Journal of Dental Medicine

Background and Aims: Achieving non-invasive methods for the proper detection of secondary caries adjacent to dental restorations has a great importance. As alterations in horizontal and vertical angles of X-ray beam would affect the detection of dental caries on radiographs, this study was designed to evaluate the effect of changing the horizontal angle of X- ray on detection of dental caries adjacent to class II amalgam restorations in posterior teeth on periapical radiographs.
Materials and Methods: In this in vitro study, artificial carious lesions were prepared in axial walls of the amalgam restoration cavities in interproximal surfaces of 27 human extracted premolar teeth. Periapical radiographies with different horizontal X- ray angles were obtained, observed, and rated by 5 maxillofacial radiologists for detection of carious lesions. For each observer, the sensitivity, specificity, accuracy, PPV, and NPV of radiographs in the individual horizontal angles were calculated and compared by nonparametric Kruskal Wallis test. Interobserver agreement was assessed by fleiss’ kappa coefficient.
Results: The highest accuracy of periapical radiographs for the detection of secondary caries of mesial dental surfaces was in 5-degree of mesial and distal X- ray angle (86.66%) and for the distal dental surfaces was allocated to 10-degree of distal X- ray angle (85.90%). Also, there was a significant difference in the accuracy between different horizontal angles (mesial and distal 0, 5, 10, 15-degree) (P=0.01). The higher agreement between observers in detecting mesial surface caries was in 10-degree of distal angle (0.86) and in detecting distal caries was in 5-degree of distal angle (0.89).
Conclusion: In the case of doubt in the existence of recurrent caries in the interproximal tooth surface, if the carious lesion is not visible on standard radiographic image with direct angle of X- ray, A 5- 10 degree of x- ray horizontal angle can improve the detection of secondary caries under amalgam restorations in interproximal dental surfaces.

Background and Aims: By using the image processing capability in Cone-Beam Computed Tomography (CBCT), obtained information can be improved. The aim of the present study was to investigate the effect of sharpen image processing filter in determining the external resorption of the root apical region in single-rooted teeth due to the proximity of the impacted tooth using CBCT.
Materials and Methods: In this laboratory study, the lateral surfaces of the apical region of the root of 40 healthy extracted teeth were artificially cut by bur and the teeth were randomly divided into four groups: control, low, moderate, and high resorption. After preparing CBCT of the teeth, the samples were then processed with and without an image sharpening processing filter and examined by two observers. The results of this study were analyzed by SPSS22 and Medcalc Statistical Software version 14. The significance level was considered P≤0.05 for all the statistical tests.
Results: Specificity (100%) and sensitivity (66%>) were either complete or very high for both modes without and with the sharpen filter. The overall accuracy (0.83>) was high in both cases and no significant difference was observed between the two overall accuracies (P>0.05). Statistical analysis of both image observations by two observers showed that the overall sensitivity and accuracy in the medium and high resorption groups was much higher than the low resorption group, but the specificity in all groups was 100%.
Conclusion: The results showed that the images with a sharpening filter did not increase the detection power compared to the unfiltered images. However, as no loss of accuracy was observed with this filter, it could be used as a processing filter.

Background and Aims: Considering the preventive and therapeutic effects of resin infiltration (RI) and the unknown effect of bleaching on the enamel treated with this method, this in-vitro study aimed to assess the effect of bleaching on color stability of enamel lesions treated with RI.
Materials and Methods: In this in-vitro, experimental study, enamel-dentin samples measuring 5×5×3 mm were prepared on the buccal and lingual surfaces of 30 extracted humans third molars with no caries, cracks or enamel defects by a microtome. The specimens were divided into three groups of 10 specimens: 1) sound enamel (control), 2) demineralized enamel, 3) demineralized enamel plus RI. White spot lesions were artificially created by immersing the samples in hydroxyethyl cellulose demineralizing gel with a pH of 4.5 for 4 days. Next, Icon RI was applied on the samples in group 3. The baseline color of the specimens was measured using a spectrophotometer. Then, 35% hydrogen peroxide was applied on the specimens in three cycles and time interval of 10 min. After the end of the last cycle, the samples were completely washed for 1 min and then, underwent colorimetry again. Data were analyzed using one-way ANOVA.
Results: The results of this study showed that the highest level of color change (ΔE) in the demineralized group was 6.3±2.003, while the least amount of ΔE in the enamel lesion group treated with resin infiltration was 3.54±0.98 and in the control group ΔE was 4.13±1.14. Therefore, there was a significant difference between demineralized and treated by infiltratant groups (P=0.005). However, there was no significant difference between control group and treated with resin infiltration group (P=0.54).
Conclusion: Bleaching induced a less change in the color of the enamel lesions treated by resin infiltration compared with that of the demineralized teeth.
 
