The evaluation of online Modified Objective Structured Examination (MOSE) as postgraduate admissions re-examination: A report from Fujian Medical University, China.

OBJECTIVES: This paper aims to explore the successful implementation of online postgraduate admissions re-examination in China, specifically focusing on the Modified Objective Structured Examination (MOSE). It introduced the specific practice of the online postgraduate admissions re-examination in China and investigated the perceptions of applicants, postgraduate supervisors and admissions staffs about the online MOSE re-examination. METHODS: Surveys were administrated 3 years after the implementation of online MOSE postgraduate admissions re-examination in China. Separate surveys were conducted with applicants, postgraduate supervisors, and admissions staff members to gather their opinions and suggestions regarding the online MOSE re-examination. RESULTS: A total of 65 applicants, 43 postgraduate supervisors and seven admissions staff members completed the surveys. Over 80% of the applicants agreed that the online MOSE comprehensively evaluated their medical humanities, communication, medical knowledge, and overall competence. Furthermore, 89.30% of postgraduate supervisors believed that the students recruited through online MOSE were either "not significantly different," "better," or "much better" compared to those recruited through on-site re-examination. Admissions staff members also expressed a favorable view of online MOSE re-examination. CONCLUSION: The online MOSE re-examination is an effective, convenient, and affirmative evaluation method for postgraduate admissions re-examination.

Effect of smile esthetics on the quality of life in a Han Chinese population.

OBJECTIVE: This study aimed to explore the influence of smile esthetics on the quality of life in a Han Chinese population. METHODS: A total of 110 Han Chinese volunteers (52 males and 58 females, mean age 26.7 years) were recruited, and frontal images of their smiles were collected. A photoediting program was used to evaluate the following components of smile esthetics: the buccal corridor ratios, the angle between the interpupillary and commissural lines, the number of visible teeth, and width-to-length ratios of the maxillary central incisors. Oral health-related quality of life (OHRQoL) in these volunteers was evaluated using the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile-14 (OHIP-14). Statistical analyses were performed by using Pearson's correlations and multiple linear regression (α = 0.05). RESULTS: Compared to males, females scored higher on psychological impact (p = 0.017). Moreover, the number of visible teeth had a significant effect on social impact, psychological impact and esthetic concern (all p < 0.05). However, the buccal corridor ratios, the angle between the interpupillary and commissural lines, and the width-to-length ratios of the maxillary central incisor did not correlate with the OHRQoL (all p > 0.05). CONCLUSIONS: The number of visible teeth significantly influenced the quality of life in a Han Chinese population. Smile esthetics had a significantly greater psychological impact on females than males. CLINICAL SIGNIFICANCE: This study highlights the effects of smile esthetics on the quality of life in a Han Chinese population. Female patients may raise more esthetic concerns in clinical practice.

Mapping of dental graduates' career paths in Hong Kong, Japan and mainland China.

Dental graduates have a variety of career-path choices. After graduation, they may join private dental practice, government- or hospital-based dental care services, research groups, academia, business or industry. With globalization and frequent international exchange, dental graduates nowadays can explore careers outside their home country. However, dental education systems and job opportunities vary widely across different regions and countries. Diversity of accreditation in dental education, different licensure requirements, and lack of global competencies in dental care often limit the globalization, operation and survival of dental practice and education worldwide. The requirements for professional education and practice can be quite diverse, and these differences will be barriers to dental graduates seeking career development outside their home home country. Fresh dental graduates have minimal experience in job hunting. More specifically, they are unfamiliar with potential career paths. This paper was based on the 4th trilateral symposium 2022 organized by The University of Hong Kong, Tohoku University, and Fujian Medical University, which offered a lecture to discuss career paths for dental graduates in Hong Kong, Japan, and mainland China. The aim of this paper was to provide dentists, particularly fresh graduated dental students, with practical insight into different career paths in Hong Kong (Special Administrative Region of China, SAR), Japan and mainland China, and factors that may influence their career options. It assists dental students in exploring possibilities in dentistry and preparing for their career development after graduation from dental school.

Bonding to zirconia: Effects of translucency and cusp inclinations using an experimental methodology.

