{"title":"Leveraging Pretrained Transformers for Efficient Segmentation and Lesion Detection in Cone-Beam Computed Tomography Scans","authors":"","doi":"10.1016/j.joen.2024.07.012","DOIUrl":"10.1016/j.joen.2024.07.012","url":null,"abstract":"<div><h3>Introduction</h3><div>Cone-beam computed tomography (CBCT) is widely used to detect jaw lesions, although CBCT interpretation is time-consuming and challenging. Artificial intelligence for CBCT segmentation may improve lesion detection accuracy. However, consistent automated lesion detection remains difficult, especially with limited training data. This study aimed to assess the applicability of pretrained transformer-based architectures for semantic segmentation of CBCT volumes when applied to periapical lesion detection.</div></div><div><h3>Methods</h3><div>CBCT volumes (<em>n</em> = 138) were collected and annotated by expert clinicians using 5 labels – \"lesion,\" \"restorative material,\" \"bone,\" \"tooth structure,\" and \"background.\" U-Net (convolutional neural network-based) and Swin-UNETR (transformer-based) models, pretrained (Swin-UNETR-PRETRAIN), and from scratch (Swin-UNETR-SCRATCH), were trained with subsets of the annotated CBCTs. These models were then evaluated for semantic segmentation performance using the Sørensen–Dice coefficient (DICE), lesion detection performance using sensitivity and specificity, and training sample size requirements by comparing models trained with 20, 40, 60, or 103 samples.</div></div><div><h3>Results</h3><div>Trained with 103 samples, Swin-UNETR-PRETRAIN achieved a DICE of 0.8512 for \"lesion,\" 0.8282 for \"restorative materials,\" 0.9178 for \"bone,\" 0.9029 for \"tooth structure,\" and 0.9901 for \"background.\" “Lesion” DICE was statistically similar between Swin-UNETR-PRETRAIN trained with 103 and 60 images (<em>P</em> > .05), with the latter achieving 1.00 sensitivity and 0.94 specificity in lesion detection. With small training sets, Swin-UNETR-PRETRAIN outperformed Swin-UNETR-SCRATCH in DICE over all labels (<em>P</em> < .001 [<em>n</em> = 20], <em>P</em> < .001 [<em>n</em> = 40]), and U-Net in lesion detection specificity (<em>P</em> = .006 [<em>n</em> = 20], <em>P</em> = .031 [<em>n</em> = 40]).</div></div><div><h3>Conclusions</h3><div>Transformer-based Swin-UNETR architectures allowed for excellent semantic segmentation and periapical lesion detection. Pretrained, it may provide an alternative with smaller training datasets compared to classic U-Net architectures.</div></div>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jasmine Wong, Angeline Hui Cheng Lee, Gary Shun Pan Cheung, Colman McGrath, Prasanna Neelakantan
{"title":"Clinician/Patient-Reported Outcomes and Their Association After Root Canal Treatment.","authors":"Jasmine Wong, Angeline Hui Cheng Lee, Gary Shun Pan Cheung, Colman McGrath, Prasanna Neelakantan","doi":"10.1016/j.joen.2024.09.009","DOIUrl":"10.1016/j.joen.2024.09.009","url":null,"abstract":"<p><strong>Introduction: </strong>The relationship between clinician-reported outcome measures (CROM) and patient-reported outcome measures (PROM) after root canal treatment is poorly understood. Oral health-related quality of life (OHRQOL) is a crucial PROM. Determination of the minimal important difference (MID) is critical for determining patients' perspective of treatment effectiveness, but the MID required to perceive any meaningful change in the OHRQOL after root canal treatment remains unclear. The aim of this prospective study was to investigate the relationship between the clinical outcome and OHRQOL after root canal treatment and to determine the corresponding MID values.</p><p><strong>Methods: </strong>Patients (N = 64) requiring primary nonsurgical root canal treatment were recruited. Clinical and radiographic (cone-beam computed tomography) assessment of treatment outcomes was performed at the 12-month follow-up. OHRQOL and pain were evaluated preoperatively and at the 12-month follow-up using the Oral Health Impact Profile-14 and visual analog scale, respectively. P < .05 was considered statistically significant. MID was assessed using distribution- and anchor-based approaches.