Journal of Dental Medicine

Background and Aims: Knowing the depth and type of the teeth impaction with radiographic approaches can guide the clinicians into selecting the most appropriate treatment and prevent surgical complications. Therefore, the purpose of this article was to evaluate the prevalence of canine and premolar impaction in the digital panoramic view of patients referred to Rasht dental school in 2019.
Materials and Methods: This annalistic-descriptive cross-sectional study comprised patients who attended the Faculty of Dentistry, Rasht, Iran in 2019. Dental records and panoramic radiographs of 500 patients were reviewed retrospectively. Demographic information as well as the type and depth of impaction, involved jaw, and also, the associated pathological lesions were recorded. Data were analyzed with SPSS24 version with significant level of P<0.05.
Results: The findings revealed that among 500 individuals (300 (60%) were females and 200 (40%) were males), 35 individuals (7%) had at least one impacted tooth, 80% of impacted teeth were canines and the others were premolars. The most common impaction type, impaction level, and pathological lesion were mesioangular, B, and carries of the adjacent tooth, respectively. A significant relation was not observed between the type and level of impaction with the involved jaw (P=0.15, P=0.99) and also, the relation between the type of pathological lesion and gender was insignificant (P=0.85).
Conclusion: Functional and esthetic complications of impacted tooth can be prevented or declined by on-time radiographic screening.

Background and Aims: Dental aesthetics has become an important issue in contemporary society. This study was designed to evaluate the patients’ satisfaction with their dental appearance and tendency to improve dental aesthetics.
Materials and Methods: In this descriptive study, a questionnaire with 17 questions was used to collect data from 200 patients referred to the dental school of Isfahan University of Medical Sciences from April-July 2019. A valid and reliable self-administrative questionnaire consisted of questions about the appearance of anterior teeth, receiving cosmetic treatments, and favorite aesthetic dental treatments was designed and used. Data were fed into SPSS22 and analyzed by Mann-Whitney, Kruskal Wallis and Spearman correlation tests (α=0.05).
Results: Among the participants, 27.5% (n=45) were dissatisfied with the appearance of their anterior teeth and the major reason for this dissatisfaction was related to the tooth color (35.8%, n=71). It was also observed that approximately 84% (n=168) of the patients had a history of smile concealment because of their teeth appearance. Among cosmetic dentistry treatments, aesthetic restorations were more commonly used than other treatments (20.5%, n=41). However, the most desired cosmetic treatments were teeth whitening (78.4%, n=156). There was no significant relationship between the satisfaction with the appearance of teeth and interest in the orthodontic treatment with age and education level (P=0.6).
Conclusion: Teeth color was the most important factor determining the degree of satisfaction with the appearance of teeth. Most of subjects desired to receive an aesthetic dental treatment and teeth whitening was the most popular aesthetic dental treatment.

Background and Aims: Due to the review of general dental courses, it was necessary to assess the students' satisfaction with this curriculum. The aim of this study was the assessment level of students’satisfaction with the new educational curriculum of the Ministry of Health at the department of restorative dentistry of Tehran university of medical sciences in 2019-2020.
Materials and Methods: In this descriptive cross-sectional trial,72 sixth year dental students of Tehran University who passed the restorative dentistry courses based on the new curriculum were studied. A questionnaire was developed and for validity content assessment, it was presented to 5 professors and then revised. For reliability approval of the questionnaire, test-retest approach was used. The questionnaire was given to the 30 students of the main pilot group in one session and two-week later and agreement percentage and Kappa index were calculated.  After conducting the "test" process and re-testing, the "questions" were statistically analyzed using STATA software.
Results: The most level of satisfaction regarding to practicality of subjects was found for fundamental of restorative dentistry including principles of amalgam class I cavity preparations and restorations on the dentic (81.94% and 76.39% acceptable respectively) and the principles of amalgam classII cavity restorations on the dentic (72.22%). The least satisfaction levels were obsereved in the first and second theoretical restorative courses including tooth-colored restorations (47.22%), onlays and inlays (47.22%) and tooth-colored classII cavity preparations and restorations (48.61%). The amount (P-value or error of the first type) was reported in all questions>0.001.
Conclusion: Despite the limitation of this study, final-year dental students’ satisfaction of theoretical restorative dentistry courses was medium, while it was high for the fundamental and practical restorative courses of 2017 educational curriculum.

