Exploration on the cultivation of holistic thinking in endodontic practice teaching / 中华医学教育探索杂志

Objective:To investigate the effect of holistic thinking training mode on establishing clinical holistic thinking in endodontic practice teaching for students.Methods:Holistic thinking training mode was applied among Batch 2013 (group A, n=174) and Batch 2014 (group B, n=92) students of Guanghua School of Stomatology, Sun Yat-sen University. The teaching results were evaluated by the scores before and after the training and questionnaire, and by comparing their scores with those of Batch 2012 (group C, n=88) students. SPSS 20.0 was used to conduct one-way ANOVA and t test. Results:Compared the scores of students in group A with group B, the total scores before and after the training and the scores of "case report" were not statistically different, but the scores of holistic thinking were significantly improved after the training. Compared with the scores of students in group C, the total scores after the training and the "case report" scores of group A and B were significantly higher. The results of the questionnaire showed that 87.9%(153/174) of the students thought the training mode was conducive to the establishment of holistic thinking, but 77.6%(135/174) thought further improvement was needed in terms of content and time allocation.Conclusion:Holistic thinking training mode has a positive effect on the endodontic practice teaching, and is worth promoting in other departments after further improvement.

Biomimetic mineralization of a single-layer reconstituted type I collagen model induced by sodium tripolyphosphate and polyacrylic acid / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the functions of sodium tripolyphosphate (STTP) and polyacrylic acid (PAA) in the process of collagen biomimetic mineralization. This would allow future applications to other collagen matrices such as bone collagen or 3-D collagen scaffolds.</p><p><b>METHODS</b>Glass cover slips and transmission electron microscopy (TEM) grids were coated with reconstituted typeIcollagen fibrils. Mineralization of the reconstituted collagens was demonstrated with scanning electron microscopy (SEM) and TEM using a Portland cement-containing resin composite and a phosphate-containing fluid in the presence of PAA and STTP. The rest were immersed in a biomimetic remineralization medium without PAA and/or STTP (control).</p><p><b>RESULTS</b>In the presence of PAA and STTP in the mineralization medium, intrafibrillar mineralization based on the non-classical crystallisation pathway could be identified. Mineral phases were evident within the collagen fibrils as early as 12 h after the initially-formed amorphous calcium phosphate nanoprecursors were transformed into apatite nanocrystals. Collagens at 72 h were heavily mineralized with periodically arranged intrafibrillar apatite platelets. Conversely, only large mineral spheres with no preferred association with collagen fibrils were observed in the absence of biomimetic analogues in the medium (control).</p><p><b>CONCLUSIONS</b>Intrafibrillar apatite deposition can be achieved via biomimetic mineralization system containing PAA and STTP when amorphous calcium phosphate precursor is stabilized.</p>

Sealing properties of three resin-based sealers / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the sealing properties of three resin- based sealers, EndoREZ, RealSEAL and RealSEAL SE.</p><p><b>METHODS</b>Forthy-eight extracted human anterior teeth with single root and canal were prepared using ProTaper files with crown-down technique to F3. The teeth were filled with three sealer respectively with hot gutta- percha vertical condensation technique simulating the clinical situation. Leakage quantity was detected using computerized fluid filtration meter with 10 samples in each group. The cross section morphology of apical parts of roots of 5 mm was observed with scanning electron microscope and transmission electron microscope in 3 samples of each group, respectively.</p><p><b>RESULTS</b>The leakage quantity of EndoREZ, RealSEAL and RealSEAL SE were (2.61±0.60), (1.43±0.11) and (1.76±0.18) µl/min, respectively. The gaps between the the sealer and the canal wall were increased in in order of RealSEAL, RealSEAL SE and EndoREZ. No obvious demineralized dentin under EndoREZ and the smear layer was not completed removed. The partly demineralized dentin was observed under RealSEAL and the smear layer was totally removed. The partly demineralized dentin was seen under RealSEAL SE and the majority of smear layer was removed.</p><p><b>CONCLUSIONS</b>Among the three resin- based sealers, RealSEAL has the best sealing properties, followed by RealSEAL SE and EndoREZ.</p>