</p><p><strong>Results: </strong>The final analysis included 47 patients. The clinical outcome was favorable for 92.6% of teeth. OHRQOL and pain showed significant improvement after treatment (P < .001). No significant association was found between clinical outcome and OHRQOL (P > .05). The mean Oral Health Impact Profile-14 score change (ie, 13.6) was greater than the range of MID values determined.</p><p><strong>Conclusions: </strong>Root canal treatment significantly improves OHRQOL. Improvement in the OHRQOL score was greater than the MID values determined, implying a clinically significant change. However, PROM (OHRQOL) does not appear to be correlated with CROM.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142347939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ectopic Dental Canal: A Case Report Highlighting a Unique Bifid Mandibular Canal Variant.","authors":"Kevin W Yu, Manal H Hamdan, Stephanie J Sidow","doi":"10.1016/j.joen.2024.09.007","DOIUrl":"10.1016/j.joen.2024.09.007","url":null,"abstract":"<p><p>Bifid mandibular canals are common anatomical findings with variations based on direction and location of branching, which carry significant clinical implications for endodontic and surgical dental procedures. This case report describes a previously unreported ectopic dental canal that branches off the superior border of the mandibular canal, enters the apex of a mandibular second molar, traverses through the root, anastomoses with the root canal system, and subsequently exits through the lingual aspect of the root. The anastomosis of this ectopic dental canal with the mesial lingual canal led to significant bleeding during rotary instrumentation. This unique anatomical variation demonstrates the importance of a thorough cone-beam computed tomography analysis to identify critical structures prior to undertaking dental procedures involving the root apices of mandibular posterior teeth and adjacent areas.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142347940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bianca Marques de Mattos de Araujo, Pedro Felipe de Jesus Freitas, Angela Graciela Deliga Schroder, Erika Calvano Küchler, Flares Baratto-Filho, Vania Portela Ditzel Westphalen, Everdan Carneiro, Ulisses Xavier da Silva-Neto, Cristiano Miranda de Araujo
{"title":"PAINe: An Artificial Intelligence-based Virtual Assistant to Aid in the Differentiation of Pain of Odontogenic versus Temporomandibular Origin.","authors":"Bianca Marques de Mattos de Araujo, Pedro Felipe de Jesus Freitas, Angela Graciela Deliga Schroder, Erika Calvano Küchler, Flares Baratto-Filho, Vania Portela Ditzel Westphalen, Everdan Carneiro, Ulisses Xavier da Silva-Neto, Cristiano Miranda de Araujo","doi":"10.1016/j.joen.2024.09.008","DOIUrl":"10.1016/j.joen.2024.09.008","url":null,"abstract":"<p><strong>Introduction: </strong>Pain associated with temporomandibular dysfunction (TMD) is often confused with odontogenic pain, which is a challenge in endodontic diagnosis. Validated screening questionnaires can aid in the identification and differentiation of the source of pain. Therefore, this study aimed to develop a virtual assistant based on artificial intelligence using natural language processing techniques to automate the initial screening of patients with tooth pain.</p><p><strong>Methods: </strong>The PAINe chatbot was developed in Python (Python Software Foundation, Beaverton, OR) language using the PyCharm (JetBrains, Prague, Czech Republic) environment and the openai library to integrate the ChatGPT 4 API (OpenAI, San Francisco, CA) and the Streamlit library (Snowflake Inc, San Francisco, CA) for interface construction. The validated TMD Pain Screener questionnaire and 1 question regarding the current pain intensity were integrated into the chatbot to perform the differential diagnosis of TMD in patients with tooth pain. The accuracy of the responses was evaluated in 50 random scenarios to compare the chatbot with the validated questionnaire. The kappa coefficient was calculated to assess the agreement level between the chatbot responses and the validated questionnaire.</p><p><strong>Results: </strong>The chatbot achieved an accuracy rate of 86% and a substantial level of agreement (κ = 0.70). Most responses were clear and provided adequate information about the diagnosis.</p><p><strong>Conclusions: </strong>The implementation of a virtual assistant using natural language processing based on large language models for initial differential diagnosis screening of patients with tooth pain demonstrated substantial agreement between validated questionnaires and the chatbot. This approach emerges as a practical and efficient option for screening these patients.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142347941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Min Chen, Chialing Tsauo, Shenghao Qiu, Weiwei Wu, Jingzhi Ma, Ove A Peters, Yuan Gao