Background and Aims: The most effective way to maintain and improve oral health is tooth brushing to physically remove dental plaque. In this regard, this study was conducted to compare the efficiency of the usual method of each person in comparison with different methods of brushing to remove dental plaque.
Materials and Methods: This study was conducted in 2020, as a randomized and open clinical trial with 72 non-dental male and female students of Tehran University of Medical Sciences. In this study, the usual method of tooth brushing with Modified Bass and Scrub Horizontal methods after training was evaluated in two random groups with plaque and gingival indices. Plaque index as a percentage and gingival index as a number (numbers between 0-1 mild inflammation, 1.1-2 moderate inflammation, 2-3 severe inflammation) were reported. The results were analyzed using SPSS25 software and paired t-test and variance equality test.
Results: The efficiency of the usual tooth brushing method in comparison with the two Modified Bass and Scrub Horizontal methods using two indicators of dental plaque and gingival indices was not statistically significant (P>0.05). Each method alone after tooth brushing significantly removed dental plaque (P<0.05).
Conclusion: The results of this study showed that the efficiency of the usual method of tooth brushing compared to trained methods in removing dental plaque and reducing gingivitis in short-term evaluation was not statistically significant.
 

Background and Aims: The aim of this study was to investigate the tooth discoloration caused by cold ceramic compared to MTA Angelus in contact with the washing solutions such as sodium hypochlorite (NaOCl) and normal saline.
Materials and Methods: 50 samples of extracted human maxillary anterior teeth were selected. After preparing the access cavity, they were divided into 4 experimental groups and 1 control group (10 in each group). The access cavities of teeth in groups 2 and 4 were rinsed with 5.25% sodium hypochlorite and those in groups 1 and 3 were rinsed with normal saline. Then, after drying, 3 mm thickness of cold ceramic (groups 1 and 2) and MTA Angelus (groups 3 and 4) were placed in the access cavities of the teeth. After setting of the materials, all specimens were restored with a resin modified glass ionomer. Based on the CIE Lab system, each sample’s total color change (∆E) was obtained before, one, and 90 days after application. Data were statistically analyzed using the Wilcoxon test.
Results: According to the results, there was no statistically significant difference in the average tooth discoloration between the groups filled with cold ceramic and in different time periods (P>0.05). While, in the groups filled with MTA Angelus, the difference in the average tooth discoloration in 90 days after application was significantly higher than one day (P<0.05).
Conclusion: The results of this study showed that compared to MTA Angelus, cold ceramic causes less tooth discoloration over time and therefore, it can be suggested as a more suitable alternative endodontic cement than MTA Angelus.

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: The surgical removal of mandibular third molar is frequently accompanied by significant postsurgical complications, and different protocols have been described to decrease such complications. The aim of this study was to compare the postoperative complications of mandibular impacted third molar removal with two conventional rotary and piezoelectric methods.
Materials and Methods: In this study 27 patients with bilateral mandibular impacted third molars were selected. The patients’ teeth were extracted by the piezoelectric method on a random side and the opposite tooth was extracted by conventional rotary technique. On operation and post operation days, edema, pain, and mouth opening were assessed. The duration of each operation was also measured. Data were analyzed by Mann-Whitney test and independent t-test.
Results: The mean duration of operation in the rotary group was less than that of the piezoelectric group, which was statistically significant (P=0.001). Pain was significantly higher in the rotary group on days 0 to 5 (P<0.05). Whereas, difference in pain on day 6 was not statistically significant (P=0.067). There was no significant difference between the two groups in each day after surgery regarding mouth opening (P>0.05). Edema was significantly higher in the rotary group on the first, third, and fifth days after surgery (P<0.05). Also, edema was higher in the rotary group on the seventh day after surgery, but not statistically significant (P=0.076).
Conclusion: According to the results of the present study, it can be concluded that pain and swelling in patients after impacted tooth surgery using time consuming piezoelectric technique can be reduced.

