抗菌剂用于牙科复合树脂的研究进展

龋病是常见的口腔疾病,填充修复是治疗的重要手段.复合树脂凭借色泽美观和理化性能优异等特点,广泛应用于牙科修复材料中.继发龋是临床应用中导致修复失败的主要原因之一.为了抑制继发龋、延长树脂使用寿命,研发具有长期抗菌功能的牙科复合树脂具有重要意义.目前,主要通过向复合树脂体系中添加抗菌型无机粒子或抗菌型有机单体赋予材料抗菌...     

Controlling Enamel Remineralization by Amyloid-Like Amelogenin Mimics

In situ regeneration of the enamel-like structure of hydroxyapatite (HAp) crystals under oral conditions is significant for dental caries treatment. However, it is still a challenge for dentists to duplicate the elegant and well-aligned apatite structure bonding to the surface of demineralized enamel. A biocompatible amelogenin-inspired matrix, a phase-transited lysozyme (PTL) film mimicking an N-terminal amelogenin with central domain (N-Ame) combined with synthetic peptide (C-AMG) based on the functional domains of C-terminal telopeptide (C-Ame) is shown here, which is formed by amyloid-like lysozyme aggregation at the enamel interface through a rapid one-step aqueous coating process. In the PTL/C-AMG matrix, C-AMG facilitated the oriented arrangement of amorphous calcium phosphate (ACP) nanoparticles and their transformation to ordered enamel-like HAp crystals, while PTL served as a strong interfacial anchor to immobilize the C-AMG peptide and PTL/C-AMG matrix on versatile substrate surfaces. PTL/C-AMG film-coated enamel induced both of the in vivo and in vitro synthesis of HAp crystals, facilitated epitaxial growth of HAp crystals and recovered the highly oriented structure and mechanical properties to levels nearly identical to those of natural enamel. This work underlines the importance of amyloid-like protein aggregates in the biomineralization of enamel, providing a promising strategy for treating dental caries.     

人工种植牙材料及表面处理的研究进展

牙齿缺失是较为常见的口腔问题,牙齿缺失不仅影响患者的面部美观,还将对患者的生理及心理造成较大影响,进而给患者的正常生活、社交、工作等带来不利影响.此外,牙齿的缺失还将影响牙槽骨的功能,降低牙槽骨代谢能力,加快牙槽脊骨质的吸收及改建.人工种植牙因其美观性、稳定性、种植无需打磨邻牙等优势,逐渐成为缺牙修复的首选方式.口腔的...     

Long-Wave Infrared Thermophotonic Imaging of Demineralization in Dental Hard Tissue

Dental caries remains the most prevalent chronic disease in both children and adults worldwide. To address this prevalence through disease prevention and management, dentists need tools capable of detecting caries at early stages of formation. Looking into the physics of light propagation in teeth, this study presents a clinically and commercially viable platform technology for thermophotonic detection of early dental caries using an inexpensive long-wavelength infrared (LWIR; 8 \(\upmu \)m to 14 \(\upmu \)m) camera. The developed system incorporates intensity-modulated light to generate a thermal-wave field inside enamel and uses the subsequent infrared emission of the thermal-wave field to detect early caries. It was found that the greater light absorption at caries sites shifts the thermal-wave field centroid, providing contrast between early caries and intact enamel. Use of LWIR detection band in dental samples is novel and beneficial over the conventional mid-wavelength infrared band (3 \(\upmu \)m to 5 \(\upmu \)m) as it suppresses the masking effect of the instantaneous radiative emission from subsurface features due to the minimal transmittance of enamel in the LWIR band. The efficacy of the LWIR system is verified though experiments carried out on nonbiological test samples as well as on teeth with natural and artificially induced caries. The results suggest that the developed LWIR technology is an affordable early dental caries detection system suitable for commercialization/translation to Dentistry.     

Oral health of hemodialysis patients: a cross-sectional study at two German dialysis centers

