This systematic review aims to investigate the relationship between voxel value obtained from Cone Beam Computed Tomography (CBCT) in studies compared to Hounsfield of Multidetector Computed Tomography (MDCT) in homogeneous and heterogeneous samples. A literature search was carried out in the databases PubMed, Scopus, Embase, and Web of Science searching for relevant literature until February 2022 (updated at July 2023). A risk of bias assessment of the studies was performed using a modified checklist based on the Cochrane Collaboration’s tool and the Journal of Biomedical Informatics. The software version 20.104 of MedCalc was used to conduct the meta-analysis of correlation coefficients. Out of 4750 articles in the initial search, 13 met the eligibility criteria. Out of the articles, eight studies were included in the meta-analysis. Both heterogeneous and homogenous samples showed a strong correlation between the voxel value of CBCT and Hounsfield Unit (HU), with high heterogeneity (r=0.900 and 0.998 respectively and I2>70%). Two other meta-analyses were conducted for kVp and voxel size, which showed a high correlation. The 95% confidence interval was used to present the estimated pooled correlation. The strong correlation of voxel value and HU indicates the possible potential of CBCT in radiographic bone density measurement. However, further research is needed to obtain an accurate conversion equation for translating voxel values of CBCT to HU. Calibration of voxel values within each scan using a reference object and consideration of both linear and non-linear regression could improve accuracy.

Conventional complete dentures cause underlying bone resorption over time, which leads to retention loss and poor adaptation of denture. These complications can be prevented in use of root-supported or tooth-supported overdentures. A tooth-retained overdenture with intra-radicular attachments is recommended in case of insufficient inter-arch space to improve denture retention, stability, function, and support. This study describes a tooth-supported overdenture to gain retention from the canine teeth, and compensate for the limitation in inter-occlusal space. This clinical report helps dental clinicians in selection of the appropriate attachment type in different conditions, and designing a suitable treatment plan. After 7 years of follow-up, no complication was observed.

Objectives: Radicular cyst (RC) and odontogenic keratocyst (OKC) are among the most commonly identified cysts in both the maxilla and mandible. With the advancements in 3D imaging techniques such as cone-beam computed tomography (CBCT), there is an opportunity to thoroughly examine the boundaries of these lesions and quantify the grayscale of CBCT images, known as the grayscale value (GSV). This study investigated the reliability of CBCT GSV in distinguishing between RC and OKC. Materials and Methods: A total of 60 specimens with confirmed pathological diagnoses of RC and OKC were meticulously selected. Before surgical biopsy of each lesion, CBCT images were obtained and analyzed using Romexis version 2.9.2 software to compute the mean GSV of each lesion. Statistical analysis was then conducted using SPSS version 1.0.0.1406, and a linear, backward regression model was used to analyze the differences in GSV between lesion categories (alpha=0.05). Results: Upon extracting the mean GSV of the selected sections of each type of lesion, no statistically significant difference was observed between the mean GSVs of the two lesion categories (P>0.05). Conclusion: The present findings regarding lack of a significant difference in the mean GSV between RC and OKC were substantial, and suggest that the GSV may not be a reliable index for differentiating these cystic lesions from each other, a conclusion that could potentially impact future diagnostic practices.

Objectives: Psychological disorders are prevalent medical conditions that can negatively affect oral health. Due to the increase in the elderly population, and higher risk of psychological conditions in this age group, this study assessed the association of mental health evaluated by the 28-Item General Health Questionnaire (GHQ-28) and oral health in the elderly patients. Materials and Methods: Overall, 150 elderly patients aged 60 years and higher presenting to the dental clinic of School of Dentistry, Tehran University of Medical Sciences in 2019 participated in this cross-sectional study. Oral and dental examinations were conducted to assess the dental caries status using the decayed, missing, and filled teeth (DMFT) index, number of existing teeth, and self-reported dry mouth. Sociodemographic status, oral hygiene behaviors, and medical history of the participants were also recorded. The GHQ-28 was used to assess their mental health. Data were analyzed by SPSS version 25 using the correlation tests (alpha=0.05). Results: Of all the participants, 64 (42.7%) were females, and the age range was 60 to 90 years (mean age: 67.56±6.42 years). The mean total GHQ score was 4±3.8. The DMFT score and number of teeth had significant associations with severe depression and social dysfunction (P<0.05). Dry mouth was directly associated with the total GHQ score and anxiety (P<0.05). Conclusion: Elderly people with severe depression suffered from poor oral health. Comprehensive oral and dental examination and paying close attention to mental health aspects should be considered in regular dental check-ups and oral health promotion programs for the elderly.

Objectives: This study aimed to examine the morphological and morphometric characteristics of the incisive foramen and incisive canal in dry human skulls. Materials and Methods: The sample consisted of 150 dry adult skulls, with no distinction regarding sex or ethnicity. The analysis included the number of incisive canals within the foramen, their dimensions (area and diameter), and their anatomical connections with the incisive fossa and the nasal cavity. Results: All incisive canals were found to communicate with the nasal cavity. The most frequently observed configuration was foramina containing two or more canals. Conclusion: Precise anatomical knowledge about the incisive canal and its foramen is essential for clinical procedures involving the anterior maxilla. Morphological variations in this region may affect surgical access, technique selection, and procedural outcomes.