Background and Aims: The white color of teeth is one of the most essential factors in smile esthetics. Therefore, various whitening agents such as bleaching mouthwashes have been produced in response to the people’s high demand for having whiter teeth. The present study evaluated the efficacy of three whitening mouthwash products on tooth enamel whiteness.
Materials and Methods: In the present in vitro study, 32 bovine incisors were assigned to four groups in terms of the mouthwash used (n=8): control (C); Xenon Smart White (ZSW), containing pyrophosphate and triphosphate; Signal White Now (SWN), containing Blue Covarine; and Pasta Del Capitano whitening mouthrinse (PCW), containing Plasdone. Colorimetry was carried out using a spectrophotometer at the baseline and 2, 4, 8, and 12 weeks after treatment with mouthwashes. Data were analyzed using CIELab parameters with ANOVA, RM two-way ANOVA, and post hoc Tukey tests (α=0.05).
Results: The results showed that the whiteness created by the SWN mouthwash was clinically visible (ΔE>3.3). However, the functions of all the mouthwashes were statistically similar with no significant differences from the control group (P>0.05).
Conclusion: Although, Blue Covarine-containing mouthwash was somewhat effective in whitening of tooth enamel, none of the mouthwashes had significant efficacy compared to distilled water.

Background and Aims: Considering the extensive connections of anatomical components in the head and neck region, it is expected that a change in one of the components of this functional unit will have effects on other parts. The aim of this study was to investigate the effect of correction of class III skeletal relationship with orthognathic surgery on the angles between cervical vertebrae.
Materials and Methods: This descriptive-analytical retrospective study was conducted in 1403 at the orthodontic department of Babol Dental School. 30 patients with class III skeletal malformations in the age group of 18 to 48 years who underwent orthognathic surgery (single jaw or double jaw) and had a good quality lateral cephalometric radiography were randomly selected and available based on entry and exit criteria. Dependent variables including 13 parameters in the cranial (angles of SNA, SNB, ANB and Wits App), cervical (the angle between the OPT and CVT lines with each other and with the true perpendicular line) and craniocervical area (the angle of the OPT and CVT lines with the horizontal planes of the head, including the mandibular and palatal plane) of the head and neck were used to evaluate the angles between the cervical vertebrae. The data were analyzed using SPSS22 software and independent t-test, and in case of non-normality, Will-Coxon test was used.
Results: In this study, a total of 30 samples were examined. None of the measured parameters of the cervical area before and after surgery showed a statistically significant change (P<0.05). By comparing the angles between the cervical vertebrae, the PP/CVT angle in the craniocervical region showed statistically significant changes (P=0.024). The values of PP/OPT, MP/OPT, SN/CVT, and MP/CVT angles increased slightly after surgery, but they were not statistically significant (P≥0.05), which showed a relative increase in the tension of the head on the upper part of the cervical spine.
Conclusion: Changing the position of the jaw following orthognathic surgery could cause head extension, but it had no effect on the position of the first 4 cervical vertebrae.

