Yan Zhou

Background: Scholastic achievement during college is important for the professional careers of dental students. Previous studies have reported that learning engagement may be the mediator between achievement goals and scholastic achievement. This study aims to examine whether learning engagement mediated the relationship between achievement goals and scholastic achievement. Methods: This study included dental students from two universities in China. This was a quantitative, cross-sectional study. The students were invited to complete an online questionnaire. A total of 679 students participated in the study. The questionnaire consisted of four main parts: demographic characteristics, an achievement goals scale, a learning engagement scale, and a scholastic achievement scale. We conducted a one-way analysis of variance (ANOVA) and correlation analysis using Statistical Package for the Social Sciences (SPSS) 26.0 software. Mplus 8.3 was used to examine the potential mediating effect of learning engagement in a structural equation model. Results: Findings demonstrated that the associations between achievement goals and the scholastic achievement of dental students were as follows: performance-approach goals ( β = 0.15, p < 0.05), mastery-approach goals ( β = 0.73, p < 0.001), performance-avoidance goals ( β = −0.03, p > 0.05), and mastery-avoidance goals ( β = −0.10, p < 0.05). Learning engagement played a mediating role in the relationship between the three achievement goals (mastery-approach, performance-avoidance, and mastery-avoidance goals) and scholastic achievement. Learning engagement did not mediate the relationship between performance-approach goals and scholastic achievement. Conclusion: Learning engagement mediated the relationship between achievement goals and scholastic achievement. These findings suggest that dental educators should prioritize cultivating achievement goals among students and enhancing learning engagement to improve professional outcomes.

Conventional hydrogen peroxide (HP) tooth whitening treatments frequently induce structural deterioration of enamel, necessitating the development of biocompatible and highly efficient alternatives. This in vitro study investigated the application of a novel functional biomaterial, the Type I aggregation-induced emission (AIE) photosensitizer CPTQ, for peroxide-free photodynamic tooth whitening. Under white-light irradiation (25 mW/cm²), CPTQ (12.5 μM) demonstrated rapid degradation of representative chromogenic molecules (crystal violet, malachite green, and rhodamine B). Extracted human teeth stained with both model pigments and complex beverage mixtures (coffee, tea, and fruit juices) were allocated into four treatment groups: negative control (NC), CPTQ, 7.5% HP, and 30% HP (n = 6 per group). Colorimetric parameters (ΔE₀₀, Δa*, Δb*, and ΔL*) and enamel-related endpoints—including surface morphology, roughness, mineral composition (Ca/P), and microhardness—were evaluated over 6 h and analyzed using one-way ANOVA. For pigment-stained teeth, the photodynamic whitening efficiency of CPTQ was comparable to that of 30% HP (ΔE₀₀, p > 0.05) during the 6 h treatment period. At 1.5 h, the ΔE₀₀ value in the CPTQ group (23.35 ± 2.32) was significantly greater than those in the NC group (15.70 ± 1.78, p < 0.05) and the 7.5% HP group (15.02 ± 1.63, p < 0.05). For beverage-stained teeth, the whitening efficiency (ΔE₀₀) of CPTQ was significantly greater than that of the control group at 1.5 h (6.22 ± 2.09 vs. 1.82 ± 0.56, p < 0.01) and was significantly greater than that of 7.5% HP at 4.5 h (10.94 ± 2.82 vs. 7.56 ± 1.78, p < 0.05). Crucially, unlike the change observed after 30% HP treatments, CPTQ treatment resulted in no statistically significant differences from NC in preserved enamel surface integrity, including morphology assessed by SEM, surface roughness (R_a and S_a, both p > 0.05), mineral composition (Ca and P, both p > 0.05), and microhardness (ΔH_V, p > 0.05). Mechanistic investigations using reactive oxygen species (ROS) scavengers (TBA and DABCO) suggested that hydroxyl radicals generated via the Type I photodynamic pathway are the primary drivers of pigment degradation, reducing ΔE₀₀ from 12.56 to 1.09 upon •OH inhibition. CPTQ achieved measurable in vitro whitening through a predominantly Type I ROS-mediated mechanism while causing limited changes in the evaluated enamel surface endpoints.

Service learning integrates community service with academic instruction, fostering reflective practice and enhancing professional competencies. In dental e

Streptococcus mutans (S. mutans) is the primary pathogen of dental caries and one of the pioneer colonizers of dental plaque biofilms. The normoxic stress experienced by S. mutans during initial adhesion is detrimental to biofilm formation. Membrane vesicles (MVs) can modulate the stress adaptability and biofilm formation of parental bacteria. However, it remains unclear whether normoxic stress influences the secretion, composition and function of MVs. We conducted characterization, omics analysis, and functional validation of MVs secreted by S. mutans under normoxic and hypoxic conditions. Furthermore, we performed a comparative analysis of protein expression profiles between MVs and their parental bacteria under normoxic stress. Compared with those of hypoxic MVs, the secretion of normoxic MVs is increased approximately 100-fold, and significantly enrich the adhesion proteins GtfC and SpaP. Normoxic MVs promote the initial adhesion and early biofilm formation of S. mutans through enhancing glucan synthesis, self-aggregation and the surface adhesion force. On the contrary, the magnitude of expression changes of GtfC and SpaP at the transcriptional and cellular levels under normoxic stress are modest. Normoxic stress enhances the secretion of adhesion-promoting MVs by S. mutans. The cargo composition of S. mutans MVs may dynamically modulate in response to environmental stresses to facilitate their colonization.

