Current Implementation of Digital Dentistry for Removable Prosthodontics in US Dental Schools.

Objectives: Although digital technology has been widely integrated into dental education, there is limited literature investigating the extent of the integration of computer-aided design and computer-aided manufacturing (CAD-CAM) for removable systems in the dental curriculum. The purpose of this study was to assess the current implementation of CAD-CAM complete and partial dentures in predoctoral (PP) and advanced graduate prosthodontic (AGP) education in US dental schools. The study also aimed to identify potential barriers to its implementation in the dental curriculum. Methods: An online survey with 15 questions was created using online survey software. The survey was distributed to the directors of predoctoral prosthodontics in 56 schools and advanced graduate programs of prosthodontics in 52 schools listed in the 2018-19 American Dental Education Association (ADEA) Directory. Results: The percentage of programs (PP and AGP) implementing CAD-CAM complete dentures (CAD-CAM CDs) and CAD-CAM removable partial dentures (CAD-CAM RPDs) in their didactic, preclinical, and clinical curricula was recorded. CAD-CAM CDs are taught in didactic courses in 54.2% of PP and 65.2% of AGP. However, CAD-CAM RPDs are only taught in 37.5% of PP and 47.8% of AGP. Programs are largely limited by a lack of funds, resources, time, and faculty members. Conclusion: While digital technologies have indeed become more prevalent in dental education, many institutions face barriers to implementation. More research must be conducted in order to support the continued incorporation of digital technologies into dental education.

3D Digital technology as an alternative educational tool in preclinical dentistry.

INTRODUCTION: The advancement of 3D digital scanners has allowed educators to uphold the quality of education whilst implementing novel methods of assessment. OBJECTIVE: The purpose of this study was to compare two evaluation methods, conventional and digital scanned assessments, on student cavity preparations and students and faculty's perceptions of these assessment methods. METHODS: Predoctoral students performed Class II amalgam and Class III resin composite preparations on simulated teeth for their preclinical competency examinations. Two calibrated faculty evaluated the students' preparations using dental instruments for conventional assessments and 3D scanned images for digital assessments. Faculty scores from both assessment methods were compared and statistically analysed (p < .05). Students also self-assessed their performance using the digital scanned images and filled out a perception survey. RESULTS: There was no statistically significant difference between the conventional (Class II; 73.3 ± 12.2 and Class III; 82.5 ± 8.9) and the digital assessment with scanned images (Class II; 71.3 ± 11.0 and Class III; 82.2 ± 8.2). Faculty scores from both methods have shown a trend of comparability. Most students agreed that digital ideal preparation models were useful (84.2%) and almost all students agreed that digital technology helped them learn operative dentistry (91.1%). In contrast, most students agreed that conventional assessment should be the main self-evaluation system (82.2%) and disagreed that digital assessment is more effective than conventional self-assessment (68.3%). CONCLUSION: Our study demonstrated that 3D digital technology could be an alternative and/or supplementary educational tool to aid in upholding the quality of dental education.

Trans-trigeminal transport of masseter-derived neprilysin to hippocampus.

OBJECTIVE: To show the possible occurrence of exosomal transport of neprilysin from masseter muscle to hippocampus via trigeminal nerve in the living mouse. DESIGN: Mouse C2C12 myotube-derived exosomes were labeled with near-infrared (NIR) dye and injected into the masseter muscle to track their fluorescence from masseter muscle to hippocampus via trigeminal nerve. A plasmid vector encoding green fluorescent protein (GFP)-tagged neprilysin (GFP-neprilysin) was transfected into masseter muscle of C57BL/6 J mice. Expression of mRNA and encoded protein of the transgene was identified in masseter muscle, trigeminal nerve and hippocampus by RT-PCR and Western blot, respectively. RESULTS: Peak of exosomal NIR in masseter muscle at time 0 rapidly reduced at 3 h and 6 h along with the subsequent increases in trigeminal nerve and hippocampus. Expression of GFP-neprilysin mRNA was detected in masseter muscle, but not trigeminal nerve and hippocampus. On the other hand, the corresponding protein of GFP-neprilysin was identified in the three tissues on day 3 after transfection into masseter muscle as a single band on Western blots with anti-GFP and anti-neprilysin antibodies. CONCLUSION: The appearance of GFP-neprilysin protein in trigeminal nerve and hippocampus without a corresponding mRNA expression indicated the protein's origin from the masseter muscle. Concomitant migration of NIR-exosomes from masseter muscle to hippocampus via trigeminal nerve suggested the possible occurrence of exosomal transport of neprilysin.

Diminished apoptotic priming and ATM signalling confer a survival advantage onto aged haematopoietic stem cells in response to DNA damage.

Ageing of haematopoietic stem cells (HSCs) contributes to deficits in the aged haematopoietic system. HSC decline is driven in part by DNA damage accumulation; yet, how ageing impacts the acute DNA damage response (DDR) of HSCs is poorly understood. We show that old HSCs exhibit diminished ATM activity and attenuated DDR, leading to elevated clonal survival in response to a range of genotoxins that was underwritten by diminished apoptotic priming. Distinct HSC subsets exhibited ageing-dependent and subtype-dependent differences in apoptotic priming and survival in response to DNA damage. The defective DDR of old HSCs was non-cell autonomous, as ATM signalling and clonal survival in response to DNA damage could be restored to levels observed in young HSCs post-transplantated into young recipients. These data indicate that defective DDR and diminished apoptotic priming provide a selective advantage to old HSCs that may contribute to mutation accrual and disease predisposition.