Purpose: The purpose of root canal filling in endodontic treatment is to tightly seal the root canal in three dimensions following root canal enlargement and washing to prevent re-infection. Bioceramic sealers currently in clinical use in the field of endodontic treatment include calcium silicate cement sealers containing mineral trioxide aggregate (MTA) and bioactive glass sealers containing calcium silicate glass. These show good sealing properties, biocompatibility, antibacterial effects due to their basicity, and precipitation of hydroxyapatite (HA: Ca₁₀(PO₄)₆(OH)₂) on the material surface. This study focused on biphasic calcium phosphate (BCP), a type of bioceramic material in which α-tricalcium phosphate and tetracalcium phosphate are evenly dispersed within the same particle, and investigated the material properties of adhesive resin sealer with different amounts of added BCP.

 Methods: BCP was prepared from dicalcium phosphate anhydrous and calcium carbonate. The adhesive resin sealer was MetaSEAL Soft Paste (MS). BCP was added to MS in differing amounts, and the flow, film thickness, setting time, solubility and disintegration, and radiopacity of the resulting BCP adhesive resin sealers were investigated. BCP adhesive sealers were also immersed in human simulated body fluid (SBF), and observations for precipitation on the material surface using a scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) using an SEM, and microscopic Fourier transform infrared spectroscopy (FTIR) were carried out for component analysis. In addition, root apex sealing tests were carried out using extracted human teeth.

 Results: With increased amounts of BCP, flow decreased, and there was no significant difference in film thickness. Setting time increased with 5-10 wt％ BCP and decreased with 20-40 wt％ BCP. No disintegration was seen in any of the conditions, and solubility increased with 5-30 wt％ BCP and decreased with 40 wt％ BCP. Radiopacity decreased with increasing amounts of added BCP. The SEM observations showed plate-like crystals, and the results of the EDS and FTIR analyses suggested that they were calcium-deficient apatite. In the root apex sealing test, 5 wt％ BCP sealer showed the same sealing properties as MS.

 Conclusion: The material properties of BCP sealer were comparable to those of MS. The precipitation of calcium phosphate crystals suggests that the sealer has properties that involve mineralization in the root dentin.

 Purpose: Dental patients’ esthetic expectations have been increasing, and bleaching has rapidly gained popularity in clinical practice. Two main bleaching methods are currently available: at-home bleaching and in-office bleaching. In-office bleaching has been increasingly recommended because it provides immediate results and is performed by dental professionals. However, adverse effects, such as the development of a chalky white appearance and reduced acid resistance of the enamel, have been reported. Therefore, the present study examined changes in enamel color and surface roughness after in-office bleaching using bleaching agents with different concentrations of hydrogen peroxide.

 Methods: Bovine mandibular anterior teeth were used in this study. Three types of in-office bleaching agents with different hydrogen peroxide concentrations were tested (experimental groups P, T, and H). An LED light-curing unit was employed as the light source. Color measurements were conducted using a microspectrophotometer and brightness and chromaticity (L^＊, a^＊, and b^＊) within the CIE1976L^＊a^＊b^＊ color space were assessed. Color differences after bleaching were calculated. Enamel surface roughness was measured using a 3D laser scanning microscope, and roughness values were obtained before and after bleaching. Enamel surfaces were also examined using scanning electron microscopy (SEM).

 Results: After bleaching, L^＊ and a^＊ values significantly increased in all groups. b^＊ values slightly decreased in groups P and T, and slightly increased in group H. No significant differences were observed after bleaching in group P. These results showed a clear bleaching effect in all groups, regardless of the hydrogen peroxide concentration. ΔE^＊ab values in all groups also indicated a significantly strong bleaching effect. SEM observations of the enamel surface after bleaching revealed a smooth appearance in groups P and T and a roughened surface in group H, in which the bleaching agent had a higher hydrogen peroxide concentration. Furthermore, surface roughness showed significant changes after bleaching in all groups.

 Conclusion: The hydrogen peroxide concentration in in-office bleaching agents affected the enamel surface structure and color changes.

 Purpose: Type H vessels, a specialized subtype of bone-forming vasculature first identified in long bones, are now recognized as critical regulators of angiogenesis-osteogenesis coupling. Defined by high expression of CD31 and endomucin (EMCN), these vessels contribute to both physiological bone growth and pathological bone loss. Although recent studies have identified type H vessels in alveolar bone, their three-dimensional (3D) organization and responses to inflammation remain poorly understood. Here, we aimed to establish a reproducible methodology for visualizing and quantifying type H vessels in murine alveolar bones under both healthy and inflammatory conditions, utilizing a mouse model of periodontitis.

