Purpose: Few studies have investigated the 2017 classification of periodontitis and its effect on the prognosis of periodontal disease in Japanese people. The aim of this study was to assess the association of the new periodontitis classification with changes in the incidence rate of periodontitis-related tooth loss during maintenance.

 Methods: A total of 286 patients (mean age: 52 years) treated for periodontitis with a follow-up period from 60 to 120 months at a dental clinic in Osaka were retrospectively categorized according to the new 2017 classification of periodontitis at baseline. The association of the new classification of periodontitis with the cumulative incidence rate of tooth loss due to periodontitis during maintenance was explored by using Kaplan-Meier survival analysis and analyzed by using the log-rank test.

 Results: Tooth loss due to periodontitis was not found in stage Ⅰ (11 participants) or Ⅱ (63 participants) or grade A (3 participants) patients during maintenance. The 91-month cumulative incidence rates of tooth loss due to periodontitis were 0.9% and 6.9% for stage Ⅲ (159 participants) and stage Ⅳ (53 participants) patients, respectively, 0.1% and 3.2% for grade B (149 participants) and grade C (134 participants) patients, respectively, and 0.4% and 2.9% for localized (145 participants) and generalized (141 participants) patients, respectively. Statistically significant differences were observed among stages and grades, and between extents. Multivariate Cox regression analysis demonstrated that the new periodontitis classification was associated with the cumulative incidence rate of periodontitis-related tooth loss.

 Conclusion: The new periodontitis classification has been shown to be associated with periodontitis-related tooth loss during maintenance.

 Purpose: At Kyushu Dental University (KDU), third-grade students of the dental school attend “Tooth Therapeutics,” which includes operative dentistry and endodontics, one of the basic clinical dentistry courses. In this course, the experience-led learning method with scenario-based pre-clinical training including some of the content of other courses is carried out. The purpose of this study, which was conducted by a questionnaire survey, was to verify the effects of the experience-led learning with scenario-based pre-clinical training on clinical clerkship and the clinical residency program as pre- and post-graduate education.

 Materials and Methods : The targets of this questionnaire survey were dental residents who completed the clinical residency program at KDU Hospital during the 3 fiscal years from 2016 to 2018. On the final day of the residency program in each year, the survey was carried out after explaining an outline of the experience-led learning with scenario-based pre-clinical training.

 Results: The questionnaire collection rate was 100% (168 dental residents). Of the dental residents who graduated from KDU, 129 (91%) were educated by the experience-led learning with scenario-based pre-clinical training, and 13 (9%) by conventional specialized practical training. Of the dental residents who graduated from other universities, 0 (0%) were educated by the experience-led learning with scenario-based pre-clinical training, 23 (88%) by conventional specialized practical training, and 3 (12%) by conventional specialized practical training in cooperation with other courses. To the question about looking back at the training contents, the rate who answered, “I could imagine the training as real clinical practice,” was higher in dental residents educated by the experience-led learning with scenario-based pre-clinical training than in those educated by conventional specialized practical training. To the question about the effect of basic clinical dentistry on pre- and post-graduate education, 151 (90%) answered “basic clinical dentistry classes were beneficial,” with or without the education by the experience-led learning with scenario-based pre-clinical training.

 Conclusion: The results of the questionnaire survey, in which most of the survey targets (91%) were educated by the experience-led learning with scenario-based pre-clinical training, suggest that the experience-led learning with scenario-based pre-clinical training is beneficial for acquiring knowledge and clinical techniques during clinical clerkship and the clinical residency program as pre- and post-graduate education.

 Purpose: Root canal sealers that directly contact the periodontal tissue after root canal filling require high biocompatibility. We aimed to evaluate the inflammatory response and surface elemental composition changes of a root canal sealer containing bioactive glass after implantation into the subcutaneous tissue of rats.

 Methods: Bioactive glass (BG)-based, calcium silicate-based (ES), zinc oxide eugenol-based (NC), and non-eugenol-based zinc oxide (NCN) sealers were implanted into the dorsal subcutaneous tissues of rats. CD68 immunostaining analysis was performed 10 and 35 days post-surgery. Histological observations and scoring of the degree of inflammatory cell infiltration were also performed using hematoxylin-eosin-stained sections. Subsequently, the border between the sealer and the subcutaneous tissue was observed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) on day 35.

