Crestal strain of two-implant mandibular overdentures with implants placed at different positions: An in vitro 3D printed simulation study.

STATEMENT OF PROBLEM: The 2-implant mandibular overdenture (2IMO) is a popular treatment for patients with mandibular edentulism. However, information on the influence of implant positions on crestal strain is lacking. PURPOSE: The purpose of this in vitro study was to evaluate the crestal strain around 2 implants to support mandibular overdentures when placed at different positions. MATERIAL AND METHODS: Edentulous mandibles were 3-dimensionally (3D) designed separately with 2 holes for implant placement at similar distances of 5, 10, 15, and 20 mm from the midline, resulting in 4 study conditions. The complete denture models were 3D designed and printed from digital imaging and communications in medicine (DICOM) images after scanning the patient's denture. Two 4.3×12-mm dummy implants were placed in the preplanned holes. Two linear strain gauges were attached on the crest of the mesial and distal side of each implant (CH1, CH2, CH3, and CH4) and connected to a computer to record the electrical signals. Male LOCATOR attachments were attached, the mucosal layer simulated, and the denture picked up with pink female nylon caps. A unilateral and bilateral force of 100 N was maintained for 10 seconds for each model in a universal testing machine while recording the maximum strains in the DCS-100A KYOWA computer software program. Data were analyzed by using 1-way analysis of variance, the Tukey post hoc test, and the paired t test (α=.05). RESULTS: Under bilateral loading, the strain values indicated a trend with increasing distance between the implants with both right and left distal strain gauges (CH4 and CH1). The negative (-ve) values indicated the compressive force, and the positive (+ve) values indicated the tensile force being applied on the strain gauges. The strain values for CH4 ranged between -166.08 for the 5-mm and -251.58 for the 20-mm position; and for CH1 between -168.08 for the 5-mm and -297.83 for the 20-mm position. The remaining 2 mesial strain gauges for all 4 implant positions remained lower than for CH4 and CH1. Under unilateral-right loading, only the right-side distal strain gauge CH4 indicated the increasing trend in the strain values with -147.5 for the 5-mm, -157.17 for the 10-mm, -209.33 for the 15-mm, and -234.75 for the 20 mm position. The remaining 3 strain gauges CH3, CH2, and CH1 ranged between -28.33 and -107.17. For each position for both implants, significantly higher (P<.05) strain values were observed on the distal strain gauge channels CH4 and CH1 than on the mesial channels CH3 and CH2 under bilateral loading and on the right side under unilateral loading. CONCLUSIONS: Peri-implant crestal strains in the 2IMO increased by increasing the distance of the implants from the midline. The stress values progressively increased from 5 to 10 mm to 15 to 20 mm from midline, represented as lateral incisor, canine, and premolar positions. The distal side of the implants exhibits higher strains than the mesial side of the implants.

Entrustable professional activities in undergraduate dental education: A practical model for development and validation.

OBJECTIVE: Entrustable professional activities (EPAs) are tasks that a person who is qualified or is in the process to be credentialed are allowed to engage. There are several levels of entrustment based on degrees of supervision assigned to each EPA. This paper aims to describe the process and outcome of creating EPAs; validate EPAs relevant to undergraduate dental training. 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.

Stress and strain patterns of 2-implant mandibular overdentures with different positions and angulations of implants: A 3D finite element analysis study.

STATEMENT OF PROBLEM: The 2-implant mandibular overdenture is a popular treatment for the edentulous mandible, but information on optimum implant positions and/or angulations and their stress and strain patterns is lacking. 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.

Effect of Implant Positions and Angulations on Retentive Strength of 2-Implant Mandibular Overdentures: An In Vitro Study with the New 3D-Printed Simulation Method.