 

Background and Aims: Atypical facial pain (AFP) is a chronic disease associated with local pain in the craniofacial area. A wide range of treatments including drug therapy, psychiatric methods and open surgery are used for its treatment. Opiorphin is a pentapeptide that can block pain and also has proven antidepressant effects. The aim of this study was conducted to investigate the opiorphin concentration in AFP patients and to compare it with healthy people.
Materials and Methods: This study was performed on 30 AFP patients and 40 healthy individuals. Unstimulated saliva was collected from both groups by spitting method. HAD-A (Hamilton Anxiety Test) and HAD-D (Hamilton Depression Test) questionnaires were completed for all patients and controls. Psychological interview with the patients and psychological analysis were performed to determine anxiety and depression scores. Data analysis was done using SPSS (ver.24) statistical software
Results: The subjects of two groups were homogeneous in terms of age and sex. The mean salivary opiorphin concentrations in the case and control groups were 1.8050±0.2923 and 1.8032±0.3682 ng/ml, respectively. According to the results of t-Test, no significant difference was observed in the mean opiorphin concentration between the AFP group and control group (P=1.000). According to the Pearson's test, no significant relationship was found between the opiorphin levels and the age, sex, and anxiety or depression score in the patient and control groups (P>0.05). Also, there was no remarkable correlation between initial VAS, duration of pain and previous treatments with opiorphin levels in the AFP patients (P>0.05). No significant correlation was found between the opiorphin concentration and menopausal period in the case and control women (P>0.05).
Conclusion: The results showed that most AFP patients had some degree of anxiety and depression. However, salivary opiorphin concentration did not significantly increase in the AFP patients.

Background and Aims: The incisive canal cyst also known as nasopalatine duct cyst (NPDC) is the most common developmental non odontogenic cyst and it is usually asymptomatic with a well corticated round, ovoid or in some cases unique heart shaped radiolucent radiographic finding. Its accurate diagnosis from odontogenic cysts, odontogenic tumor, and benign non-odontogenic tumors using clinical and radiographic findings leads to eradication of pathologic condition with minimum residual defects and patient discomfort. In this case report, the clinical and radiographic findings of a 60-year-old female with the chief complaint of swelling was reviewed. There were typical histologic and radiographic findings related to nasopalatine duct cyst. The surgical management is explained. Follow up visit showed satisfactory healing and no dehiscence. It could be suggested that heart shaped radiographic finding in 3-D reconstructed image in the maxillary midline would be a good predictor for NPDC.

Background and Aims: Root canal treatment failures are often attributed to incomplete removal of bacteria, particularly Enterococcus faecalis. While, chlorhexidine and sodium hypochlorite serve as conventional treatments. herbal medicine has been today considered as an alternative to synthetic medicine due to its safety. Therefore, the aim of the present study was to compare the antibactrial effect of Scrophularia Striata extract with chlorhexidine and sodium hypochlorite on Enterococcus Faecalis in the tooth root canal. Materials and Methods: In this study, sixty extracted teeth were examined. Following the infection of dental canals with Enterococcus faecalis, materials were tested in 3 groups: 1) chlorhexidine 2% (18 teeth), 2) sodium hypochlorite 2.5% (18 teeth), and 3) Scrophularia striata (at the concentration obtained from MIC, 20%; 18 teeth). Additionally, the positive control and negative control were included (3 teeth in each group). Samples were then cultured on bile esculin agar. After 72 hours, black colonies were eaxamined. Chi-squared test was used to analyze the results. Results: Enterococcus faecalis bacteria grew in 6, 8, and 17 out of the 18 teeth within the sodium hypochlorite, chlorhexidine, and Scrophularia striata extract groups, respectively. Consequently, the bactericidal effects for sodium hypochlorite, chlorhexidine, and Scrophularia striata extract were 66.6%, 55.5%, and 5.55%, respectively.

Conclusion: The antibacterial effect of the Scrophularia striata extract was significantly lower than chlorhexidine and sodium hypochlorite on Enterococcus faecalis in dental canals viewed as a suitable replacement to the already in use synthetic therapeutic irrigants.