Background and Aims: Dentists faced the highest risk of infection during the COVID-19 pandemic. Educating competent students is the first task of the dental school to overcome the created problems and thus, it is necessary to recognize the created educational deficiencies. This study aimed to assess the students' perspectives from the Dental School at Tehran University of Medical Sciences during the academic year 2019-2020, concerning the competencies expected to be developed during the clinical phase of the general dentistry curriculum during the COVID-19 pandemic. The findings are intended to inform the formulation of educational strategies in the post-pandemic period to address identified gaps in training.
Materials and Methods: During the academic year 2019-2020, a cross-sectional descriptive study was conducted at the School of Dentistry, Tehran University of Medical Sciences, Iran. The study consisted of three phases: checklist design, psychometrics, and a survey of general dentistry students in their third to sixth year. The checklist design phase involved a team of four individuals, including educational officials from the faculty, academic staff members, and medical education experts. Experts confirmed the content validity of the checklist, while reliability was assessed using the Intraclass Correlation Coefficient (ICC), which indicated favorable validity and reliability. Subsequently, questionnaires formatted as Google Forms and a census approach were distributed to all students enrolled in the general dental course within the clinical section of the School of Dentistry at Tehran University of Medical Sciences. Ultimately, following the data collection process, statistical analysis was conducted utilizing descriptive statistics, including the mean and standard deviation, and the findings were communicated to the group managers.
Results: The assessment of content validity was established at a minimum of 71%, based on the evaluations provided by five experts. Additionally, reliability was measured using an intra-cluster correlation coefficient (ICC) exceeding 0.79, signifying a strong level of both validity and reliability. 122 students (53%) in the clinical stage completed the forms related to the pre-clinical/clinical units passed during the Covid era. Despite having enough training, basics Removable Partial Prosthodontics, Surgery 1, and Restorative 3 courses needed more training. In addition, Basics Removable Partial Prosthodontics, Surgery 1, and Surgery 4 needed the most practical training to acquire the necessary competencies.
Conclusion: The findings of this research indicated that the dental students expressed a desire for increased practice across various levels of pre-clinical and clinical courses. This would suggest that the challenges associated with patient interactions during the COVID-19 pandemic may not be the sole contributing factor. Consequently, alongside the need for educational planning to address the requirements of enrolled students, it appears essential to conduct similar studies in the post-pandemic context. Furthermore, this approach may also prove beneficial in evaluating educational needs for ongoing professional development courses.

Background and Aims: Idiopathic osteosclerosis is an asymptomatic local growth of cortical bone and is discovered incidentally on panoramic radiographs. The purpose of this study is to evaluate the frequency of idiopathic osteosclerosis and its radiographic features in panoramic images of patients referred to the Department of Maxillofacial Radiology, Faculty of Dentistry, Arak University of Medical Sciences (Iran) in 2022-2023.
Materials and Methods: In this cross-sectional study, 460 panoramic images from the radiology department of Arak Faculty of Dentistry were randomly selected and analyzed. The demographic information of patients, frequency of idiopathic osteosclerosis, location, and also its relationship with adjacent teeth in terms of proximity to lamina dura and periodontal ligament and radiographic features in terms of size and morphology were evaluated. The data were analyzed using the SPSS24 software.
Results: Panoramic images of 460 patients (266 men and 194 women) with an average age of 38.12 (11.75) years were evaluated. The frequency of idiopathic osteosclerosis was 6.1% (28 images). 92.9% of the lesions were in the lower jaw and 46.4% of them were near the premolar teeth. In 39.3% of the cases, the lesion was adjacent to the periodontal ligament and laminadora of the tooth. In 3.6% of the cases, it was associated with a small displacement of the adjacent tooth, and 17.9% was associated with tooth root resorption. According to the results, there was no correlation between the incidence of this lesion with age and gender (P>0.05).
Conclusion: According to the findings of this study, the frequency of idiopathic osteosclerosis in the patients referred to Arak dental school was reported as 6.1%. Most of these lesions were observed in the back of the lower jaw and thus, it is important to be able to distinguish this lesion from the radiopaque lesions of the jaw which need treatment.

