PURPOSE: The purpose of this finite element analysis study was to evaluate stress and strain distribution patterns in 2-implant mandibular overdentures with different positions and angulations of implants under unilateral and bilateral loading.
MATERIAL AND METHODS: A cone beam computed tomography (CBCT)-based, 3-dimensional (3D) model of the mandible and an intraoral scanning-based 3D model of the denture were developed in the Mimics software program. A 3D model of a standard-sized implant with a low-profile overdenture attachment (LOCATOR) was developed in the Solidworks software program. Two implants were inserted in the 3D model of the mandible, with implants placed at different positions, 5, 10, 15, and 20 mm from the midline, and different distal angulations, 0-5, 0-10, 0-15, 5-5, 10-10, and 15-15 degrees (at 10-mm distance), in the 3Matics software program. Unilateral and bilateral vertical loads of 100 N were applied on the first molars in the ANSYS software program to record maximum von Mises stresses and strain values.
RESULTS: The stresses in the implants were maximum when placed at a 20-mm distance (4.18 MPa under unilateral and 4.2 MPa under bilateral loading), while for the implants placed at 5 mm, 10 mm, and 15 mm, the indicated stresses were less than 2.46 MPa following an increasing trend with an increase in the distance. The stresses in the implants were maximum when placed at 15-15-degree angulations (0.93 under unilateral and 0.92 MPa under bilateral loading). For lower angulations, the stresses on the implants ranged from 0.05 to 0.87 MPa. No specific trend was observed in stresses and strains with 0-5-, 0-10-, and 0-15-degree angulations, but an increasing trend was observed with 5-5-, 10-10-, and 15-15-degree angulations under unilateral loading. Under bilateral loading, the stresses and strains on the implants and the mandible showed negligible variations across all 6 angulations.
CONCLUSIONS: The most posterior position of implants (20 mm) exhibited the highest stresses and strains on the implants and the mandible under both loading conditions. Implants placed with 15-15-degree angulations exhibited the highest stresses. Stresses and strains were similar in implants with lower angulations.
METHODS: A total of 208 CBCT images were examined retrospectively. Prevalence of an extra root/canal and internal morphology based on Vertucci's classification were observed in human maxillary and mandibular permanent teeth. Variations in the external and internal morphology were compared in relation to gender and tooth side (left vs right) using Pearson Chi-square and Fisher's exact tests with significance level set at p
METHODOLOGY: This study was approved by the institutional Joint Research and Ethics Committee, International Medical University, Malaysia (number 373/2016); consisted of 180 eligible pre-school children from a private school. Study tools included demographic, clinical oral health data form, the Early Childhood Oral Health Impact Scale (ECOHIS) and family functioning-12-item general functioning subscale. Written consent was sought prior to data collection. Data were analysed by SPSS v.22.0; descriptive statistics for socio-demographic details, clinical information, HRQoL and FAD scores. The parametric tests included independent sample t test and ANOVA to evaluate the associations between the dependent variable. Binary logistic regression models were applied to assess the impacts on OHRQoL (P value
DESIGN: A cross-sectional questionnaire survey was conducted on 14-18 years from four different public schools in Kuala Lumpur. Socio-demographic, pain symptoms, and social impacts data were collected as well as medication use and visiting a dentist for tooth pain.
RESULTS: Of 1473 questionnaires distributed, 1452 (98.6%) completed questionnaires were returned, with 269 (18.5%) reported having experienced tooth pain in the past 1 month. Those who identified as Indian (26.1%) were more likely to report tooth pain compared to Chinese (16.5%) and Malay (20.9%). In regression analysis, no factors were identified as independently associated with medication use, but Chinese and Indians compared to Malays, and those expressing difficulty sleeping were more likely to report visiting a dentist for treatment.
CONCLUSION: Racial variations in the tooth pain experience and care-seeking have been identified. This may be related to socio-economic status, but further research is needed on the role of culture-related care-seeking and accessibility of dental services.
HIGHLIGHT: There were conflicting results regarding sexual dimorphism and population characterization of the palatal rugae patterns. All rugae showed positional changes, increased lengths, and lower numbers, but no significant shape changes with growth. The lengths, numbers, and positions of the rugae were affected by orthodontic treatment, especially their lateral points, but their individual characteristics did not change.
CONCLUSION: The diversity in rugae patterns and their potential for sex discrimination among different populations showed differing results due to individual variations and the complex influence of genetic, growth, and environmental factors on their morphology.
MATERIALS AND METHODS: Dental academics in Malaysian dental schools were invited to complete a questionnaire by email and post. The survey comprised questions on research activities in the past 12 months, socio-demographic and professional characteristics, and the R&D Culture Index. Principal components factor analysis was carried out to confirm the factor structure of the R&D Culture Index. Chi-square test was used to identify association of research activities with R&D culture, and socio-demographic and professional characteristics. Binary logistic regression was carried to identify predicators of research activities.
RESULTS: Of 256 potential participants contacted, 128 (50%) useable responses were returned. Three R&D Culture factors accounting for 57.4% of variance were extracted. More positive perception of R&D Support was associated with Malaysians (0.025) and those employed in Government schools (0.017). R&D Skills and Aptitude were associated with older respondents (0.050), PhD qualification (0.014) and more years in academia (0.014). R&D Intention was associated with any of the socio-demographic characteristics. Thirty (23.4%) respondents reported a peer-review research publication in the past 12 months, which was associated with having a PhD (OR 12.79, CI 1.28-127.96), after adjustment in regression analyses.
DISCUSSION: Postgraduate research training should be encouraged to promote participation in research activities. R&D culture did not appear to impact on research productivity. Other factors such as individual attitudinal interests should be studied.