Background and Aims: To be successful in root canal therapy, the dentists must be aware of the possible variation in the root canal and should know not only the natural anatomy of the pulp, but also a variety of possible morphologies. Frst of all, the dentists should be familiar with the possible anatomy of the root canal and then with the extraction of organic tissue from pulp chamber and root canal, increasing the chances of treatment success. Therefore, in this study, we decided to investigate the internal anatomy of root canals in the maxillary permanent molar teeth in Khoy city. Materials and Methods: In this in vitro study, 100 extracted human molars in Khoy city in West Azerbaijan province were collected. In all teeth, the access cavities were prepared, then they were decalcified and colored with India ink and evaluated by clearing technique. Data were collected based on Vertucci's classification which entered into SPSS23 software. The descriptive statistics in the form of numbers and percentages in tables and graphs were used to analyze the data. Results: The most common type observed in the mesiobuccal root of the first molars was type IV by 44%, in distobuccal root was type I by 92%, and in palatal root was type I by 94%. Also, in the mesiobuccal root of the second molars, the most common type was type I by 70%, in distobuccal root was type I by 94%, and in palatal root was type I by 96%. Conclusion: The mesiobuccal root of the first molar had the most variation in the internal anatomy. Also, the most common type of Vertucci in the mesiobuccal root of first molar was type IV and in the other roots of the first and second molar teeth was type I.

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 present investigation was conducted on the evaluation of the microstructure, phase transformation behavior, mechanical properties, and fatigue resistance of nickel-titanium rotary endodontic files. The main purpose of this investigation was to find the effect of microstructural parameters on the performance of these files.
Materials and Methods: Three rotary tools with brand names Denco, Edgeendo, and Eighteeth were studied. To evaluate the microstructure and transformation behavior of tools, metallography, X-ray diffraction, and differential scanning calorimetry methods were used. The bending test was used to check the behavior of superelasticity and memory and the microhardness test was used to evaluate the hardness of the samples. Also, cyclic fatigue behavior in a mold containing a simulated tooth canal was investigated and calculated by parametric statistical analysis. The fracture surface of the samples was also studied by scanning electron microscope.
Results: Analyses revealed the existence of a high volume fraction of R phase in the microstructure of the Edgeendo file. Rotary files with higher volume fraction of martensitic phase showed higher shape memory effect and fatigue resistance. Denco and Edgeendo rotary files with better surface quality and high volume fraction of martensitic phases in the microstructure showed better fatigue resistance compared with the Eighteeth file. In all the results, the P-value was less than 0.05.
Conclusion: Multiphase microstructure containing austenite and martensite together with appropriate phase transformation and hardness of the alloy have key roles on functional properties of rotary files. This study provides dentists with a deeper understanding of the fatigue behavior and mechanical properties of these files, enabling them to make more informed decisions in choosing the appropriate instruments for endodontic treatment.

Background and Aims: The foundations of a successful root canal treatment are adequate adaptation of the gutta-percha to the canal wall and the establishment of an impermeable apical seal. Despite the common use of M3 and Neoniti rotary files by dentists, no study has been conducted to examine the compliance of gutta-percha in curved canals prepared with M3 and Neoniti files using CBCT. The present study was designed and compiled with the aim of investigating the adaptation of gutta-percha in curved canals prepared with M3 and Neoniti files by CBCT.
Materials and Methods: This randomized controlled laboratory study was conducted ex vivo on 30 permanent human first molar teeth. The teeth were randomly divided into two groups (the first group with M3 and the second group with neoniti), after finding and fixing the appropriate canal path with the examined rotary files. All groups were filled with Single Cone method using F2 gutta-percha and AH26 sealer. Then, the gutta adaptation was assessed using clinical criteria (visual and radiographic) and after the specimens were evaluated using CBCT. All the images obtained from CBCT were converted into the JPEG format and then entered into image J software. The gap between the canal walls and gutta was measured in each canal, and the obtained data were analyzed using the Mann–Whitney U test.
Results: The results showed that the average and standard deviation of gap in M3 files (0.181 ± 0.089) was higher than that of Neoniti file (0.173 ± 0.033). However, no significant difference in the gutta-percha adaptation in curved canals prepared between the M3 and Neoniti files  was observed (P>0.05).
Conclusion: Considering the acceptable adaptation of gutta-percha in canals prepared with M3 and Neoniti files, the use of these two files is recommended in curved canals.