{"title":"Micro-Computed Tomographic Analysis of Radicular Dentin Thickness in Mandibular Second Molars Across Diverse Anatomic Root Variations: Identifying Potential Danger Zones.","authors":"Min Chen, Chialing Tsauo, Shenghao Qiu, Weiwei Wu, Jingzhi Ma, Ove A Peters, Yuan Gao","doi":"10.1016/j.joen.2024.09.005","DOIUrl":"10.1016/j.joen.2024.09.005","url":null,"abstract":"<p><strong>Introduction: </strong>This study aimed to investigate radicular dentin thicknesses in mandibular second molars (MSMs), considering variations in root configuration and the morphology of the pulp chamber floor (PCF). The types of radicular grooves and potential danger zones were also identified.</p><p><strong>Methods: </strong>A total of 149 MSMs were scanned with micro-computed tomographic imaging and classified into 4 groups according to root fusion and PCF morphology as follows: (1) 45 with fused roots and C-shaped PCFs, (2) 45 with fused roots and non-C-shaped PCFs, (3) 14 with a single canal, and (4) 45 with separated roots. The first 2 groups were subdivided into Ω-shaped, U-shaped, and V-shaped radicular groove subgroups. Measurements included minimum and mean dentin thickness from the start of the radicular groove or root bifurcation extending 5 mm apically, the ratio of outer to inner dentin thickness, and the distribution of dentin thickness.</p><p><strong>Results: </strong>Ω-shaped and U-shaped subgroups showed significant thinner minimum inner wall thickness than V-shaped subgroups at 2-5 mm from the starting point of the radicular groove in both C-shaped and non-C-shaped pulp floor categories (P < .05). The mesial roots of separated rooted MSMs showed significant thinner dentin than a non-C-shaped floor regarding minimum and mean inner thickness and mean outer thickness (P < .05). Teeth with a single canal had significantly thicker walls compared with the other 3 groups.</p><p><strong>Conclusions: </strong>In MSMs, caution must be exercised, especially in the presence of Ω-shaped and U-shaped grooves in C-shaped roots and around the root furcation of separated roots.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patrick Wilson Quelis Baltieri, Lucas Peixoto de Araújo, Brenda P F A Gomes, José Flávio Affonso de Almeida, Caio Cezar Randi Ferraz, Adriana de-Jesus-Soares
{"title":"Outcome of Nonsurgical Root Canal Retreatment of Teeth with Persistent Apical Periodontitis Treated with Foraminal Enlargement and 2% Chlorhexidine Gel: A Retrospective Cohort Study.","authors":"Patrick Wilson Quelis Baltieri, Lucas Peixoto de Araújo, Brenda P F A Gomes, José Flávio Affonso de Almeida, Caio Cezar Randi Ferraz, Adriana de-Jesus-Soares","doi":"10.1016/j.joen.2024.09.006","DOIUrl":"10.1016/j.joen.2024.09.006","url":null,"abstract":"<p><strong>Introduction: </strong>Nonsurgical root canal retreatment (NS-RCRT) becomes necessary when primary endodontic procedures fail. This study evaluates the efficacy of NS-RCRT using 2% chlorhexidine gel and foraminal enlargement techniques, aiming to assess whether these approaches enhance periapical healing outcomes and success rates compared to traditional NS-RCRT techniques reported in the literature.</p><p><strong>Methods: </strong>This retrospective cohort study analyzed 120 teeth diagnosed with persistent apical periodontitis, from 80 patients who underwent NS-RCRT between January 2014 and December 2018 at a specialist's private practice. Data were collected following the Preferred Reporting Items for Observational Studies in Endodontics 2023 guidelines. Periapical healing was evaluated using digital periapical radiographs by three calibrated examiners. The outcome of the treatment was analyzed through descriptive statistics and bivariate analyses, including the Chi-Square and Fisher's Exact tests. Treatment outcomes were deemed successful if they showed complete or incomplete repair and unsuccessful if no repair was observed.