Background and Aims: The display of an individual's teeth varies in different facial expressions, which significantly affects the beauty of the lower face and overall appearance. The ideal display of incisors is influenced by lip morphology and is an essential aspect of treatment planning. This study aimed to evaluate the ideal display of incisors at rest in women with different lip forms, as assessed by dentists and laypeople.
Materials and Methods: This was a cross-sectional study that was conducted in 2024 at Babol University of Medical Sciences. 46 dentists and 92 laypeople were selected and included in the study in an easy and accessible way. The distance between the uppermost area from the lower edge of the vermilion of the upper lip to the imaginary line between the two commissures was used to classify the lip shape, which was divided into three categories: straight (0-3 mm), medium (3-6 mm) and long (more than 6 mm). Smile images of three women in the age range of 15-30 years were collected and manipulated, resulting in six new images from each original image with varying degrees of incisor display using Photoshop (a total of 18 images). The designed images were randomly placed in a booklet and given to participants, who scored each image on a scale of zero to 100. The data were analyzed by SPSS software version 22 and using the Mann-Whitney test at a significance level of 0.05.
Results: A total of 138 participants took part in the study, including 46 dentists (33.3%), comprising 17 males (37%) and 29 females (63%), and 92 laypeople (66.7%), including 46 males (50.0%) and 46 females (50.0%). Laypeople gave higher scores to images of straight and moderate lip forms than dentists. However, this difference was not statistically significant (P>0.05). In addition, dentists gave significantly higher scores to all images related to the  long lip form than laypeople (P<0/05). In addition, among laypeople, men gave a higher score than women to images related to straight and moderate lip form, which was statistically significant (P<0.05).
Conclusion: The findings of this study indicated that a 2.5 mm incisal display at rest was suitable for patients with a straight lip form. In general, it can be concluded that by changing the shape of the lip from straight to long, there is a preference for increasing the amount of incisal display in the resting state.

Background and Aims: Dentists’(specialists and general practitioners) perceptions of smile esthetics, which are often shaped academically based on standard criteria and hard and soft tissue relationships, may differ from those of the general public and patients, potentially failing to meet patients’ expectations of treatment. This study aimed to assess and compare the views of dental specialists, general dentists, and members of the general public regarding the influence of different labio-palatal inclinations of maxillary incisors on smile esthetics.
Materials and Methods: This descriptive cross-sectional study was conducted in 2024 on general dentists, dental specialists, and laypersons. General dentists and specialists practicing in Mazandaran Province were recruited, while laypersons were selected through convenience sampling from patients attending the Faculty of Dentistry in Babol-Iran. One male and one female subject were chosen based on the clinical and lateral cephalometric criteria, and two photographs (neutral facial expression and smiling) were taken of each. After image editing, five final photographs of each subject were prepared and presented in a questionnaire to evaluate participants’ perceptions of smile esthetics according to different labio-palatal inclinations of maxillary incisors, rated on a five-point Likert scale. Data were analyzed using SPSS software with independent t-tests and ANOVA.
Results: A total of 92 laypersons, 47 general dentists, and 141 specialists (47 orthodontists, 47 restorative dentists, and 47 oral and maxillofacial surgeons) participated in this study. Across all three groups, the most attractive male smile was associated with the -5° inclination (medium negative), whereas, the most attractive female smile was rated at 0°. Conversely, the least attractive smile in all groups was the −10° inclination (severe negative) in female images. Photographs with −10° inclination received the lowest scores for both male and female subjects. Specialists assigned lower mean scores to the 0° inclination images compared to general dentists and laypersons.
Conclusion: The divergence between dentists’ and laypersons’ perceptions of the impact of different labio-palatal inclinations of maxillary incisors on smile esthetics highlights the need for greater attention to patients’ expectations and treatment goals.

Background and Aims: Dental caries is one of the most prevalent chronic oral diseases worldwide. Timely and accurate diagnosis of dental caries plays a crucial role in preventing lesion progression and reducing complications. This study aimed to systematically review the studies on dental caries detection using machine learning algorithms applied to periapical radiographs.
Materials and Methods: A comprehensive search was conducted in PubMed, Scopus, Web of Science, IEEE Xplore, and Google Scholar databases up to the end of 2024. Inclusion criteria comprised studies using machine learning algorithms for detecting dental caries in periapical or intraoral radiographs. The quality of studies was assessed using the QUADAS-2 tool.
Results: From 825 initial articles, 13 studies met the inclusion criteria. All studies used Convolutional Neural Networks (CNNs) with various architectures including ResNet, VGG, Inception, DenseNet, and YOLO. ResNet-based models and their hybrid variants showed the best performance with diagnostic accuracy ranging from 82% to 98%. Comparison with human experts in 6 studies revealed that deep learning algorithms demonstrated similar or superior performance.
Conclusion: From the results, deep learning especially convolutional neural networks, had significant potential for improving dental caries detection in periapical radiographs. However, challenges such as limited high-quality training data and generalizability issues need further investigation.

