Objectives: The purpose of this study was to investigate the pattern of mandibular third molar (MTM) impaction and associated carious lesions in adjacent mandibular second molars (MSMs) in a sample of Emirati individuals.Methods: This retrospective study assessed 2000 orthopantomograms of Emirati patients who visited the Specialized Fujairah Dental Center between 2015 and 2020. The depth, ramus relation and angulation of the impacted MTMs were assessed according to the Pell and Gregory classification and Winter’s classification. In addition, carious lesions in adjacent MSMs associated with the evaluated parameters were identified.Results: A total of 461 (23.05%) of the patients had at least one impacted MTM. The mean age of the study population was 26.24 years. Mesioangular, level B, and class II impactions were the most common, at 47.37% (χ² = 382.134;p < 0.001), 45.48% (χ² = 56.889;p < 0.001), and 74.05% (χ² = 513.099;p < 0.001), respectively. There was a higher percentage of level C impaction among females than among males (χ² = 19.178;p < 0.001). A total of 126 impacted teeth (18.36%) had associated carious lesions. These carious lesions were predominantly found in teeth with mesioangular impactions (χ² = 59.430;p < 0.001), level A and B impactions (χ² = 23.301;p < 0.001), and class II and I impactions (χ² = 17.918;p = 0.006).Conclusions: It is imperative to raise awareness of soft tissue mesioangular-impacted MTMs, as they are the most frequently associated with the development of carious lesions in adjacent MSMs. Approximately one quarter of evaluated Emiratis had at least one impacted MTM, with the most prevalent pattern being class II, level B, and mesioangular impactions. Furthermore, surgical removal is expected to be more challenging for females than for males.

Objectives. Particle size and shape can influence the properties of materials. However, to improve the physicochemical and biological properties of mineral trioxide aggregate (MTA), silicate‐based hydraulic cements were introduced. This study aimed to evaluate and compare the major constituents and crystalline structures along with the surface morphology of different types of calcium silicate‐based cement (CSC). Materials and Methods. Six different types of CSC (white Portland cement, white ProRoot MTA, white MTA Angelus, Biodentine, and Endosequence, both putty and paste) were used in this study. Five samples of each material were analyzed in both uncured and cured cement using scanning electron microscopy/energy‐dispersive X‐ray (SEM/EDX), X‐ray diffraction (XRD), and Fourier transform‐infrared spectroscopy (FTIR). Results. SEM analysis showed that the surfaces of all materials consisted of particle sizes ranging from 0.194 μm to approximately 51.82 μm. The basic elements found in both uncured and cured cement of all tested materials using EDX were carbon, calcium, silicon, and oxygen. A difference was observed in the presence or absence of magnesium, aluminum, bismuth, zirconium, and tantalum. XRD showed that all tested materials were composed mainly of tricalcium silicate and dicalcium silicate, which are the main components of Portland cement. FTIR analysis showed aromatic rings, phosphine PH, alkyl halides, and alcohol O‐H groups in all tested materials but at different wavenumbers. Conclusions. The different types of CSCs tested in this study were primarily modified types of Portland cement with the addition of radiopacifiers. ProRoot MTA and MTA Angelus contained bismuth oxide, Biodentine contains zirconium oxide, whereas Endosequence root repair materials (both putty and paste) contained zirconium oxide and tantalum oxide. Endosequence root repair materials showed smaller particle sizes than the other groups. White PC had the most irregular and large particle sizes. CSC had a smaller particle size, except for MTA Angelus. Clinical Relevance. The composition of CSC has a direct influence on the properties of these cements, which may affect the clinical outcome of the treatment.

The objective of the present study was to determine the accuracy of machine learning (ML) models in the detection of mesiobuccal (MB2) canals in axial cone-beam computed tomography (CBCT) sections. A total of 2500 CBCT scans from the oral radiology department of University Dental Hospital, Sharjah were screened to obtain 277 high-resolution, small field-of-view CBCT scans with maxillary molars. Among the 277 scans, 160 of them showed the presence of MB2 orifice and the rest (117) did not. Two-dimensional axial images of these scans were then cropped. The images were classified and labelled as N (absence of MB2) and M (presence of MB2) by 2 examiners. The images were embedded using Google's Inception V3 and transferred to the ML classification model. Six different ML models (logistic regression [LR], naïve Bayes [NB], support vector machine [SVM], K-nearest neighbours [Knn], random forest [RF], neural network [NN]) were then tested on their ability to classify the images into M and N. The classification metrics (area under curve [AUC], accuracy, F1-score, precision) of the models were assessed in 3 steps. NN (0.896), LR (0.893), and SVM (0.886) showed the highest values of AUC with specified target variables (steps 2 and 3). The highest accuracy was exhibited by LR (0.849) and NN (0.848) with specified target variables. The highest precision (86.8%) and recall (92.5%) was observed with the SVM model. The success rates (AUC, precision, recall) of ML algorithms in the detection of MB2 were remarkable in our study. It was also observed that when the target variable was specified, significant success rates such as 86.8% in precision and 92.5% in recall were achieved. The present study showed promising results in the ML-based detection of MB2 canal using axial CBCT slices.

The role of inflammatory mediators in dental pulp is unique. The local environment of pulp responds to any changes in the physiology that are highly fundamental, like odontoblast cell differentiation and other secretory activity. The aim of this review is to assess the role of cathelicidins based on their capacity to heal wounds, their immunomodulatory potential, and their ability to stimulate cytokine production and stimulate immune-inflammatory response in pulp and periapex. Accessible electronic databases were searched to find studies reporting the role of cathelicidins in pulpal inflammation and regeneration published between September 2010 and September 2020. The search was performed using the following databases: Medline, Scopus, Web of Science, SciELO and PubMed. The electronic search was performed using the combination of keywords “cathelicidins” and “dental pulp inflammation”. On the basis of previous studies, it can be inferred that LL-37 plays an important role in odontoblastic cell differentiation and stimulation of antimicrobial peptides. Furthermore, based on these outcomes, it can be concluded that LL-37 plays an important role in reparative dentin formation and provides signaling for defense by activating the innate immune system.

The etiology and pathogenesis of odontogenic lesions are poorly understood. Keratin 15 (K15) is a type I cytoskeletal protein that provides structural support to the cells and has been considered to be a stem cell marker. The aim of the present study was to evaluate the expression of K15 in the epithelial lining of dentigerous cysts (DCs), odontogenic keratocysts (OKCs) and ameloblastomas (ABs). The study included 41 samples of DCs (n=13), OKCs (n=12), and AB tissues (n=16). K15 protein expression was evaluated via immunohistochemistry and data were statistically analyzed using a Kruskal‑Wallis test. K15 was expressed in the majority of the studied lesions with various distributions in the different study samples. The Kruskal‑Wallis test revealed non‑significant differences in the expression of K15 among the three odontogenic lesions (P=0.380). The present study confirmed the high expression of K15 in the different epithelial layers of DC, OKC and AB. This type of expression excludes the reliability of regarding K15 as a stem cell marker in DC, OKC and AB. However, K15 may reflect the abnormal differentiation of pathological epithelial cells in these lesions.