Assessment of knowledge, attitude, and practice on early childhood caries among dental undergraduates and residents in China.

BACKGROUND: Early childhood caries (ECC) causes severe, widespread oral health issues in children. Dental undergraduates and residents are expected to have a solid understanding of ECC for children's oral health promotion. This study aimed to evaluate the knowledge, attitude, and clinical practice on ECC among dental undergraduates and residents in China. METHODS: A 23-item electronic questionnaire was distributed to 598 dental undergraduates (4th- and 5th-year undergraduates) and residents (1st-, 2nd-, and 3rd-year residents) at the School of Stomatology, Wuhan University, China (in April-May 2023). SPSS Statistics was used to analyze the data using the Chi-square test at a significance level of 0.05. RESULTS: A total of 422 questionnaires were completed by participants (recovery rate: 70.6%) from various academic levels. Around 77.3% of participants had heard of ECC (mainly from textbooks), and only 27.5% considered themselves familiar with it. Residents (79.8%) had higher risk awareness of ECC on children's overall health than undergraduates (58.3%) (p < 0.05), but only 54.0% of participants correctly defined ECC. Most participants had a positive understanding of ECC's pathogenic factors and preventive measures, including feeding patterns (71.6%), fluoride application (93.4%), and teeth cleaning (93.1%). Furthermore, only 50.2% of participants encountered ECC cases in clinic. CONCLUSIONS: Despite having a suboptimal level of ECC-related knowledge and practice, dental undergraduates and residents in China demonstrated a more positive attitude towards its etiology-based prevention. Strengthening ECC education, guidance, and practice may enable them to gain a better understanding of ECC learning, which would benefit children's oral health.

Treatment outcomes of immature permanent necrotic evaginated teeth: A retrospective study comparing regenerative endodontic procedures with apexification.

BACKGROUND: Few studies have compared the outcomes of regenerative endodontic procedures (REPs) and calcium hydroxide apexification focusing on necrotic teeth with dens evaginatus. AIM: To qualitatively and quantitatively compare the treatment outcomes of REPs and calcium hydroxide apexification in teeth with dens evaginatus. DESIGN: Immature permanent necrotic evaginated teeth treated with REPs or calcium hydroxide apexification for a follow-up period of at least 12 months were included. Tooth success and survival rates were analyzed. Changes in radiographic root length, apical diameter, and radiographic root area (RRA) were quantified. Prognostic factors that might influence RRA were identified via multivariate linear regression analysis. RESULTS: A total of 112 teeth (50 REP cases and 62 apexification cases) with a median follow-up period of 26.5 months were included. Regenerative endodontic procedures and calcium hydroxide apexification exhibited similar satisfactory success and survival rates (p > .05). Additionally, 88 teeth were quantitatively analyzed. The REP group presented a significantly greater percentage increase in RRA and less decrease in apical diameter than the calcium hydroxide apexification group (p < .05). Teeth treated with REPs and with Stages 7 and 8 of root development showed a better gain in RRA (p < .05). CONCLUSION: While REP and calcium hydroxide apexification had similar success and survival rates, teeth with REPs showed an increase in RRA, indicating that REP is the preferred choice.

Small-Molecule-based Supramolecular Plastics Mediated by Liquid-Liquid Phase Separation.

Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non-recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid-liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non-covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young's modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self-heal with more absorbed water. Finally, responsiveness enabled the material to be highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco-friendly supramolecular plastics that are potential substitutes for conventional polymers.

Recent advances in antibacterial coatings for orthodontic appliances.

In the process of orthodontic treatment, the presence of orthodontic appliances makes it difficult to clean tooth surfaces. This can lead to an increased level of bacterial colonization, resulting in enamel demineralization and periodontal diseases. Considering the large surface area that orthodontic appliances usually have and that they can be in direct contact with bacteria throughout the treatment, modifications in the form of coatings on the surface of orthodontic appliances can be an effective and practical approach to reducing bacterial proliferation and preventing relevant adverse effects. In this mini-review, we discuss various antibacterial coatings which have been applied onto orthodontic appliances in recent 5 years, as well as their antibacterial mechanisms and methods for the preparation of these coatings. From this mini-review, both orthodontists and researchers can get the latest findings in the field of antibacterial coatings onto orthodontic appliances, which is helpful for the decision-making in clinical practice and research activities.

