Second mesiobuccal canal segmentation with YOLOv5 architecture using cone beam computed tomography images.

The objective of this study is to use a deep-learning model based on CNN architecture to detect the second mesiobuccal (MB2) canals, which are seen as a variation in maxillary molars root canals. In the current study, 922 axial sections from 153 patients' cone beam computed tomography (CBCT) images were used. The segmentation method was employed to identify the MB2 canals in maxillary molars that had not previously had endodontic treatment. Labeled images were divided into training (80%), validation (10%) and testing (10%) groups. The artificial intelligence (AI) model was trained using the You Only Look Once v5 (YOLOv5x) architecture with 500 epochs and a learning rate of 0.01. Confusion matrix and receiver-operating characteristic (ROC) analysis were used in the statistical evaluation of the results. The sensitivity of the MB2 canal segmentation model was 0.92, the precision was 0.83, and the F1 score value was 0.87. The area under the curve (AUC) in the ROC graph of the model was 0.84. The mAP value at 0.5 inter-over union (IoU) was found as 0.88. The deep-learning algorithm used showed a high success in the detection of the MB2 canal. The success of the endodontic treatment can be increased and clinicians' time can be preserved using the newly created artificial intelligence-based models to identify variations in root canal anatomy before the treatment.

A Bioinformatics Systems Biology Analysis of the Current Oral Proteomic Biomarkers and Implications for Diagnosis and Treatment of External Root Resorption.

External root resorption (ERR) is a silent destructive phenomenon detrimental to dental health. ERR may have multiple etiologies such as infection, inflammation, traumatic injuries, pressure, mechanical stimulations, neoplastic conditions, systemic disorders, or idiopathic causes. Often, if undiagnosed and untreated, ERR can lead to the loss of the tooth or multiple teeth. Traditionally, clinicians have relied on radiographs and cone beam computed tomography (CBCT) images for the diagnosis of ERR; however, these techniques are not often precise or definitive and may require exposure of patients to more ionizing radiation than necessary. To overcome these shortcomings, there is an immense need to develop non-invasive approaches such as biomarker screening methods for rapid and precise diagnosis for ERR. In this review, we performed a literature survey for potential salivary or gingival crevicular fluid (GCF) proteomic biomarkers associated with ERR and analyzed the potential pathways leading to ERR. To the best of our knowledge, this is the first proteomics biomarker survey that connects ERR to body biofluids which represents a novel approach to diagnose and even monitor treatment progress for ERR.

Effect of propolis on proliferation and apoptosis of periodontal ligament fibroblasts.

The most critical factors affecting the prognosis of an avulsed tooth are extraoral dry time and storage media used before replantation. Studies have analyzed different storage media to determine the ideal solution to preserve periodontal ligament (PDL) cell viability. Propolis has anti-inflammatory and antimicrobial properties, and has been previously suggested as a storage medium. The purpose of this study was to assess not only cell viability but also physiological health of PDL cells after exposure to propolis. PDL cells were exposed to different concentrations of propolis or Hanks balanced salt solution, and the apoptotic levels were determined using apoptosis assay and flow cytometry. Additional cell viability and proliferation were analyzed by XXT assay in dry and wet conditions. Propolis not only decreased apoptosis but also increased the metabolic activity and proliferation of PDL cells. This study suggests that propolis is a suitable storage medium for avulsed teeth.

A quantitative and qualitative analysis of ultrasonic versus sonic endodontic systems on canal cleanliness and obturation.

OBJECTIVE: The purpose of this study was to compare 2 irrigation techniques by evaluating canal cleanliness and obturation of lateral/accessory canals. STUDY DESIGN: Seventy-five extracted canines were instrumented to a size #40/0.06 taper. The EndoActivator (EA) was compared with an ultrasonic unit for final irrigation. Each unit was used for 1 minute each with 6.15% NaOCl and 17% EDTA. A control group received syringe irrigation. Thirty teeth were sectioned and evaluated for debris removal and open dentinal tubules at 3/5 mm from the apical foramen with a scanning electron microscope. Forty-five teeth were examined for obturation of lateral canals. RESULTS: The EA was significantly better in removing debris at all levels when compared with other treatment groups (P < .05) and resulted in obturation of significantly more numbers of lateral canals (P < .01.) CONCLUSIONS: The EA provided better obturation of lateral and accessory canals and resulted in less remaining debris.