Objectives: To evaluate the retentive strength of overdenture attachments in 2-implant mandibular overdenture (2IMO) with implants placed at different positions and angulations. Materials and Methods: Edentulous mandibular models were 3D-printed using CBCT images and Materialise Mimics software and the denture models using the intraoral scanner. Two standard implants were placed parallel at different positions from midline (5, 10, 15, and 20 mm) with 0-0 degree angulations and with different distal angulations (0-5, 0-10, 0-15, 5-5, 10-10, and 15-15 degrees) at 10±mm from midline representing 10 study groups. Low-profile male attachments were attached to the implants and the female pink attachments were picked up in the denture. A total of 4 simulated overdenture model sets for each of the 10 study groups were subjected to the universal testing machine thrice to measure a peak load (N) to disengage the attachments vertically. Data were analyzed using one-way ANOVA and Tukey's post hoc test at 0.05 significance level. Results: Varying implant positions had a statistically significant effect on the retentive strengths of the attachments (F = 5.61, P = 0.002). Peak load-to-dislodgement values (in increasing order) were 49.64 ± 8.27 N for 5 mm, 53.26 ± 11.48 N for 10 mm, 60.24 ± 12.31 N for 15 mm, and 64.80 ± 6.78 N for 20 mm groups. The retentive strength of the 20 mm group was significantly higher than 5 mm (P = 0.003) and 10 mm (P = 0.03) groups. Varying implant angulations had a significant effect on the retentive strengths of the attachments (F = 7.412, P = 0.000). The peak load-to-dislodgement values (in increasing order) were 48.20 ± 15.59 N for 5-5 degrees, 53.26 ± 11.48 N for 0-0 degrees, 54.96 ± 8.25 N for 0-5 degrees, 57.71 ± 7.62 N for 10-10 degrees, 66.00 ± 17.54 N for 15-15 degrees, 66.18 ± 14.09 N for 0-10 degrees, and 77.38 ± 10.33 N for 0-15 degrees. Retentive strength of 0-15 degrees was significantly (P < 0.05) higher than those of 0-0, 0-5, 5-5, and 10-10 degrees and that of 5-5 degrees was significantly (P < 0.05) lower than those of 0-10, 0-15, and 15-15 groups. Conclusions: Retentive strength of the 2IMO increased with increase in distance of implants from midline and increased with increase in distal angulations.

Different implant diameters and their effect on stress distribution pattern in 2-implant mandibular overdentures: A 3D finite element analysis study.

STATEMENT OF PROBLEM: The edentulous mandible is commonly treated with a 2-implant overdenture. A change in diameter of the implants may affect the biomechanical behavior of the overdenture, but information on these effects is lacking. 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.

The effect of transactional analysis training on emotional intelligence in health professions students.

BACKGROUND: Emotional intelligence (EI) is considered to present a significant predictor of work performance whereas Transactional analysis (TA) is the relational perspective in communication in managing emotions. We evaluated the effect of psycho-educational training in EI and TA (TEITA) on EI among health professions undergraduates, with post-training, and at 1-month follow-up. METHODS: A total of 34 participants participated in the study where 17 participants were in the TEITA group and another 17 were in the control group. A quasi-experimental non-randomised, controlled cohort study was conducted, in which participants in the TEITA group were introduced to EI and TA concepts on a weekly basis for four weeks, at 90 min each time, and provided with opportunities for experiential sharing of emotions and coping mechanisms experienced in the previous week. Both TEITA and control groups received weekly EI and TA reading materials. All completed the 16-item Wong and Law EI Scale at baseline and post-training. The training group also completed the questionnaire at a 1-month follow-up. Wilcoxon Signed Ranks and Mann Whitney tests were used to analyse within a group and between group changes in EI scores. RESULTS: Baseline EI scores in the TEITA group were lower than the control group. On completion of TEITA, EI scores in the TEITA group increased, and differences were not detected between groups. Within the TEITA group, paired increases in all domains were statistically significant, whereas, in the control group, the paired increase was only detected in the domain addressing regulations of emotion (ROE). Pre to post-training increases in EI scores were statically significantly greater in TEITA compared to control groups. At the 1-month follow-up, EI scores were sustained. CONCLUSION: The psycho-educational training based on EI and TA is effective in enhancing EI among health professions undergraduates. Future research should investigate the effect of such training on observable inter-personal and socio-economic behaviours.

A randomized controlled trial of 6-month dental home visits on 24-month caries incidence in preschool children.