Immunocolocalization of Interferon Regulatory Factory 5 with Tumor Necrosis Factor Receptor-associated Factor 6 and AKT2 in Human Apical Periodontitis.

INTRODUCTION: Interferon regulatory factor 5 (IRF5) is critical for the regulation of immune and inflammatory responses in health and diseases. However, the presence of IRF5 in human apical periodontitis remains unknown. This study aimed to explore the expression and colocalization of IRF5 with tumor necrosis factor receptor-associated factor 6 (TRAF6) and AKT2 in human apical periodontitis. METHODS: A total of 39 human periapical tissues, including healthy gingival tissues (n = 12), periapical granulomas (PGs, n = 13), and radicular cysts (RCs, n = 14), were used in this study. The inflammatory infiltrates of lesions were evaluated by hematoxylin-eosin staining. The expression of IRF5 was detected by immunohistochemistry. Double immunofluorescence assessment was performed to colocalize IRF5 with CD68, TRAF6, and AKT2, respectively. Data were analyzed using the Kruskal-Wallis test. RESULTS: Immunohistochemistry revealed significantly higher expressions of IRF5 in PGs and RCs than the healthy control group. IRF5-CD68 double-positive cells were more predominant in RCs and PGs than the healthy control group. Significant differences of the IRF5-TRAF6 and IRF5-AKT2 double-positive cells were detected in periapical lesions compared with the healthy control tissues. CONCLUSIONS: IRF5 was highly expressed in macrophages of human periapical tissues and was colocalized with TRAF6 or AKT2 in human periapical tissues. These findings may provide new clues for understanding the pathogenesis of periapical diseases.

Impact of COVID-19 on advanced dental education: Perspectives of dental residents in Wuhan.

PURPOSE: This study investigated the impact of coronavirus disease 2019 (COVID-19) from the perspectives of dental residents in Wuhan, the former COVID-19 epicenter of China. METHODS: A survey form was sent to 424 residents in the School of Stomatology, Wuhan University (WHUSS) in September 2020. The form included 23 questions on demographics, study situation of residents during the COVID-19 outbreak, effect of COVID-19 on graduates, and status of residents who returned to clinic training. RESULTS: A total of 361 (85%) survey forms were collected. Over 70% of respondents felt anxious during Wuhan lockdown. Most respondents continued studying (94%) mainly through free online resources (79%). The majority reported improvement in didactic knowledge (80%), but the respondents' perceptions of their clinical skills, especially those in Wuhan, did not change (41%) or worsened (40%) (p < 0.05). Most graduates (88%) reported having found jobs or continued study. Among the 209 responders who returned to clinical training, 52% felt no concern about COVID-19 infection, 89% thought they were equipped with adequate personal protective equipment (PPE), and 57% indicated that they received sufficient knowledge for preventing COVID-19 in clinic. Most respondents agreed that the way to gain the knowledge for preventing COVID-19 in clinic was training at dental school (93%). CONCLUSION: Although online study has been appreciated by residents, concern about clinical skill learning in the COVID-19 hardest-hit area has arisen. Most graduates felt that the impact of COVID-19 on their immediate postgraduation career was limited. Teaching about infection control in dental schools seemed effective to develop a positive attitude for residents after they returned to clinical training.

Characteristics of Endodontic Emergencies during Coronavirus Disease 2019 Outbreak in Wuhan.