Purpose To investigate the effects of translucency and cusp inclination on the micro-shear bond strength (µSBS) of zirconia to self-adhesive resin cement (SARC).Methods Sixty U-shaped zirconia specimens with 1.0 mm thickness consisting of three planes (0°, 20°, and 30°) simulating different cusp inclinations were fabricated from zirconia blocks of high, moderate, and low translucency (n=20). SARC was bonded to the specimen and light-cured for 40 s. The µSBS was tested using a universal testing machine with a cross-head at a speed of 0.5 mm/min and fracture mode was observed using a stereomicroscope (×50). Two-way analysis of variance followed by a post hoc Tukey's honest significant difference test was used for the statistical analyses (α=0.05).Results Varied µSBS values were found in the test groups (7.1-14.9 MPa). Within the zirconia of the same translucency, the µSBS value of the plane 0° specimen was significantly higher than that of the 20° and 30° planes (all p<0.05). Within the zirconia of the same cusp inclination, the µSBS value of highly translucent zirconia was significantly higher than that of moderate and low translucent zirconia (all p<0.05). There was no significant interaction between cusp inclination and translucency (p=0.525). Among the fracture modes, 83.33% were adhesive failure, 11.11% mixed failure, and 5.56% were cohesive failure.Conclusions Translucency and cusp inclination significantly affect the µSBS of zirconia to SARC. The higher the translucency, the greater are the µSBS values; the higher the cusp inclination, the lower are the µSBS values.

Effects of Aging on the Color and Translucency of Monolithic Translucent Y-TZP Ceramics: A Systematic Review and Meta-Analysis of In Vitro Studies.

BACKGROUND: Monolithic restorations made of translucent yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) have become popular over the past few decades. However, whether aging affects the color and translucency of monolithic translucent Y-TZP is unclear. OBJECTIVE: The aim of this systematic review and meta-analysis of in vitro studies was to evaluate the effects of aging on the color and translucency of monolithic translucent Y-TZP ceramics. MATERIALS AND METHODS: This systematic review/meta-analysis was reported according to the PRISMA statement and registered in the OSF registries (https://osf.io/5qjmu). Four databases including Medline via the PubMed, Embase, and Web of Science databases and the Cochrane Library were searched using no publication year and language limits. The last search was executed on November 20, 2020. In vitro studies comparing the translucency and/or color of monolithic translucent Y-TZP ceramics before and after simulated aging were selected. Meta-analyses were performed using Review Manager software (version 5.3, Cochrane Collaboration, Oxford, UK) with random-effects models at a significance level of 0.05. A risk-of-bias assessment was also performed for the included studies. RESULTS: Of the 188 potentially relevant studies, 13 were included in the systematic review. The hydrothermal aging duration ranged from 1 to 100 h at relatively similar temperatures (~134°C). In the general meta-analyses, the aged Y-TZP ceramics exhibited similar translucency parameter (TP), L∗, and b∗ values compared with the nonaged controls (P = .73, P = .49, and P = .62, respectively). Moreover, there was a significant difference between the aged and nonaged Y-TZP ceramics in the a∗ value (P = .03; MD = -0.26; 95% CI = -0.51 to - 0.02), favoring the nonaged Y-TZP ceramics. The subgroup analyses showed that the duration of aging contributed to changes in the translucency and color of the Y-TZP ceramics. CONCLUSIONS: The optical properties of monolithic translucent Y-TZP ceramics were stable after hydrothermal aging at 134°C and 0.2 MPa for ≤20 h. Moreover, clinically unacceptable changes in the translucency and color of monolithic translucent Y-TZP ceramics were found after hydrothermal aging for >20 h.

[Effect of ultrasonic scaling on micro-leakage of all-ceramic crowns].

