Journal of Dental School

Objectives Pleomorphic adenoma is the most common benign salivary gland tumor. Since the studies conducted on the histopathology of pleomorphic adenoma have different results and this tumor can mimic other salivary gland tumors, and due to the high prevalence of this lesion, this study was conducted to investigate the clinical and histopathological differences of pleomorphic adenoma in the major and minor salivary glands.

Methods A total of 72 cases with the diagnosis of pleomorphic adenoma were reviewed by the oral and maxillofacial pathologists, and the findings were analyzed using Fisher's Exact and Pearson chi-square tests to compare the frequency distribution of variables between major and minor salivary gland lesions with the first type error of 0.05.

Results The most common age group was 41-50 years old, and the gender preference was for women. The clinical symptoms were mostly painless swelling. The most common locations for the major and minor salivary glands were in the parotid and in palate, respectively. The most common histopathological classification was classic; and the most common cells observed in the major and minor salivary glands were squamous and plasmacytoid, respectively. The most common microscopic pattern was solid, the most common stromal subtypes in the major and minor salivary glands were myxoid and hyalinized, respectively; and the most common capsular forms in the major and minor salivary glands were thin and partial, respectively. Keratin pearls were observed in both major and minor salivary gland lesions.

Conclusion The findings of this study are consistent with previous studies in many cases. Osteoid and fatty changes in stroma were seen in this study which are remarkable findings. Partial encapsulation is more common in minor salivary glands, which could be associated with recurrence.

Objectives This study aimed to assess the knowledge, attitude, and practice of Iranian pedodontists regarding preventive measures during the coronavirus disease 2019 (COVID-19) pandemic.

Methods This cross-sectional study was conducted on 180 Iranian pedodontists. Data regarding their knowledge, attitude, and practice related to COVID-19 were collected through a valid and reliable researcher-designed questionnaire and analyzed using the independent t-test, analysis of variance (ANOVA), and Tukey test (alpha = 0.05).

Results The majority of the participants were between 30 and 50 years old. The attitude and practice scores of participants aged over 50 were significantly higher than those of younger participants (P < 0.05). The majority of the participants were female, but the mean practice score of males was significantly higher than that of females (P = 0.018). The participants’ mean knowledge, attitude, and practice scores had no significant association with their work experience or practice location (P > 0.05). The participants had a good level of knowledge regarding self-protection; however, they needed to update their knowledge.  

Conclusion The Iranian pedodontists’ levels of knowledge, attitude, and practice were generally good, and they adhered well to the infection control protocols, social distancing measures, and taking thorough medical histories.

Objectives This study used a newly designed mesiodistal guide set to assess and compare the precision of the mesiodistal positioning of dental implants relative to adjacent teeth. The cost-effective and convenient guide set was compared to the conventional freehand surgery technique in partially edentulous patients.

Methods The study enrolled 38 patients requiring at least one implant. Participants were divided into case and control groups, receiving 30 implants in each group: 10 in free-end areas, and 20 in single-tooth edentulous spaces. In the case group, implants were placed using the mesiodistal guide set, while the control group underwent the freehand procedure. The postoperative evaluation involved taking parallel periapical radiographs to measure distances and angles between the implants and adjacent teeth using Photoshop CS4. The data was rigorously analyzed using the Generalized Estimating Equations (GEE) method, a statistical technique for modeling clustered data, with statistical significance set at p<0.05.

Results Measurements of the mesiodistal distances between implants and adjacent teeth showed reduced deviations in the case group, with statistically significant differences in mesial (P=0.001) and distal (P=0.036) distances. The tooth-supported area exhibited better outcomes compared to the free-end area. However, there were no significant differences in implant-tooth angulation, whether mesial (P=0.503) or distal (P=0.188).

Conclusion The study indicated that the mesiodistal guide set offers practical guidance for positioning implants next to teeth in partially edentulous patients. This finding has significant practical implications, providing tangible evidence for the clinical application of the guide set. Despite some limitations, the findings fall within clinically acceptable parameters, and the guide set proved to enhance accuracy over the freehand method.

Objectives Well-formed communication between dentists and dental technicians is an important factor for the fabrication of dental prostheses. Numerous articles have highlighted the lack of sufficient communication between dental clinics and laboratories. The present study aimed to assess the communication between dentists and dental technicians in Iran.