INTRODUCTION: In late 2019, an outbreak of a new coronavirus named severe acute respiratory syndrome coronavirus 2 was detected in Wuhan, China. A great percentage of patients with this disease developed symptoms of dry cough, malaise, and a high fever. During this time, several patients requiring assessment and treatment of endodontic emergencies were directed to the School and Hospital of Stomatology at Wuhan University, Wuhan, China. We examined the characteristics of these patients. METHODS: A total of 96 patients with a mean age of 42.24 ± 18.32 years visited the general and emergency department of the School and Hospital of Stomatology at Wuhan University because of endodontic emergencies during the peak period of February 22 to March 2, 2020. Patient information was collected and organized by date of visit, sex, age, and systemic disease history. Body temperature was measured and acquired for each patient, a coronavirus disease 2019 (COVID-19) epidemiologic investigation questionnaire was given to each patient, an endodontic diagnosis was determined for the offending tooth, and a verbal numerical rating scale (VNRS) was used to record pain levels. RESULTS: Of the total patient visits during this period, 50.26% of visits were for endodontic treatment. No patients had a fever (>37.2°C). One patient with a confirmed COVID-19 history was admitted after recovery. Three admitted patients had been exposed to confirmed or suspected COVID-19 patients. Twelve admitted patients (12.5%) with a mean age of 62.42 ± 13.77 years had a history of systemic diseases. The most common age group for endodontic emergencies was 45-64 years (30.21%), and patients of this group showed a significantly higher mean VNRS score compared with that of the 6- to 19-year age group and the 20- to 34-year age group (P < .05). The majority of endodontic emergency diagnoses were diseases of symptomatic irreversible pulpitis (53.10%). Patients who were diagnosed with symptomatic irreversible pulpitis, symptomatic apical periodontitis, and acute apical abscess showed a significantly higher mean VNRS score than that of other groups (P < .05). CONCLUSIONS: Endodontic emergencies, with symptomatic irreversible pulpitis being the most common, consist of a much higher proportion of dental emergencies in a COVID-19 high-risk area than normally. Vital pulp therapy can advantageously reduce treatment time, resulting in a reduced risk of infection for vital pulp cases. Rubber dams, personal protective equipment, and patient screening are of great importance during the COVID-19 outbreak in protecting clinicians.

Resumption of Endodontic Practices in COVID-19 Hardest-Hit Area of China: A Web-based Survey.

INTRODUCTION: The purpose of this study was to investigate the resumption of endodontic practices in Hubei Province, China 1 month after the end of the lockdown. METHODS: A Web-based survey was sent to 1069 active endodontic specialists and general dentists who provided endodontic care in Hubei Province from May 7 to May 9, 2020. The survey consisted of 18 questions on demographics, the current situation of endodontic practice for the participants, and concerns regarding contracting or spreading the virus in newly opened endodontic practices. RESULTS: A total of 322 participants completed the survey. Most respondents (62%) were from Wuhan. Almost 83% of the respondents have resumed their endodontic practice partially or fully. Most respondents in practice (99%) would take measures to screen patients before treatment including paid screening measures. More than 93% of the respondents reported having taken special measures for routine endodontic treatment at this stage, with the most common measure taken being wearing an N95 mask. The rubber dam was recognized as efficient in preventing infection by most respondents. Many respondents were concerned about contracting coronavirus disease 2019 (COVID-19) as a result of routine endodontic practice at this stage, and respondents with more than 11 years of endodontic experience were significantly less concerned about infection compared with those with fewer than 5 years of experience (P < .05). CONCLUSIONS: There is a fear of contracting/spreading COVID-19 among endodontic clinicians, the fear is negatively associated with years of practice, and most clinicians believe that rubber dam isolation can protect them and their patients from COVID-19.

Overexpression of Cyclophilin A in Human Periapical Lesions.

INTRODUCTION: Cyclophilin A (CypA) is a cytosolic protein involved in multiple biological functions, such as inflammation, tissue remodeling, tumorigenesis, and vascular diseases. Human periapical lesions are induced by bacterial infections. However, the expression of CypA in human periapical lesions remains unclear. This study aimed to investigate the presence of CypA in human periapical lesions and the possible association of CypA with angiogenesis, inflammatory cell infiltration, and alveolar bone degradation during inflammatory development. METHODS: Fifty-eight human periapical tissues, including periapical granulomas (PGs, n = 28), radicular cysts (RCs, n = 24), and healthy control tissues (control group, n = 6) were collected. Samples were fixed and analyzed. CypA expression was detected and analyzed by immunohistochemistry in different cross sections. Double immunofluorescence was assessed to colocalize CypA with CD34, CypA with matrix metalloproteinase 9 (MMP-9), and CD147 with MMP-9. RESULTS: CypA was significantly overexpressed in the RC and PG groups compared with the control group (P < .05), but the difference between the RC and PG groups was insignificant (P > .05). CypA-positive cells were mainly lymphocytes, endothelial cells, epithelial cells, and plasma cells. The double-labeling analysis of CypA with CD34 suggested that CypA expression was associated with angiogenesis during periapical lesions. MMP-9 colocalized with both CypA and CD147 indicated that CypA may colocalize with CD147 and may be associated with the degradation of soft and hard tissues around human periapical lesions. CONCLUSIONS: CypA may be involved in the development of periapical lesions with an increase in inflammatory cell infiltration, angiogenesis acceleration, and alveolar bone degradation.