 Methods: Experimental periodontitis was induced in C57BL/6 mice by placing 5-0 silk ligatures around the maxillary second molar for 0, 3, 7, or 14 days. For 3D vascular analysis, maxillary bone samples underwent tissue clearing with the X-CLARITY system to achieve optical transparency while preserving the antigenicity of the molecules of interest. Type H vessels were identified by dual immunofluorescence staining for CD31 and EMCN, followed by confocal microscopy. The captured digital images were reconstructed for quantification using Imaris software. Alveolar bone loss and microstructural changes were evaluated using micro-computed tomography (micro-CT). Gingival tissues were harvested to assess inflammatory or osteoblast-associated gene expression by qPCR. In parallel, bone marrow-derived endothelial cells (BMECs) were stimulated with recombinant TNF-α or rIL-1β, and changes in EMCN and CD31 expression were analyzed by qPCR and flow cytometry.

 Results: The clearing protocol yielded optically transparent maxillary alveolar bone while preserving tissue architecture and immunoreactivity. Confocal imaging revealed abundant CD31^＋EMCN^＋type H vessels in the control healthy periodontal tissue. Quantitative 3D analysis revealed a time-dependent reduction in type H vessel volume following ligature-induced periodontitis in mice. Strikingly, regions exhibiting diminished type H vasculature spatially coincided with areas of alveolar bone resorption identified by micro-CT and with elevated gingival Tnf and Il1b expression, indicating a link between vascular rarefaction and inflammatory bone loss. In parallel, the expression of osteogenic markers, including Alpl, Col1a1, and Bglap, was significantly decreased during murine periodontitis. In vitro, both recombinant TNF-α and IL-1β suppressed the expression of EMCN, a hallmark molecule of type H vessels, in BMECs.

 Conclusion: This study provides the first 3D visualization and quantitative characterization of type H vessels in murine alveolar bone with or without periodontitis using a tissue-clearing-based approach. We demonstrate that inflammatory conditions associated with periodontitis cause marked loss of type H vasculature, thereby disrupting angiogenesis-osteogenesis coupling. These findings underscore the possible role of the vascular niche in periodontal disease pathogenesis and suggest that therapeutic preservation or restoration of type H vessels could represent a novel strategy to prevent inflammation-driven alveolar bone loss and enhance periodontal regeneration.

 Purpose: This study aimed to investigate a new regenerative endodontic procedure (REP) that uses platelet-rich plasma (PRP) as a scaffold for the regeneration of the dentin-pulp complex following pulpectomy of immature teeth.

 Methods: Molars of 6-week-old male Wistar rats were subjected to pulpectomy. After root canal shaping, the canals were treated with ethylenediaminetetraacetic acid (EDTA) for one minute, then rinsed with sodium hypochlorite (NaOCl), and under microscopic examination, removal of canal contents and hemostasis were confirmed. PRP was prepared by centrifuging whole blood collected from the rats twice and injecting it into the root canal up to the cervical area. Mineral trioxide aggregate (MTA) was packed on the PRP, and the top of the MTA was filled with a resin-based backfilling material and composite resin. After 4 and 8 weeks of treatment, the specimens were fixed in 4％ paraformaldehyde solution, demineralized with EDTA, and embedded in paraffin to obtain 5-μm serial sections. The specimens were chemically and immunologically stained and observed under an optical microscope.

 Results: An increase in the root length was observed in all rats. Most of the root canals were periodontal ligament-like tissues, but regeneration of the dentin-pulp complex was confirmed in one of six cases. Pulps containing odontoblasts, pulp cells, blood vessels, nerves, and dentin-containing odontoblast-like protrusions were also observed. This hard tissue was formed with uniform thickness throughout the entire root canal wall, from just below the cervical MTA to the apex, and the root length and thickness increased.

 Conclusions: This method of applying PRP for pulpectomy in immature teeth suggests the possibility of a new endodontic therapy that regenerates the dentin-pulp complex.

 Purpose: Vital pulp therapy induces extracellular matrix remodeling at the exposure site, resulting in reparative dentin formation. This study examined the spatiotemporal expression of three small integrin-binding ligand N-linked glycoproteins, namely bone sialoprotein (BSP), osteopontin (OPN), and dentin matrix protein-1 (DMP1), during pulpal healing after pulpotomy.

 Methods: The Niigata University Committee on Animal Experimentation approved this study (Approval No. SA00903). Under anesthesia, pulpotomy was performed on the left maxillary first molars of 8-week-old Wistar rats. After irrigation with sodium hypochlorite and hydrogen peroxide, mineral trioxide aggregate was placed on the pulp exposure site, and cavities were sealed with composite resin. After the treated molars were extracted at 6 h, 1 day, 3 days, and 7 days, they were processed for histology, including hematoxylin and eosin staining, immunohistochemistry, and double immunofluorescence.

