A comparison study of dental pulp stem cells derived from healthy and orthodontically intruded human permanent teeth for mesenchymal stem cell characterisation.

The objective of this study was to compare the characteristics of Dental Pulp Stem Cells (DPSCs) derived from healthy human permanent teeth with those that were orthodontically-intruded to serve as potential Mesenchymal Stem Cells (MSC). Recruited subjects were treated with orthodontic intrusion on one side of the maxillary first premolar while the opposite side served as the control for a period of six weeks before the dental pulp was extracted. Isolated DPSCs from both the control and intruded samples were analyzed, looking at the morphology, growth kinetics, cell surface marker profile, and multilineage differentiation for MSC characterisation. Our study showed that cells isolated from both groups were able to attach to the cell culture flask, exhibited fibroblast-like morphology under light microscopy, able to differentiate into osteogenic, adipogenic and chondrogenic lineages as well as tested positive for MSCs cell surface markers CD90 and CD105 but negative for haematopoietic cell surface markers CD34 and HLA-DR. Both groups displayed a trend of gradually increasing population doubling time from passage 1 to passage 5. Viable DPSCs from both groups were successfully recovered from their cryopreserved state. In conclusion, DPSCs in the dental pulp of upper premolar not only remained viable after 6 weeks of orthodontic intrusion using fixed appliances but also able to develop into MSCs.

Students' perception on flipped classroom in contrast to live demonstration for teaching orthodontic wire-bending skills: A focus group study.

OBJECTIVE: This study aimed to explore students' perceptions of flipped classroom (FC) compared to live demonstration (LD) in transferring skills of fabricating orthodontic wire components for orthodontic removable appliances. METHODS: Forty third-year undergraduate dental students were randomly assigned to two groups: FC (n = 20) and LD (n = 20). Students in group FC attended FC, while students in group LD attended LD. Both groups underwent a series of standardized teaching sessions to acquire skills in fabricating six types of orthodontic wire components. Eight students (four high achievers and four low achievers) from each group were randomly selected to attend separate focus group discussion (FGD) sessions. Students' perceptions on the strengths, weaknesses, and suggestions for improvement on each teaching method were explored. Audio and video recordings of FGD were transcribed and thematically analyzed using NVivo version 12 software. RESULTS: Promoting personalized learning, improvement in teaching efficacy, inaccuracy of three-dimensional demonstration from online video, and lack of standardization among instructors and video demonstration were among the themes identified. Similarly, lack of standardization among instructors was one of the themes identified for LD, in addition to other themes such as enabling immediate clarification and vantage point affected by seating arrangement and class size. CONCLUSIONS: In conclusion, FC outperformed LD in fostering personalized learning and improving the efficacy of physical class time. LD was more advantageous than FC in allowing immediate question and answer. However, seating arrangement and class size affected LD in contrast to FC.

The effect of live demonstration and flipped classroom with continuous formative assessment on dental students' orthodontic wire-bending performance.

BACKGROUND: Wire-bending skills is commonly taught through live demonstrations (LD) though flipped classroom (FC) method has gained popularity. Continuous formative assessment promotes personalised learning via closely monitored progress, with the identification of students' strengths and weaknesses. This study aims to evaluate the effects of LD and FC teaching methods, supplemented with continuous formative assessment, on dental students' learning of wire-bending skills for six types of removable orthodontic appliance components. A deeper understanding of the relative effectiveness between LD and FC teaching methods can help identify the most appropriate method to achieve student learning objectives, which is especially important given the current Covid-19 pandemic. METHODS: Forty third-year undergraduate dental students were randomly assigned into FC (n = 20) or LD (n = 20) cohort. Each student attended six teaching sessions, each to teach students' competency in fabricating one type of wire component, for a total competency in fabricating six wire components over the course of six teaching sessions. Either LD or FC teaching methods were used. After each session, wire assignments had to be submitted. Wire assignments were then evaluated using a blinded wire-bending assessment protocol. As part of their formative assessment, the assessment results were distributed to students, lecturers, and technicians before the next session. After the first session (T0) and at the end of all six sessions (T1), students completed a self-reported questionnaire. RESULTS: The mean wire-bending scores for FC were significantly higher than LD for two of the six assignments, namely the Adams clasp (p < 0.01) and Z-spring (p = 0.03). Scores for both LD and FC increased significantly over time, which may be attributed to formative assessment. There was no statistically significant correlation between wire-bending scores and video usage. Students were satisfied with both teaching methods, according to T0 and T1 questionnaires. CONCLUSIONS: Both LD and FC are equally effective in transferring practical orthodontic wire-bending skills and well-received by students. Continuous formative assessment may have enhanced students' learning of orthodontic wire-bending skills. Further studies with control group are recommended to investigate the effect of formative assessment on teaching practical dental skills.