Positive Correlation between Activated CypA/CD147 Signaling and MMP-9 Expression in Mice Inflammatory Periapical Lesion.

AIM: Cyclophilin A (CypA)/CD147 signaling plays critical roles in the regulation of inflammation and bone metabolism. This study aimed to investigate the participation of CypA/CD147 in mice periapical lesions progression and its relationship with bone resorption. METHODOLOGY: Periapical lesions were induced by pulp exposure in the first lower molars of 40 C57BL/6J mice. The mice were sacrificed on days 0, 7, 14, 21, 28, 35, 42, and 49. Mandibles were harvested for X-ray imaging, microcomputed tomography scanning, histologic observation, immunohistochemistry, enzyme histochemistry, and double immunofluorescence analysis. Western blot was employed to further detect the related molecular signaling pathways in LPS-stimulated RAW 264.7 cells treated with CypA inhibitor. RESULTS: The volume and area of the periapical lesions increased from day 0 to day 35 and remained comparably stable until day 49. Immunohistochemistry demonstrated that the CypA expression levels also increased from day 0 to day 35 and decreased until day 49, similar to CD147 expression (R 2 = 0.4423, P < 0.05), osteoclast number (R 2 = 0.5101, P < 0.01), and the expression of osteoclastogenesis-related matrix metalloproteinase 9 (MMP-9) (R 2 = 0.4715, P < 0.05). Serial sections further confirmed the colocalization of CypA and CD147 on osteoclasts with immunohistochemistry. And the distribution of CypA-positive or CD147-positive cells was positively correlated with the dynamics of MMP-9-positive cells by using immunofluorescence analysis. Furthermore, CD147 and MMP-9 expression in RAW 264.7 cells were both downregulated with CypA inhibitor treatment (P < 0.05). CONCLUSIONS: The present study reveals the positive correlation of CypA/CD147 signaling and osteoclast-related MMP-9 expression in mice inflammatory periapical lesions progression. Therefore, intervention of CypA/CD147 signaling could probably provide a potential therapeutic target for attenuating inflammatory bone resorption.

The Expression of Interferon Regulatory Factor 8 in Human Periapical Lesions.

INTRODUCTION: Interferon regulatory factor 8 (IRF8) is a critical transcription factor in innate immune responses that regulates the development and function of myeloid cells. Human periapical lesions are caused by endodontic microbial infections. However, the presence of IRF8 in human periapical lesions remains elusive. This study aims to explore the expression of IRF8 in human periapical lesions and the possible association of IRF8 with macrophages, nuclear factor kappa B (NF-κB) signaling, and the autophagy process. METHODS: Thirty-nine human periapical tissues, including healthy control tissues (n = 15), radicular cysts (RCs, n = 11), and periapical granulomas (PG, n = 13), were examined. Tissues were fixed in paraformaldehyde and analyzed. The inflammatory infiltrates of lesions were evaluated by hematoxylin-eosin, and the expression of IRF8 was analyzed by immunohistochemistry. Double immunofluorescence assessment was performed to colocalize IRF8 with CD68, NF-κB p65, and LC3B. RESULTS: The expression of IRF8 was significantly higher in RCs and PGs than in the healthy control group, but no significant difference was found between RCs and PGs. There were significantly more IRF8-CD68 double-positive cells in RCs and PGs than in the healthy control group, but no significant difference was observed between RCs and PGs. Double-labeling analysis of IRF8 with NF-κB and LC3B indicated that IRF8 expression is associated with NF-κB signaling and the autophagy process during periapical lesions. CONCLUSIONS: IRF8 could be observed and might possibly be involved in macrophages in the development of periapical lesions.

From the Cover: Activation of NF-κB-Autophagy Axis by 2-Hydroxyethyl Methacrylate Commits Dental Mesenchymal Cells to Apoptosis.