 Results: Before reparative dentin formed, BSP, OPN, and DMP1 accumulated at the exposure site; however, their expression patterns differed. DMP1 was detected at 6 h, whereas BSP and OPN first appeared at day 1. OPN and DMP1 exhibited nearly identical spatial distributions, whereas BSP displayed a markedly more restricted pattern. Additionally, on days 3 and 7, colocalization of BSP, OPN, and DMP1 was observed.

 Conclusion: Differences in the spatiotemporal expression of BSP, OPN, and DMP1 suggest they are derived from distinct cellular sources. In addition, their colocalization raises the possibility that a substrate capable of adsorbing these proteins is present at the exposure site.

 Purpose: Essential amino acids (EAAs) are required for protein synthesis and tissue repair. However, their role in gingival tissue wound healing remains unclear. This study aimed to evaluate the effects of dietary EAA deficiency on gingival tissue wound healing in rats.

 Methods: Seven-week-old Sprague-Dawley rats were divided into two groups: one was fed a standard diet containing EAAs (＋EAA group) and the other was fed a diet without EAAs (−EAA group). Body weight and size were monitored throughout the experimental period. Standardized gingival wounds were created, and wound healing was assessed by measuring the wound area over time, histologically examining the connective tissue, and evaluating re-epithelialization.

 Results: Rats in the −EAA group exhibited lower body weight gain and smaller overall body size than those in the ＋EAA group. Wound area measurements revealed delayed contractions and slower closures in the −EAA group. The results of histological analysis revealed impaired granulation tissue formation and reduced tissue organization in the −EAA group. Furthermore, re-epithelialization across the wound surface was significantly slower in the −EAA group than in the ＋EAA group, which showed continuous epithelial coverage and more organized connective tissue repair.

 Conclusion: Dietary EAA deficiency adversely affects gingival tissue wound healing by impairing systemic growth, delaying wound closure, and suppressing tissue regeneration and re-epithelialization. These findings highlight the importance of adequate EAA intake in maintaining the healing capacity of the oral tissue and suggest that nutritional support could be a valuable addition to periodontal therapy.

 Purpose: Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and systemic immune dysregulation, which are induced by an exaggerated immune response against self-antigens. Although the involvement of autoimmune disease in pulpitis and periodontitis pathogenesis has been reported, the effects of autoimmune diseases on the healing process remain poorly understood. This study aimed to elucidate the influence of autoimmunity on pulp healing following direct pulp capping using a murine model of RA.

 Methods: Female SKG mice (RA model, n＝24) and BALB/c mice (controls, n＝24) were subjected to direct pulp capping with mineral trioxide aggregate (MTA) on the maxillary first molars following pulp exposure at 8 weeks old. Histological analyses of hematoxylin-eosin staining, nestin immunostaining, terminal deoxynucleotidyl transferase dUTP nick-end labeling, and macrophage marker (i.e., F4/80 and CD206) staining were performed at 7 and 14 days post-treatment.

 Results: All data were statistically analysis by the Kolmogorov-Smirnov test, ANOVA and Tukey test (p＜0.05). Compared with BALB/c mice, SKG mice exhibited sustained inflammatory cell infiltration, persistent necrosis, lower nestin expression indicative of suppressed odontoblast regeneration, and higher levels of apoptosis. Macrophage polarization skewed toward a pro-inflammatory M1-like phenotype, with delayed recruitment of F4/80- and CD206-positive cells, which were significantly more abundant by day 14.

 Conclusions: Immune dysregulation associated with RA may contribute to prolonged inflammation, impaired apoptotic clearance, and suppressed tissue regeneration in the dental pulp, ultimately disrupting the healing process after direct pulp capping.

 Purpose: We report a rare case of atypical external root resorption in the mid-root region of a mandibular molar following direct pulp capping (DPC), despite the tooth consistently exhibiting normal responses to pulp sensibility tests. We discuss the diagnostic challenges presented by such cases, focusing on the limitations of conventional pulp testing, the potential role of pathological pulp fibrosis, and the importance of cone-beam computed tomography (CBCT) in early detection and accurate diagnosis.

 Case: A 38-year-old male patient presented with a chief complaint of chronic discomfort and distal gingival swelling in the right mandibular second molar. The tooth had undergone DPC with calcium hydroxide nine years earlier due to pulp exposure following complete caries removal. Clinical examination revealed mild gingival swelling and slight tenderness to percussion, with normal periodontal probing depths. The electric pulp test (EPT) and cold test showed normal responses, which were consistent with the results from a previous visit six years earlier. A dental radiograph taken six years earlier showed no abnormalities; however, comparison with the radiograph obtained at presentation revealed extensive external root resorption localized to the mid-root area of the mesial root. CBCT images confirmed that the resorption had perforated the dentin and reached the pulp chamber, accompanied by substantial loss of lingual alveolar bone. The prognosis was ultimately deemed poor, and the tooth was extracted. The extracted tissue was subjected to histopathological examination using hematoxylin and eosin staining. Histopathological analysis revealed extensive fibrosis in the pulp tissue without bacterial infection. In addition, chronic inflammatory granulation tissue, mainly with neutrophil infiltration, was observed in the area of external root resorption.

