Alterations in salivary biomarkers in relation to periodontal health and obesity among Hong Kong adolescents.

OBJECTIVES: To explore the association among salivary biomarkers, periodontal inflammation, and adiposity status in adolescents. METHODS: This study included 180 Hong Kong adolescents aged 12-15 years. Anthropometric measurements including central obesity surrogate, waist-to-height ratio (WHtR), and dental examinations were conducted. The participants were classified into four groups as follows: with normal WHtR and less extensive periodontal inflammation (NW+LP); with high WHtR and less extensive periodontal inflammation (HW+LP); with normal WHtR and more extensive periodontal inflammation (NW+P); and with high WHtR and more extensive periodontal inflammation (HW+P). Saliva were collected to measure salivary physicochemical parameters, total bacterial load, and levels of protein biomarkers including secretory phospholipase A2 group IIA (sPLA2-IIA) and interleukin-6 (IL-6). Data were analysed by Kruskal-Wallis test and Spearman correlation coefficient. RESULTS: Salivary IL-6 levels and sPLA2-IIA and IL-6 output differed significantly between groups (P = 0.041, 0.027, and 0.043, respectively). The NW+P group had significantly higher salivary IL-6 output than the NW+LP group (P = 0.034) and significantly lower salivary sPLA2-IIA output than the HW+LP group (P = 0.038). Salivary IL-6 levels were negatively correlated with the number of sextants with healthy gingivae and positively correlated with salivary sPLA2-IIA levels in participants with normal WHtR. Salivary sPLA2-IIA levels were negatively correlated with total salivary bacterial load in participants with high WHtR. CONCLUSIONS: Salivary IL-6 levels were associated with the extent of periodontal inflammation in participants with normal WHtR but not in those with high WHtR. Adolescents with different adiposity status may have different mechanisms of periodontal inflammation. CLINICAL SIGNIFICANCE: Investigating salivary biomarkers of periodontal health holds potential benefits in identifying individuals at risk and customizing oral health promotion strategies for individuals with varying levels of adiposity, even as early as adolescence.

Bottom-Up Assembling Hierarchical Enamel-Like Bulk Materials with Excellent Optical and Mechanical Properties for Tooth Restoration.

Enamel has good optical and mechanical properties because of its multiscale hierarchical structure. Biomimetic construction of enamel-like 3D bulk materials at nano-, micro-, mesh- and macro-levels is a challenge. A novel facile, cost-effective, and easy large-scale bottom-up assembly strategy to align 1D hydroxyapatite (HA) nanowires bundles to 3D hierarchical enamel structure with the nanowires bundles layer-by-layer interweaving orientation, is reported. In the strategy, the surface of oleate templated ultralong HA nanowires with a large aspect ratio is functionalized with amphiphilic 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Furtherly, the MDP functionalized HA nanowire bundles are assembled layer-by-layer with oriented fibers in a single layer and cross-locked between layers at a certain angle at mesoscale and macroscale in the viscous bisphenol A-glycidyl methacrylate (Bis-GMA) ethanol solution by shear force induced by simple agitation and high-speed centrifugation. Finally, the excessive Bis-GMA and ethanol are removed, and (Bis-GMA)-(MDP-HA nanowire bundle) matrix is densely packed under hot pressing and polymerized to form bulk enamel-like materials. The composite has superior optical properties and comparable comprehensive mechanic performances through a combination of strength, hardness, toughness, and friction. This method may open new avenues for controlling the nanowires assembly to develop hierarchical nanomaterials with superior properties for many different applications.

Facial growth and development trajectories based on three-dimensional images: geometric morphometrics with a deformation perspective.