Background and Aims: To prevent dental caries, investigations have focused on finding new antibacterial and anti-biofilm agents without the drawbacks of the currently used synthetic agents. This study aimed to assess the effect of methanolic extract of Zingiber officinale (Z. officinale) on expression of virulence genes of Streptococcus mutans (S. mutans) using real-time polymerase chain reaction (PCR).
Materials and Methods: In this in vitro study, which was conducted in the year 1402, at the Microbiology Department of the Faculty of Medicine and the Faculty of Dentistry at Shahid Beheshti University of Medical Sciences, the methanolic extract of Z. officinale was obtained by the maceration technique. 10 clinical isolates of S. mutans were obtained from the patients with dental infection. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against S. mutans were determined by the microtiter plate technique. The effect of extract on the expression of relA, comDE, brpA, gtfC, and spaP virulence genes by the clinical isolates was evaluated by the real-time polymerase chain reaction (PCR) technique. Data were analyzed by the Wilcoxon and Mann-Whitney tests (alpha=0.05).
Results: The mean MIC and MBC of the methanolic extract of Z. officinale against S. mutans were 32±11.8 and 64±26.12 mg/mL, respectively. The extract caused down-regulation of relA, comDE, brpA, and gtfC by 50%, 40%, 70%, and 70%, respectively. It also caused 4 times reduction in expression of spaP gene.
Conclusion: The methanolic extract of Z. officinale caused significant down-regulation of gtfC, brpA, relA, comDE, and spaP genes, indicating its optimal efficacy to control the virulence of S. mutans.

Background and Aims: Despite documentation on the antiviral effects of cetylpyridinium chloride (CPC) and nano-silver colloid (Ag) on herpes simplex virus type 1, the synergistic effect of these two materials at different concentrations is unknown. This study aimed to evaluate the antiviral effect of various concentration combinations of cetylpyridinium chloride and nano-silver colloid on herpes simplex virus type 1.
Materials and Methods: This laboratory study conducted at the molecular virology department of Iran Pasteur Institute in the year 1400. After testing the cytotoxicity of different concentrations of CPC and Ag, the disinfecting effect of safe concentrations of each substance individually and also in the form of three compounds, was examined on the cells infected with herpes simplex virus type 1. The study groups included groups 1 to 6 with 0.01 µg/ml to 1000 µg/ml of Ag, groups 7 to 12 with 0.1 µg/ml to 10000 µg/ml of CPC, and combination groups of Ag 10 µg/ml + CPC 10 µg/ml (G13), Ag 10 µg/ml + CPC 1 µg/ml (G14), and Ag 1 µg/ml + CPC 10 µg/ml (G15). Data were analyzed using One-Way ANOVA and Games-Howell and Tukey HSD pair comparison tests at a significance level of 0.05.
Results: Based on the MTT test and the cell viability exposed to herpes simplex virus type 1, the highest number of living cells belonged to the 10 µg/ml Ag group, followed by 10 µg/ml CPC, 10 µg/ml Ag + 10 µg/ml CPC, 1 µg/ml Ag + 10 µg/ml CPC, and 10 µg/ml Ag + 1 µg/ml CPC groups. In terms of antiviral effect, there was a significant difference between group 1 and groups 3, 4, 5, 6, and 10 (P<0.001), between groups 2 and 3 (P=0.40), between groups 2 and 4 (P=0.041), between group 2 and groups 5 and 6 (P=0.035), between group 7 and groups 10, 11, and 12 (P<0.001), between group 8 and groups 10, 11, and 12 (P<0.001), and between group 9 and groups 10, 11, and 12 (P<0.001). Among combination groups, the most antiviral effect and the least cell toxicity was found in the 10 µg/ml Ag + 10 µg/ml CPC group, while the least antiviral effect was observed in the Ag 10 µg/ml + CPC 1 µg/ml group.
Conclusion: The highest cell viability rate belonged to the 10 µg/ml Ag group, followed by the 10 µg/ml CPC group, and their combination resulted in a reduction of its effect in this area. The antiviral effect of these materials individually was greater than in their combined state. Additionally , the most antiviral effect and the least cell toxicity was found in the 10 µg/ml Ag + 10 µg/ml CPC group among the combination groups.

