Purpose: In December 2016, the periodontal regenerative medicine REGROTH (Kaken Pharmaceutical, Tokyo, Japan), the whole active ingredient of which is basic fibroblast growth factor (FGF-2), was launched. In this study, we evaluated the clinical outcome of periodontal tissue regeneration therapy using REGROTH at Osaka University Dental Hospital (Department of Periodontology).

 Methods: 131 teeth from 94 patients (28 men and 66 women), who had been diagnosed with periodontitis and treated with REGROTH (140 sites), were registered. The patients underwent initial preparation, flap surgery combined with REGROTH and then supportive periodontal therapy (SPT) or maintenance. Each test site demonstrated a vertical bone defect with a probing depth (PD) of 4 mm or more and a bone defect depth of 3 mm or more. In this study, the therapeutic effect of REGROTH was evaluated by measuring the tooth mobility, PD, bleeding on probing (BOP) and new bone formation rate (radiographic analysis) before and after the administration of REGROTH.

 Results: The average value of PD at the test site was 6.00±1.50 mm before surgery, and decreased to 3.81±1.31 mm at 3-5 months after surgery, and 3.54±1.07 mm at 9 months or more after surgery. BOP was observed in 70% of the test site before surgery, and decreased to approximately 20% at 3-5 months after surgery, and remained a low value thereafter. The average value of new bone formation gradually increased over time: 24.4±24.5% at 3-5 months after surgery, 35.7±24.3% at 6-8 months after surgery and 49.4±27.6% at 9 months or more after surgery.

 Conclusion: Clinical outcome of periodontal tissue regeneration by REGROTH therapy at Osaka University Dental Hospital was equal to or greater than that of the phase III clinical trial during the development of REGROTH.

 Purpose: The present study investigated the shaping ability of the WaveOne Gold (WOG) in torque generation with and without establishing different glide paths.

 Materials and Methods: Endo-training resin, blocks were divided into three groups: two glide-path groups (ProGlider (PG), WaveOne Gold Glider (WGG)), and a no-glide-path group. Each group was subdivided into two subgroups for the shaping instrument WOG and the ProTaper Next (PTN) as the control. The shaping time and torque generation were calculated, and the canal centering ability was compared between the different glide paths and the no-glide-path group.

 Results: The shaping time and total generated torque for the WOG were significantly reduced by a glide path (p<0.05). The WOG generated a higher maximum torque than the PTN regardless of the glide path (p<0.05). The canal centering ratio of the WOG for both glide paths was significantly lower than that for the no-glide-path group, although that of the PTN for both glide paths was not different.

 Conclusions: The establishment of a glide path (PG, WGG) and the mechanical properties of the WOG significantly affect the shaping time, torque generation and canal centering ability.

 Purpose: Periodontitis is characterized by the loss of tooth-supporting bone and common periodontal disease in people over 40 years old. While the colonization of dental biofilms triggers onset of the disease, various genetic and environmental factors affect its onset and progression. However, the relative contribution of genetic factors and environmental factors to the progression of periodontal diseases in elderly persons has not been fully clarified.

 Methods: The twin research method is considered the “gold standard” to elucidate the ratio of the roles of genetic and environmental factors for lifestyle diseases, such as type 2 diabetes mellitus or atherosclerosis. In this study, we compared the clinical phenotypes of periodontitis between monozygotic (MZ) and dizygotic (DZ) pairs in Japanese elderly twins to evaluate the relative contributions between genetic and environmental factors.

 Results: The concordance rates for clinical features of periodontitis in MZ twin pairs were not high in the elderly group. Twin intra-class correlations for the average of probing depth and the percentage of BOP sites in MZ twins were higher than those in DZ twins. On the other hand, twin intra-class correlations for the number of total remaining teeth and score of bone resorption in MZ twins were almost the same as those in DZ twins.

 Conclusion: Host genetic factors affect periodontitis. However, the relative contribution of environmental factors to periodontitis is relatively high in the Japanese elderly population, compared with genetic factors.