Background and Aims: Third molar teeth extraction is one of the common treatments procedure in dentistry. The proximity of mandibular third molar teeth to the inferior alveolar nerve canal may make the surgery challenging and cause adverse complications. The purpose of this study was to determine the accuracy of diagnostic and evaluation of panoramic radiography findings in two classification methods (Rood-Shehab and Tanaka) according to CBCT in mandibular third molar extraction surgery.
Materials and Methods: This cross-sectional analytical study was conducted on 65 patients of a private radiology clinic in Qom who had simultaneous panoramic and CBCT radiography. Panoramic and CBCT radiographs were imported into Scanora and Ondemand softwares, respectively. The relation of the mandibular third molar with the inferior alveolar nerve was evaluated according to Tanaka's classification and Rood-Shehab radiographic signs and compared with CBCT radiographs. Finally, the obtained data were analyzed by chi-square test, ROC curve and SPSS software version 24. The significant level was considered at P<0.05.
Results: Out of 65 samples, 23.1% were men and 76.9% were women. The mean age of participants was 26.9±8.77. There was a significant relation between the Tanaka's classification of panoramic radiographs and proximity to the nerve in CBCT radiographs (P=0.011). This relationship was significant when the number of radiographic signs of the Rood-Shehab classification increased (P=0.044). Root darkening and diversion of mandibular nerve canal signs of Rood-Shehab classification showed more diagnostic accuracy in the nerve canal contact determination than that of other signs.
Conclusion: The probability of contact of third molar root with the inferior alveolar nerve canal increases with increasing in the number of Rood-Shehab radiographic signs. The root darkening sign was more accurate and followed by mandibular canal diversion sign. Tanaka’s classification can be used in differentiating cases without contact to the nerve canal.

Background and Aims: Musculoskeletal disorders are the most common and costly occupational injuries, and dentists are more prone to musculoskeletal problems than other medical professionals. This study aimed to investigate the effect of a course of corrective exercises on the alignment of the thoracic spine and balance in female dentists with increased kyphosis.
Materials and Methods: This research was a quasi-experimental study with a pre-test/post-test design, conducted in the field. Thirty female dentists from Amol and Babol cities (Iran) with increased kyphosis were selected using purposive sampling. The patients were randomly assigned into two groups: control (n=15) and intervention (n=15). In the pre-test, the thoracic curvature angle, static balance, and dynamic balance were assessed using a flexible ruler, the stork balance test, and the Y balance dynamic test, respectively. Then, the intervention group were assigned to perform the exercises for six weeks, while the control group only engaged in daily activities. After completing the exercises, the post-test was conducted. Paired t-tests and analysis of covariance were used to compare intra-group and inter-group differences.
Results: The statistical analysis  showed a significant difference between the two groups in the thoracic curvature angle (P=0.001), static balance (P=0.001), and dynamic balance (P=0.001). The intervention group demonstrated significant improvement in these parameters compared to the control group.

Conclusion: Based on the results of this study, it is recommended that corrective exercises under the supervision of a specialist be included in the weekly exercise program of female dentists with increased kyphosis.

 This article presents a challenging case of a 64-year-old man with episodic fever, urticarial rash, and arthralgia, prompting a detailed diagnostic process. Despite initial considerations of adult-onset Still's disease, the atypical symptoms led to further investigations, revealing a periapical abscess through a dental examination. The patient's symptoms significantly improved following dental intervention, challenging the initial diagnostic inclination towards a rheumatological disorder. This case underscores the importance of thorough physical examinations and interdisciplinary collaboration in reaching accurate diagnoses. The ultimate diagnosis of systemic presentation due to an occult dental abscess, highlights the need for a comprehensive approach to medical evaluations, considering various clinical aspects and avoiding diagnostics biases. This case study serves as a reminder of the evolving landscape of medical diagnostics and the continued significance of holistic patient assessments and physical examination as valuable practicing skills.