Methods In this cross-sectional study, a structured questionnaire containing 23 questions about the effectiveness of communication between dentists and dental laboratories was distributed among 154 dental technicians. After data collection, the data were entered into SPSS-24 software and analyzed. Independent t-tests and analysis of variance (ANOVA) were used to analyze the data with independent variables.

Results The communication between dental laboratory and clinic had a significant relationship with gender, job characteristics, laboratory location, and laboratory activity in all areas (p-value <0.001). Moreover, 77.3% of the participants perceived their communication as constructive and encouraging, and 50% believed that the dentist followed their opinion after consulting with the dental prosthesis laboratory.

Conclusion Training in medical professionalism, as an essential element contributing to communication between dentists and dental technicians, must be included in the dental schools’ curricula.

Objectives This study aimed to assess the changes in alveolar ridge dimensions following immediate implantation with and without buccal gap filling using cone-beam computed tomography (CBCT).

Methods This prospective randomized clinical trial was conducted on 15 patients (mean age = 44.7 years) with 26 hopeless teeth. The teeth were extracted and immediately replaced with implants. The patients were randomly assigned to two test and control groups (N=13 implants each). In the test group, the gap around the implants was filled with allograft, while the control group did not receive buccal gap filling. CBCT scans were obtained at two days and four months postoperatively. The buccolingual ridge dimensions, buccal plate thickness, and buccal gap distance were measured at the implant platform and 2 and 4 mm apical to it, and changes were analyzed by the mixed-effects model (alpha = 0.05).

Results In cases with a sound buccal plate having a minimum thickness of one millimeter, the alveolar ridge and buccal plate resorption were the same in the test and control groups.

Conclusion: The results revealed that immediate implantation with and without buccal gap filling did not prevent alveolar ridge and buccal plate resorption

Objectives The present study aimed to assess the level of shear bond strength (SBS) of universal adhesives (G-premio Bond Universal (GBU) and All Bond Universal (ABU) on zirconia without surface preparation, zirconia sandblasted by 50-micron aluminum oxide particles, and zirconia glazed by low-fusing ceramics after the thermocycling process.

Methods Two Ceramill ZI zirconia blocks were used to prepare 18 cubes with dimensions of 10×10×10 mm. Then, based on the type of surface preparation, these 18 sintered zirconia cubes were classified into three groups of six, including the control group, sandblasted group, and glazed group. Each group was classified into two subgroups based on the type of universal adhesive (ABU/GBU). On each cube, four cylinders filled with Panavia F2 resin cement with a diameter of 1.5 mm and a height of 2 mm were attached by the universal adhesive of the related subgroup (n = 72). The samples were subjected to 5000 thermal cycles in the thermocycler, each sample was assessed to test SBS, and the type of failure observed in each group was finally observed under a stereomicroscope. The data were analyzed using a two-way analysis of variance (ANOVA) test, Tukey’s post hoc test, and independent t-test, with a significance level of 0.05.

Results There was a statistically significant difference in SBS between the control group and the other two groups (p-value < 0.05). At the same time, there was no statistically significant difference between the sandblasted zirconia group and the glazed zirconia group (p-value = 0.13).

Conclusion: Applying a low-fusing glazed layer to prepare the zirconia surface leads to an increased SBS of dual-cured self-etch resin cement, equivalent to sandblasting with 50-micron aluminum oxide after the thermocycling process.

Objectives Ensuring strong adhesion of silicate-based cement to dentin during root canal therapy is crucial for achieving optimal results. This review aims to evaluate how different intracanal medicaments impact the tensile bond strength of silicate-based cement in root canal treatments.

Methods A thorough electronic search was performed using the PubMed and Google Scholar databases for articles published from 2000 to 2023.

Results The studies included in this review evaluated the effects of various intracanal medicaments, including calcium hydroxide, chlorhexidine, triple antibiotic paste, double antibiotic paste, simvastatin, and bioactive glass, on the bond strength of silicate-based cements like mineral trioxide aggregate (MTA), Biodentine, and calcium-enriched mixture (CEM) cement. The results demonstrated varied impacts of these medicaments; some improved bond strength, while others had minimal effect. Specifically, calcium hydroxide frequently enhanced bond strength, and some antibiotic pastes showed similar benefits. In contrast, medicaments such as phenolic preparations and formaldehyde were found to have limited efficacy and potential toxicity.

