Graduate and undergraduate geriatric dentistry education in a selected dental school in Japan

Geriatric dentistry and its instruction are critical in a rapidly ageing population. Japan is the world's fastest-ageing society, and thus, geriatric dentistry education in Japan can serve as a global model for other countries that will soon encounter the issues that Japan has already confronted. This study aimed at evaluating geriatric dental education with respect to the overall dental education system, undergraduate geriatric dentistry curricula, mandatory internships, and graduate geriatric education of a selected dental school in Japan. Bibliographical data and local information were collected. Descriptive and statistical analyses (Fisher and chi-squared test) were conducted. Japanese dental schools teach geriatric dentistry in 10 geriatric dentistry departments as well as in prosthodontic departments. There were no significant differences found between the number of public and private dental schools with geriatric dentistry departments (P=0.615). At Showa University School of Dentistry, there are more didactic hours than practical training hours; however, there is no significant didactic/practical hour distribution difference between the overall dental curriculum and fourth-year dental students' geriatric dental education curriculum (P=0.077). Graduate geriatric education is unique because it is a 4-year PhD course of study; there is neither a master's degree programme nor a certificate programme in geriatric dentistry. Overall, both undergraduate and graduate geriatric dentistry curricula are multidisciplinary. This study contributes to a better understanding of geriatric dental education in Japan; the implications of this study include developing a clinical/didactic curriculum, designing new national/international dental public health policies, and calibrating the competency of dentists in geriatric dentistry

Comparison of apical centring ability between incisal-shifted access and traditional lingual access for maxillary anterior teeth

The aim of this study was to compare the apical centring ability of incisal-shifted access (ISA) with that of traditional lingual access (TLA). Fifteen three-dimensional printed resin models were prepared from the computed tomography data for a human maxillary central incisor and divided into ISA (n = 7), TLA (n = 7) and control (n = 1) groups. After access preparation, these models were shaped to the working length using K-files up to #40, followed by step-back procedures. An apical portion of the model was removed at 0.5 mm coronal to the working length. Microscopic images of each cutting surface were taken to measure the preparation area and the distance of transportation. TLA created a larger preparation area than ISA (P < 0.05). The distance of transportation (mean ± standard deviation) was 0.4 ± 0.1 mm for ISA and 0.7 ± 0.1 mm for TLA (P < 0.05). Access cavity preparation has a significant effect on apical centring ability. ISA is beneficial to maintaining apical configuration

Pink Tooth of Mummery in the Maxillary Left Canine after Fixed Partial Denture (FPD) Preparation

Pink tooth of Mummery is typically found after trauma. However, this case report describes an unusual occurrence of pink tooth in a 67-year-old Caucasian male after fixed partial denture (FPD) tooth preparation. Pink tooth in this case may be due to one or more factors: tooth reduction and heat generation during tooth preparation; heat generation during polymerization of provisional material; and hyperocclusion of a provisional FPD. This case highlights the importance of choosing the appropriate materials and techniques to avoid pulpal complications after dental prosthesis work

Education of dentists in Thailand

Thailand is geographically located in southeast Asia and its population is 63 million. Little has been published on dental education in Thailand. This paper provides information about Thailand regarding its dental history, dental school system including curriculum and dental licensure. There are eight public and one private dental school in Thailand. A six-year dental education leads to the DDS degree. On graduation from the public dental schools, dentists are required to work in the public system for three years. Currently, there are approximately 8,000 active dentists, with a dentist: population ratio of approximately 1:7,000

Comparison of the dental education systems in Korea and Japan

In recent years, international relationships in dentistry have grown stronger through journals, books, academies, seminars, researcher exchanges and so forth. Korea and Japan are neighbours in East Asia. However, no comparison of the dental education systems of the two countries has been published. Therefore, the authors have provided the present comparison to promote mutual understanding and to familiarise dentists around the world with dental education in these two countries. The number of dentists, life expectancy at birth, and number of decayed, missing, and filled teeth (DMFT) at age 12 years in Korea and Japan are summarised

Particle Size and Shape of Calcium Hydroxide

The aim of this study was to examine the particle length, width, perimeter, and aspect ratio of calcium hydroxide powder using a flow particle image analyzer (FPIA). Five sample groups each with 10 mg of calcium hydroxide were mixed with 15 mL of alcohol and sonicated. Digital images of the particle samples were taken using the FPIA and analyzed with a one-way analysis of variance. The overall averages ± standard deviation among the five groups for particle length (μm), width (μm), perimeter (μm), and aspect ratio were 2.255 ± 1.994, 1.620 ± 1.464, 6.699 ± 5.598, and 0.737 ± 0.149, respectively. No statistical significance was observed among the groups for all parameters. When the total of 46,818 particles from all five groups were classified into the five length categories of 0.5-μm increments, there were significant differences in width, perimeter, and aspect ratio (all p values <0.0001). In conclusion, calcium hydroxide particles have a size and shape that may allow direct penetration into open dentin tubules