 Results: The CD68 immunostaining intensities (pixel×1,000) of the BG, ES, NC, and NCN groups were 2.8, 1.9, 6.4, and 6.6, respectively, at 10 days, and 0.3, 0.5, 3.5, and 1.8, respectively, at 35 days. The intensity was significantly lower in the BG and ES groups than that in the NC and NCN groups. No significant differences were observed between the BG and ES groups. The inflammatory cell infiltration scores of the BG, ES, NC, and NCN groups were 1.7, 1.5, 2.6, and 2.7, respectively, on day 10, and 1.4, 1.5, 2.2, and 2.3, respectively, on day 35. The scores in the BG and ES groups were significantly lower than those in the NC and NCN groups. On SEM and EDX analyses, Ca and P were detected approximately 200 μm deep from the BG sealer surface. The Ca and P intensities were strong at the sealer surface and gradually decreased away from it. In the ES group, Ca, P, and Si, the main components of ES, were detected overall, and the intensity of Ca was high approximately 40 μm from the sealer surface. Additionally, regions containing Ca- and P-like precipitation were observed in the subcutaneous connective tissue close to the sealer. In the NC and NCN groups, C and P, which may be related to biological tissue components, were found, in addition to Zn.

 Conclusion: The BG and ES sealers showed less inflammatory cell infiltration than did the NC and NCN sealers and exhibited good biocompatibility in rat subcutaneous tissue. Ca and P were detected on the surfaces of BG and ES sealers, suggesting that calcium phosphate precipitated on the surface after in vivo implantation.

 Purpose: Periodontal disease is caused by periodontal pathogens that induce inflammation of periodontal tissues and alveolar bone resorption. In this process, periodontal pockets are formed by downgrowth of gingival epithelial cells. PDLIM5 (PDZ and LIM Domain 5) belongs to the PDZ-LIM family and is known to be involved in cell proliferation and migration. In this study, we aimed to clarify the role of PDLIM5 in the proliferation and migration of gingival epithelial cells.

 Methods: The expression of PDLIM5 in Ca9-22 cells, a gingival epithelial cell line, was measured by real-time RT-PCR and Western blotting. Small interference RNA (siRNA) was used to knockdown the expression of PDLIM5 in Ca9-22 cells. The role of PDLIM5 in cell proliferation and migration in gingival epithelial cells was examined by cell proliferation assay and scratch assay using PDLIM5 knockdown Ca9-22 cells. We also examined the role of lipopolysaccharide (LPS) in PDLIM5 expression, proliferation and migration in Ca9-22 cells.

 Results: LPS from Porphyromonas gingivalis upregulated PDLIM5 mRNA expression and protein expression in Ca9-22 cells, and PDLIM5 knockdown Ca9-22 cells showed reduced cell proliferation and migration compared to cells transfected with the non-targeting control. On the other hand, LPS did not affect cell proliferation or migration of Ca9-22 cells.

 Conclusion: It is suggested that PDLIM5 regulates the proliferation and migration of gingival epithelial cells positively.

 Purpose: The aim of this study was to clarify the relationship between blood pressure and oral factors based on the results of physical and dental examinations performed on the first- and fourth-grade students at Matsumoto Dental University, and to examine changes in oral and systemic factors over a 3-year period.

 Methods: The subjects were 101 first-grade students (54 males and 47 females, mean age 20.3±2.7 years) at Matsumoto Dental University who were followed for 3 years. In the physical examination, the presence or absence of systemic diseases, height, weight, body mass index (BMI), and blood pressure (BP; systolic blood pressure [mmHg] /diastolic blood pressure [mmHg] ) were examined; in the dental examination, the number of present teeth, decayed teeth, filled teeth, missing teeth, DMFT index, and community periodontal index (CPI) were examined. BP was classified into two groups: (1) normal BP/high normal BP (120-129 mmHg and<80 mmHg) and (2) higher BP (130-139 mmHg and/or 80-89 mmHg) /hypertension group. Statistical analysis was performed using the t-test and chi-squared test for BP, oral status, and general status in the first and fourth grade. In addition, oral and systemic factors associated with BP were analyzed using binomial logistic regression analysis in the first and fourth grade. Finally, multinomial logistic regression analysis was used to compare the “no change” group and “improvement” group and the “no change” group and “worsening” group BP levels at 3 years, and to analyze related oral and systemic factors.