PURPOSE: To investigate the effect of ultrasonic scaling on micro-leakage of all-ceramic crowns. METHODS: 48 first premolars of the similar shape and size were collected and prepared by one attending doctor. Two groups were randomly divided (zirconia crown group and glass ceramic crown group, with 24 in each group), and each group was randomly divided into two subgroups (resin cement group and resin modified glass cement subgroup, n=6). After the crowns were bonded and solidified for 24 h, 3 samples were randomly selected from each subgroup for ultrasonic scaling for 60 s, and the other 3 samples were used as the negative control group. After all samples were soaked in 5% fuchsin solution at room temperature for 48 h, buccal and lingual incisions were made, and double-blind scoring was performed for micro-leakage at the crown edge of each sample. SPSS 17.0 software package was used for statistical analysis. RESULTS: There were significant differences between the negative group and the ultrasonic group in micro-leakage of crowns which were cemented with resin modified glass cement(P<0.05), but there was no significant difference between the negative group and the ultrasonic group in micro-leakage of crowns which were cemented with resin cement(P>0.05). When the same adhesive was used, there was significant difference in microleakage between the zirconia crown and the glass-ceramic crown, whether ultrasonic supragingival scaling was performed or not(P<0.05). CONCLUSIONS: Ultrasonic scaling had significant effect on micro-leakage of crowns which were cemented with resin modified glass cement, and but had no significant effect on micro-leakage of crowns which were cemented with resin cement.

Stress and its association with academic performance among dental undergraduate students in Fujian, China: a cross-sectional online questionnaire survey.

BACKGROUND: The aim of this study was to investigate the amount and sources of stress in dental undergraduate students in Fujian, China, and the factors associated with stress. METHODS: This cross-sectional study was conducted during the second semester of the 2017-2018 academic year at the School of Stomatology, Fujian Medical University, China. A total of 396 students were surveyed with the Dental Environment Stress Questionnaire (DES) and the Perceived Stress Scale (PSS) using an online survey system. The participants' demographic information, including sex, age, year of study, and grade point average (GPA) was also collected. One-way analysis of variance (ANOVA) was performed to compare the stress scores. Pearson correlation and multiple linear regression analyses were conducted to explore the associated factors of stress and academic performance. All statistical analyses were performed at a significance level of 5%. RESULTS: A total of 347 undergraduate students participated in the present study, for a response rate of 87.6%. There were no significant differences in the DES and PSS total scores among students of different grades and sexes. Significant differences were found in the DES "workload" and "self-efficacy beliefs" scores among students from different study years (all P < 0.05). The Multiple linear regression showed that DES and PSS scores were negatively correlated with GPA, while sex was positively correlated with GPA (all P < 0.05). Female students had significantly higher GPAs than male students. CONCLUSIONS: Dental undergraduates in Fujian, China experienced moderate levels of stress. While the amount of stress did not differ by year of study, the sources of stress did differ. Stress scores and sex were negatively correlated with academic performance.

Effects of Different Root Canal Obturation Techniques on the Bond Strength of Fiber Post to Intraradicular Dentine.

OBJECTIVE: To evaluate the bond strength of fiber posts to intraradicular dentine pretreated with two root canal obturation techniques and three postspace irrigation solutions. METHODS: A total of 96 human premolars were collected and treated with complete or partial root canal obturation techniques. The roots were further divided into three subgroups (n = 16) based on postspace irrigation solutions: 2.5% NaOCl, 37% phosphoric acid etching, and distilled water. The fiber posts were bonded with self-adhesive resin cement, and the roots were sectioned into three slices (cervical, middle, and apical regions) after 5,000 thermocycles. The push-out bond strengths were determined and subjected to analysis of variance (α = 0.05). A stereomicroscope was used to observe the failure modes of the specimens. RESULTS: The irrigation solution, root canal obturation technique, and root region had significant effects on bond strength (P < 0.001). The completely obturated root canals showed significantly lower bond strength than the partially obturated root canals. The 2.5% NaOCl treatment produced the highest bond strength among the three irrigation solutions. Among the root regions, the cervical part showed significantly greater bond strength than the middle and apical parts. The most common failure mode was mixed failure. CONCLUSION: The partial root canal obturation technique provided better bond strength of the fiber post to intraradicular dentine. Irrigation with 2.5% NaOCl solution and phosphoric acid etching before cementation improved the push-out bond strength of the fiber posts to intraradicular dentine.

In Vitro Cytotoxicity of Self-Adhesive Dual-Cured Resin Cement Polymerized Beneath Three Different Cusp Inclinations of Zirconia.