Developmental changes of facial shape are commonly investigated through geometric morphometrics. A limitation with this approach is the inability to investigate patterns of morphological changes at local scale. This could be addressed through quantifying the deformation required to deform one shape to another. This study aimed to investigate changes in mean, rate and variance of facial shape at local scale using geometric morphometrics through deformation perspective. A total of 2112 Europeans 3 to 40 years old from the three-dimensional Facial Norms project were included. Shape and rate trajectories from partial least-squares regressions revealed that the developmentally protrusive nasal bridge was due to local expansion in surrounding tissues as opposed to shape changes in nasal bridge per se. Local expansion of the supraorbital region, in particular the medial part in males, resulted in the sloping forehead and deep-situated eyes with development. Facial shape variation increased nonlinearly with age (p < 0.05), with features having larger rate of change becoming more developmentally diversified. In summary, our deformation perspective facilitates unravelling morphogenetic processes underlying shape changes. Our extended analytical scope inspires novel measures worthy of consideration while establishing facial growth charts. The analytical framework in this study is broadly applicable for analysis of shape changes in general.

Salivary and gingival crevicular fluid biomarkers of periodontal health and/or obesity among children and adolescents: A systematic review and meta-analysis.

Objectives: To investigate the association of salivary and gingival crevicular fluid (GCF) biomarkers with periodontal status and obesity in children and adolescents. Data/sources: A literature search up to July 2023 was conducted through PubMed, Web of Science, Embase, ProQuest Medical Database, ProQuest SciTech Premium Collection, and the Cochrane Library. Observational studies comparing salivary and GCF biomarkers in children and adolescents with compromised periodontal status and/or obesity were included for data extraction. A meta-analysis was performed to estimate the overall standardised mean difference. Study selection: Fifteen observational studies met the inclusion criteria and were included in this systematic review. Meta-analysis was only applicable in synthesising the dyadic relationship between GCF biomarkers and obesity. The results demonstrated that children and adolescents with obesity had significantly higher GCF levels of tumour necrosis factor-alpha (SMD:0.56; 95% CI:0.07, 1.04), adiponectin (SMD:0.33; 95% CI:0.06, 0.60), leptin (SMD:0.52; 95% CI:0.15, 0.90), and interleukin-1 beta (SMD:0.71; 95% CI:0.44, 0.99) than those with normal weight. Conclusion: To date, no study has well addressed the triadic association between salivary or GCF biomarkers, periodontal status, and obesity among children and adolescents. Further in-depth, high-quality studies are required to investigate these associations. Clinical significance: Periodontal disease and obesity are growing public health crises worldwide. Their relationship has been intensively studied. Investigating the salivary or GCF biomarkers alterations could help better understand the relationship between periodontal disease and obesity, which would assist in tailoring future oral health promotion programs.

Colloidal Phenol-Amine Coating on Implants for Improved Anti-Inflammation and Osteogenesis.

Phenol-amine coatings have attracted significant attention in recent years owing to their adjustable composition and multifaceted biological functionalities. The current preparation of phenol-amine coatings, however, involves a chemical reaction within the solution or interface, resulting in lengthy preparation times and necessitating specific reaction conditions, such as alkaline environments and oxygen presence. The facile, rapid, and eco-friendly preparation of phenol-amine coatings under mild conditions continues to pose a challenge. In this study, we use a macromolecular phenol-amine, Tanfloc, to form a stable colloid under neutral conditions, which was then rapidly adsorbed on the titanium surface by electrostatic action and then spread and fused to form a continuous coating within several minutes. This nonchemical preparation process was rapid, mild, and free of chemical additives. The in vitro and in vivo results showed that the Tanfloc colloid fusion coating inhibited destructive inflammation, promoted osteogenesis, and enhanced osteointegration. These remarkable advantages of the colloidal phenol-amine fusion coating highlight the suitability of its future application in clinical practice.

Development and accuracy of artificial intelligence-generated prediction of facial changes in orthodontic treatment: a scoping review. / äººå·¥æ™ºèƒ½é¢„æµ‹æ­£ç•¸é¢éƒ¨å˜åŒ–çš„ç ”ç©¶è¿›å±•å’Œå‡†ç¡®åº¦ï¼šæ¦‚å†µæ€§ç³»ç»Ÿç»¼è¿°.