OBJECTIVES: This paper reports on the effect of 6-month dental home visits compared to no dental home visits on 24-month caries incidence in 5- to 6-year-olds. METHODS: 5- to 6-year-olds attending kindergartens were randomized to receive either 6-month dental home visits and education leaflets (Intervention group) or education leaflets alone (Control group) over 24 months. To detect a 15% difference in caries incidence with a significance level of 5% and power of 80%, 88 children were calculated to be needed in the Intervention group and 88 in the Control. Baseline clinical data included oral examinations at the kindergartens. Follow-up visits were made on the 6th, 12th and 18th month. At the end of the 24 months, both the Intervention and Control groups were visited for oral examinations. The primary outcome was caries incidence, measured by the number and proportion of children who developed new caries in the primary molars after 24 months. The secondary outcome was the number of primary molars that developed new caries (d-pms). Frequency distributions of participants by baseline socio-demographic characteristics and caries experience were calculated. The chi-square test was used to test differences between the caries experience in the Intervention and Control groups. The t test was used to compare the mean number of primary molars developing new caries between the Intervention Group and the Control Group. The number of children needed to treat (NNT) was also calculated. RESULTS: At the 24-month follow-up, 19 (14.4%) developed new caries in the Intervention Group, compared to 60 (60.0%) in the Control Group (p = .001). On average, 0.2 (95% CI = 0.1-0.3) tooth per child in the Intervention Group was observed to have developed new caries compared to 1.1 (95% CI = 0.8-1.3) tooth per child in the Control Group (p = .001). The number of children needed to treat (NNT) to prevent one child from developing new caries was 2.2. CONCLUSIONS: The present study has demonstrated that 6-month home visits to families of 5- to 6-year-olds are effective in caries prevention in 5- to 6-year-olds of low-income families in a middle-income country where access to health services, including oral health promotion services, is limited.

Clinical audit of orthodontic chart documentation by dental undergraduates.

INTRODUCTION: Clinical audit is a quality improvement process that seeks to improve patient care and outcomes through the systematic review of care against explicit criteria and the implementation of change. The objective of this audit was to evaluate the quality of orthodontic chart documentation by dental undergraduates against established guidelines. MATERIALS AND METHODS: An audit checklist with 13 criteria for good documentation was adapted from guidelines proposed by the American Association of Orthodontists and British Orthodontic Society. Orthodontic chart documentation in 103 removable appliance therapy patients under 4th and 5th year dental undergraduates' care was retrieved from the electronic record of the University dental clinic and audited. The audit exercise explored in detail the thirteen criteria for good documentation and eight assessment attributes of the first criterion, namely, basic orthodontic examination. The level of compliance was measured as the percentage records meeting the criteria. The data were statistically analysed using SPSS 26.0 (SPSS, Inc., Chicago, IL, USA). RESULTS: There was no complete compliance for any of the criteria. Thirty-five (33.9%) patient charts reported basic orthodontic examination documentation adequately. Compliance was the highest for documentation of treatment modality (77.6%), appliance delivery encounters (77.6%), and appliance adjustment appointments (83.5%). About 51.4% of the 68 patient charts (treatment of 35 patients of the total 103 were in the progress stage) stated adequately the outcome of treatment. Only 22% of the 68 patient charts had the details for retention protocol. There was statistically significant difference in chart documentation between male and female students for basic orthodontic assessment and appliance delivery and patient instructions attributes. CONCLUSION: The clinical audit demonstrated poor compliance with the criteria for orthodontic chart documentation. The audit should be repeated after the provision of learning opportunities and self-critical analysis.

Does Emotional Intelligence of Dental Undergraduates Influence Their Patient Satisfaction?

OBJECTIVES: The research aimed to investigate if emotional intelligence (EI) scores of dental undergraduates influenced their patients' satisfaction with the treatment received. 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.

Role of family functioning and health-related quality of life in pre-school children with dental caries: a cross-sectional study.

