مجله دانشکده دندانپزشکی مشهد
سال چهل و ششم شماره 3 (پیاپی 122، پاییز 1401)

Plaque accumulation during orthodontic treatment is commonly seen around orthodontic brackets and the cervical margin of the bands. Glass ionomer cement is generally used for cementing orthodontic bands. Although glass-ionomer can release fluoride, it cannot prevent tooth demineralization during orthodontic therapy. This experimental study aimed to determine the effect of adding propolis on mechanical and antimicrobial properties of glass ionomer luting cement used in orthodontics. Initially, ethanolic extract of propolis (EEP) was prepared. To evaluate the antibacterial activity, the minimum inhibitory concentration (MIC) and minimum inhibitory bactericidal concentration (MBC) of the mixture of glass ionomer with different concentrations of EEP were determined using the broth dilution method. To assess the shear bond strength, 75 sound premolar teeth were selected and randomly divided into three groups. In the first group, premolar bands were cemented with glass ionomer cement. In the second and third groups, the bands were cemented with glass ionomer cement mixed with 0.05 and 0.075 g propolis, respectively. The maximum force required for debanding was measured with an Instron machine. Mean shear bond strength was compared between the three groups using the Kruskal-Wallis test. The MIC and MBC values of the mixture of glass ionomer and propolis were determined at 0.05 mg/ml and 0.1 mg/ml propolis, respectively. There was not a significant difference between the three groups regarding their mean bond strength. Adding propolis extract to glass ionomer cement increased the antibacterial propolis without adverse effects on the shear bond strength of orthodontic bands.

The prevalence of obesity as the most common metabolic disorder has increased recently. It is a life-threatening condition and a risk factor for several diseases, including diabetes type II, cardiovascular disease, and hypertension. The results of recent studies have indicated the existence of an association between periodontal disease and obesity in different populations. The present study aimed to determine if there was any relationship between obesity and periodontal disease among the Iranian adult population.

A sample of 367 was selected from 20-50-year-old patients referring to the Dental Clinic of Golestan University of Medical Sciences, Gorgan, Iran, for the first time. Periodontal examinations and anthropometric measurements were performed on all participants. Periodontitis was defined based on the presence of one or more teeth with one or more sites with a periodontal probing depth of ≥ 4 mm and clinical attachment loss of ≥ 3 mm.

It was found that 155 (42.2%) participants were diagnosed with periodontitis, 84 (54.2%) of whom were overweight and obese. It was revealed that a higher body mass index (BMI) was significantly related to the increased odds of periodontitis (odds ratio [OR]:1.9 and 95% confidence interval [CI]: 1.2, 3.2). After adjusting for age and gender, no significant association was found in this population between an increase in waist circumference (WC; OR: 1.6, 95% CI: 0.8, 3.4) and the waist-to-hip ratio (WHR; OR: 0.6, 95% CI: 0.3, 1.2) with increased odds of periodontitis.

It was revealed that a BMI of ˃ 25 was a potential risk factor for periodontitis. No evidence was found regarding the relationship between high WHR and an increased risk of periodontitis in our study population.

Although different methods have been recommended for cleaning orthodontic retainers, a standard method has not yet been introduced. The present study aimed at evaluating the antibacterial effect of three different methods in cleaning Hawley and Essix retainers. A total of 30 patients with orthodontic appliances who were candidates for receiving orthodontic retainers after their treatment were divided into two groups, including Hawley and Essix (n=15 each). Each patient used three home disinfection protocols for cleaning the retainers. Protocol 1: the patients were instructed to clean their retainer using their received toothbrush and toothpaste 3 times a day. Protocol 2: the patients cleaned their retainers the same as in protocol 1. In addition, they were instructed to spray the retainer with 0.12% chlorhexidine for 30 min every night. Protocol 3: the patients were instructed to soak their retainer in distilled white vinegar (50%) for 15 min every night and then clean their retainer in the same way as in protocol 1. Each protocol was applied for 2 weeks, and there was a 2-week wash-out interval between the protocols. At the end of each protocol, samples were taken from each retainer and the number of Streptococcus mutans colonies was counted and compared between the groups. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis (P≤0.05). Antibacterial effectiveness of the three cleaning protocols did not show a significant difference in the Essix and Hawley groups (P=0.510 and P=0.095, respectively). However, a significant difference between the two types of retainers was observed when the patients used protocol 2 for cleaning the retainers. Spraying chlorhexidine or soaking in vinegar following brushing of the retainers was equally effective as brushing the retainers with toothpaste alone.