</p><p><strong>Results: </strong>The average follow-up period was 30 months. Under loose criteria, 92.50% (n = 111) of the teeth were categorized as successful, and 7.5% (n = 9) as unsuccessful. Bivariate analysis indicated that the radiographic restoration of apical transportation was the only factor that significantly influenced the outcome.</p><p><strong>Conclusions: </strong>NS-RCRT performed in a single visit using the foraminal enlargement technique and 2% chlorhexidine gel demonstrated high success rates and may be an effective alternative to tooth extraction. This method promoted periapical healing and could significantly improve NS-RCRT protocols. Further prospective studies are recommended to corroborate these findings.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Teaching a New Obturation Technique in Preclinical Endodontic Training: Assessment of Student Learning Experience, Performance, and Self-Evaluation.","authors":"Meltem Kucuk, Mohini Ratakonda, Lucila Piasecki","doi":"10.1016/j.joen.2024.09.004","DOIUrl":"10.1016/j.joen.2024.09.004","url":null,"abstract":"<p><strong>Introduction: </strong>This study investigated the impact of implementing hydraulic condensation (HC) as a second obturation technique in the Endodontic Preclinical course for dental students trained in warm vertical compaction (WVC).</p><p><strong>Methods: </strong>A total of 70 students performed root canal treatment of 2 extracted molars; they performed the HC technique for the first time after a demonstration. The combination of the obturation technique (WVC or HC) and the type of molar (maxillary or mandibular) was randomly assigned, resulting in 4 groups (n = 35). The students answered a questionnaire appraising their learning experience and completed a self-evaluation rubric. Masked instructors graded projects. Data were statistically analyzed (significance set at 5%).</p><p><strong>Results: </strong>Most of the students (91%) considered learning 2 obturation techniques relevant and considered it difficult to perform the downpack in molars (P < .05). About half of the students (45.7%) responded that HC resulted in fewer errors and disagreed that WVC derives in a more homogeneous obturation; accordingly, 52.9% of the students selected the highest self-grading for HC obturations, while only 38.6% for WVC. No significant difference was found in the distribution of grades attributed by students and instructors (P > .05). Students reported significantly higher levels of confidence for HC and difficulty for WVC (P < .05). No difference was found between the techniques regarding the presence of voids. The presence of multiple errors was more frequent for WVC (P < .05).</p><p><strong>Conclusion: </strong>The findings indicate a positive learning experience and comparable performance among preclinical dental students in implementing HC as an alternative obturation technique.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marie Alnæs, Torgeir Storaas, Hilde Kristin Vindenes, Anne Berit Guttormsen, Lars Björkman
{"title":"Anaphylaxis after Treatment with an Endodontic Material Containing Polyethylene Glycol.","authors":"Marie Alnæs, Torgeir Storaas, Hilde Kristin Vindenes, Anne Berit Guttormsen, Lars Björkman","doi":"10.1016/j.joen.2024.09.002","DOIUrl":"10.1016/j.joen.2024.09.002","url":null,"abstract":"<p><p>Polyethylene glycol (PEG) is sometimes included in temporary endodontic filling materials to modify viscosity. PEG is considered a low hazard chemical, but parenteral PEG exposure is associated with a risk of anaphylaxis. We report 2 cases of anaphylaxis after treatment with an endodontic temporary filling material containing PEG. One patient survived after hospital treatment, but the second case was fatal. Extensive investigations were needed to find the culprit. Allergic reactions to PEG are increasingly reported and have significant implications for the patient. Precautionary measures are discussed.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C G Nogales, R X R Cazares, L C L Nardello, M P A Mayer, G Gavini, M Zehnder, E T Pinheiro