The aim of the study was to investigate the oral hygiene behavior and state of oral health of hemodialysis (HD) patients in Germany. HD patients attending two dialysis centers were asked to participate in the study. Anamneses and oral hygiene behavior were recorded in a questionnaire. Dental examination included the dental status (DMF-T) and the degree of gingival inflammation (PDI: Periodontol Disease Index). Of 129 patients contacted, 54 (42%), aged 63.9 ± 13.0 years (23 women and 31 men), took part in the study. At an average, dialysis was required for 4.1 years. The cause of terminal renal failure was glomerulonephritis in 30% of patients and diabetic nephropathy in 22% of patients. Since dialysis therapy, 63% of the patients (n = 34) only visited a dentist when they had complaints. In 46 cases (85%), the dentist had been informed about the patient's requirement for dialysis, and in most cases (70%), the dental treatment took place on the day after dialysis. The mean DMF-T of the HD patients was 22.1 ± 6.5. The proportion of carious teeth was low (D-T: 0.7 ± 1.2), of missing teeth (M-T) high (16.2 ± 9.3). The median degree of gingival inflammation (PDI) was 1. Availing themselves of dental treatment after patients needed to have dialysis was mostly "complaint oriented." In addition to a high proportion of missing teeth, a good level of restoration of caries was found. The gingiva showed only a low level of inflammatory changes.     

Remineralization of initial enamel caries in vitro using a novel peptide based on amelogenin

Dental caries is the most common oral disease with high incidence, widely spread and can seriously affect the health of oral cavity and the whole body. Current caries prevention measures such as fluoride treatment, antimicrobial agents, and traditional Chinese herbal, have limitations to some extent. Here we design and synthesize a novel peptide based on the amelogenin, and assess its ability to promote the remineralization of initial enamel caries lesions. We used enamel blocks to form initial lesions, and then subjected to 12-day pH cycling in the presence of peptide, NaF and HEPES buffer. Enamel treated with peptide or NaF had shallower, narrower lesions, thicker remineralized surfaces and less mineral loss than enamel treated with HEPES. This peptide can promote the remineralization of initial enamel caries and inhibit the progress of caries. It is a promising anti-caries agent with various research prospects and practical application value.     

牙科陶瓷材料的疲劳研究进展

全瓷材料制作的修复体因其良好的美学效果和生物相容性，逐渐被临床接纳，但由于陶瓷材料的脆性，限制了全瓷修复体的广泛应用。对陶瓷材料的疲劳研究，尤其是循环疲劳研究，能更贴切地反应全瓷修复体在口腔功能状态下的力学性能。综述了近年来牙科陶瓷材料疲劳研究方法、疲劳模式、影响因素及临床意义。     

Highly flexible and sensitive wearable strain and pressure sensor based on porous graphene paper for human motion

The demand for high-performance multifunctional wearable devices drives the rapid development of sensors with flexibility, sensitivity and easy preparation. Here, we report an efficient preparation method to fabricate a wearable strain and pressure sensor based on porous graphene paper (PGP), which is prepared by polymethylmethacrylate (PMMA) microsphere as a template. The prepared PGP-based strain and pressure sensor can detect multi-dimensional deformation and shows good flexibility even after more than 1000 s of repeated deformation cycles, while the rapid response time can be up to approximately 60 ms. Moreover, the obtained PGP-based sensor exhibits a good sensitivity that the gauge factor (GF) is up to 77 when the strain is in the range of 4–8%, much higher than other graphene materials. Importantly, the porous microstructure created by the PMMA microsphere in the PGP plays a vital role in the good comprehensive performance of the PGP-based sensor. The device shows potential applications in smart wearable devices to detect or monitor the posture and movement information of human beings.

     

Manufacture of Co-Cr dental crowns and bridges by selective laser Melting technology

Currently, one of the most important applications of the Selective Laser Melting (SLM) process is dental frameworks manufacturing. The objective of the present study is to analyse mechanical and microstructural properties of dental crowns and bridges manufactured by SLM technology from Co-Cr alloy using a Phenix PM 100T Dental Machine over a production period of 14 months. The obtained results show clearly a successful application of the SLM technology to the design and manufacture of dental crowns and bridges. Dental parts with adequate density, geometrical accuracy, mechanical properties, and microstructure have been produced. Based on regular analyses results, of initial Co-Cr powder materials and final crowns properties characteristics, one can conclude that the Selective Laser Melting Process can be used for the manufacturing of dental parts in correlation with the required traditional standards. The good repeatability of the SLM process has been demonstrated.     