In vitro evaluation of dentinal tubule penetration and biomineralization ability of a new root-end filling material

Introduction: Capasio is being developed as a new generation of endodontic material with potential use as a root-end filling material. The aim of this study was to compare the ability of Capasio and mineral trioxide aggregate (MTA) to penetrate human dentinal tubules and examine the interaction of Capasio and MTA with a synthetic tissue fluid (STF) and root canal walls in extracted human teeth. Methods: Root-end preparations were filled with Capasio or MTA, allowed to set for 4 weeks in STF, and then sectioned at 1, 2, and 3 mm from resected surface. Depth of penetration was evaluated by using scanning electron microscopy (SEM). Next, Capasio and MTA samples were prepared both in 1-g pellets and in root-end preparations. Samples were placed in STF, allowed to set, and then characterized by using SEM, energy dispersive x-ray analysis (EDXA), and x-ray diffraction (XRD) techniques. Results: Penetration of Capasio into dentinal tubules was observed at all levels. No penetration of MTA into dentinal tubules was observed at any level. Both Capasio and MTA formed apatite crystals in the supernatant, on their exposed surfaces, and in the interfacial layers that were similar in structure and elemental composition when evaluated by using SEM and EDXA. XRD analysis of these crystals corresponds with those reported for hydroxyapatite. Conclusions: When used as a root-end filling material, Capasio is more likely to penetrate dentinal tubules. Both Capasio and MTA promote apatite deposition when exposed to STF

Dentin permeability reduction by a sequential application of calcium and fluoride-phosphate solutions

Objective: A sequential topical application of calcium and fluoride-phosphate solutions was reported to occlude open dentin tubules, mainly with fluoroapatite precipitates by a rapid ionic reaction, and to be effective at treating dentin hypersensitivity. However, its ability to reduce dentin permeability (Lp) is unknown. The aim of this in vitro study was to evaluate the effect of this treatment on Lp. Methods: Nine extracted human third molars were sectioned transversely to obtain 0.5 mm-thick discs, which were then etched and rinsed. Aqueous solutions of 5% (w/w) disodium phosphate containing 0.3% (w/w) sodium fluoride (A) and 10% (w/w) calcium chloride (B) were prepared. The sequential application of the A&amp;B solutions was repeated three times on each disc, which was then rinsed with distilled water. The Lp of the discs was measured before and after the application using a modified Pashley's fluid flow measuring system. The differences in the Lp values between the conditions before and after the solution applications were analysed using a generalized estimating equation method and paired t-test. Scanning Electron Microscopy (SEM) was used to observe the dentin surfaces. Results: All nine discs consistently indicated reduced Lp following the application of the A&amp;B solutions. There was a significant decrease in the mean Lp [μL/(cm2 s cm H 2O)] from baseline (-0.27 ± 0.25, p = 0.011). Overall, an average decrease of 34% Lp occurred after the application of the A&amp;B solutions. SEM observation indicated that the reaction products covered the entire dentin disc surface. Conclusion: The application of the A&amp;B solutions was effective at reducing the Lp of the dentin discs

Root dentin body moisture changes caused by ascorbic acid

Objectives: To quantify in vitro the root dentin moisture (DM) when soaked in 10% ascorbic acid solution (Group A) and distilled water (Group B) for up to 14 days. Methods: Forty-four extracted human mandibular single-rooted teeth were sectioned perpendicular to the long axis at the CEJ to access the root dentin. The samples were divided into Groups A and B. Baseline (day 0) DM was measured using a digital grain moisture meter. One sample was placed in each tube, which was then filled with solution. All tubes were kept at 37 °C and 100% humidity. DM was measured after 1, 3, 7, and 14 days. The baseline DM value was used as a covariate in the generalized estimating equation (GEE) analysis to account for the difference in the baseline DM between the two groups. Results: The mean DM (%) values ± standard deviation on days 0, 1, 3, 7, and 14 were 11.4 ± 1.08, 17.1 ± 0.87, 18.2 ± 0.76, 18.4 ± 0.77, and 17.9 ± 0.90 in Group A, and 10.2 ± 0.95, 12.8 ± 0.90, 13.3 ± 0.95, 13.0 ± 0.91, and 13.2 ± 0.89 in Group B, respectively. Group A had significantly higher baseline DM than Group B (p = 0.006). After adjusting for differences in the baseline, the GEE analysis indicated that, on average, Group A had a significantly higher increase in DM than Group B, with means ± standard deviation of 4.35 ± 0.26. Conclusions: The moisture increase in the ascorbic acid group was greater than that in the distilled water group. Soaking root dentin in the unreplenished ascorbic acid solution or distilled water beyond 3 days did not further increase DM