Artificial intelligence (AI) has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning, although its reliability has not been systematically assessed. This scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment, as well as to comprehensively evaluate its prediction accuracy. Six electronic databases (PubMed, EBSCOhost, Web of Science, Embase, Cochrane Library, and Scopus) were searched up to March 14, 2023. Clinical studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were included. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Joanna Briggs Institute (JBI) appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias, while the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) assessment was conducted to evaluate the certainty of outcomes. After screening 2500 studies, four non-randomized clinical trials were finally included for full-text evaluation. We found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction, whereas the lower lip and chin seemed to be the least predictable regions. Furthermore, the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably true. Since all of the included studies that were not randomized clinical trials (non-RCTs) showed a moderate to high risk of bias, more well-designed clinical trials with sufficient sample size are needed in future work.

Er:YAG Laser Physical Etching and Ultra-High-Molecular-Weight Cross-Linked Sodium Polyacrylate Chemical Etching for a Reliable Dentin Dry Bonding.

Dentin bond interface stability is the key issue of dental adhesion in present clinical dentistry. The concept of selective extrafibrillar demineralization has opened a new way to maintain intrafibrillar minerals to prevent interface degradation. Here, using ultra-high-molecular-weight sodium polyacrylate [Carbopol (Carbo) > 40 kDa] as a calcium chelator, we challenge this concept and propose a protocol for reliable dentin dry bonding. The results of high-resolution transmission electron microscopy revealed periodic bands of 67 nm dentin collagen fibrils after Carbo etching, and the hydroxyproline concentration increasing with prolonged chelating time denied the concept of extrafibrillar demineralization. The results that wet and dry bonding with Carbo-based demineralization produced a weaker bond strength than the traditional phosphoric acid wet adhesion suggested that the Carbo-based demineralization is an unreliable adhesion strategy. A novel protocol of Er:YAG laser physical etching followed by Carbo chemical etching for dentin adhesion revealed that a micro-/nano-level rough, rigid, and non-collagen exposed dentin surface was produced, the micro-tensile bond strength was maintained after aging under dry and wet bonding modes, and in situ zymography and nanoleakage within the hybrid layers presented lower signals after aging. Cell culture in vitro and a rabbit deep dentin adhesion model in vivo proved that this protocol is safe and biocompatible. Taken together, the concept of extrafibrillar demineralization is limited and insufficient to use in the clinic. The strategy of Er:YAG laser physical etching followed by Carbo chemical etching for dentin adhesion produces a bonding effect with reliability, durability, and safety.

Development and accuracy of artificial intelligence-generated prediction of facial changes in orthodontic treatment: a scoping review. / äººå·¥æ™ºèƒ½é¢„æµ‹æ­£ç•¸é¢éƒ¨å˜åŒ–çš„ç ”ç©¶è¿›å±•å’Œå‡†ç¡®åº¦ï¼šæ¦‚å†µæ€§ç³»ç»Ÿç»¼è¿°.

Artificial intelligence (AI) has been utilized in soft-tissue analysis and prediction in orthodontic treatment planning, although its reliability has not been systematically assessed. This scoping review was conducted to outline the development of AI in terms of predicting soft-tissue changes after orthodontic treatment, as well as to comprehensively evaluate its prediction accuracy. Six electronic databases (PubMed, EBSCOhost, Web of Science, Embase, Cochrane Library, and Scopus) were searched up to March 14, 2023. Clinical studies investigating the performance of AI-based systems in predicting post-orthodontic soft-tissue alterations were included. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Joanna Briggs Institute (JBI) appraisal checklist for diagnostic test accuracy studies were applied to assess risk of bias, while the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) assessment was conducted to evaluate the certainty of outcomes. After screening 2500 studies, four non-randomized clinical trials were finally included for full-text evaluation. We found a low level of evidence indicating an estimated high overall accuracy of AI-generated prediction, whereas the lower lip and chin seemed to be the least predictable regions. Furthermore, the facial morphology simulated by AI via the fusion of multimodality images was considered to be reasonably true. Since all of the included studies that were not randomized clinical trials (non-RCTs) showed a moderate to high risk of bias, more well-designed clinical trials with sufficient sample size are needed in future work.