{"title":"Evaluating the Impact of Ultrasonic Irrigation on Bacterial Levels and Activity Following Chemomechanical Procedures.","authors":"C G Nogales, R X R Cazares, L C L Nardello, M P A Mayer, G Gavini, M Zehnder, E T Pinheiro","doi":"10.1016/j.joen.2024.09.001","DOIUrl":"https://doi.org/10.1016/j.joen.2024.09.001","url":null,"abstract":"<p><strong>Aim: </strong>This single-arm interventional trial aimed to investigate the efficacy of ultrasonic irrigation as a supplementary disinfection approach after chemomechanical procedures using molecular techniques based on ribosomal RNA (rRNA) and rRNA genes (referred to as DNA).</p><p><strong>Methodology: </strong>Samples were collected from 35 single-rooted teeth with radiographic evidence of apical periodontitis. Samples were taken after gaining root canal access (S1), chemomechanical procedures (CMP, S2), and ultrasonic irrigation (S3). DNA-targeted qPCR using universal primers was used to estimate total bacterial levels, while rRNA-targeted qPCR was used to assess bacterial activity. Ratios between rRNA and DNA levels were calculated to search for active bacteria in the samples (rRNA/ DNA ≥ 1). Wilcoxon matched-pairs signed-rank test was used to compare the differences in DNA levels between samples and DNA and rRNA levels within samples (P <.05).</p><p><strong>Results: </strong>DNA-based methods revealed a significant decrease in bacterial levels from S1 to S2 and S2 to S3 (both P <.05). Notably, 11 out of 35 (31.4%) root canals did not harbor bacterial DNA after CMP, whereas ultrasonic activation increased DNA-negative samples to 17 (48.6%). However, all DNA-positive samples were also positive for rRNA, with significantly higher rRNA than DNA levels (P <.05), indicating bacterial activity at the sampling time.</p><p><strong>Conclusions: </strong>Ultrasonic irrigation improved the disinfection of root canals after chemomechanical procedures by reducing bacterial levels. However, persisting bacteria remained active in the root canals after CMP and ultrasonic irrigation.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinsung Park, Yeonjin Lim, Chaeyeon Park, Kee-Yeon Kum, Cheol-Heui Yun, Ok-Jin Park, Seung Hyun Han
{"title":"Heat-killed Lancefieldella Rimae Induces Bone Resorption by Promoting Osteoclast Differentiation.","authors":"Jinsung Park, Yeonjin Lim, Chaeyeon Park, Kee-Yeon Kum, Cheol-Heui Yun, Ok-Jin Park, Seung Hyun Han","doi":"10.1016/j.joen.2024.08.014","DOIUrl":"10.1016/j.joen.2024.08.014","url":null,"abstract":"<p><strong>Introduction: </strong>Apical periodontitis, mainly caused by bacterial infection in the dental pulp, is often accompanied by abscess, periapical inflammation, and alveolar bone loss. Lancefieldella rimae has been detected in the root canals of patients with apical periodontitis. Here, we investigated whether L. rimae is associated with bone resorption.</p><p><strong>Methods: </strong>L. rimae was anaerobically cultured and heat-killed (HKLr). A mouse calvarial implantation model was used to determine the bone resorption in vivo. Committed osteoclasts prepared from C57BL/6 wild-type or Toll-like receptor 2 (TLR2)-deficient mice were differentiated into mature osteoclasts in the presence or absence of HKLr. The mRNA expression of tartrate-resistant acid phosphatase (TRAP), ATPase H<sup>+</sup> transporting V0 subunit D2, cathepsin K, interleukin-6, tumor necrosis factor-α, and glyceraldehyde 3-phosphate dehydrogenase was quantified using real-time reverse transcription-polymerase chain reaction. The protein levels of c-Fos and NFATc1 were determined by Western blot analysis.</p><p><strong>Results: </strong>Implantation of HKLr onto the mouse calvaria induced the bone destruction with an increase of TRAP-positive areas. While HKLr enhanced the differentiation of osteoclasts, this effect was not observed in TLR2-deficient osteoclasts. HKLr dose-dependently increased the mRNA expression of genes associated with osteoclast differentiation including TRAP, ATPase H<sup>+</sup> transporting V0 subunit D2, and cathepsin K. In addition, HKLr enhanced the expression of c-Fos and NFATc1, which are important transcription factors for osteoclast differentiation. Moreover, HKLr increased the expression of interleukin-6 and tumor necrosis factor-α.</p><p><strong>Conclusion: </strong>L. rimae induces bone resorption by enhancing osteoclast differentiation through the TLR2 signaling pathway, implying that L. rimae is a causative agent responsible for the alveolar bone resorption accompanying apical periodontitis.</p>","PeriodicalId":15703,"journal":{"name":"Journal of endodontics","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142055768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}