Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis

Phage PEf771 for the Treatment of Periapical Periodontitis Induced by Enterococcus faecalis YN771

Enterococcus faecalis was the main causative bacteria of refractory periapical periodontitis (PP), there is a pressing need to explore effective methods for eradicating E. faecalis in patients with refractory PP. This study aimed to assess the anti-infective effectiveness of phage PEf771 in treating periapical inflammation in rats. We developed a rat model of PP through E. faecalis YN771 induction. Micro-computed tomography and hematoxylin-eosin staining were utilized to evaluate bone destruction and inflammation in experimental teeth for seven consecutive weeks. Subsequently, rats with PP caused by E. faecalis YN771 were treated with phage PEf771, calcium hydroxide preparation, and 2% chlorhexidine gel. The healing progress of bone defects and inflammation in the apical region was monitored over three consecutive weeks using imaging and histopathology assessments. The PP rat model was successfully developed, and bone destruction and inflammatory cell infiltration in the apical region of the experimental tooth peaked at 4 weeks. The area of bone destruction in rats treated with phage PEf771, calcium hydroxide preparation, and 2% chlorhexidine gel was significantly smaller than that in the untreated group. Phage PEf771, calcium hydroxide preparation, and 2% chlorhexi-dine gel all have the effect of promoting the healing of apical lesions. Therapeutic effects of phage PEf771 on periapical inflammation infected by E. faecalis YN771 enhanced with time. Phage PEf771 promoted the healing of apical lesions, presenting a promising new approach for the treatment of refractory PP using bacteriophages.

Magnetic resonance imaging versus cone beam computed tomography in diagnosis of periapical pathosis – A systematic review

Objective

The diagnosis of any dental pathology can vary from being simple to challenging. While the use of cone beam computed tomography (CBCT) is well established, magnetic resonance imaging (MRI) remains a proof of concept. This systematic review aims to compare the diagnostic ability of MRI with CBCT in diagnosing periapical pathosis.

Materials and Methods

This systematic search was performed using the electronic databases of MEDLINE, Cochrane Library, Google Scholar, and Science Direct to identify relevant articles from 2010 to 2020. The search terms used were magnetic resonance imaging, cone beam computed tomography, diagnosis, and periapical diseases.

Result

In total, 3218 potentially relevant abstracts and titles were identified. After removing duplicates, 1288 articles were reviewed for titles and abstracts, and 29 articles were selected for full-text reading. From those, 19 articles were finally selected that included original research studies, case reports, and case series and were included for systematic review. Most of the studies included in this review suggested that the combined use of CBCT and MRI is needed for a better and more precise diagnosis of complex periapical pathoses. The main advantage of MRI is its ability to image soft tissues usingnonionizing radiation, and the main disadvantage in the case of CBCT is overdiagnosis of the lesion.

Conclusion

MRI has various advantages over CBCT with similar diagnostic utility. When diagnosing periapical pathogens, both MRI and CBCT are needed for an accurate diagnosis.

Crosstalk between Wnt/β-catenin signaling and NF-κB signaling contributes to apical periodontitis

In physiology conditions, the crosstalk of signaling pathways has been considered to extend the functions of individual pathways and results in a more complex regulatory network. The Wnt3a/β-catenin and NF-κB signaling pathways have been demonstrated involving in apical periodontitis (AP). As AP progresses, ultimately causes tooth loss. In the present study, we investigate the contribution of the crosstalk between the Wnt3a/β-catenin and NF-κB signaling pathways to the development of AP. Clinically, utilizing 60 human AP and healthy tissues (30 samples for each group), we found that the expression levels of Wnt3a/β-catenin and NF-κB were elevated in the Ap tissues compared to that in the healthy group. To further study the roles of Wnt3a/β-catenin and NF-κB signaling pathways in the development of AP, and the contribution of the crosstalk between these two signaling pathways to AP, we established the AP animal model and observed that, first, both pathways are activated in the AP group compared to the control group. Interestingly, by immunoprecipitation and western blot experiments, we revealed that there is greater interaction between NF-κB (phorspho-p65) and β-catenin in AP tissues compared to the control tissues. Importantly, when the NF-κB signaling pathway was blocked by its inhibitor, pyrrolidine dithiocarbamate (PDTC), the activity of the Wnt3a/β-catenin signaling pathway was abolished, and consequently led to the attenuation of the inflammation response in LPS-induced human periodontal ligament cells (hPDLCs). Thus, our data indicate that the crosstalk between Wnt3a/β-catenin and NF-κB signaling pathway contributes to the development of AP, and provide a therapeutic strategy for the treatment of AP as well.

Inflammatory myofibroblastic tumor manifesting as recurrent generalized gingival enlargement: Report of a rare case

Oral inflammatory myofibroblastic tumor (IMT) is extremely rare and its manifestation as generalized gingival enlargement (GGE) has never been reported. We are reporting the case of 50-year-old female patient presenting with recurrent GGE for 4 years. Panoramic radiograph revealed severe bone loss in posterior sextants and root resorption in some teeth. Initial incisional biopsy was suggestive of chronic inflammatory infiltrate with fibrocollagenous tissue. Definitive treatment comprised of surgical excision of the enlarged gingiva with a tapering dose of steroid therapy. Histopathological and immunohistochemical examination from a repeat biopsy of deeper tissues was suggestive IMT. No recurrence was found at 2 years follow up. Recurrent GGE with advanced bone loss and external root resorption should raise the suspicion of a locally aggressive lesion. Dentists should be aware of oral IMT and include it in differential diagnosis of gingival enlargements for comprehensive management to avoid recurrence of the lesion.