Chronic sinusitis has been the most reported chronic and multifactorial disease in the last decades. The relationship between the anatomical diversity of the sinonasal complex and sinusitis is still under discussion. Computed tomography (CT) is the modality of choice for the evaluation of the sinuses and anatomic factors that predispose one to sinusitis. This study aimed to investigate the relationship between the anatomical variations of sinonasal complex and sinusitis of the maxillary sinuses using multi-slice CT scans.

In this study, we evaluated CT scans from the paranasal sinuses of 106 patients (212 maxillary sinuses) referring to the Shahid Kamyab Hospital in Mashhad, Iran, that were prepared by 16-slice spiral CT machine (cutting thickness: 0.75 mm). Normal anatomic variations which included agger nasi cells, ethmoid bulla, concha–bullosa, paradoxical middle concha, and nasal septal deviation, were evaluated and recorded. The samples were divided into a healthy group, that showed no increase in mucosal thickness in the maxillary sinus walls, and a patient group (with sinusitis) that showed an increase of more than 2 mm in mucosal thickness of at least one wall. Chi-squared test and independent t-test were used to determine the association between the anatomic variations with maxillary sinusitis.

Chi-square test showed a statistically significant relationship between the presence of paradoxical middle concha and the deviation of the middle nasal septum with an increase in the thickness of the sinus mucosa (sinusitis) (P≤0.001). Moreover, Student's t-test showed no statistically significant difference between the healthy and patient groups in the dimensions of concha bullosa, agger nasi cell, and ethmoid bulla.

The findings of our study showed a relationship between paradoxical middle concha and deviation of the middle nasal septum with sinusitis of maxillary sinus. However, other sinonasal anatomical variations were not associated with the development of sinusitis.

Curriculum evaluation should be concerned with solving problems and improving the present situation. The goal of the general dentistry curriculum is to train dentists with the minimum expected ability. The present study aimed to determine the views of faculty members and dental students on the educational curriculum during the academic year 2018-19.

The present study was descriptive cross-sectional and enumerative. A total of 61 fourth- to sixth-year dental students and 18 faculty members of the School of Dentistry of Rafsanjan University of Medical Sciences, Rafsanjan, Iran participated in the present study during the academic year 2018-19. Inclusion criteria were students who were studying at the time of conducting the study. Data were collected using two questionnaires by Elon Kashkoli. Data analysis was performed by SPSS software (version 21). Descriptive data were presented with mean and standard deviation. Kolmogorov-Smirnov, t-test, Spearman correlation, ANOVA, and Tukey's test were used. A P-value of less than 0.05 is considered to be statistically significant.

The mean score of the attitude of students and faculty members were 68.87 and 62.11, respectively. The attitude of faculty members was moderate and that of students was positive toward the educational curriculum (P= 0.083). The mean scores of the attitude of fourth and fifth-year students are not significantly different from each other (P=0.883). Sixth-year students scored significantly higher compared to the other students (P= 0.01).

Overall, the mean score of the attitude of faculty members and students toward the educational curriculum was moderate. The educational curriculum seems to need to be reviewed in educational titles and practical and theoretical education should be considered in modern teaching methods.