Conclusion The type, concentration, and application site of intracanal medicaments significantly impact bond strength. This review highlighted the potential advantages of these medicaments, including improved root canal disinfection and enhanced push-out bond strength of commonly used dental cements. These insights can help dental professionals optimize root canal treatments and improve patient outcomes.

Dental diseases affect children’s performance at schools and their future success in life. It has been reported that children with dental problems are 12 times more likely to miss school or experience activity restriction than their healthy peers, that might threaten their emotional and social well-being. ¹. Dental caries is still a common problem in Iran. According to the last national survey, only 26% of 12-year-old students and 0.5 % of 15-year-old students were caries-free. ²

Schools provide an effective and ideal platform for improving the oral health of children and adolescents. Since oral health behaviors, beliefs, and attitudes are shaped during childhood; oral health messages can be reinforced throughout the school years. In addition, schools can provide supportive measures to promote oral health, including policies and programs to increase school safety to reduce facial and dental trauma, to improve student healthy nutrition patterns, to educate them about their oral health, and to identify children in need of dental treatment at early stages and refer them to receive timely treatments. Schools also have plenty of opportunities to communicate with families and increase their awareness toward the oral health of children. ³

Therefore, schools can be considered a special place to implement oral health promotion programs. The experience of running "Oral Health-Promoting Schools" in different parts of the world testifies to this claim. ^{4, 5}. Key steps recommended by the WHO to consider in this protocol include establishing or involving a school health team and a community advisory committee, conducting a situational analysis, obtaining political, parental, and community commitments, establishing supportive school health policies, and setting goals and objectives. ⁶.

 Although some health issues are considered in the primary schools in Iran, there is not an established comprehensive plan for oral health promotion. On the other hand, by overcoming the health-oriented approach at the policy making levels of Ministry of Health and Medical Education, dental schools have carried a strong potential for improving public oral health. The Department of Community Dental Health in dental schools of Iran is responsible for teaching the oral health promotion concepts, strategies, and programs and creating the necessary attitude and awareness among dental students to empower them in providing preventive services. Therefore, there is a good opportunity in the general dental practitioner curriculum to teach students how to use their potential in line with targeted population oral health promotion.

In a pilot program designed, implemented and evaluated at the Isfahan University of Medical Sciences during Sept 2018- June 2021, coordinated efforts were initiated to integrate the dental education curriculum headlines and the recommended principles of “oral health promoting (OHP) schools”.⁷ In this program, in coordination with the Province Education Council and the Vice Chancellery of Province Health, dental students -as part of their dental public courses- were to attend some selected primary schools, where they had the responsibility for oral health screening of the schoolchildren, determining their preventive and restorative needed care, and referring them to receive the proper care. Also, they were to provide face-to-face education in small groups using flipcharts and big-size demonstration toothbrush and dental arches, disclosing tablets (Svenska Dentorama, Sweden), dental floss, disposable mirrors, soft toothbrush and fluoridated paste and supervised toothbrushing in the schools’ yards. In addition, dental students were asked to educate parents in two-day workshops organized by the school administrators. Two printed worksheets were also designed, published and distributed in the selected schools to reinforce and remind the headings taught by dental students. As part of the dental public health practical courses, schoolchildren were invited to dental school clinics, where fissure sealant treatment and fluoride varnish therapy were provided to them free of charge by dental students. The final part of this integrated program was the provision of primary and secondary preventive care to schoolchildren using portable dental equipment placed in the schools. All of the provided educations and cares were under the supervision of the Dental Public Health Department professors. The evaluation phase indicated the effectiveness of this model in terms of knowledge and practice improvement among schoolchildren, their parents, and teachers, and in increasing the coverage of professional preventive care and simultaneously, the effective community-based training of dental students. ⁸ 

This model of OHP schools would be a good opportunity to both promote the oral health of schoolchildren at a critical age that permanent teeth and oral health behaviors are shaped and also to utilize the potentials of dental schools to provide oral hygiene instructions and working in community-based fields. This project might also improve and strengthen the interdisciplinary cooperation between the health sector and educational council which could be a good example of advocacy in health system. In addition, this project could increase the awareness of supportive members (teachers and parents) about the importance of OH.  Therefore, it worth planning to implement this model by other dental schools at least in Iran. Considering the number of dental schools in the country and current dental students (about 2000), this model can benefit both the schoolchildren in deprived schools and also university students.