Background and Aims: Bimaxillary dentoalveolar protrusion (BDP) is a common orthodontic anomaly characterized by protrusive dental arches and lip prominence. Extraction of the first premolars is a frequently employed treatment approach in these patients. However, the effect of this intervention on Bolton ratios-particularly the overall and anterior ratios-remains unclear. This study aimed to evaluate the impact of first premolar extractions on Bolton ratios in patients with BDP.
Materials and Methods: This experimental study was conducted on archived physical models of 34 Class I patients with BDP and functional lip incompetency (>4 mm) accompanied by lip protrusion, available at the Orthodontics Department of School of Dentistry, Babol, in 2024. All patients had a full complement of teeth from the first incisor to the first molar in each quadrant. After digitizing the models, mesiodistal tooth widths and the overall and anterior Bolton ratios were calculated. Digital simulation of first premolar extraction was performed, followed by reassessment of Bolton ratios. Pre- and post-treatment values were statistically compared using paired t-tests in SPSS (significance level set at 0.05).
Results: Among 34 studied casts, 67.6 % belonged to females. The mean overall Bolton ratio decreased significantly from 90.33 ± 2.23% to 87.72 ± 2.39%, and the anterior ratio declined from 78.19 ± 2.96% to 77.85 ± 3.03% (P<0.001). Additionally, 15 patients exhibited residual space post-treatment, primarily in the mandibular arch.
Conclusion: Based on the results of the present study, first premolar extraction significantly reduced both the overall and anterior Bolton ratios in patients with bimaxillary dentoalveolar protrusion. However, the likelihood of residual space—particularly in the lower arch-should be carefully considered during orthodontic treatment planning to ensure long-term stability and success.

Background and Aims: Musculoskeletal disorders (MSDs) are among the most common occupational health problems faced by dentists. Given their impact on dentists’ health and performance, the present study aimed to investigate the prevalence of MSDs among general and specialist dentists practicing in Babol, Iran.
Materials and Methods: In this cross-sectional study, the standardized Nordic questionnaire, consisting of general and specific sections, was distributed in person among dentists practicing in Babol, based on data obtained from the local Medical Council. Distribution was carried out after a telephone invitation and confirmation of willingness to participate. The questionnaire included items regarding pain and discomfort in different body regions such as the neck, shoulders, and lower back. The frequency of participants with MSDs was assessed based on gender, right/left handedness, specialty, playing sports, and participating in a specific sport. The mean age, weight, height, body mass index, weekly working hours, and work experience of dentists with and without MSDs were also compared. Data were analyzed using SPSS software version 22, employing independent t-tests, Chi-square tests, and Fisher’s exact test, with a significance level set at 0.05.
Results: Of the 182 dentists approached, 17 declined participation and 5 met the exclusion criteria. A total of 160 dentists (mean work experience: 15.65 ±9.26 years) were included in the study; of these, 100 (62.5%) were male, 95 (59.4%) were general practitioners, and 65 (40.6%) were specialists. The overall prevalence of MSDs in this population was reported to be 90%. The most commonly affected region was the neck (76.4%), while the least affected was the ankle (3%). A statistically significant association was found between engaging in a specific type of regular physical activity and a reduced incidence of MSDs (P<0.001). No significant associations were observed with other variables such as gender, handedness, specialty, or field of specialization (P>0.05). Furthermore, no significant differences were found in the mean height, weight, body mass index, weekly working hours, or years of experience between dentists with and without MSDs (P>0.05).
Conclusion: Musculoskeletal disorders are highly prevalent among dentists in Babol. Given this high prevalence, the development and implementation of educational programs on ergonomics, along with recommendations for targeted physical activity appear to be essential.