Oxidized Dopamine Acrylamide Primer to Achieve Durable Resin-Dentin Bonding.

The durability of the resin-dentin bonding interface is a key issue in clinical esthetic dentistry. Inspired by the extraordinary bioadhesive properties of marine mussels in a wet environment, we designed and synthetized N-2-(3,4-dihydroxylphenyl) acrylamide (DAA) according to the functional domain of mussel adhesive proteins. DAA's properties of collagen cross-linking, collagenase inhibition, inducing collagen mineralization in vitro, and as a novel prime monomer for clinical dentin adhesion use, its optimal parameters, and effect on the adhesive longevity and the bonding interface's integrity and mineralization, were evaluated in vitro and in vivo. The results showed that oxide DAA can inhibit the activity of collagenase and cross collagen fibers to improve the anti-enzymatic hydrolysis of collagen fibers and induce intrafibrillar and interfibrillar collagen mineralization. As a primer used in the etch-rinse tooth adhesive system, oxide DAA can improve the durability and integrity of the bonding interface by anti-degradation and mineralization of the exposed collagen matrix. Oxidized DAA (OX-DAA) is a promising primer for improving dentin durability; using 5% OX-DAA ethanol solution and treating the etched dentin surface for 30 s is the optimal choice when used as a primer in the etch-rinse tooth adhesive system.

Burden, Trends, and Inequality of Dental Caries in the U.S., 1990-2019.

INTRODUCTION: Over the past 2 decades in the U.S., the reduced burden and narrowed inequality in oral health among children are in stark contrast with the high burden and widening inequality in adult oral health. This study aimed to explore the burden, trends, and inequalities of untreated caries in permanent teeth in the U.S. during 1990-2019. METHODS: Data on burden of untreated caries in permanent teeth were extracted from the Global Burden of Disease Study 2019. A set of advanced analytical methods were applied to provide an in-depth characterization of the epidemiologic profile of dental caries in the U.S. Analyses were conducted during April 2022-October 2022. RESULTS: In 2019, age-standardized incidence and prevalence of untreated caries in permanent teeth were respectively 39,111.7 (95% uncertainty interval=35,073.0-42,964.9) and 21,722.5 (95% uncertainty interval=18,748.7-25,090.3) per 100,000 person-years. Population growth was the primary driver of the increased caries cases, which contributed 31.3% and 31.0% of the increase in the number of incident and prevalent caries cases, respectively, during 1990-2019. The highest caries burden was noted in Arizona, West Virginia, Michigan, and Pennsylvania. The slope index of inequality remained stable (p=0.076), whereas the relative index of inequality increased significantly (average annual percent change=0.04, p<0.001) in the U.S. The burden of untreated caries in permanent teeth remained significant with a widening cross-state inequality during 1990-2019. CONCLUSIONS: The oral healthcare system in the U.S. needs to prioritize health promotion and prevention with a focus on expanding access, affordability, and equity.

Effect of Enterococcus faecalis on osteoclastogenesis under cobalt-mimicked hypoxia in vitro.