METHODS: A draft set of EPA statements was developed based on the consensus of an expert panel. These were then mapped to the nationally determined minimum experience thresholds (clinical and procedural experiences/competencies) and aligned to task-based instructional strategy. The EPAs were validated to improve the relevance by using a criterion-based rubric.
RESULTS: An end-to-end process workflow led to the development of an EPA-based educational framework to bridge the gaps in the curriculum. The process identified a total of 41 EPAs and out of which, 10 EPAs were notated as core EPAs and will be subjected to structured workplace-based assessment complying to the national standards. The validation exercise rated core EPAs with an overall score matching close to the cut-off of 4.07 (Equal rubric).
CONCLUSION: The end-to-end process workflow provided the opportunity to elaborate a structured process for the development of EPAs for undergraduate dental education. As validation is a continuous process, feedback from implementation will inform the next steps.
METHODS: 240 extracted human teeth were sectioned to obtain 6 mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9 mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into eight groups (n = 30) according to the intracanal medicament placed: group I: saline, group II: chitosan, group III: propolis100 µg/ml (P100), group IV: propolis 250 µg/ml (P250), group V: chitosan-propolis nanoparticle 100 µg/ml (CPN100), group VI: chitosan-propolis nanoparticle 250 µg/ml (CPN250), group VII: calcium hydroxide(CH) and group VIII: 2% chlorhexidine (CHX) gel. Dentine shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of day one, three and seven. The non-parametric Kruskal Wallis and Mann-Whitney tests were used to compare the differences in reduction of CFUs between all groups and probability values of p
Methods: A 33-item EI questionnaire was completed by 46 dental undergraduates in a cross-sectional study. Responses, measured on a five-point Likert scale, were summed to yield EI scores. Patients treated by the same undergraduates were invited to complete a patient satisfaction (PS) questionnaire. EI and PS scores were calculated and compared by undergraduates' gender and the patients' age and education status. The four EI factors (optimism/mood regulation, appraisal of emotions, utilization of emotions, and social skills of students) were correlated with PS using Spearman's correlation test with a significance level set at p < 0.05.
Results: EI scores did not differ significantly between male (N = 23) and female (N = 23) undergraduates (p=0.218). PS was not associated with patients' gender, but those educated to the secondary school level were more likely to be satisfied compared to those educated to the college/university level (p=0.022). Of the four EI factors, optimism/mood regulation was positively correlated with PS (p=0.049).
Conclusion: The results of the study suggest that the EI of the students can influence PS. Practical Implications. Interventions to enhance EI can be developed to improve the patient experience.
PURPOSE: The purpose of this 3D finite element analysis study was to evaluate the biomechanical behavior of 2-implant mandibular overdentures (2IMO) and their individual components by using implants of different diameters.
MATERIAL AND METHODS: A 3D mandibular model was obtained from the cone beam computed tomography (CBCT) images of a 59-year-old edentulous man, and a 3D denture model was developed from intraoral scanning files in the Mimics software program. A 3D model of different diameters of implants (2.5 mm, 3.0 mm, 3.5 mm, and 4.0 mm) with a LOCATOR attachment was developed in the Solidworks software program. Two same-sized implants were inserted in the mandibular model at 10 mm from the midline in the 3Matics software program. A vertical load of 100 N was applied on the first molar region on the right side or both sides in the ANSYS software program. The maximum von Mises stresses and strains were recorded and analyzed.
RESULTS: Stresses within the implants decreased with an increase in diameter (from 2.5 mm to 3 mm, 3.5 mm, and 4.0 mm) of the implants. The highest stresses were observed with 2.5-mm-diameter implants (0.949 MPa under unilateral and 0.915 MPa under bilateral loading) and the lowest with Ø4-mm implants (0.710 MPa under unilateral and 0.703 MPa under bilateral loading). The strains on the implants ranged between 0.0000056 and 0.0000097, and those on the mandible ranged between 0.0000513 and 0.0000566 across all diameters of the implants without following a specific trend.
CONCLUSIONS: In 2IMO, the stresses in the implants and mandible decreased with an increase in the diameter of the implants. The implants of lesser diameter (2.5 mm) exhibited the highest stresses and strains, and the implants of the largest diameter (4 mm) exhibited the lowest stresses and strains under unilateral and bilateral loading conditions.
OBJECTIVE: The objective of this study is to evaluate the cost-effectiveness of dental home visits and oral health information, in the form of educational leaflets, in preventing new caries development in young children, compared to those receiving only educational leaflets over a period of two years. Cost-effectiveness analysis will be used to evaluate the cost-effectiveness of dental home visits.
METHODS: This is a collaborative project with the Oral Health Division of the Ministry of Health Malaysia. The Oral Health Division will provide access to a subsample from the National Oral Health of Preschoolers Survey which was carried out in 2015. The population of interest is children aged 5 and 6 years from kindergartens in the Selangor state of Malaysia. The study adopted a societal perspective for cost-effectiveness analysis and all types of resources that are of value to society will be included in analyzing the costs; such as cost to the patient, cost to the provider or institution, and indirect costs because of loss of productivity.
RESULTS: The trial has been approved by the International Medical University Malaysia's Joint Research and Ethics Committee (Project ID: IMU R157-2014 [File III - 2016]). This trial is currently recruiting participants.
CONCLUSIONS: The number of young children in Malaysia who have been referred to the hospital children's dentistry service for severe caries is disturbing. The cost of dental treatment in young children is high due to the severity of the caries which require an aggressive treatment, and the need for general anesthesia or sedation. This study will provide information on the cost and effectiveness of DHVs in caries prevention of young children in Malaysia.
REGISTERED REPORT IDENTIFIER: RR1-10.2196/10053.