 Purpose: Recently, a number of studies have revealed that various systemic diseases are associated with periodontitis. In this study, dental data, saliva, serum, and medical data from general medical checkup examinees were examined to explore the relationship between systemic and periodontal conditions and to investigate a new screening system to detect periodontitis based on medical data.

 Materials and Methods: This study was a cross-sectional, single-center clinical study in Japan, and was conducted from July to August 2015. We performed a periodontal examination on the general medical checkup examinee, and the results of the oral examination and medical checkup were analyzed to clarify the relationship between the systemic status and periodontal condition. To evaluate the periodontal status, we performed a bacteriological examination, by real-time polymerase chain reaction (PCR) using saliva, and a periodontal examination, including measurement of probing pocket depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP) at six points of all residual teeth by experienced periodontists. For the statistical analysis, multiple regression analysis was performed.

 Results: Overall, 67 participants (mean age 53.3±1.6 years, 65.7% males) were subjected to data analysis. Mean Body Mass Index (BMI) was 23.36±0.48, and the number of participants who were suffering from diabetes mellitus, cardiovascular disease and chronic kidney disease were 4, 3 and 1, respectively. Thirty-nine participants were non-smokers, 19 were past smokers, and 9 were current smokers. The numbers with periodontal diagnosis of healthy, mild, moderate and severe were 18, 26, 15 and 8, respectively. Multiple logistic regression tests confirmed a statistically significant association between the progression of periodontitis and the number of Porphyromonas gingivalis in saliva, triglyceride level, and bone density after adjustment for age, sex, smoking, BMI, blood pressure, blood glucose, and cholesterol (sensitivity 0.61, specificity 0.95, AUC 0.85).

 Conclusion: This study showed the possibility that the results of medical checkup and bacteriological examination for P. gingivalis by saliva can be used to screen the progression of periodontitis.

 Introduction: About 20% of mandibular first premolars are reported to have two or more apical foramina, but although they are frequently encountered in clinical practice, they are difficult to manage and treat. We report a case in which we carried out root canal treatment with the use of cone-beam computed tomography (CBCT) and surgical microscopes.

 Case Report: A 49-year-old woman had undergone root canal treatment of the mandibular left first premolar at another clinic, but as her symptoms did not improve, she was referred to the Department of Endodontics of Tokyo Dental College. Clinical examination revealed tenderness at the apical region, and dental X-rays revealed a radiolucency around the apex. CBCT also showed the presence of a main root canal on the lingual side. Chronic apical periodontitis was diagnosed, and the decision was made to perform root canal treatment. Informed consent to participate in this research was obtained from the patient, who was given a full explanation of the research purpose and content orally and in writing before the start of treatment (Tokyo Dental College Ethics Committee approval No. 924). Root canal treatment was started under dental dam. The position of the wall on the lingual side near the site of the aperture was measured on pretreatment CBCT images, and this was explored to identify the aperture. Following flare enlargement, negotiation was performed, the glide path was established, and enlargement was carried out by the single-length technique using an Ni-Ti rotary file. After final irrigation of the root canal, filling was performed by the continuous wave of condensation technique. The abutment was constructed by the direct technique, and a temporary crown was adjusted and fitted.

 Course: One year after root canal filling, as there were no clinical symptoms and dental X-rays showed that the apical radiolucency had disappeared, the patient was diagnosed as recovered.

 Discussion: Lingual root canals of mandibular premolars are mostly present at either an acute angle or a right angle on the lingual side, and are difficult to discover, even by surgical microscopes. However, treatment using surgical microscopy after their observation on pretreatment CBCT and measurement of the position where the canals bifurcate is extremely useful.

 Conclusions: In the present case, we assessed root canal morphology by using pretreatment CBCT and explored the root canals under visual inspection by surgical microscopes during treatment. This enabled the treatment to proceed in a predictable manner, with good results.