2-hydroxyethyl methacrylate (HEMA) is the major resin monomer that is released from incomplete polymerized dental restorative and adhesive biomaterials during dental therapy. Autophagy and apoptosis are biologically connected and the relationship between autophagy and apoptosis is complex under various circumstances. This study aimed to determine whether autophagy is activated by HEMA and further explore the function of autophagy during the HEMA-induced apoptosis of dental mesenchymal cells (DMCs). We exposed DMCs to different concentrations of HEMA. Cell viability showed a time- and concentration-dependent decrease when exposed to HEMA. We showed that HEMA exposure increased autophagic vacuoles and the expression of autophagic biomarkers (Beclin1, Atg5 and LC3). Pre-incubated with autophagy inhibitors (3-methyladenine and chloroquine) significantly prevented HEMA-induced apoptosis. Interestingly, HEMA initiated nuclear factor-κB (NF-κB) expression and nuclear translocation, whereas the NF-κB inhibitor (Bay 11-7082) markedly suppressed HEMA-induced autophagic activation and apoptosis. As is consistent with the in vitro results, HEMA treatment resulted in dental pulp tissue toxicity and activation of typical autophagic vacuoles in the tooth slice organ culture model ex vivo. In summary, we demonstrated that NF-κB signaling functioned upstream of HEMA-inducecd autophagy in DMCs and that the activation of NF-κB-autophagy axis was responsible for HEMA-induced apoptosis. Our findings provide novel insights into the mechanisms of resin monomer-mediated dental pulp damage during dental treatment, highlighting the activation of NF-κB-autophagy axis as an important mechanism of HEMA-mediated apoptosis.

Autophagy in resin monomer-initiated toxicity of dental mesenchymal cells: a novel therapeutic target of N-acetyl cysteine.

Dental restorative biomaterials are commonly used to restore the teeth impaired by caries, erosion, or fracture. Resin monomers released from polymerized restorative composite materials could disturb cell viability and cause toxicity of oral eukaryotic cells, which remains a medical challenge. However, the intracellular processes or underlying mechanisms of resin monomer-mediated toxicity and the potential preventive/therapeutic strategy are still far from clear. The present study aimed to determine the role of autophagy in resin monomer triethylene glycol dimethacrylate (TEGDMA)-induced cytotoxicity and explore autophagy as a potential therapeutic target of anti-oxidant N-acetyl cysteine (NAC) in vitro and ex vivo. The results showed that TEGDMA exposure resulted in several specific features of autophagy in human dental mesenchymal cells (DMCs), including the formation of acidic vesicular organelles, appearance of autophagic vacuoles, and LC3-II accumulation. By pharmacological and genetic approaches, the inhibition of autophagy significantly prevented TEGDMA-induced apoptosis in DMCs. Moreover, the autophagy activated by TEGDMA occurred via the AMPK/mTOR pathway, which could be abrogated by NAC pretreatment. More importantly, the tooth slice organ culture model provided further evidence of autophagy involvement in TEGDMA-triggered dental mesenchymal tissue toxicity and as a therapeutic target of NAC ex vivo. Our findings provide novel insights into the mechanisms of resin monomer-mediated toxicity and highlight autophagy as a promising therapeutic target of NAC for improving dental restorative biomaterials that enable dental tissue protection.

Determination of urinary aromatic amines in smokers and nonsmokers using a MIPs-SPE coupled with LC-MS/MS method.

Urinary aromatic amines (AAs) could be used as biomarkers for human exposure to AAs in cigarette smoke. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of urinary AAs (i.e. 1-naphthylamine (1-NA), 2-naphthylamine (2-NA), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP)) in smokers and nonsmokers. A molecularly imprinted polymers (MIPs) solid phase extraction (SPE) cartridge was applied to purify urine samples and no derivatization reaction was involved. Each analytes used respective stable isotope internal standards, which could well compensate matrix effect. Lower limit of detections (LODs) for four AAs were obtained and in the range of 1.5-5ngL(-1). Recovery ranged from 87.7±4.5% to 111.3±6.4% and precision were less than 9.9%. The method was applied to analyze urine samples of 40 smokers and 10 nonsmokers. The 24h urinary excretion amounts of total AAs were higher for smokers compared with nonsmokers. What's more, 1-NA, 3-ABP and 4-ABP excretion amounts showed significant differences (p<0.05) between smokers and nonsmokers.