Being a new non-ceramic hydroxyapatite artificial bone substitute with biological activity , calcium phosphate cement is widely applied in clinical therapy due to its biocompatibility , osteoconductivity , degradability and possibility of being drug carriers . In addition, it also has a good performance in root canal filling , apexification, plerosis of pulp floor perforation and alveolar defects . However , it is necessary to resolve the issues , such as selecting appropriate hardening time and how to enhance compressive strength . This article presents a review of the research progress on the biological properties and clinical application of calcium phosphate cement in stomatology .

BACKGROUND: Hydroxyapatite/chitosan (HA/CS) complex may act as a drug carrier for drug release, but little is reported about the release amount and antibacterial effect of minocycline-HA/CS (Mino-HA/CS) complex. OBJECTIVE: To investigate the in vitro release and antibacterial property of Mino-HA/CS complex. METHODS: HA/CS and Mino-HA/CS were prepared using co-precipitation method. The surface and cross-section features of the complexes were observed under scanning electron microscopy. The porosities were measured according to Archimedes Principle. The release of minocycline hydrochloride was measured by high performance liquid chromatography with the simulated saliva as drug release media. In vitro antibacterial effect on Porphyromonas gingivalis and Staphylococcus aureus were measured by bacteria-inhibiting ring method. Biological toxicities were evaluated via cel counting kit-8cel proliferation assay. RESULTS AND CONCLUSION: The porosity of Mino-HA/CS was larger than that of HA/CS, with the average porosity of 53.99%. Single-day release amount of Mino-HA/CS could maintain at the level of 0.5-1 μg per day for a long-term. Bacteriostatic rings of Porphyromonas gingivalis and Staphylococcus aureus stil existed clearly after 7 days. Cel proliferation assays showed that Mino-HA/CS extract had the significant effect on promoting cel proliferation. These findings indicate that the Mino-HA/CS sustains the release of minocycline at a relatively stable level within a longer period, shows good inhibitory effect on Porphyromonas gingivalis and Staphylococcus aureus and promotes the proliferation of periodontal ligament cel s.

Objective:To investigate the application and effect of the virtual reality (VR) combined with the augmented reality (AR) integrated teaching system in stomatology general medical education of clinical medicine students.Methods:A total of 160 undergraduates from the five-year clinical medicine Batch 2015 of Naval Medical University were randomly divided into VR+AR group and traditional group, with 80 students in each group. A comparative analysis was made on the previous and teaching achievements of the two groups of students, and a questionnaire survey was conducted after the completion of the class. Epidata 3.0 was used to input questionnaire data, and SPSS 23.0 software was used to carry out t test, chi-square test and Fisher precision test. Results:There was no statistical difference in written test scores between the VR+AR group and the traditional group [(52.65±3.76) vs. (51.90±3.46), P=0.516], but the VR+AR group was significantly higher than the traditional group in case analysis scores [(35.85±2.56) vs. (31.40±2.96), P < 0.001] and overall performance [(88.50±4.95) vs. (83.30±4.86), P= 0.002]. The questionnaire survey results showed that the scores of "teaching mode" [(92.30±6.90) vs. (85.20±7.30), P<0.001], "teaching method" [(91.70±5.90) vs. (86.00±6.70), P=0.012] and "teaching improvement" [(90.70± 8.70) vs. (82.30±8.40), P<0.001] in VR + AR group were significantly higher than those in the traditional teaching group. Conclusion:The VR combined with AR integrated teaching system can significantly improve teaching performance and teaching quality, and is convenient for teaching demonstrations and simulation operations in small oral spaces, and is especially suitable for oral general medical education for clinical medicine.