A comparison of two gutta-percha obturation techniques to replicate canal irregularities in a split-tooth model.

OBJECTIVE: The purpose of this study was to compare a modified injectable gutta-percha (MIGP) obturation technique with continuous wave technique (CWT) for the ability to fill the root canal system (RCS) and replicate artificially created intracanal defects at the apical third, using a split-tooth model. STUDY DESIGN: A maxillary canine was use to build a split-tooth model. The root canal was cleaned and shaped using crown-down technique with rotary files to size #40 at the apex. Intracanal defects were created in the dentin of the root canal walls with a half-round bur at the apical third. The canal was obturated 48 times with gutta-percha and sealer. Twenty-four obturations were performed for each technique, MIGP and CWT. After each obturation, the model was separated in 2 halves; buccal and lingual. Each obturation was examined and photographed under operating microscope at ×5 magnification. The images were blindly evaluated by 2 endodontists for the length of gutta-percha fill, ability to fill the RCS, presence of voids, and replication of the canal defects. RESULTS: Results were analyzed with the Mann-Whitney U test and showed statistical difference between the 2 groups in the quality of the obturation (P < .05). CONCLUSIONS: The MIGP technique appeared to replicate the canal defects at the apical third better than CWT, with fewer voids in between the canal walls and the gutta-percha mass.

A comparative evaluation of the sealing ability of 2 root-end filling materials: an in vitro leakage study using Enterococcus faecalis.

OBJECTIVE: The purpose of this study was to evaluate the sealing ability of EndoSequence Bioceramic Root-end Repair (BCRR) material when compared with white mineral trioxide aggregate (WMTA). STUDY DESIGN: Forty single-rooted teeth were instrumented, obturated with gutta-percha, root-end resected, and retrofilled with 2 different materials: white ProRoot MTA (WMTA) (n = 15) and BCRR (n = 15). Unfilled specimens (n = 10) received no retrofill and were used as controls. All groups received E. faecalis in a created reservoir coronal to the root filling and the presence of microleakage was evaluated by counting the colony-forming units from each specimen. The results were analyzed with 1-way analysis of variance. RESULTS: There was no significant difference in leakage between the 2 experimental groups, but there was a significant difference with the control (P ≤ .05). CONCLUSIONS: This study suggests that BCRR is equivalent in sealing ability to WMTA when used as root-end filling material in vitro.

Propolis inhibits osteoclast maturation.

Propolis, a natural product produced by the honey bee, has been successfully used in medicine as an anti-inflammatory and antimicrobial agent. Traumatic injuries to the teeth, especially avulsion injuries, present a challenging situation for the clinician because of post-treatment complications, such as inflammatory and/or replacement resorption. Agents that reduce osteoclast numbers and activity may be useful in the treatment of traumatic injuries to the teeth. In this study, we evaluated propolis as an anti-resorptive agent. Calcitriol-stimulated mouse marrow cultures, which contain both osteoclasts and osteoblasts, were exposed to the ethanol extracts of propolis or vehicle control and stained for tartrate-resistant acid phosphatase (TRAP)-activity to identify osteoclasts. A significant, dose-dependent reduction in multinuclear TRAP+ cells was demonstrated, although the propolis treatment accommodated cell growth and survival (P < 0.05). Propolis also reduced the formation of actin rings in pure cultures of RAW 264.7 osteoclast-like cells, suggesting that it exerts direct actions on osteoclast maturation. In summary, our data suggest that propolis inhibits late stages of osteoclast maturation including fusion of osteoclasts precursors to form giant cells and formation of actin rings. This supports the hypothesis that it may prove useful as a medicament to reduce resorption associated with traumatic injuries to the teeth.

C-Shaped Canal: uma variaçäo anatômica / C-Shaped Canal: an anatomical variation

Este trabalho apresenta uma revisäo de uma variaçäo anatômica do espaço do canal radicular. Esta variaçäo, denominada C-Shaped canal, ocorre, mais frequentemente, com o segundo molar inferior e representa uma situaçäo desafiadora para o profissional durante a instrumentaçäo e obturaçäo do sistema de canais radiculares