BACKGROUND: The aim of this cross-sectional study was to evaluate the effect of family functioning on oral health related quality of life (OHRQoL) and dental caries status among 4- to 6-year-old Chinese pre-school children in Malaysia. 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 < 0.05). RESULTS: A response rate of 80.5% was achieved. Sample means for FAD-GF12 scores ranged < 2, indicating normal family functioning. The ECOHIS scores mean was 0.52 (SD = 0.68). In the children impact section the highest score of impacts 20 was noted followed by family impact section with the score of 12. It was observed that children with dental caries had a significant (P = 0.014) negative impact on OHRQoL (mean 0.72, SD = 0.50) as compared to children with no caries (mean 0.34 SD = 0.39). The bivariate regression analysis after getting adjusted indicated three predictors associated to poor HRQoL: having two or more siblings (OR = 4.73, P = 0.013), relationship (mother) of the respondent to the child (OR = 2.86, P = 0.013) and having dental caries (OR = 8.12, P ≤ 0.001). CONCLUSION: Findings of this study indicates that number of siblings, relationship of the respondent to the child and dental caries status are independently associated with health-related quality of life. However, family functioning does not mediate poor HRQoL in association to dental caries.

Personality Traits and Annual Income Determine the Willingness to Pay for a Single Tooth Implant.

The objective of this study was to evaluate the factors influencing the willingness to pay for a single tooth implant in Malaysia and to assess if an additional evidence-based patient education video increases the willingness to pay. A total of 100 subjects seeking single tooth replacement at the Oral Health Centre, International Medical University (IMU), Kuala Lumpur, Malaysia, were asked to complete questionnaires about personal demographics and personality traits. Subsequently, they were randomly allocated into two groups. Group C received a conventional patient-dentist interaction on treatment options for missing teeth, while Group EV received the same content with an additional evidence-based video on the survival rate and complications for each option from recent meta-analyses. Willingness to pay the median price and the highest price that the subjects were willing to pay were assessed by a structured bidding process. A higher annual income was significantly associated with willingness to pay the median price for a single tooth implant (χ2 = 6.91, p = 0.03). Dominant personality traits of openness (r = -0.25), conscientiousness (r = -0.30) and agreeableness (r = -0.20) were negatively correlated with the highest price that the patients were willing to pay for a single tooth implant (Pearson's correlation test, p < 0.05). No significant difference in willingness to pay was found between Group C and Group EV (χ2 = 0.05, p > 0.05). In conclusion, patient education strategies for single tooth replacements with dental implants should be customized based on a patient's personality and income to maximize effectiveness.

Effect of Propolis Nanoparticles against Enterococcus faecalis Biofilm in the Root Canal.

To determine the antibacterial effect of propolis nanoparticles (PNs) as an endodontic irrigant against Enterococcus faecalis biofilm inside the endodontic root canal system. Two-hundred-ten 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 seven groups, with 30 dentinal blocks in each group including: group I-saline; group II-propolis 100 µg/mL; group III-propolis 300 µg/mL; group IV-propolis nanoparticle 100 µg/mL; group V-propolis nanoparticle 300µg/mL; group VI-6% sodium hypochlorite; group VII-2% chlorhexidine. Dentin shavings were collected at 200 and 400 µm depths, and total numbers of CFUs were determined at the end of one, five, and ten minutes. The non-parametric Kruskal-Wallis and Mann-Whitney tests were used to compare the differences in reduction in CFUs between all groups, and probability values of p < 0.05 were set as the reference for statistically significant results. The antibacterial effect of PNs as an endodontic irrigant was also assessed against E. faecalis isolates from patients with failed root canal treatment. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to PNs. A Raman spectroscope, equipped with a Leica microscope and lenses with curve-fitting Raman software, was used for analysis. The molecular interactions between bioactive compounds of propolis (Pinocembrin, Kaempferol, and Quercetin) and the proteins Sortase A and ß-galactosidase were also understood by computational molecular docking studies. PN300 was significantly more effective in reducing CFUs compared to all other groups (p < 0.05) except 6% NaOCl and 2% CHX (p > 0.05) at all time intervals and both depths. At five minutes, 6% NaOCl and 2% CHX were the most effective in reducing CFUs (p < 0.05). However, no significant difference was found between PN300, 6% NaOCl, and 2% CHX at 10 min (p > 0.05). SEM images also showed the maximum reduction in E. faecalis with PN300, 6% NaOCl, and 2% CHX at five and ten minutes. CLSM images showed the number of dead cells in dentin were highest with PN300 compared to PN100 and saline. There was a reduction in the 484 cm-1 band and an increase in the 870 cm-1 band in the PN300 group. The detailed observations of the docking poses of bioactive compounds and their interactions with key residues of the binding site in all the three docking protocols revealed that the interactions were consistent with reasonable docking and IFD docking scores. PN300 was equally as effective as 6% NaOCl and 2% CHX in reducing the E. faecalis biofilms.