OBJECTIVE: The bone destruction in persistent apical periodontitis associated with infection and a periapical hypoxic microenvironment is not well known. Thus, we aimed to investigate the effects of Enterococcus faecalis on osteoclastogenesis under cobalt-mimicked hypoxia. MATERIALS AND METHODS: Mouse bone marrow-derived macrophages (BMMs) were isolated as osteoclast precursors and stimulated by heat-killed E. faecalis in an environment of cobalt-mimicked hypoxia environment. The cell proliferation and apoptosis were detected using CCK-8 and flow cytometry, respectively. Osteoclast differentiation was determined via tartrate-resistant acid phosphatase staining (TRAP) and immunofluorescence staining. The osteoclastogenic protein and gene expressions were measured by western blotting and real-time PCR. RESULTS: Under cobalt-mimicked hypoxia, E. faecalis markedly inhibited the proliferation of the BMMs and significantly promoted the apoptosis of the BMMs. The differentiation of the BMMs into osteoclasts was enhanced in the presence of the E. faecalis under hypoxia, and the expression of Blimp, c-Fos, and NFATc1 was up-regulated, while the expression of RBP-J was inhibited. CONCLUSIONS: E. faecalis markedly promotes osteoclast differentiation under cobalt-mimicked hypoxia in vitro.

Management of fear and anxiety in dental treatments: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: This systematic review was to compare the effects of interventions for the management of fear and anxiety for dental treatments. METHODS: This research project was applied to PubMed, CENTRAL, Web of Science, Cochrane library databases. The last search was run on March 31st, 2021. A list of references of relevant articles and previous reviews were checked. Qualitative and quantitative analyses were performed. RESULTS: A total of 20 eligible randomized controlled trials were included, and 969 participations in experimental group and 892 participations in the control group were involved. Anxiety levels decreased more in intervention groups than in control groups (Z = 3.47, P = 0.0005, SMD = - 0.62, 95% CI - 0.98 to - 0.27). For adults, there was statistical difference between experimental and control groups [Z = 2.14, P = 0.03, 95% CI - 0.54 (- 1.03, - 0.04)], while there was not no such statistical difference in children and adolescents [Z = 1.62, P = 0.11, 95% CI - 0.60 (- 1.32, 0.13)]. Patients experienced a significant decrease in anxiety level using sedation drugs [Z = 2.44, P = 0.01, 95% CI - 0.61 (- 1.10, - 0.12)] and audio-visual distractions [Z = 3.1, P = 0.002, 95% CI - 0.86 (- 1.40, - 0.32)]. For the informative intervention groups, patients did not show significant difference than control groups [Z = 1.22, P = 0.22, 95% CI - 0.55 (- 1.43, 0. 33)]. There was no statistical difference in vital signs [Z = 1.39, P = 0.16, 95% CI - 0.25 (- 0.61, 0.10)] and pain levels [Z = 0.69, P = 0.49; SMD = - 0.06, 95% CI (0.27, 0.11)] between intervention and control groups. CONCLUSIONS: Interventions should be used in managing anxiety and fear for dental treatment. It might be effective for anxiety alleviating for adults, but there was a low certainty of evidence that interventions could reduce anxiety level in children and adolescents. Sedation drugs and audio-visual distractions might be useful for managing dental fear and anxiety. Pain levels and vital signs could not be improved form our study. High-quality randomized clinical trials are required for further study.

Fabrication of Multilayered Biofunctional Material with an Enamel-like Structure.

The oral cavity is an environment with diverse bacteria; thus, antibacterial materials are crucial for treating and preventing dental diseases. There is a high demand for materials with an enamel-like architecture because of the high failure rate of dental restorations, due to the physical differences between dental materials and enamel. However, recreating the distinctive apatite composition and hierarchical architecture of enamel is challenging. The aim of this study was to synthesize a novel material with an enamel-like structure and antibacterial ability. We established a non-cell biomimetic method of evaporation-based bottom-up self-assembly combined with a layer-by-layer technique and introduced an antibacterial agent (graphene oxide) to fabricate a biofunctional material with an enamel-like architecture and antibacterial ability. Specifically, enamel-like graphene oxide-hydroxyapatite crystals, formed on a customized mineralization template, were assembled into an enamel-like prismatic structure with a highly organized orientation preferentially along the c-axis through evaporation-based bottom-up self-assembly. With the aid of layer-by-layer absorption, we then fabricated a bulk macroscopic multilayered biofunctional material with a hierarchical enamel-like architecture. This enamel-inspired biomaterial could effectively resolve the problem in dental restoration and brings new prospects for the synthesis of other enamel-inspired biomaterials.