 Discussion: This case highlights the limitations of relying solely on pulp sensibility tests for assessing pulp health. Especially in teeth with a history of DPC and chronic symptoms, underlying pathological changes, such as fibrosis, may not alter nerve responses until later stages. Atypical external root resorption can occur secondary to these changes, potentially progressing significantly without typical symptoms or radiographic signs on conventional 2D imaging. CBCT proved useful for identifying the precise location, extent, and perforation of the resorption lesion, underscoring its value in diagnosing complex endodontic-periodontal conditions.

 Conclusion: Early use of CBCT should be considered in teeth with persistent symptoms after DPC, even in patients with normal pulp sensibility tests results, to facilitate timely diagnosis and appropriate management.

 Introduction: This report describes the case of a patient with severe chronic periodontitis complicated by traumatic root resorption and tooth mobility due to vertical bone defects. Periodontal tissue regeneration therapy achieved favorable treatment outcomes at the 10-year follow-up.

 Case: A 55-year-old woman had sustained a severe blow to the face in a traffic accident three years earlier. Four days prior to presentation, the patient had experienced pain in the upper front teeth and occlusal discomfort. Radiographic examination revealed external root resorption resulting in an inverted crown-to-root ratio, and vertical bone loss extending to the apex was observed on the distal aspect of tooth #12. In addition to the chief complaint site, redness and swelling were observed at other locations. Sites with probing depths (PD) ≥6 mm accounted for 1.9％, and bleeding on probing was positive at 30.2％ of sites. Grade I furcation involvement was noted on the buccal aspect of tooth #26. Plaque control record score at the initial visit was 50.8％ and oral hygiene was poor. In addition, implants had been placed in the regions corresponding to teeth #47, #46, #36, and #37. PDs were ≥3 mm and radiographic examination revealed vertical bone loss around the implants at sites #36 and #37. Based on these findings, generalized severe chronic periodontitis, stage III, grade C, was diagnosed.

 Course: Following initial periodontal therapy, periodontal regenerative therapy was applied to tooth #21. At tooth #15, flap operation was carried out. At tooth #16, flap operation combined with odontoplasty for removal of an enamel pearl, osteoplasty, and autogenous bone grafting were performed. Due to gingival recession in the maxillary anterior region and the desire of the patient for esthetic improvement, crown shape modification was performed. For implant sites with PD ≥4 mm, meticulous plaque control as well as scaling and root planning were performed. Notably, radiographic examination of the implants corresponding to teeth #36 and #37 demonstrated bone flattening and the presence of an alveolar lamina dura. Subsequently, the case was transitioned to supportive periodontal therapy (SPT).

 Conclusion: In this case, root resorption caused by a traffic accident resulted in an unfavorable crown-to-root ratio and severe vertical bone resorption extending to the apex in a tooth with severe chronic periodontitis. Approximately 10 years have passed since the transition to SPT, and the condition has been maintained in a favorable state.

 Apical periodontitis is highly prevalent among dental diseases. Accurate diagnosis requires a combination of clinical symptoms, radiographic findings, and histopathological examination. While most cases are managed with root canal treatment, surgical apicoectomy is indicated when conservative therapy fails.

 Case: A 27-year-old male presented with persistent discomfort in the mandibular left central incisor. Clinical examination revealed no tenderness to percussion or apical palpation, and a sinus tract was present on the labial gingiva. Radiography showed diffuse radiolucency around the root apex. A diagnosis of chronic suppurative apical periodontitis was made, and non-surgical root canal treatment was performed. Despite completion of root canal filling, the sinus tract persisted. Postoperative radiographs revealed periapical radiolucency in the mandibular right central incisor, suspected to be the source of the persistent sinus tract. Cone-beam computed tomography (CBCT) identified a cemental tear near the apex of the left central incisor and an untreated canal in the right central incisor, with contiguous periapical lesions affecting both teeth. Retreatment of the right incisor improved periapical tissues, but the sinus tract in the left incisor remained. Apicoectomy was subsequently performed. Histopathological examination confirmed necrotic cementum and a radicular cyst.

 Course: Postoperatively, both central incisors were asymptomatic, and periapical radiolucency decreased, indicating favorable healing.

 Conclusion: Careful assessment of clinical signs, imaging, and treatment outcomes enabled minimally invasive management and successful healing. Continued follow-up is planned.