Racial variations in tooth pain and care-seeking in adolescents in Malaysia.

OBJECTIVE: Tooth pain among adolescents is a common event that impacts substantially on quality of life. The purpose of this paper is to explore the role of race in the tooth pain experience and associated care-seeking. 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.

Effectiveness of chitosan-propolis nanoparticle against Enterococcus faecalis biofilms in the root canal.

BACKGROUND: The successful outcome of endodontic treatment depends on controlling the intra-radicular microbial biofilm by effective instrumentation and disinfection using various irrigants and intracanal medicaments. Instrumentation alone cannot effectively debride the root canals specially due to the complex morphology of the root canal system. A number of antibiotics and surfactants are being widely used in the treatment of biofilms however, the current trend is towards identification of natural products in disinfection. The aim of the study was to determine the antibacterial effect of chitosan-propolis nanoparticle (CPN) as an intracanal medicament against Enterococcus faecalis biofilm in root canal. 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 < 0.05 were set as the reference for statistically significant results. The scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to CPNs. The effectiveness of CPNs were also evaluated against E. faecalis isolated obtained from patients having failed root canal treatment. RESULTS: The treatments of chitosan, P100, P250, CPN100, CPN250, CH and 2% CHX reduced the CFUs significantly compared to saline (p < .05). On day one and three, at 200 and 400-µm, CPN250 showed significant reduction of CFUs compared to all other groups (p < .05), while CPN100 was significantly better than other groups (p < .05) except CPN250 and 2% CHX. On day seven, at 200-µm CPN250 showed significant reduction of CFUs compared to all other groups (p < .05) except CPN100 and CHX, while at 400 µm CPN250 showed similar effectiveness as CPN100, CH and 2% CHX. SEM images showed root canal dentin treated with CPN250 had less coverage with E. faecalis bacteria similarly, CLSM images also showed higher percentage of dead E. faecalis bacteria with CPN250 than to CPN100. CONCLUSION: CPN250 was the most effective in reducing E. faecalis colonies on day one, three at both depths and at day seven CPN250 was equally effective as CPN100 and 2% CHX.

The Heritability of Palatal Rugae Morphology Among Siblings*, †.

Although there is clinical applicability of the palatal rugae as an identification tool in forensic odontology, controversy exists whether the palatal rugae patterns are stable or variable. The greater the genetic component, the higher the probability that palatal rugae patterns are stable. The aim of this study was to compare the palatal rugae morphology between full siblings and the proportion of variability due to genetic component. This cross-sectional study was conducted on digital models of 162 siblings aged 15-30 years old. The palatal rugae patterns were assessed with Thomas and Kotze (1983) classification using Geomagic Studio software (3D Systems, Rock Hill, SC). The palatal rugae morphology between siblings showed significantly similar characteristics for total number of left rugae (p = 0.001), left primary rugae (p = 0.017), secondary rugae for right (p = 0.024) and left sides (p = 0.001), right straight rugae (p = 0.010), and right convergent rugae (p = 0.005) accounting for at least 6.25%-12.8% of the variability due to heredity. Despite the similarities found, the palatal rugae patterns showed significant differences between siblings of at least 46.9% (p = 0.001). Zero heritability was found in 9 of the 14 rugae patterns. Meanwhile, total number of rugae, primary, backward, and convergent rugae showed moderate heritability (h2  > 0.3) and total number of secondary rugae showed high heritability (h2  > 0.6). In conclusion, despite the individuality characteristics, an appreciable hereditary component is observed with significant similarities found between sibling pairs and the palatal rugae patterns were both environmentally and genetically influenced.

Morphological patterns of the palatal rugae: A review.

BACKGROUND: Palatal rugae are asymmetric ridges of connective tissue located behind the incisive papilla over the anterior hard palate. They serve as stable superimposition landmarks to assess tooth movement in orthodontics and as identification aids in forensic odontology. However, the stability of palatal rugae remains controversial. This review aimed to describe the genetic, growth, and environmental factors that may influence the palatal rugae patterns. A broad search of PubMed and ScienceDirect databases was conducted. A total of 193 articles were identified, of which 73 met the selection criteria. Data were extracted into a table that presented the details of the study, sample description, and changes in the palatal rugae patterns. 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.

