The diagnosis, treatment, and prevention of vertical root fractures are important for securing occlusion and maintaining oral function. Vertical root fractures can occur at the cervix of the tooth and extend toward the apex, or at the apex and extend toward the cervix. In the present study the frequency of these fractures was roughly the same in both directions. The main treatments involved removing bacteria from the root canal and fracture gap, sealing the fracture, and preventing re-fracture. The prognosis was greatly influenced by the extent of periodontal tissue destruction, the prosthetic treatment used such as abutment construction, and the applied occlusal force. In cases where treatment was started before periodontal tissue destruction occurs, the survival rate after 10 years was over 90％. Conservative treatment was considered sufficient in some cases of vertical root fractures.

According to the Survey of Dental Diseases focusing to the numbers of lost natural teeth by Japanese Ministry of Health and Welfare, the recent statistics revealed that more than half of those surveyed have achieved the goal of “Status 80 years old -with 20 natural teeth: STATUS 8020” in the year of 2022. This achievement, however, has piggybacked another challenge; the elderly presented with a large number of periodontal pockets over 4mm at the same time. Clinical needs to these patients show still a great role to play on the dental clinicsʼ part in maintaining the oral health. Periodontal disease is the most common cause of missing dentition, and it is likely that this high risk status will persist even after periodontal treatment has been completed. Therefore, the prosthetic treatment of patients with missing dentition should include preventive measures against the recurrence of periodontal disease—i.e. the design, fabrication and maintenance of RPDs that facilitate the plaque control and post-operative maintenance. In this review article, presented are the discussions on above mentioned themes by several leading clinicians.

The early 1990s saw a major shift in the methodology of medical research due to the spread of EBM. The diagnosis and treatment of TMD were strongly influenced by this change. The author describes this shift and outlines the clinical results and natural history of the various treatment methods, showing that TMD is a disease that often relieves symptoms over time. He also discussed the risks of therapeutic intervention when the occlusal position must be altered for prosthetic reasons, focusing on the changes that splint placement can cause in the joint space, and explained the degree of tolerance for bite raising according to Farrar's (Farrar & McCarty, 1982) classification of TMD pathophysiology. This article is based on a review of the general dental clinician's practice—in particular, the diagnosis of TMD and the appropriateness of intervention by general practitioners when changing the occlusal position due to prosthetic reasons.

This report is to present the collaboration between the dentist and the dental laboratory technician in impression taking, bite taking, and trial fitting is described through a satisfactory case of the complete denture fabrication for an edentulous patient with fully edentulous jaws. The division of roles between dentists and dental technicians in the fabrication of complete dentures is based on legal agreements. The dentist examines, diagnoses, takes impressions, obtains occlusion, designs, and gives instructions, and the dental technician performs arrangement of artificial teeth, festooning, polymerization, and occlusal adjustment according to the information shared with the dentist and given conditions. First, in taking impressions of the mandible, it is important to trim three-dimensionally including the cheek zone and the polished surface of the modiolus area, and to trim the inside and outside of the denture base margin by exaggerating the neck of the S-curve of the lingual floor margin after muscle trimming using the functional movement of the patient. The three-dimensional integration with the impression during the postimpression tilting test and bite registration provides information on the arrangement of artificial teeth. The more information on the arrangement and festooning, the better the denture can be fabricated. In denture fitting, the occlusal plane is to be checked against standard references namely, vertical dimension being bilaterally even and a little lower than the dorsum of tongue at rest in order to facilitate the physiological coordination of the cheeks and tongue during mastication and to avoid any difficulty with speaking..

The cumulative survival rate (CSR) of 112 Eichner index C2 and C3 edentulous cases with implant overdenture (IOD) was analyzed by means of Kaplan Meier survival curve and logLank test. The CSR was calculated from days after IOD superstructure placement to implant removal due to periimplantitis or implant fracture. The femaleʼs CSR showed higher CSR than male and mandibular lOD showed higher CSR than maxilla, respectively. On the other hand, Eichner indexʼs subclass C3 showed higher CSR than C2. In gender comparison of C3 also showed higher female CSR than male and higher CSR in the mandibular than maxilla. Further long-term studies are required to take into account the diversity in the form of defects in the opposing jaws and the designs of prosthetics.

The responsibilities of dental hygienists have diversified in response to aging population and changing disease demographics. Notably, the field of implant treatment has seen rapid development and widespread acceptance. The advancements in examinations, diagnostics, and the growing significance of patient subjective assessments in treatment planning have diversified the roles of dental hygienists. It is our belief that successful implant treatment requires collaboration among patients, dental staff, and practitioners. in this new era of implantology, dental hygienists equipped with up to-date knowledge are expected to play a crucial role in gathering preoperative information and explaining the treatment to patients. This article is to review two cases where dental hygienists actively engaged in prosthetic-related examinations, providing objective information, and incorporated patient-reported outcome measures to capture subjective information essential for implant treatment. The involvement of dental hygienists in the decision-making process facilitated smooth information sharing among patients, dental staff, and dentists. Furthermore, presenting examination results and obtained data to patients using numerical values and diagrams enabled hygienists to uncover previously unnoticed issues. As a result, effective communication and shared decision-making were achieved, contributing to satisfactory outcomes in the follow-up of implant treatments. These are important roles that only dental hygienists can play and highlight their valuable contributions in implant dentistry.