Evaluating the effectiveness of a novel digital evaluation technology on dental preclinical crown preparation training.

OBJECTIVES: To evaluate the assessment scores of a novel digital training program versus traditional training in dental preclinical crown preparation. METHODS: Crown preparations in two consecutive preclinical training sessions were retrospectively collected and assigned to three groups: traditional group (TG), scanning group (SG), and digital evaluation group (DG). Students in the TG (n = 20) were taught by conventional visual grading, while students in the SG (n = 25) received three-dimensional feedback from digitally scanned preparations. All the SG students continued with supplementary digital evaluation and preparations were allocated into the DG (n = 25). Comparison of total scores between groups was investigated using independent samples t-test and paired samples t-test. Mann‒Whitney U-test and Wilcoxon signed-rank test were used to statistically analyze the differences in subdividing categories. The level of significance was p < 0.05. Questionnaires on the digital evaluation procedure were answered by students in DG. RESULTS: The results showed a significant improvement (p < 0.01) in the total scores of DG than those of TG and SG, while there were no statistically significant differences between TG and SG. Scores of surface finish and undercut improved significantly in DG compared to TG and SG. The reduction scores of DG were significantly higher than those of SG. Students' feedback indicated a positive perspective on the implementation of the novel digital evaluation technology. CONCLUSIONS: These findings suggest that digital evaluation technology is useful for preclinical crown preparation training. Attention should also be paid to studying the optimal integration of digital dentistry into traditional dental curricula and its effects on students' learning curves.

Digitally printed custom trays assembled with occlusion rims and gothic arch tracing devices attached with tenon-and-mortise joints for biofunctional complete dentures: A dental technique.

A novel technique of digitally printed custom trays assembled with occlusion rims and gothic arch tracing devices attached with tenon-and-mortise joints for biofunctional complete dentures that could be delivered in 2 visits is presented. This technique takes advantage of closed-mouth impressions and objective jaw relation records by following the biofunctional prosthetic system concept with high efficiency and reduced labor.

[Effects of Ethanol Extracts of Phellinus lonicerinus on Hepatic Stellate Cells of Fibrosis Liver in Rats].

OBJECTIVE: To study the effects of ethanol extracts of Phellinus lonicerinus on hepatic stellate cells of fibrosis liver in rats. METHODS: The model rats of hepatic fibrosis were established by intraperitoneally injection of CCl4 olive oil solution at the dose of 2 mL/kg. And then the model rats were administered orally ethanol extract of Phellinus lonicerinus with 1 g/(kg · d) and 0.5 g/( kg · d) for consecutive eight weeks. Serum transforming growth factor-ß1, (TGF-ß1), liver total antioxidant capacity (T-AOC), total superoxide dismutase( T-SOD) activity and the content of malondialdehyde ( MDA) were determined. The α-smooth muscle actin (α-SMA), matrix metalloproteinases-1 (MMP-1) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) were determined by immunohistochemical. RESULTS: Compared to the model group, the ethanol extracts of Phellinus lonicerinus decreased the content of serum TGF-ß1 and MDA in liver tissue, as well as increased the activity of T-SOD and the level of T-AOC. Immunohistochemical showed that the ethanol extracts of Phellinus lonicerinus downregulated the expression of α-SMA in liver tissue and the expression of TIMP-1, as well as upregulated the expression of MMP-1. CONCLUSION: The ethanol extracts of Phellinus lonicerinus has good antioxidative activity with application prospects in prevention of hepatic fibrosis. The mechanism may be related to inhibiting the activation of hepatic stellate cells induced by oxidative stress,reducing the TGF-ß1, and cytokines activating the hepatic stellate cells,and upregulating the expression of MMP-1 promoting the collagen degradation.

Estrogenic and anti-estrogenic activities of hispolon from Phellinus lonicerinus (Bond.) Bond. et sing.

Hispolon was the main antitumor active ingredient in Phellinus sensu lato species. In order to confirm the dual regulating estrogenic ingredient and obtain more effective natural estrogen replacement drugs, hispolon was separated from Phellinus lonicerinus (Bond.) Bond. et sing. Hispolon exhibited significant anti-proliferative effect against estrogen-sensitive ER (+) MCF-7 cells in the absence of estrogen, and exhibits antagonistic effects on 17ß-estradiol (E2)-induced MCF-7 cell proliferation when E2 and the different concentrations of hispolon were treated simultaneously. Hispolon also inhibited the proliferation of estrogen-negative ER (-) MDA-MB-231 cells at the concentration of 5.00×10(-5) M. The yeast two-hybrid experiments showed that hispolon had strong and non-selective effects on the estrogen receptor (ER) α and ERß at a concentration of 1.00×10(-6) M. The ERß-binding ability of hispolon was larger than ERα in the concentration range of 1.00×10(-9) M and 1.00×10(-7) M. Hispolon could increase the body weight coefficient, serum E2 and progesterone contents in immature female mice at dose of 9.10×10(-6) mol/kg, and increase coefficient of thymus and spleen in mice. The Gscores of hispolon-ERα and hispolon-ERß docked complexes were -7.93 kcal/mol and -7.79 kcal/mol in docking simulations. Hispolon presented dual regulating estrogenic activities, which showed estrogenic agonist activity at low concentration or lack of endogenous estrogen, and the estrogenic antagonistic effect was stimulated at high concentrations or too much endogenous estrogen. Hispolon could be used for treating the estrogen deficiency-related disease with the benefit of non-toxic to normal cells, good antitumor effects and estrogenic activity.

[Study on the chemical constituents of Phellinus lonicerinus].

OBJECTIVE: To study the chemical constituents of Phellinus lonicerinus. METHODS: The constituents were seperated and purified by silica column chromatography, Sephadex LH-20 and other column chromatography, then their structures were identified by spectral methods. RESULTS: Six compounds were isolated and identified as ergosta-6,22-dien-3beta, 5beta, 8beta-triol (1), erogosterol (2), vanillin (3), 3,4-dihydroxy benzalacetone (4), beta-sitosterol (5), docosanoic acid (6). CONCLUSION: All compounds are isolated from Phellinus lonicerinus for the first time and compound 4 isa new natural product.