The masking ability of dental ceramics has an important role in the final color of all-ceramic restorations. The masking ability of super-high translucent zirconia is not clearly determined. This study aimed to evaluate the masking ability of two super high translucent zirconia (Zolid fx and DD cubeX2) in comparison to lithium disilicate reinforced glass ceramic (IPS e.max CAD LT).

In this experimental study, 30 ceramic discs with 1 mm thickness and 10 mm diameter in two groups of super-high translucent zirconia (Zolid fx and DD cubex2) and one group of lithium disilicate reinforced glass ceramic (IPS e.max CAD LT) were fabricated (n=10). To determine the masking ability value (ΔE), a spectrophotometer was used to measure the color parameters of each sample (L*, a *, b*) in black and white backgrounds. One-way ANOVA and Tukey Post Hoc statistical tests were used to analyze the data. The level of significance was considered at 0.05.

The mean of ΔE in the three groups of IPS e.max CAD LT, Zolid fx, and DD Cubex2 were 8.37±0.47, 9.87±0.25, and 9.11±0.78 respectively. Significant differences were found in the ΔE values in the three groups (P<0.001).

The masking abilities of two super high translucent zirconia Zolid fx and DD CubeX2 were lower than IPS e.max CAD LT. This ability was lower in Zolid fx than in DD cubeX2.

The microleakage of restorative material can cause secondary caries. The application of laser for tooth preparation has been recently studied. The present study aimed to determine the microleakage of two types of glass ionomers in class V cavities prepared by conventional method and laser Er-YAG.

A total of 28 extracted caries-free premolar teeth were selected and assigned to four groups, including Group A(preparation method bur/restorative material: conventional glass ionomer), Group B(preparation method bur/restorative material: resin-modified glass ionomer), Group C(preparation method Er-YAG laser/restorative material: conventional glass ionomer), and Group D(preparation method Er-YAG laser/ restorative material: resin-modified glass ionomer). Class V cavities with the same dimensions (in a way that occlusal margin was in enamel and gingival margin in cementum) were prepared on buccal surface of 14 teeth by bur and other 14 teeth by laser Er-YAG. Glass ionomer self-cure and resin modified glass ionomer was used for the restoration of the cavities. After thermocycling of the teeth, they were immersed for 24 h in Fushin 2%; thereafter, the samples were sectioned buccolingually at the center of each restoration and evaluated by stereomicroscope. To analyze the data, the Fisher-exact test, Kruskal-Wallis and Mann-Whitney tests were used.

The groups did not significantly differ in the gingival margin. There was a statistically significant difference between group B (preparation method bur/restorative material: resin-modified glass ionomer) and other groups. According to the Mann-Whitney test, there was a significant difference between occlusal and gingival margin only in group B.

Due to the statistically significant difference between group B and other groups in occlusal microleakage and the lower mean rank microleakage in group B, compared to that in other groups, it can be concluded that the laser method and conventional glass ionomer had higher microleakage than the conventional method and resin-modified glass ionomer.

The present study aimed to evaluate vascular density in giant cell lesions with different biologic behavior. Therefore, CD34 expression in central and peripheral giant cell granulomas and the aneurysmal bone cyst was evaluated by immunohistochemistry.

A total of 15, 15, and 8 samples of PGCG, CGCG, and ABC were selected from the archives of the Dentistry School of Mashhad University and Ghaem Hospital, Mashhad, Iran, respectively. Immunohistochemical evaluation of CD34 expression was performed according to the manufacturer's instructions to assess microvessel density (MVD). MVD was calculated in five microscopic fields and the mean MVD of samples was evaluated. Findings were analyzed using t-test, ANOVA, and Pearson’s correlation coefficient.

CD34 expression was 31.53, 31, and 26.40 in CGCG, ABC, and PGCG samples, respectively. Although the highest MVD was in CGCGs, no statistical difference was observed between the studied groups (0.270).

