.
Conclusion: Senior dental students despite their general knowledge and positive attitude toward caries risk assessment, tended to aggressively manage the incipient lesions in the enamel and DEJ. Delivering prevention as integrated in the comprehensive care unit in order to improve oral hygiene status of patients is recommended.

Conclusion: Many elderly people avoid the treatment of oral diseases during coronavirus pandemic due to fear of coronavirus, high dental costs, lack of access to appropriate services, and this causes irreparable problems in their health. Therefore, it is recommended to provide practical solutions to facilitate the dental treatment of elderly patients.

Background and Aims: The need to use a highly effective sealer in order to create a complete seal along the canal is essential for the basic treatment of tooth roots. Therefore, the aim of this study was to investigate the sealing ability of cold ceramic and gutta-percha with sealer by applying the bacterial leakage and electrochemical method.
Materials and Methods: In this in-vitro experimental study, fifty human single-rooted teeth were selected and their crowns were cut from the cervical region. The canals were prepared and washed with 17% EDTA. Then the teeth were randomly divided into four groups: group 1 gutta-percha with AH26 sealer (Dentsply Detrey, Germany) (n=20), group 2 cold ceramic (Yazd, Iran) (n=20), negative and positive control groups which each consisted of 5 teeth. Samples were kept in an incubator at 37° C for 48 hrs. Two coats of nail polish were used for covering the root, except for the last 2 mm, and microleakage in the fillings was measured by the bacterial leakage and electrochemical methods. The microleakage of the two groups was statistically analyzed in the electrochemical technique by Student's t-test, and in the bacterial leakage method by Fisher's exact test.
Results: In bacterial leakage method, in the first group (gutta-percha) 7 samples (35%) and in the second group (cold ceramic) 3 samples (15%) had bacterial leakage, but no significant difference was observed between the two groups on different days (P>0.05). The mean microleakage based on the electrochemical technique in gutta-percha was significantly higher than that of cold ceramic (P=0.0001).
Conclusion: According to the lower microleakage values in the use of cold ceramic compared to gutta-percha, cold ceramic  can be used to fill root canals to reduce microleakage, although further studies are needed.

Background and Aims: Malocclusion in orthodontics is one of the dental and jaw abnormalities that can cause psychosocial and social problems. Personality traits, body image, and self-concept are different in orthodontic applicants due to the different effects of malocclusions on appearance and psychological well-being. The aim of this study was to investigate the personality traits, body image, and self-concept in patients seeking orthodontic treatment in Tabriz-Iran in 1400.
Materials and Methods: The statistical population of the study included all patients requesting orthodontic treatment whom were referred to one of the orthodontic clinics in Tabriz during 1399-1400. This study was performed on 149 patients seeking orthodontic treatment (127 females and 22 males) by Convenience Sampling method. Neo personality traits, the Body Image Concern, and Marsh body self-concept questionnaires were used. SPSS software was used for data analysis.
Results: According to the results, neuroticism, agreement, conscience, extraversion and openness to experience were high in orthodontic patients (P<0.05). The average dissatisfaction with body image was high (P<0.05). Also, the body outside self-concept was low and the self-esteem was high (P<0.05).
Conclusion: Personality factors, body image, and self-concept are three effective psychological characteristics in patients seeking orthodontic treatment. Therefore, the request for orthodontic treatment is largely due to psychological factors such as differences in personality traits, body image, and self-concept.

Background and Aims: Incorrect prescription of antibiotics for odontogenic infections can endanger patients' lives. This study aimed to determine the pattern of antibiotic prescription by general dentists in Tehran and to compare it with the guidelines recommended by maxillofacial surgeons at Tehran University of Medical Sciences in 2019.
Materials and Methods: A cross-sectional study was conducted on 141 randomly selected dentists in Tehran. The dentists reported their antibiotic prescriptions for various odontogenic infections by completing a questionnaire. The frequency of prescribed antibiotics was calculated considering the severity of the infection, penicillin sensitivity, pregnancy and lactation status of women, and children. These were compared with the guidelines suggested by 15 maxillofacial surgery specialists at Tehran University of Medical Sciences in 2019. Descriptive analysis and binary logistic regression were used. Data analysis was performed using SPSS software version 25.
Results: Among patients sensitive to penicillin with severe infection, 61% of the dentists prescribed the correct medication. The correct prescription rate was 0% in patients with severe infection, 24.82% in pregnant and lactating women with mild infection, 65.24% in children with mild infection, 62.41% in patients with mild infection and penicillin sensitivity, 36.69% in children with severe infection, and 33.82% in pregnant and lactating women with severe infection. The results showed that older dentists were significantly more likely prescribe antibiotics correctly for odontogenic infections (P=0.036, B=0.28).
Conclusion: General dentists in Tehran did not optimally prescribe antibiotics for odontogenic infections. Therefore, training courses to improve their clinical performance are essential.

Background and Aims: Over the past two decades, the use of mini-screws in orthodontics has become increasingly common. Various factors such as design, length, diameter, and insertion angle of the miniscrew, as well as the quality and thickness of the patient's bone, would influence the success and stability of miniscrews. This study aimed to investigate the effects of miniscrew shape, cortical and cancellous bone thickness, and insertion/removal torque on the stress distribution in the mandibular bone surrounding the miniscrew.
Materials and Methods: This study was conducted using finite element analysis (FEA). Bone thickness parameters were extracted from the literature, and the mandibular bone along with cylindrical and tapered miniscrew models were simulated using ABAQUS software. By altering the relevant variables, the resulting stress were evaluated.
Results: An increase in both insertion and removal torque led to a corresponding rise in the stress around the miniscrew. Stress variations were more pronounced in tapared miniscrews in response to the changes in bone thickness and torque. The influence of cancellous bone thickness on stress distribution was found to be minimal.
Conclusion: Although, the tapered miniscrews offer greater retention and stability compared to the cylindrical types, their heightened sensitivity to variations in parameters such as bone thickness and torque necessitates cautious application.