Evaluation on a teaching software for removable partial denture framework design.

BACKGROUND: Removable partial dentures (RPDs) are widely used as a dental prosthesis and have a wide application scope. OBJECTIVE: To explore the effect of using design software in the preclinical teaching of removable partial dentures (RPDs). METHODS: Unreal Engine software was used to build the RPD framework design teaching and training software. All 131 undergraduate students majoring in stomatology in the class of 2018, Kunming Medical University, were randomly divided into three groups and received either traditional experiment teaching, flipped classroom teaching, or software teaching for RPD design. The application effect of the software in the preclinical teaching of RPD design was evaluated by analyzing the examination results and through the use of a questionnaire survey. RESULTS: The differences in the theoretical examination scores among the traditional teaching group, the flipped classroom group, and the software teaching group were not statistically significant (P> 0.05), while the average design scores of upper Kennedy Class I and lower Kennedy Class II subclass II in the software teaching group were significantly higher than those in the traditional teaching group (P< 0.05). Overall, 75% of the students in the software teaching group reported that this teaching method could improve their learning initiative, a higher percentage than in the traditional teaching group (55.8%, P< 0.05). Meanwhile, 90.9% of the students in the software teaching group reported that the software could make RPD-related theoretical knowledge more visual and intuitive, and 93.2% of these students felt it was helpful for understanding the RPD three-dimensional (3D) spatial structure. These percentages were higher than those in the traditional teaching and flipped classroom groups (P< 0.05). CONCLUSION: In the preclinical teaching of RPD design, software training helped the students better understand the 3D structure of RPDs and establish clear design ideas, and it may also be valuable for in-depth research and promotion purposes.

Emerging Bioactive Agent Delivery-Based Regenerative Therapies for Lower Genitourinary Tissues.

Injury to lower genitourinary (GU) tissues, which may result in either infertility and/or organ dysfunctions, threatens the overall health of humans. Bioactive agent-based regenerative therapy is a promising therapeutic method. However, strategies for spatiotemporal delivery of bioactive agents with optimal stability, activity, and tunable delivery for effective sustained disease management are still in need and present challenges. In this review, we present the advancements of the pivotal components in delivery systems, including biomedical innovations, system fabrication methods, and loading strategies, which may improve the performance of delivery systems for better regenerative effects. We also review the most recent developments in the application of these technologies, and the potential for delivery-based regenerative therapies to treat lower GU injuries. Recent progress suggests that the use of advanced strategies have not only made it possible to develop better and more diverse functionalities, but also more precise, and smarter bioactive agent delivery systems for regenerative therapy. Their application in lower GU injury treatment has achieved certain effects in both patients with lower genitourinary injuries and/or in model animals. The continuous evolution of biomaterials and therapeutic agents, advances in three-dimensional printing, as well as emerging techniques all show a promising future for the treatment of lower GU-related disorders and dysfunctions.

The effect of age and abstinence time on semen quality: a retrospective study.

This study analyzed the effects of male age and abstinence time on semen quality and explored the best abstinence time for Chinese males among different age groups. Semen parameters, including sperm kinetics, morphology, and DNA fragmentation index (DFI), were reviewed from 2952 men. Samples were divided into six age groups (≤25 years, 26-30 years, 31-35 years, 36-40 years, 41-45 years, and >45 years) and were divided into six groups according to different abstinence time (2 days, 3 days, 4 days, 5 days, 6 days, and 7 days). The differences in semen quality between the groups were compared, and the effect of age and abstinence time on semen quality was analyzed. Significant differences were observed in semen volume, progressive motility (PR), and DFI among the age groups (all P < 0.05), and no significant differences were observed in sperm morphological parameters (all P > 0.05). There were significant differences in semen volume, PR, and DFI among different abstinence time groups (all P < 0.05) and no significant differences in sperm morphological parameters (all P > 0.05). Pearson analysis showed that male age and abstinence time were both significantly correlated with sperm kinetics and DFI (both P < 0.05), while no significant correlation was found with sperm morphological parameters (all P > 0.05). The box plots and histograms of men's age, abstinence time, and semen quality show that most semen quality parameters differ significantly between the 2 days and 7 days abstinence groups and other groups at different ages. Except for the sperm morphology parameters, sperm kinetic parameters and sperm DFI are linearly related to male age and abstinence time.

