Relation between number of teeth, malnutrition, and 3-year mortality in elderly individuals ≥85 years.

OBJECTIVE: The number of teeth has been shown to affect mortality. However, it is unclear why the number of teeth is associated with mortality. We focused on the number of teeth and malnutrition and examined whether these differences affect 3-year all-cause mortality among very elderly individuals. METHODS: This analysis was conducted using data from the Tokyo Oldest Old Survey on Total Health study. Altogether 513 participants ≥85 years were categorized based on remaining teeth (0, 1-7, 8-18, ≥19). All-cause mortality was determined by calculating the cumulative 3-year survival rate according to the remaining number of teeth and the presence/absence of malnutrition. Further, hazard ratios (HRs) were analyzed using Cox regression analyses. RESULTS: No difference was observed according to the number of teeth (p = 0.638), but the presence/absence of malnutrition was significantly associated with mortality (p < 0.001). Malnutrition was independently associated with higher HRs, even after adjusting for confounding factors associated with mortality. (HR: 2.315, 95% CI: 1.431-3.746). Additionally, adjusting for the number of teeth, HR remained significant (HR: 2.365, 95% CI: 1.449-3.853). CONCLUSION: In the very elderly, malnutrition-but not the number of teeth-was independently associated with 3-year all-cause mortality after adjusting for various health issues.

Human Gingival Fibroblast Attachment to Smooth Titanium Disks with Different Surface Roughnesses.

Peri-implantitis is a significant problem associated with dental implants. It has been hypothesized that creating a soft-tissue seal around the implant neck prevents peri-implantitis. This study aims to clarify the effects of the surface smoothness of titanium disks on soft tissues. Thus, titanium disks were prepared through electrolytic composite polishing (ECP), sisal buffing (SB), hairline polishing (HP), and laser cutting (LC). The surface roughness values of seven items was measured. For ECP, SB, HP, and LC samples, the Ra values were 0.075, 0.217, 0.671, and 1.024 µm and the Sa values were 0.005, 0.115, 0.500, and 0.676, respectively, indicating that the surface roughness was remarkably lower with ECP. Moreover, the Wsk values for ECP, SB, HP, and LC were 0.521, 1.018, -0.678, and -0.558, respectively. The smooth surfaces produced by ECP and SB were biased toward the concave surface, whereas those produced by HP and LC were biased toward the convex surface. The Rku values for ECP, SB, HP, and LC were 2.984, 11.774, 14.182, and 26.232, respectively. Only the ECP exhibited a moderate bias peak and produced an extremely smooth surface. The contact angles in the cases of ECP, SB, HP, and LC were 60.1°, 66.3°, 68.4°, and 79.3°, respectively, indicating the hydrophobicity of the titanium disks. Human oral fibroblasts were then incubated on each disk for 24 and 48 h to measure cell attachment, and no significant differences were observed. The differences in Ra and Sa did not affect cell attachment. Therefore, by applying ECP to the abutment or implant neck, the cell attachment required for soft-tissue formation while preventing bacterial adhesion can be achieved.

Education and licensure of dental technicians.

The Japanese Health, Labour, and Welfare Ministry in 2020 identified the following issues for training and recruitment of dental technicians: early involvement of students in dental practice and dental laboratory work, a curriculum in line with the times, and an extension of the years of training. This paper investigates the education and qualifications of dental technicians in other countries to discuss these issues. The survey method was to use the database PubMed to search the literature since 2001 using the keywords "dental technician," "education," and license" to collect literature related to the pre-graduate education of dental technicians. Information on educational institutions was also included in the survey. The results showed that the countries that introduced joint education between dental technicians and dentists into their educational programs, and the examinations and years of training required for each certification varied from country to country. The curriculum for dental technicians in Japan changed from a time-based to a credit-based system on April 1, 2018. The credit system is characterized by the possibility of each training institution actively engaging in flexible curriculum organization. Dental technician education programs in other countries can provide a valuable reference for each training institute to demonstrate its uniqueness.

A new dental unit for both patients in wheelchairs and general patients.

OBJECTIVE: To develop a dental unit to accommodate both patients in wheelchairs and general patients, and to evaluate the acceptability of the new chair for patients and dentists. DESIGN: To integrate a unit for patients in wheelchairs and a unit for general patients into a single dental unit. RESULTS: (1) The newly developed dental unit could be used for both patients in wheelchairs and general patients and could be installed in nearly the same space as occupied by a conventional dental unit. (2) The dentists could take the home position because of the height-adjusting and tilting mechanisms. (3) The patients could be treated with a sense of assurance because of the wheelchair immobilizer and the safety devices. (4) The dentists could perform patient treatment safely. (5) As patients did not need to be transferred from their wheelchairs, assistance was unnecessary. (6) From the questionnaires, both patients and dentists rated the newly developed dental unit favourable. CONCLUSIONS: The new dental unit for patients in wheelchairs and general patients permitted dentists to perform and patients to receive dental treatment safely and in a comfortable position. Also, as a single unit could be used for treatment of both types of patients, it required no extra space. Therefore, it has the potential to be installed in the clinics of general dental practitioners to treat both groups of patients.