According to the findings of the present study, evaluation of microvessel density with CD34 expression indicates no pathogenesis and different biological behavior of the studied groups. Therefore, further research seems necessary.

Endodontically treated teeth are prone to fracture and cracks. Accordingly, different types of posts are used to increase the fracture resistance of teeth. This study was performed to compare the dentinal microcracks in resected roots with cast and fiber posts.
This experimental study was conducted on 40 single-canal premolars extracted for orthodontic or periodontal reasons. Initially, the teeth were examined under an endodontic microscope for microcracks and mounted using acrylic and randomly assigned into two groups: cast post and fiber post (n=20 teeth per group), 24 h after endodontic treatment. A metal crown was made for the teeth after post cementation in each group. Finally, teeth were cut (3 mm apical) using a diamond fissure bur perpendicular to the longitudinal axis of the root. The samples were examined for the presence or absence of microcracks using an endodontic microscope. The Chi-square test and Fisher’s exact test were used to analyze the data.
Based on the obtained results, the frequencies of dentinal microcracks were 30% and 40% in the apically resected roots with cast and fiber posts, respectively.
The frequencies of dentinal microcracks were similar in cast post and fiber post groups.

Iron drops are often prescribed to children less than 2 years of age. Due to their low pH, these drops may soften the enamel and accelerate its destruction. The present study aimed to evaluate the enamel hardness of deciduous teeth after being exposed to various iron drops.

A total of 48 healthy deciduous anterior teeth were randomly assigned to four groups (n=12 in each group). The samples were exposed to three drops of Sideral iron, Ferrosomal, and Ferrous sulfate for 5 min. Surface hardness was measured before and after iron drop exposure. Four groups were exposed to HCL, and the obtained data were analyzed using the least significant difference (LSD) test and analysis of variance (ANOVA).

In all groups, a decrease was observed in the surface hardness of surface enamel. In the Sideral group, the average initial hardness was 358.81, the secondary hardness was 337.23, and the tertiary hardness was 221.19. In the Ferosomal group, the average primary hardness was 375.67, the secondary hardness was 336.80, and the tertiary hardness was 208.23. In the Ferrous sulfate group, the average initial hardness was 383.41, the secondary hardness was 301.73, and the tertiary hardness was 149.13. Therefore, the three groups statistically differ before and after the iron drop. After the use of iron drop in an acidic environment, there was a statistical difference between Ferrous sulfate and two other drops (P<0.05). Between Sideral and Ferosmal, the difference was not significant (P=0.864).

As evidenced by the results of this study, it can be concluded that all three types of iron droplets in the environment, similar to human saliva, significantly reduced the hardness of enamel. In an acidic environment, all three types of iron drop reduced the hardness of the enamel of deciduous teeth. The Ferrous sulfate group demonstrated the most significant reduction in the microhardness of the enamel, and the Sideral group had the most negligible decrease in enamel hardness.

Dentists always prioritize the preservation of the dental pulp. Nowadays, minimally invasive endodontic techniques such as Vital Pulp Therapy (VPT) are considered due to their affordability and remarkable success compared to conventional treatments such as Root Canal Treatment (RCT). VPT aims at preserving healthy portions of the exposed pulp while removing the inflamed parts with biocompatible materials to seal the pulp.The present case report aimed to describe a successful VPT of a right mandibular permanent first molar with reversible pulpitis using Calcium Enriched Mixture (CEM) cement in an 18-year-old female patient. As pulp exposure happened regarding extensive caries removal, 2 mm of the inflamed pulp was removed and replaced with CEM cement. CEM was covered with Resin-modified glass ionomers (RMGI) and the tooth was restored with amalgam. Regular follow-ups were performed at 3 and 6 months and 1, 2, and 4 years after treatment.

The tooth was clinically and radiographically functional without signs and symptoms of infection or inflammation. The result of this case suggests that pinpoint pulp exposure during deep caries excavation can be successfully treated with VPT using CEM cement.