Background and Aims: Posterior crossbite is a common malocclusion disorder in the primary dentition that affects masticatory function. Therefore, early detection and treatment of crossbite teeth is essential to prevent further dental complications and guarantee proper jaw development. This study investigated a reasonable and computationally efficient diagnostic system for detecting characteristics between children with and without unilateral posterior crossbite in the primary dentition using the surface electromyography (sEMG) activity of masticatory muscles.
Materials and Methods: The present study was an experimental in vitro study that used sEMG signals and support vector machine (SVM) to develop artificial intelligence systems capable of decoding muscle activity for diagnosing the crossbite. The core idea of SVM is to find the optimal separating hyperplane that maximizes the margin between two classes (presence or absence of crossbite disease) in the sEMG signal. In this study, 40 children (4  to 6 years old) were selected and divided into unilateral posterior crossbite (UPCB) (n=20) and normal occlusion (n=20) groups. The sEMG activity of the bilateral masticatory muscles was recorded during two 20-s gum-chewing sequences. Then, the time domain and frequency domain features had been obtained. In this study, eighteen time domain features and nine frequency domain features were employed. Finally, these features were used as inputs to the SVM method for data classification and crossbite disease diagnosis. In this paper, four kernel functions of SVM including linear, 2nd order polynomial, 3rd order polynomial and radial basis function were considered.
Results: Based on the obtained results, the crossbite disease had a significant effect on the EMG signals. The results demonstrated that this disease affected the amplitude of the signal more than the frequency. Therefore, using the time features of EMG signals, the SVM method was able to provide a more accurate prediction of crossbite disease. The findings indicated that the mean absolute value feature achieved a 95% accuracy in predicting posterior crossbite. Finally, the results revealed that the RBF method could exhibit superior performance.
Conclusion: The proposed method can be utilized in clinical applications for diagnoses of unilateral posterior crossbite. The findings of the study showed an influence of crossbite on the electrical activity of the temporal and masseter muscles. Therefore, the crossbite problem can be  reasonably diagnosed by an appropriate learning strategy using EMG signals.

Background and Aims: Orphaned children are one of vulnerable groups in society. The aim of this study was to compare oral health, treatment needs, and oral health behaviors of orphaned children under the protection of welfare organization with the guardian children.
Materials and Methods: In this historical cohort study, all 7–12-year-old children under the protection of welfare organization in Isfahan were compared with their classmates’ counterparts in 2019. Clinical examination recorded DMFT/dmft, plaque index, and treatment needs. Children were asked about their oral health behaviors including the frequency of tooth brushing, flossing, fluoride toothpaste, and snacking. Mann-Witney U test, Chi-Squared test, and Fisher's exact test served for  analysis (P<0.05).
Results: The mean score of dmft and DMFT among orphaned children were 3.64±2.54 and 2.93±2.54, respectively, which showed no significant differences with comparison group (P>0.05). No significant difference revealed between the two groups in terms of mean number of deciduous teeth in need of treatment (P=0.175). Only the mean number of permanent teeth requiring treatment was higher in orphaned children (2.46) than that of the comparison group (1.28) (P<0.049). Also, the percentage of children with poor plaque index was higher in orphaned children (P=0.009). There was no significant difference between two groups regarding oral health behaviors (P>0.05).
Conclusion: No significant difference existed between orphaned children and their classmates’ counterparts in terms of dental caries index and oral health behaviors. Only plaque index and the number of permanent teeth requiring treatment was higher in orphaned children. Educational interventions are recommended to promote oral hygiene and to facilitate the orphaned children’s access to dental treatment.

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: In recent years, the use of artificial intelligence (AI) has become increasingly common in dentistry because it facilitates the process of diagnosis and clinical decision-making. It is necessary for dentists to be aware of the advantages and disadvantages of artificial intelligence before implementing it. The present study aimed to comprehensively review the various applications of artificial intelligence in the diagnosis of dental diseases along with its challenges and disadvantages.
Materials and Methods: For this review article, a complete search was conducted on the PubMed and Google Scholar databases and studies published in recent years as well as studies published in 2024 were collected using the keywords "artificial intelligence," "dentistry," "diagnosis." Finally, the relevant articles were selected and evaluated, focusing on artificial intelligence in dentistry and the diagnosis of dental diseases.
Results: Advances in artificial intelligence in dental imaging, particularly through machine learning (ML) and artificial neural networks (ANN), have dramatically transformed the way dental disease is diagnosed. These technologies help dentists to analyze complex information and produce more accurate results by using algorithms that allow systems to learn and respond to data. The most recent development in this area is deep learning (DL), which uses multiple layers of neural networks to process unlabeled data and predict outcomes. These techniques are used in various fields such as diagnostic imaging, periodontology, dental caries detection, and osteoporosis screening, which help to improve the quality of dental services. Despite the benefits of AI in clinical dentistry, three controversial challenges remain and need to be addressed: ease of use, return on investment, and evidence of performance, or reliability.
Conclusion: Based on the results, the most important advantage of AI is the diagnosis of dental diseases. AI has great potential to reduce the pressure on health systems by automating routine tasks and improving patient care. However, this technology can never replace human expertise and must be guided by ethical principles. Ultimately, AI is recognized as a valuable tool in dentistry and the final decision-making always remains with the dentist.