Omar M.M. Rodis

Culture-based PCR analysis of plaque samples of Japanese school children to assess the presence of six common cariogenic bacteria and its association with caries risk.

The aim of the study was to assess the presence of six common cariogenic bacteria from Cariostat-inoculated plaque samples of Japanese elementary school children through PCR analysis and check its associations with caries risk testing the validity of Cariostat as a caries risk assessment tool. This epidemiological school-based study investigated plaque samples of 399 Japanese elementary school children. Assessed using the Cariostat, 48.2% of the children had high caries risk. DNA detection of Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus fermentum and both S. mutans and S. sobrinus was seen in 65.2%, 24.1%, 69.7%, 17.5%, 7.8%, 19.3%, and 17.3% of the participants, respectively. Except for S. salivarius, the presence of all other investigated bacteria resulted in a statistically significant increase among the proportion of subjects with high caries risk. Caries risk assessed using Cariostat was significantly influenced by the presence of cariogenic bacteria. Being a selective medium for cariogenic bacteria, the Cariostat can be a useful and direct source of cariogenic bacterial DNA for PCR analysis while effectively assessing caries risk.

Cariogenic Bacteria and Caries Risk in Elderly Japanese Aged 80 and Older with at Least 20 Teeth

OBJECTIVES: To assess caries risk and check the presence of four commonly found oral cariogenic bacteria in “8020” achievers.

Comparison between flipped classroom and team-based learning in fixed prosthodontic education

PURPOSE We previously investigated the effects of team-based learning (TBL) on fixed prosthodontic education and reported that TBL could have higher efficiency with high student satisfaction than traditional lecture. In the current report, we introduced flipped classroom to the fixed prosthodontic education and compared their effectiveness based on the final examination score in addition to TBL. METHODS Participants were 41 students from Tokushima University School of Dentistry who attended a fixed prosthodontics course. The first six classes adopted the flipped classroom style while the latter eight classes adopted TBL. To evaluate the relationship between learning styles and their effectiveness, we compared results from the term-end examination between the curriculum covered by flipped classroom and TBL-style classes. To draw comparisons, a referential examination with the same questions was conducted to eight faculty members who had not attended any of these classes. RESULTS Term-end examination results showed that TBL classes had slightly higher scores than flipped classroom classes. Referential examination results also showed higher scores for the same curriculum and no significant interaction was found between class formats and the term-end and referential examination scores. Analysis revealed no noticeable difference in the effectiveness of the class formats. CONCLUSION Our previous study reported that TBL had higher efficiency than traditional style lecture. In the current study, there was no statistical difference in the examination score between flipped classroom and TBL. Therefore, we conclude that both styles are highly effective than traditional style lecture and constitute valid formats for clinical dental education.

The relationship between body balance and occlusal balance of Japanese children during the deciduous dentition period

Abstract The relationship between childrens deciduous dentition occlusal balance and bodys gravity center movement was studied. The participants of this study were 128 children with Hellmans Dental Age IIA stage at a nursery school. The distance and the area of gravity center movement (GCM) when the participants had their eyes-opened and eyes-closed were measured with automatic posture analytical devices. Occlusal abilities including occlusal contact area, average pressure, maximum occlusal pressure, occlusal force and occlusal balance were measured with the Dental Prescale® system. Analysis of occlusal balance was determined by separating the middle group (|x|≤5mm) from the deflection group (|x|>5 mm) based on the position of occlusal balance center. A significant difference was found between the occlusal balance of the middle group (n=96) and the occlusal balance of the deflection group (n=32) in the distance and area of gravity center movement with eyes-opened and closed. The distance and area of gravity center movement of the middle group was less than that of the deflection group. Analysis of body balance was determined by the good balance group and bad balance group based on the GCM area with eyes-closed. A difference was found between the good balance group and the bad balance group in the occlusal contact area and occlusal force. The occlusal contact area and occlusal force of good balance group were higher than the bad balance group. Body and occlusal balance was observed to have some interactive influence during Hellmans Dental Age IIA period. The influence of occlusal balance on body balance is much stronger and obvious than the influence of body balance over occlusal balance. Occlusal balance can influence on the body balance most of the time while body balance can sometimes influence on the occlusal balance.