 Results: Students classified in the higher BP/hypertension group had significantly more decayed teeth in the first grade, with an odds ratio of 1.339 (95% confidence interval [CI] 1.102-1.627, p=0.003), and those in the fourth grade were more likely to have more than 4 mm PPD with an odds ratio of 3.882 (95% CI 0.863-17.453, p=0.077). Students whose BP worsened during the 3-year period were also more likely to experience an increase in BMI with an odds ratio of 1.711 (95% CI 1.129-2.592). Therefore, it is suggested that high BP is associated with oral health status and BMI.

 Conclusions: Students with hypertension or higher BP were associated with a greater likelihood of having more untreated dental caries remaining and the presence of periodontitis in some parts of the oral cavity; students with worsening blood pressure over 3 years were more likely to experience an increase in BMI.

 Purpose: Dens invaginatus most commonly affects the maxillary lateral incisors. Two-dimensional dental radiography is widely used to evaluate and classify dens invaginatus cases. Recently, the effectiveness of cone-beam computed tomography (CBCT) in determining the horizontal extent of the root canal has been reported for the treatment of dens invaginatus. This report presents the treatment progress and prognosis of a maxillary left lateral incisor with Oehler’s type Ⅲ dens invaginatus, wherein the pulp was non-vital, and an internal root resorption-like radiolucency was observed 19 months after trauma.

 Case: A 11-year-old girl, who presented with a chief complaint of a treatment of the maxillary left lateral incisor.

 Her systemic history was unremarkable. Nineteen months earlier, she had tripped while playing in a classroom and hit a desk, chipping her maxillary central incisor. There was no spontaneous pain or abnormal findings of the periodontal tissue in the trauma-affected area from the maxillary left to right canines. However, direct pulp capping was performed because of the exposed pulp tissue caused by the enamel-dentin crown fractures of the maxillary right and left central incisors. Nineteen months after the trauma, although there were no clinical symptoms during observation, there was no pulpal response of the maxillary left lateral incisor to electric, heat and cold stimuli. Clinical examination: spontaneous pain (−), percussion pain (−), gingival swelling (−), mobility (degree 0), root apical palpation pain (−), sinus tract (−) and probing depth (2 mm). The pulp sensitivity test was negative. Dental radiography and CBCT showed the presence of Oehler’s type Ⅲ dens invaginatus and radiolucency indicative of internal root resorption and apical periodontitis.

 Diagnosis: Pulp necrosis, asymptomatic apical periodontitis, Oehler’s type Ⅲ dens invaginatus in the maxillary left incisor.

 Treatment process: There were no clinical symptoms during the follow-up after the trauma, including spontaneous pain or percussive pain. However, the pulp sensitivity test showed negative after 19 months. CBCT showed radiolucency suggesting internal root resorption, complicated root canal morphology due to the invagination and radiolucency around the root apex. Hence, endodontic treatment including removal of the infection of the invagination was started. Careful exposure of the orifice of the main root canal and the invagination was performed under a magnified view using a dental operating microscope. After enlargement of the upper part of the main root canal and the invagination, negotiation and glide path were performed with reference to the CBCT image. After mechanical root canal preparation with Ni-Ti files and hand files, selective removal of the infected part with hand instruments and root canal irrigation with various instruments and devices were performed under the magnified view to achieve aseptic conditions. The main root canal and the invagination were filled with gutta-percha points and root canal sealer after disappearance of the sinus tract and radiolucency indicative of apical periodontitis. The patient had no new clinical symptoms after the treatment, and the preoperative radiolucent finding on CBCT disappeared. Hence, the prognosis was considered good and monitoring was continued.

 Conclusion: Using CBCT, intraoperative observation with a dental operating microscope, the latest root canal irrigation instruments and devices, and high-fluidity root canal filling sealers, this case of Oehler’s type Ⅲ dens invaginatus was successfully treated while preserving the tooth structure.