Comparison of the Anterior Tooth and Lip Esthetic Characteristics of Hani and Han Youth in China When Speaking.

OBJECTIVE: This study aims to measure and analyze the lip and tooth dynamic esthetic characteristics at rest and during speech in order to provide a reference for its esthetic design and restoration among the Hani and Han populations in Yunnan Province, China. METHODS: Subjects of Hani and Han ethnicity in Yunnan were selected using multistage stratified sampling and inclusive criteria. The lip and tooth dynamic esthetic characteristics of the subjects at rest and during the pinyin pronunciation of "me", "yi", "fu", and "si" were recorded using digital photography and analyzed with computer software. RESULTS: No statistical difference was detected between the Hani and Han groups in the upper central-incisor display, when pronouncing the pinyin "yi". Furthermore, there were no statistical differences in lip dynamic esthetic parameters between the Hani and Han groups, except for the distance between the upper and lower lips when pronouncing "si". There were three kinds of correlation between the upper central-incisor edge and lower lip: separation, contact, and overlap. CONCLUSION: The display of upper central incisors and the mouth width of Hani people are larger than those of Han people when at rest. When the pinyin "si" is pronounced, the display of upper central incisors and the upper-lower lip distance of Hani people is less than that of Han people due to labial muscle movement.

[Effect of porcelain thickness and substrate on optical properties of porcelain veneers for tetracycline stained teeth].

PURPOSE: To analyze the effect of porcelain layer thicknesses and substrates on color properties and translucency of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth. METHODS: Porcelain specimens with different core and veneer thickness (veneer/core thickness: 0.25 mm/0.25 mm, 0.50 mm/0.25 mm, 0.25 mm/0.50 mm, 0.50 mm/0.50 mm, and 0.25 mm/0.75 mm) were fabricated by heat-press layering technique. CIE L*a*b* parameters were measured under simulated tetracycline backgrounds and black and white backgrounds by a spectrophotometer, color differences ΔE001 between specimens on simulated tetracycline backgrounds and backgrounds themselves and ΔE002 between specimens on simulated tetracycline backgrounds and white background were calculated. The translucent parameter(TP) was also calculated. The data were submitted to statistical analysis with SPSS 17.0 software package. RESULTS: ΔE001 increased with increase of thickness of the core and veneer layer, but there was no significant difference between 0.25 mm and 0.50 mm core thickness groups with 0.50 mm veneer in thickness (P>0.01). Except for light grey, ΔE002 decreased over other substrates with increase of thickness of the core and veneer layer, but there was no significant difference between 0.50 mm and 0.75 mm core thickness groups with 0.25 mm veneer in thickness (P>0.01). Both ΔE001 and ΔE002 were significantly different over different substrates（P<0.01）. TP decreased as the increase of core and veneer thickness and TP was significantly different with different core and veneer thickness（P<0.01）. CONCLUSIONS: Both the core/veneer thickness and the substrate have significant influence on color matching and masking ability of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth. As for IPS e.max LT porcelain veneers, the color property was the best when yellowish tetracycline stained teeth were restored, while the light grey was worst. The thickness of core and veneer has significant influence on the translucency of porcelain laminate veneers.

[Clinical study of complete dentures supported by two endosteal magnetic-attachment implants].

OBJECTIVE: To evaluate treatment outcomes of mandibular complete denture supported by two endosteal magnetic-attachment implants in edentulous patients with severe mandibular alveolar ridge absorption. METHODS: Eight edentulous patients with severe mandibular alveolar ridge absorption were chosen. Each of them was treated with a complete denture supported by two CDIC implants. The implants were inserted at the areas of two the first premolars respectively. After five months, two magnets were adhered to the inside of the complete dentures. Retention, masticatory efficiency and maximal masticatory force were measured before and after the magnets were adhered and six months later. RESULTS: Statistical analysis revealed that retention, masticatory efficiency and maximal masticatory force were all increased after the magnets were adhered (P < 0.01) and six months later (P < 0.01). CONCLUSION: Retention, maximal masticatory force and masticatory efficiency were significantly increased after the endosteal magnetic attachment implants were applied. It is concluded that mandibular complete denture supported by two endosteal magnetic attachment implants is an effective method for severe alveolar ridge absorption cases.