Risk behaviors and its association with caries activity and dental caries in Japanese children

Abstract The aim of this study was to assess risk behaviors and its association with caries activity and dental caries in Japanese children. The subjects were 392 young Japanese children who underwent dental health check-up at 18, 30 and 42 months of age. Oral examinations, Cariostat tests and dental health questionnaires were carried out at each time. The caries prevalence of children was 1.5% at 18 months, 9.9% at 30 months and 28.1% at 42 months. Caries activity based on the Cariostat scores of children was correlated with caries status (caries-free/carious) at 42 months. In children with caries during each examination period at 42 months, eating snacks while playing was ranked as the most important behavioral risk ( P P P P P P P

Viability of the Cariostat® medium as a source of DNA for further analysis through polymerase chain reaction

Abstract This simulation study was carried out to analyze and evaluate Cariostat-inoculated samples through a conventional PCR protocol specific for Streptococcus mutans strains and also for the purpose of establishing acceptable storage conditions for Cariostat-inoculated samples in cases in which optimal storage conditions are not feasible. A reference strain of Streptococcus mutans (ATCC 25175) was used in the study. The samples were subjected to different inoculation, incubation and storage conditions, and bacterial viability was checked through a conventional PCR technique and by assessment of colony growth on different agar media. Band detection of all samples incubated for even up to 120 hours at 37°C was still possible, indicating less DNA degradation. Samples stored at −20°C yielded results closest to those of samples incubated normally (without storage), followed by samples stored at 4°C and then samples stored at room temperature. The difference in these results, however did not influence the quality of DNA to an unsatisfactory level. For bacterial viability through agar plating, even if there were no more viable growth on the plates, band detection from strains inoculated and stored in Cariostat was still possible. From these results, we conclude that samples stored under various conditions can be further analyzed using DNA extraction protocols for conventional qualitative PCR amplification.

Presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat®-inoculated plaque samples from Japanese mother-child pairs

Abstract The aim of this study was to determine the presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat-inoculated plaque samples obtained from Japanese mother-child pairs through a conventional PCR technique and to establish the presence of these bacteria and caries risk. Oral examination and caries risk assessment using the Cariostat ® were carried out on 168 children, aged 6–31 months, and their mothers. The presence of S. mutans and S. sobrinus in Cariostat-inoculated plaque samples was checked through PCR and tested for relevance with caries risk. A significant correlation ( P S. mutans or S. sobrinus in plaque samples from their children in the 19–31-month-old age range. However, no significant relationship found between the presence of either strain in the plaque of younger children (6–18 months) and caries risk of mothers. Likewise, high caries risk was seen in 49.1% of the 19–31-month-old children of highrisk mothers ( P P S. mutans and S. sobrinus in plaque samples obtained from mothers and their children through conventional PCR techniques.

A proposed core curriculum for dental English education in Japan

BackgroundGlobalization of the professions has become a necessity among schools and universities across the world. It has affected the medical and dental professions in terms of curriculum design and student and patient needs. In Japan, where medicine and dentistry are taught mainly in the Japanese language, profession-based courses in English, known as Medical English and Dental English, have been integrated into the existing curriculum among its 83 medical and 29 dental schools. Unfortunately, there is neither a core curriculum nor a model syllabus for these courses.MethodsThis report is based on a survey, two discussion forums, a workshop, and finally, the drafting of a proposed core curriculum for dental English approved by consensus of the participants from each university.ResultsThe core curriculum covers the theoretical aspects, including dental English terms and oral pathologies; and practical aspects, including blended learning and dentist-patient communication. It is divided into modules and is recommended to be offered for at least two semesters.ConclusionsThe core curriculum is expected to guide curriculum developers in schools where dental English courses are yet to be offered or are still in their early development. It may also serve as a model curriculum to medical and dental schools in countries in Asia, Europe, Africa, and Central and South America, where English is not the medium of instruction.

Postural stability and occlusal status among Japanese elderly

BACKGROUND There are still no data available on the relationship between postural stability and occlusal status among the elderly. OBJECTIVES To examine relationships between postural stability and occlusal status through a cohort study among elderly Japanese. METHOD Oral examination, occlusal status, postural stability and a questionnaire were conducted and given to 87 community-dwelling Japanese at enrolment. RESULTS The average occlusal pressure of the female group was statistically higher than the male group while average occlusal pressure and postural stability length were lesser in the group with more remaining teeth. Postural stability area and number of remaining teeth showed statistically significant correlations. Postural stability length was lesser in the group with strong occlusal force. Furthermore, the number of decayed teeth was fewer in the good hygiene group. CONCLUSIONS This study identified a close relationship between occlusal status and postural stability of Japanese older individuals. Occlusal hypofunction was observed more in those with occlusal problems, and a decrease in their occlusal functions resulted in postural instability.

Risk behaviors and their association with presence of S.mutans or S.sobrinus and caries activity in 18-month-old Japanese children

Abstract The purpose of this study was to investigate risk behaviors associated with the presence of S. mutans or S. sobrinus and caries activity. The subjects were 448 mother-child pairs who underwent dental health examinations between February 2004 and November 2004 when the children were 18 months old. Caries activity was assessed by the Cariostat test. The presence of S. mutans and S. sobrinus was detected using PCR techniques. Questionnaires regarding risk behaviors were completed by the mothers. A statistically significant correlation was found for the detection of S. mutans and/or S. sobrinus in children and mothers ( P P P P P P P P P