Impact of Antiretroviral Therapy on Oral Health among Children Living with HIV: A Systematic Review and Meta-Analysis.

Oral health is an integral component of general health and well-being but might be undermined among children living with HIV (CLWH) due to the condition itself or the antiretroviral therapy (ART) received. This review summarises the current evidence and compares the oral health status of the CLWH who were treatment-naïve with those undergoing different ART medications. Fourteen studies were included in the final qualitative and quantitative analyses. This review identified no significant difference in the prevalence of caries, periodontal conditions, and tooth development between both groups. Orofacial opportunistic infections were more prevalent in the CLWH without ART. Children undergoing ART with a duration longer than 3 years had a significantly lower prevalence of oral candidiasis and CD4+ T-cell counts. However, due to the insufficient number of well-administered case-control studies with adequate sample size, the quality of the evidence in all outcomes was of very low certainty.

Oral Health Status of Children and Adolescents Living with HIV Undergoing Antiretroviral Therapy: A Systematic Review and Meta-Analysis.

Antiretroviral therapy (ART) increases the survival of HIV-infected children, but might also bring in oral health-related side effects and increase their risks of oral diseases. The review compared the oral health status of children living with HIV (CLWH) undergoing ART with healthy controls. Dual independent screening and study selection from four electronic databases and manual searches, data extraction, risk of bias assessment, and quality-of-evidence evaluation with Grading of Recommendations Assessment Development and Evaluation were performed. Twelve studies were included in qualitative and quantitative analysis. CLWH taking ART had a significantly higher prevalence of periodontal diseases (OR = 3.11, 95% CI 1.62-5.97), mucosal hyperpigmentation (OR = 20.35, 95% CI 3.86-107.39), and orofacial-related opportunistic infections than healthy controls. No significant differences regarding caries prevalence and tooth development were identified. Those with CD4+ T-cell counts below 250 cells/mm3 were more likely to manifest opportunistic infections, while medication duration had minimal influence on the prevalence of orofacial opportunistic infections. The current findings did not identify HIV and antiretroviral status as predisposing factors to dental caries, but affirmed the associated increased risk of periodontal diseases, mucosal hyperpigmentation and candidiasis.

Childhood Caries Management.

Dental caries, also known as tooth decay or cavities, result from the breakdown of teeth due to bacterial acids [...].

Synthesis of a graphene oxide/agarose/hydroxyapatite biomaterial with the evaluation of antibacterial activity and initial cell attachment.

Various materials are used in bone tissue engineering (BTE). Graphene oxide (GO) is a good candidate for BTE due to its antibacterial activity and biocompatibility. In this study, an innovative biomaterial consists of GO, agarose and hydroxyapatite (HA) was synthesized using electrophoresis system. The characterization of the synthesized biomaterial showed that needle-like crystals with high purity were formed after 10 mA/10 h of electrophoresis treatment. Furthermore, the calcium-phosphate ratio was similar to thermodynamically stable HA. In the synthesized biomaterial with addition of 1.0 wt% of GO, the colony forming units test showed significantly less Staphylococcus aureus. Initial attachment of MC3T3-E1 cells on the synthesized biomaterial was observed which showed the safety of the synthesized biomaterial for cell viability. This study showed that the synthesized biomaterial is a promising material that can be used in BTE.

The Efficacy of a Multi-Theory-Based Peer-Led Intervention on Oral Health Among Hong Kong Adolescents: A Cluster-Randomized Controlled Trial.