The aim of the present study was to evaluate the in vitro cytotoxicity of self-adhesive dual-cured resin cement (SADRC) polymerized beneath three different cusp inclinations of zirconia with different light curing time. A commercial SADRC (Multilink Speed) was polymerized beneath zirconia (ZrO2) with three different cusp inclinations (0°, 20°, and 30°) for 20 s or 40 s. After being stored in light-proof box for 24 h, the ZrO2-SADRC specimens were immersed in DMEM for 72 h and then we got the extract solution, cultured the human gingival fibroblasts (HGF, 8 × 103 per well) with 100% or 50% concentrations of the extract solution for 24 h, 72 h, and 120 h, respectively, and evaluated cytotoxicity of the polymerized SADRC with CCK-8 assay in optical density (OD) values, relative growth rates (RGR), and cytotoxicity grades. Statistical analysis was conducted using a two-way ANOVA followed by post hoc Student-Newman-Keuls test. The OD values varied from 0.8930 to 3.2920, the RGR varied from 33.93% to 98.68%, and the cytotoxicity grades varied from 0 to 2. There was significant difference in the OD values among the different cusp inclinations of zirconia (P < 0.001), and there was significant difference in the OD values between the different light curing times in some situations (P < 0.05). The cusp inclination of zirconia affects the in vitro cytotoxicity of SADRC. Prolonging the light curing time from 20 s to 40 s can reduce the in vitro cytotoxicity of SADRC when the cusp inclination of zirconia is smaller than 20°.

Effects of Cusp Inclination and Light-curing Time on Microshear Bond Strength of a Dual-cure, Self-adhesive Composite Cement to Zirconia.

PURPOSE: To evaluate the effect of cusp inclination and light-curing time on the microshear bond strength (µSBS) between zirconia and a dual-cure self-adhesive composite cement and zirconia. MATERIALS AND METHODS: Forty U-shaped specimens with angled surfaces, simulating different cusp inclinations (0 degrees, 20 degrees, and 30 degrees), were fabricated from zirconia blocks (Zenostar, Wieland). The specimens were randomly divided into two groups (n = 20) according to different light-curing times of the adhesive composite cements (20 s and 40 s). Three polyethylene tubes filled with a dual-curing self-adhesive composite cement (Multilink Speed, Ivoclar Vivadent) were bonded to the surfaces of each specimen with light-curing times of 20 s and 40 s. The µSBS was tested using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure analysis was performed. Two-way ANOVA (cusp inclination and light-curing time) followed by two independent samples t-test were used for statistical analyses (α = 0.05). RESULTS: The composite cement showed various bond strengths to angled zirconia surfaces (7.07 ± 1.69 to 13.91 ± 3.11 MPa). The µSBS between composite cement and 0-degree zirconia surfaces was statistically higher than that of 20- and 30-degree zirconia surfaces. The composite cement light cured for 40 s showed nonsignificantly higher µSBS than did the composite cement cured for 20 s. Adhesive failure was the most common failure mode. CONCLUSIONS: Cusp inclination affected bond strength between the dual-curing self-adhesive composite cement and zirconia.

Hydrogen peroxide bleaching induces changes in the physical properties of dental restorative materials: Effects of study protocols.

OBJECTIVE: The purpose of this study was to evaluate the influence of study protocols on the effects of bleaching on the surface roughness, substance loss, flexural strength (FS), flexural modulus (FM), Weibull parameters, and color of 7 restorative materials. MATERIALS AND METHODS: The test materials included 4 composite resins, 1 glass-ionomer cement, 1 dental ceramic, and 1 polyacid-modified composite. The specimens were randomly divided into 4 groups (n = 20) according to different study protocols: a bleaching group at 25°C (group 25B), a bleaching group at 37°C (group 37B), a control group at 25°C (group 25C), and a control group at 37°C (group 37C). The specimens in the bleaching group were treated with 40% hydrogen peroxide for 80 min at the respective environmental temperatures. The surface roughness, substance loss, FS, FM, and color of the specimens were measured before and after treatment. FS data were also subjected to Weibull analysis, which was used to estimate of the Weibull modulus (m) and the characteristic strength (σ0 ). RESULTS: Surface roughness increased and significant color changes were observed for all tested specimens after bleaching treatment, except for the ceramic. After bleaching at 37°C, the polyacid-modified composite showed significantly reduced FS, FM, m, and σ0 values in comparison to the control specimens stored at 37°C in whole saliva. Significant differences were also found between the 37B and 25B polyacid-modified composite groups in terms of surface roughness, FS, m, σ0 , and color changes. CONCLUSIONS: Varying effects of bleaching on the physical properties of dental restorative materials were observed, and the influences of the study protocols on bleaching effects were found to be material-dependent. CLINICAL SIGNIFICANCE: The influence of study protocols on the effects of bleaching on the surface roughness, flexural properties, and color of dental restorative materials are material-dependent and should be considered when evaluating the effects of bleaching on dental restorative materials.