Dental caries, primarily caused by Streptococcus mutans (S. mutans) biofilms, remains a global health concern. Antimicrobial photodynamic therapy (aPDT) has shown promise in controlling cariogenic bacteria by generating reactive oxygen species (ROS), but the aggregation-caused quenching (ACQ) effect of traditional photosensitizers limits its efficacy. In this study, we developed a novel aggregation-induced emission (AIE) photosensitizer, CPTQ, with an enhanced photodynamic antibacterial efficacy and intrinsic antibacterial properties. CPTQ exhibited superior ROS generation, effective bacterial labeling, and strong membrane anchoring, leading to a significant disruption of bacterial membrane homeostasis and interference with bacterial metabolism. Moreover, CPTQ induced ferroptosis-like bacterial death by triggering lipid peroxidation and oxidative stress, providing a synergistic antibacterial strategy. In vitro results demonstrated that CPTQ effectively inhibited S. mutans growth, while in vivo studies in a rat dental caries model showed significant reductions in cariogenic bacterial load and caries progression. Given its excellent biocompatibility and dual antibacterial mechanisms, CPTQ offers a promising and innovative strategy for the prevention and treatment of dental caries.

Dental caries arise from intricate interactions among oral microorganisms, impacting ecological stability and disease progression. This study delves into the bacterial-fungal dynamics in severe early childhood caries (S-ECC) among 61 children aged 3-4 years with complete deciduous dentition. We evaluated environmental factors such as saliva pH, buffering capacity, and trace elements (iron, fluoride). We examined the performance of 16S rRNA V1-V9 regions gene and internal transcribed spacer (ITS) primers for bacteria and fungi from plaque and saliva to characterize community compositions and diversity. Saliva pH and buffering capacity were also measured. Findings revealed significant shifts in bacterial diversity in S-ECC saliva samples, marked by decreased diversity and elevated abundance of cariogenic species, particularly Streptococcus mutans . Candida albicans was notably more prevalent in the S-ECC group, implicating its potential role in pathogenesis. Iron and fluoride concentrations showed no significant correlation with microbial community structure. Network analyses uncovered complex intra- and inter-kingdom interactions, underscoring cooperative and competitive dynamics. S-ECC children exhibited higher abundances of bacteria ( Streptococcus mutans , Granulicatella , Actinomyces ) and fungi ( Candida albicans ), with specific microbial taxa associated with reduced saliva pH. Importance: This study illuminates the intricate relationship between bacteria and fungi within the oral microbial community of children, specifically highlighting differences between those with severe early childhood caries (S-ECC) and those without caries. Through an extensive analysis of the microbial composition in both saliva and dental plaque, we identified a significant increase in the abundance of specific bacterial taxa (e.g., S. mutans, Granulicatella, Actinomyces) and fungal species (e.g., C. albicans) in the oral cavities of children with S-ECC. This finding underscores the potential role of these microorganisms in the development of caries. Contrary to previous studies that emphasize the importance of iron and fluoride in oral health, our research found no significant correlation between the concentrations of these elements and the composition of oral microbial communities. This result challenges conventional understanding and opens new avenues for future research. Additionally, we discovered an association between certain microbial species and reduced salivary pH, offering fresh insights into the relationship between the oral microenvironment and caries development. The implications of our findings are substantial for the development of prevention and intervention strategies targeting childhood caries. They also underscore the critical need for a deeper exploration of oral microbial interactions and their environmental influences.

Dental caries is a widespread bacterial infectious disease that imposes a significant public health burden globally. The primary culprits in caries development are cariogenic bacteria, notably Streptococcus mutans (S. mutans), due to their robust biofilm-forming capabilities. To address this issue, a series of cationic pyridinium-substituted photosensitizers with aggregation-induced emission have been designed. All of these aggregation-induced emission luminogens (AIEgens) exhibit outstanding microbial visualization and photodynamic killing of S. mutans, thanks to their luminous fluorescence and efficient singlet oxygen generation ability. Notably, one of the membrane-anchored AIEgens (TDTPY) can inactivate planktic S. mutans and its biofilm without causing significant cytotoxicity. Importantly, application of TDTPY-mediated photodynamic treatment on in vivo rodent models has yielded commendable imaging results and effectively slowed down caries progression with assured biosafety. Unlike traditional single-mode anticaries materials, AIEgens integrate the dual functions of detecting and removing S. mutans and are expected to build a new caries management diagnosis and treatment platform. To the best of our knowledge, this is also the first report on the use of AIEgens for anticaries studies both in vitro and in vivo.

Objectives To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial. Materials and methods A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05. Results After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026). Conclusion Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years. Clinical relevance To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing. Trial registration Registered at http://www.chictr.org.cn; Feb 15th, 2020; No. ChiCTR2000029862.

Parents may influence children’s intake of sweets and sugar-sweetened beverages through their feeding styles. This study prospectively assessed the association between parental feeding styles and caries risk in preschool children. In November and December 2021, we recruited 1181 preschool children aged 3–4 years in Guangzhou, China, and then conducted a follow-up visit after 15 months. The children were examined for dental caries, and their parents answered the Chinese version of the Parental Feeding Style Questionnaire. Data were analyzed using logistic regression analysis. At baseline, ‘control over eating’ was found to be negatively associated with early childhood caries (OR = 0.60, 95%CI = 0.44, 0.83). After 15 months, no significant association between baseline parental feeding styles and the risk of a new carious lesion was found. When considering changes in parental feeding styles between the baseline and the follow-up visit, we found children with increasing scores on ‘instrumental feeding’ during the 15 months had a higher risk of a new carious lesion (OR = 1.91, 95%CI = 1.18, 3.12). However, children with always-intermediate scores (OR = 0.51, 95%CI = 0.30, 0.86), always-high scores (OR = 0.42, 95%CI = 0.23, 0.77), or increasing scores (OR = 0.50, 95%CI = 0.31, 0.83) on ‘control over eating’ had a lower risk of a new carious lesion. Our study highlighted the influence of parental feeding styles on caries risk in preschool children.