PURPOSE: This study aimed to investigate the effects of a peer-led oral health intervention based on the Health Belief Model and the Social Cognitive Theory on improving oral health among Hong Kong adolescents. METHODS: The study adopted a cluster-randomized controlled trial design, and 1184 students in 12 schools were randomized to intervention or control groups. After baseline assessment, the intervention group received a peer-led theory-based oral health intervention, while the control group received booklets for oral health promotion. Self-reported brushing and flossing, Health Belief Model/Social Cognitive Theory constructs, and oral health-related quality of life (OHRQoL) were measured at baseline, 6 months, and 12 months, and dental plaque accumulation and caries status were measured at baseline and 12 months. The trial was registered at https://www.clinicaltrials.gov (NCT03694496). RESULTS: Brushing, flossing, and OHRQoL improved more in the experimental group than in the control group at the 6-month follow-up compared with baseline (p < .001). The mean gain score difference was .81 for brushing, .47 for flossing, and -2.51 for OHRQoL. At the 12-month follow-up, the mean gain score of brushing frequency, plaque index, caries status, and OHRQoL were .18, -.28, -.32, and -2.79, respectively, which all sustained the significant difference (p < .001). CONCLUSIONS: Our findings suggested that the Health Belief Model combined with Social Cognitive Theory in a peer-led intervention is effective to increase self-reported brushing frequency and improve oral hygiene status and OHRQoL among adolescents.

An enamel-inspired bioactive material with multiscale structure and antibacterial adhesion property.

Conventional dental materials lack of the hierarchical architecture of enamel that exhibits excellent intrinsic-extrinsic mechanical properties. Moreover, restorative failures frequently occur due to physical and chemical mismatch between artificial materials and native dental hard tissue followed by recurrent caries which is caused by sugar-fermenting, acidogenic bacteria invasion of the defective cite. In order to resolve the limitations of the conventional dental materials, the aim of this study was to establish a non-cell-based biomimetic strategy to fabricate a novel bioactive material with enamel-like structure and antibacterial adhesion property. The evaporation-based, bottom-up and self-assembly method with layer-by-layer technique were used to form a large-area fluorapatite crystal layer containing antibacterial components. The multilayered structure was constructed by hydrothermal growth of the fluorapatite crystal layer and highly conformal adsorption to the crystal surface of a polyelectrolyte matrix film. Characterization and mechanical assessment demonstrated that the synthesized bioactive material resembled the native enamel in chemical components, mechanical properties and crystallographic structure. Antibacterial and cytocompatibility evaluation demonstrated that this material had the antibacterial adhesion property and biocompatibility. In combination with the molecular dynamics simulations to reveal the effects of variables on the crystallization mechanism, this study brings new prospects for the synthesis of enamel-inspired materials.

The efficacy of peer-led oral health programs based on Social Cognitive Theory and Health Belief Model among Hong Kong adolescents: a cluster-randomized controlled trial.

Oral diseases are preventable through the building of good oral health behaviors. Theory-based behavior change was key to the efficacy of oral health promotion since conventional promotion strategies achieved only short-lived and limited improvements. The objective of the study was to investigate the efficacy of a peer-led oral health intervention based on the health belief model (HBM) and the social cognitive theory (SCT) on oral self-care behaviors among Hong Kong adolescents. One thousand one hundred and eighty-four adolescents in 12 schools participated and were randomly assigned to either intervention or control group, utilizing a cluster-randomized controlled trial design. Brushing/flossing frequency, HBM/SCT constructs, oral health knowledge, and dental anxiety were measured at baseline and 6-month follow-up. Changes in behaviors were assessed using mixed-effects model and the mediators of behavioral change were identified with parallel multiple mediation analysis. At 6 months, the intervention group showed a significant increase in the frequency of brushing and flossing compared with the control group. Self-efficacy was identified as mediator between treatment condition and behavioral changes of brushing and flossing. Combining theories of HBM and SCT is a promising avenue for efficacy in oral health behaviors. The effects were mediated through cognitive variables, which provided guidance for both theory and health intervention development.