[Cytocompatibility of Co-Cr ceramic alloys after recasting].

PURPOSE: To evaluate the cytocompatibility of Co-Cr ceramic alloys after recasting. METHODS: Cobalt-chromium (Co-Cr) ceramic alloys were recasted for 1-3 times. Samples of Co-Cr ceramic alloys were immersed in DMEM culture medium. The concentration of ions of leaching liquor was determined by ICP-MS total quantization method. L-929 cells were cultured with leaching liquor, flow cytometry was used to test cell cycle progression, Annexin-V-FITC/PI apoptosis staining kit was used to quantitatively detect cell death patterns. SPSS 13.0 software package was used for statistical analysis. RESULTS: After casting for 1-3 times, no significant increase in the concentration of ions of Co-Cr ceramic alloys was noted (P>0.05) except Ga (P<0.05) . No significant differences in L-929 cell cycle were found in Co-Cr ceramic alloys between the samples cast for 1 time and for 2~3 times (P>0.05). No significant difference in the rates of apoptosis and necrosis was found (P>0.05). CONCLUSIONS: The biocompatibility of Co-Cr ceramic alloys casted for 1-3 times is not changed.

Virtual Simulation Teaching Centre in Dental Education: a Report from Fujian Medical University, China.

This report gives a brief introduction to the Virtual Simulation Teaching Centre of Fujian Medical University School of Stomatology (VSFMUSS), China. As one of the best dental simulation laboratories in China, the VSFMUSS aims to train dental students and clinicians to be professionals who are able to provide optimal oral health care by giving them the best virtual patient care experience possible in a nonclinical setting. The features, achievements and future directions of the VSFMUSS are addressed. Moreover, the role of the VSFMUSS was evaluated and discussed based on the students' and faculties' perceptions, rate of employment after graduation, and so on.

Nanomedicine-based paclitaxel induced apoptotic signaling pathways in A562 leukemia cancer cells.

In the present study, we have synthesized an amphiphilic pH-sensitive structure of poly(ethylene glycol) methyl ether-b-(poly lactic acid-co-poly(b-amino esters)) (MPEG-b-(PLA-co-PAE)) to load paclitaxel to increase the therapeutic efficacy in leukemia. The micelles exhibit excellent drug-loading capacities for paclitaxel (PTX) and exhibited a typical pH-responsive drug release pattern. The release of PTX from the micelles was significantly accelerated by decreasing pH from 7.4 to 5.0 which just fitted the pathological process. The most important advantage of this design is that the polymeric micelles provide an effective approach for rapid transport of cargo into the cytosol, which significantly increases the antitumor efficacy of PTX against K562 cancer cells. Paclitaxel-loaded polymer micelles (PTX-M) showed significantly higher cytotoxic effect than that of free PTX. The PTX-M exhibited a superior apoptosis effect in cancer cells compared to that of free PTX at all time points. We have showed that the PTX-M activated upstream of apoptosis signaling and inhibited the anti-apoptotic factors. The PTX-M remarkably increased the upregulation of Bax, caspase-3, caspase-9, and PARP-1 expression and downregulated the Bcl-2 expression in K562 cancer cells. The results show that PTX-M induced cell apoptosis through intrinsic apoptotic signaling pathway. Importantly, PTX had a remarkably prolonged plasma circulation time after administration of PTX-M. Overall, this novel cancer specific, pH-responsive, and potentially in vivo stable unimolecular micelles may provide a very promising approach for targeted cancer therapy in the effective treatment of Leukemia.

