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Extended Reality (XR) applications are considered useful for skill acquisition in dental education. In this study, we examined the functionality and usefulness of an application called "SR View for Endo" that measures root canal length using a Spatial Reality Display (SRD) capable of naked-eye stereoscopic viewing. Three-dimensional computer graphics (3DCG) data of dental models were obtained and output to both the SRD and conventional 2D display devices. Forty dentists working at the Kanagawa Dental University Hospital measured root canal length using both types of devices and provided feedback through a questionnaire. Statistical analysis using one-way analysis of variance evaluated the measurement values and time, while multivariate analysis assessed the relationship between questionnaire responses and measurement time. There was no significant difference in the measurement values between the 2D device and SRD, but there was a significant difference in measurement time. Furthermore, a negative correlation was observed between the frequency of device usage and the extended measurement time of the 2D device. Measurements using the SRD demonstrated higher accuracy and shorter measurement times compared to the 2D device, increasing expectations for clinical practice in dental education and clinical education for clinical applications. However, a certain percentage of participants experienced symptoms resembling motion sickness associated with virtual reality (VR). [ABSTRACT FROM AUTHOR]

Dental operating microscopes are considered to provide easier and more accurate endodontic treatment; however, evidence-based reports of this advantage are lacking. The purpose of this study was to compare mineral trioxide aggregate (MTA) root fillings carried out under three working conditions: with unaided vision, with loupes, and with the microscope. Cavities were prepared on eight extracted human teeth (columnar cavity, depth: 3 mm) using a water laser (Millennium, BioLase). MTA was filled into the root cavity under the three working conditions. All specimens were stored in distilled water for 1 week. The marginal adaptation of each specimen was observed and evaluated using confocal laser scanning microscopy (OLS1100, Olympus). The specimens were also subjected to a dye penetration test for 2 hours using 2% methylene blue to evaluate marginal leakage. The laser scanning microscopy evaluations revealed that fillings performed using the operating microscope showed better marginal adaptation than those performed with unaided vision or loupes. Regarding microleakage, the infiltration of the methylene blue decreased as the magnification increased, and the difference between groups was significant (P < .05). It was concluded that procedures performed with the operating microscope provided better results than those obtained with unaided vision or with dental loupes. [ABSTRACT FROM AUTHOR]

Background: Incadronate (YM175, disodium cycloheptyl-aminomethylenediphosphonate monohydrate), a bisphosphonate, has been suggested to prevent the bone resorption associated with periodontitis by inhibiting osteoclast activity. The purpose of this study was to investigate the effect of incadronate in preventing periodontal destruction in rats with Porphyromonas gingivalis-induced periodontitis. Methods: Periodontitis was induced in 35 Wister rats by inoculating P. gingivalis into the oral cavity and feeding the rats a soft diet for 4 weeks. Incadronate or placebo was administered to the oral cavity of the rats 2 days per week for 2, 4, or 8 weeks. Results: P. gingivalis infection resulted in destruction of the periodontal ligament, reduced bone density, and caused inflammatory cell migration. Radiographic, morphometric, and histological results showed that incadronate had the ability to increase the bone mineral density (quantum level score: cortex 518.9 [placebo 612.8]; sponge 579.8 (placebo 672.0]) and to prevent periodontal ligament destruction (width 0.16 mm [placebo 0.20 mm]; area 0.36 mm² [placebo 0.54 mm²]) after 8 weeks' administration. Furthermore, the polymorphonuclear leukocyte (PMN) infiltration in gingival tissue was significantly decreased. Conclusion: These results showed that incadronate inhibits bone resorption and PMN migration in P. gingivalis-induced periodontitis. [ABSTRACT FROM AUTHOR]

In postnatal dentin formation, odontoblast differentiation occurs in the pulp tissue regenerative process under pathological condition. Odontoblasts and newly differentiated odontoblast-like cells beneath the caries lesion form tertiary dentin and are highly odontogenic. To observe the activity of dentinogenesis occur within the hard tissue, a combination of immunohistological analysis and immunodetection of dentinogenesis specific molecules, such as dentin sialophosphoprotein (DSPP) and/or its cleaved products dentin sialoprotein (DSP) and dentin phosphoprotein (DPP), is a reliable approach. Besides, recent studies have revealed that the expression of CCN family member 2 (CCN2), a member of the CCN family protein, is confirmed in accordance with tooth development and reparative dentin formation. Therefore, CCN2 could serve as a marker for dentinogenesis. Here, we describe a method for visualizing the CCN2 signal as an odontogenic activity in formalin-fixed paraffin-embedded (FFPE) sections of demineralized human teeth and human dental pulp cells.