Root canal morphology of permanent teeth in a Malaysian subpopulation using cone-beam computed tomography.

BACKGROUND: To determine the root canal morphology of human permanent maxillary and mandibular teeth in a Malaysian subpopulation using cone-beam computed tomography (CBCT). 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 < 0.05. RESULTS: In the maxillary arch, the prevalence of three canals were observed in 0.3% of first premolars and two canals in 46.5% of second premolars. Males displayed significantly higher prevalence of two canals in maxillary second premolars than females (p < 0.05). The prevalence of a second mesiobuccal canal in maxillary first and second molars were 36.3 and 8.5%, respectively. Males displayed significantly higher prevalence of a second mesiobuccal canal in maxillary second molars than females (p < 0.05). The prevalence of a second palatal canal in maxillary first and second molars were 0.9 and 0.6%, respectively. In the mandibular arch, the prevalence of two canals were observed in 5.1% of central incisors, 12.3% of lateral incisors, 6.1% of canines, 18.7% of first premolars and 0.5% of second premolars. The prevalence of a middle mesial canal, second distal canal and extra root (radix entomolaris) were detected in 1.9, 19.5 and 21.4% of mandibular first molars, respectively. The prevalence of a C-shaped canal was observed in 48.7% of mandibular second molars. Females displayed significantly higher prevalence of a C-shaped canal in the right mandibular second molars than males (p < 0.05). No other statistically significant differences in root anatomy and root canal morphology were observed in relation to gender and tooth side. CONCLUSIONS: Wide variations in the root canal morphology exist among Malaysians. CBCT is a clinically useful tool in the identification of external and internal morphological variations in the human teeth.

Dental Home Visits for Caries Prevention Among Preschool Children: Protocol for a Cost-Effectiveness Analysis on a Randomized Control Trial.

BACKGROUND: In 2012, nearly 4000 children in Malaysia were referred to hospital pediatric dental services due to dental caries. Recent research has reported the effectiveness of dental home visits in preventing caries development in young children. Dental home visits (DHVs) are described as an ongoing relationship between the dentist and their patients, providing all aspects of a preventive oral health care program in the presence of the parents at home. 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.

Factors associated with faculty participation in research activities in dental schools.

BACKGROUND: To quantify participation in dental research activities in Malaysia, and investigate its association with socio-demographic and professional characteristics, and perceptions of research and development (R&D) culture. 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.

Dental students' compliance with antibiotic prescribing guidelines for dental infections in children.

CONTEXT: To investigate the antibiotic prescribing training received by dental students, clinical experience in treating child patients, awareness of antibiotic prescribing guidelines, preparedness in antibiotic prescribing, and compliance with antibiotic prescribing guidelines for the management of dental infections in children. METHODS: This was a cross-sectional study involving final year dentals students from Malaysian and Asian dental schools. A self-administered questionnaire consisting of five clinical case scenarios was e-mailed to all final year students at selected dental schools. Students' responses were compared for each clinical case scenario with the prescribing guidelines of the American Academy of Pediatric Dentistry and the American Dental Association. Compliance in each scenario was tested for association with their preparedness in antibiotic prescribing, previous training on antibiotic prescribing and awareness of antibiotic prescribing guidelines using Chi-square test. Data collected were analyzed using SPSS statistics version 20. RESULTS: A total of 108 completed responses were received. About 74 (69%) students were from Malaysian dental schools. The compliance rate with prescribing guidelines ranged from 15.7% to 43.5%. Those attending Malaysian dental schools (47.3%) and those who had treated child patient more often (46.3%) were more likely (P < 0.05) to be aware of the guidelines. Those who had received antibiotic prescribing training (21.3%) were more likely to think they were well prepared in antibiotic prescribing (P < 0.05). CONCLUSIONS: Final year dental students had low awareness and compliance with antibiotic prescribing guidelines. Further research is needed to investigate how compliance with the guidelines may be enhanced.