[Cytotoxicity of 3 resin cements to human gingival fibroblasts].

PURPOSE: To study the cytotoxicity of 3 resin cements to human gingival fibroblasts (HGFs). METHODS: Three resin cements (Panavia F, RelyXTM Unicem and Multilink Speed) test samples were immersed and incubated in the culture medium for 48 h at 37degrees centigrade. Cultured HGFs were exposed to two concentrations (50% and 100%) of material elutes for 24 h, 72 h and 120 h. The proliferation rate was evaluated using CCK-8 assay. The data were statistically analyzed by one-way analysis of variance using SPSS 20.0 software package. RESULTS: Relative growth rate(RGR) of all experimental groups ranged from 10.67% to 100.02%, the cytotoxicity grade of all groups was 0 to 4. There was no significant difference in the RGR among 3 resin cements, but the experimental group of Panavia F (uncovered with antioxidant) showed significantly lower RGR than other experimental groups. CONCLUSIONS: Panavia F, RelyXTM Unicem and Multilink Speed exhibit no cytotoxicity to HGFs, Panavia F(uncovered with antioxidant) shows moderate cytotoxicity.

Effects of recasting on the biocompatibility of a Ni-Cr alloy.

OBJECTIVE: To evaluate the effects of recasting on the biocompatibility of a commercially available Ni-Cr alloy. METHODS: The alloy tested was cast and subsequently recast four more times. For each cast condition, 24 disk shaped specimens were fabricated (5 mm in diameter, 0.5 mm in thickness). All the recasting was performed without adding new alloy. After the first cast and following each recast, the surface composition and microstructure of the alloy were determined using an X-ray fluorescence spectrometer and optical microscope, respectively. The in vitro cytotoxicity and in vivo mucous irritation potential of the cast and recast Ni-Cr alloy were investigated. The results were statistically analysed at the significance level of 0.05. RESULTS: Recasting neither yielded to cytotoxicity or to changes in the surface composition of the Ni-Cr alloy tested. However, an increase in impurities and porosity of the surface structure was observed with recasting. Also, the segregation of the impurities to grain boundaries was evident after multiple castings. After the fourth recast, the alloys showed significantly greater mucosal irritation than the control. CONCLUSION: After fourth recast, the alloy of this type may contribute to mucosal inflammation. Furthermore, there is a need for diverse methods addressing different biological endpoints for the evaluation of dental alloys.

[Construction expression and biologic activity of recombinant human sCR1 eucaryotic cell].

AIM: To express human soluble complement receptor type 1(sCR1)protein using ferment cell secreting type carrier and study the extraorgan biologic activity of recombinant human sCR1 fusion protein. METHODS: Total human RNA was extracted from peripheral blood. The full length cDNA of human sCR1 gene was obtained by RT-PCR and them, cloned into Pichia pastoris eukaryotic expression vector pPIC9k to construct the recombinant plasmid pPIC9k-sCR1 containing human sCR1.After identified by DNA sequencing, the recombinant plasmid pPIC9k-sCR1 was transformed into Pichia pastoris SMD1168. The ferment cell line of the recombinant sCR1 which was chosen by G418 resistance was identified by PCR, After methanol induction, the expressed protein products were verified by SDS-PAGE and Western blot, purified by Ni(2+)-NTA agarose affinity chromatography, and its biologic activity was identified. RESULTS: The obtained Pichia pastoris secretion type yeast carrier pPIC9k-sCR1 was chosen by G418 and identified by PCR to get a highly copied and integral recombinant ferment cell line. The recombinant human sCR1 fusion protein was expressed by yeast cells containing pPIC9k-sCR1 induced by methanol. It was a protein band about M(r) 31 000 in gel, which could be identified by CD35 of anti-sCR1 protein monoclonal antibody with Western blotting technique. The highly purified sCR1 fusion protein and its biologic activity were detected obtained by Ni(2+)-NTA agarose affinity chromatography. CONCLUSION: The recombinant human sCR1 fusion protein can be highly expressed in the Pichia pastoris expression system, which resembles the human natural protein's antigenicity and biologic activity.