Objectives: Dentin hypersensitivity (DH), characterized by a short, sharp, and intense pain response to a stimulus, is the most commonly encountered patient complaint. Various in-office and at-home methods including the recently introduced nano-hydroxyapatite (n-HA) and zinc carbonate-hydroxyapatite (Zn-CHA)-based products reduce the DH discomfort. This study compared the effectiveness of commercially available n-HA and Zn-CHA toothpastes for occlusion of dentinal tubules for management of DH. Materials and Methods: In this in vitro study, 40 tooth samples were randomly assigned to 4 groups (n=10): negative control): brushing without toothpaste,Aclaim n-HA toothpaste,Biorepair Zn-CHA toothpaste, andShyNM calcium sodium phosphosilicate (CSPS) toothpaste. After demineralization with 17% ethylenediaminetetraacetic acid, the mounted specimens were brushed with an electric pressure-sensitive toothbrush and the respective toothpaste. Occlusion of dentinal tubules was subsequently evaluated under a scanning electron microscope (SEM). Elemental composition of the occluding plug was analyzed by energy-dispersive X-ray spectroscopy (EDX). Results: The test n-HA and Zn-CHAand the positive control (CSPS) groups revealed significantly higher tubular occlusion compared to the negative control group (p= 0.001). The highest tubular occlusion was achieved in n-HA and Zn-CHA groups (80%); while negative control showed no occlusion (0%). Elemental analysis of dentinal plug showed significant differences in carbon, oxygen, calcium, and phosphorus levels among the groups (p<0.05). Conclusion: The tubular occlusion capacity of Zn-CHA and n-HA were similar to CSPS-based toothpaste, and CHA in Zn-CHA enabled the formation of stable dentinal plugs.

Objectives: Lack of a proper apical seal is one of the most common reasons for root canal treatment failure. Several sealers have been developed in an attempt to enhance the quality of apical seal. Nevertheless, it is essential to evaluate their effectiveness in preventing bacterial penetration. The present study employed a bacterial leakage model to assess and compare the apical sealing ability of three root canal sealers namely AH26, Endoseal MTA, and Sure-Seal Root. Materials and Methods: This in vitro study evaluated 148 extracted single-rooted permanent teeth with almost identical root lengths. The teeth were prepared using the modified crown-down technique, and underwent cleaning and shaping using ProTaper rotary files. Five teeth were selected as positive controls, and five as negative controls. The remaining teeth were randomly assigned to three groups (n=46), and obturated using the abovementioned root canal sealers according to the manufacturers’ instructions. A bacterial leakage model was used to evaluate microleakage. The samples were evaluated daily regarding turbidity resulting from microbial microleakage. The data were analyzed with the Chi-square test and the log-rank test using SPSS 24 (alpha=0.05). Results: The highest bacterial microleakage was recorded in the Sure-Seal Root group (7.21%), while the lowest microleakage was noted in the AH26 group (2.16%). However, there was no significant difference in bacterial microleakage among the three sealer groups (P=0.718). Conclusion: According to the results of this in vitro study, the three sealers evaluated in the present study exhibited a similar performance regarding apical microleakage.

Due to the global burden of oral diseases, knowledge production and transfer are essential for clinical practice and policy. This descriptive study assessed 28 Iranian Oral Health Research Centers (OHRCs) from 13 medical universities (2019–2021), using indicators like research output, high-quality publications, international collaboration, citations, and H-index for production, and Altmetrics for transfer. Over three years, these centers published 4,428 articles in indexed databases, with approximately 20% (883 articles) appearing in first-quartile (Q1) journals. More than 16% of publications involved international co-authorship. In knowledge production, the Dental Research Center of Tehran University of Medical Sciences ranked first, followed by the Dental and Periodontal Research Center of Tabriz and the Dental Research Center of Shahid Beheshti University. For knowledge transfer, the Dental Materials Research Center of Babol ranked first, followed by Mashhad’s center. The findings demonstrate substantial scientific productivity among Iranian OHRCs, with notable variation in research performance across institutions.

Solitary Fibrous Tumor (SFT) is a rare benign neoplasm primarily associated with the pleura. However, it has also been identified in diverse locations, including the skin, deep soft tissues, genitourinary system, gastrointestinal tract, and the head and neck region, including the oral cavity. There is no gender predilection for SFT of the oral cavity and it can occur at any age. We herein present a case of SFT on the lower lip of a 19-year-old male patient and describe our diagnostic approach. The histopathological findings showed typical features of SFT with immunoexpression of CD34, CD99, BCL2, and STAT6, along with low expression of Ki67 in 10% of the tumor cells.

Objectives: Lithium disilicate is commonly used for restoring worn teeth. Various preparation designs have been introduced for occlusal overlay restorations, potentially impacting the properties of the restoration. This study evaluated the fracture resistance, marginal gap, and internal gap of lithium disilicate occlusal veneers prepared with two different preparation designs. Materials and Methods: In this in vitro study, 22 extracted mandibular molars were randomly assigned to two groups (n=11). In the non-retentive (NR) preparation group, the occlusal surface was reduced by 0.8 mm in the fissures and 1 mm at the cusp tips. In the retentive (R) group, in addition to occlusal reduction, the axial surfaces were reduced with a round-end shoulder finish line created around the axial wall, with both height and depth measuring 1 mm. Occlusal veneers were fabricated using lithium disilicate (IPS e.max Press). The marginal and internal gaps were measured using the silicone replica technique before cementation. After cementation, the restorations underwent thermocycling and load cycling, followed by fracture resistance testing in a universal testing machine. Data were analyzed by independent t-test. Results: The fracture resistance of the R group was insignificantly higher than that of the NR group (P=0.310). The marginal gap (P=0.001) and internal gap (P=0.021) of the R veneers were significantly larger than those of the NR veneers. Conclusion: Both R and NR occlusal veneers exhibited sufficient strength for posterior tooth restorations. The marginal and internal gaps of R and NR occlusal veneers fabricated from lithium disilicate (IPS e.max Press) were found to be within the acceptable range.