Atomically Transition Metals on Self‐Supported Porous Carbon Flake Arrays as Binder‐Free Air Cathode for Wearable Zinc−Air Batteries

Metal single‐atom materials with their high atom utilization efficiency and unique electronic structures usually show remarkable catalytic performances in many crucial chemical reactions. Herein, a facile and easily scalable “impregnation‐carbonization‐acidification” strategy for fabricating a class of single‐atom‐anchored (including cobalt and nickel single atoms) monolith as superior binder‐free electrocatalysts for developing high‐performance wearable Zn–air batteries is reported. The as‐prepared single atoms, supported by N‐doped carbon flake arrays grown on carbon nanofibers assembly (M SA@NCF/CNF), demonstrate the dual characteristics of excellent catalytic activity (reversible oxygen overpotential of 0.75 V) and high stability, owing to the greatly improved active sites' accessibility and optimized single‐sites/pore‐structures correlations. Furthermore, wearable Zn–air battery based on Co SA@NCF/CNF air electrode displays superior stability under deformation, satisfactory energy storage capacity, and good practicality to be utilized as an integrated battery system. Theoretical calculations reveal a mechanism for the promotion of the catalytic performances on single atomic sites by lowering the overall oxygen reduction/evolution reaction barriers comparing to metal cluster co‐existing configuration. These findings provide a facile strategy for constructing free‐standing single‐atom materials as well as the engineering of high‐performance binder‐free catalytic electrodes.     

牙科热压技术对新型玻璃陶瓷微观结构和化学稳定性的影响

实验的目的是分析牙科热压技术对新型二硅酸锂玻璃陶瓷微观结构和化学稳定性的影响.对Li2O-SiO2-K2O-Al2O3-Zr02-P2O2玻璃系统进行晶化热处理,应用牙科热压技术制备化学稳定性测试试件.X射线衍射(XRD)分析热压前后玻璃陶瓷的物相组成,扫描电镜(SEM)观察微观结构,根据ISO6872标准测试材料的化学稳定性.结果表明,热压前后玻璃陶瓷的晶相组成均以二硅酸锂(Li2Si2O5)为主,热压后,主峰强度增高,晶体尺寸增大,并且呈现沿热压方向的定向排列趋势.热压前后玻璃陶瓷的化学稳定性均符合ISO6872标准要求,热压组试件对化学腐蚀有较强的抵抗性.牙科热压技术能够改变实验玻璃陶瓷的微观结构,进而提高材料的化学稳定性.     

Evaluation of the oral health status in Chinese hemodialysis patients

Chronic kidney disease has become a worldwide public health problem, and it negatively affects oral health. However, the data of the hemodialysis (HD) patients in Chinese population is unknown. This study was aimed to evaluate the dental health status and oral hygiene behavior of the HD patients in China. Patients undergoing HD therapy at two hospitals were asked to finish a questionnaire and receive dental examination (DMF‐T). A total of 306 patients, aged 24–88 (58.09 ± 14.06), took part in this study. Although majority of the patients (77.78%) brushed their teeth at least twice a day, few (less than 5%) had ever used dental floss or mouthwash. More than half of the patients have not visited a dentist since the commencement of HD therapy. The dental examination showed that DMF‐T was 9.63 ± 7.54, and the number of filled teeth (F‐T) was only 0.70 ± 1.48. Moreover, the average caries restoration ratio and replacement index were 17.57% and 32.59%, respectively. HD therapy seems to prevent patients from visiting a dentist, and there is a great need for dental treatment for Chinese HD patients.     

Detection of the molecular changes associated with oral cancer using a molecular-specific fluorescent contrast agent and single-wavelength spectroscopy

There is currently no standard screening technique for oral cancer and its precursors other than visual identification and biopsy of suspicious lesions. To aid noninvasive early detection of oral neoplasia in vivo, we previously developed a molecular-specific contrast agent targeted against epidermal growth factor receptor. Here, we present a simple fluorescence spectroscopy system to detect the presence of this contrast agent in biological models representative of living tissues in order to demonstrate the feasibility of using a spectroscopy system in conjunction with a contrast agent as a screening technique for oral cancer. The spectroscopy system was tested for the ability to detect the contrast agent in four in vitro models: multilayer tissue phantoms made of cells pre-labeled with the contrast agent, multilayer tissue phantoms labeled with the contrast agent from the surface in conjunction with a permeability enhancing agent, fresh tissue slices from normal and abnormal oral cavity biopsies, and whole normal and abnormal oral cavity biopsies. The optical signal from samples labeled with the contrast agent was 3--32 times stronger compared to controls and was detected with a signal-to-noise ratio greater than 10. These results demonstrate that an inexpensive and simple spectroscopy system can be used in biological models of living systems to detect the optical signal from a contrast agent targeted toward a cancer-related biomarker with good signal-to-noise ratios. Coupling inexpensive fluorescence spectrometers with molecular-specific contrast agents has the potential to improve the early detection of oral neoplasia by providing a low-cost screening tool.     

Multiscale Humidity Visualization by Environmentally Sensitive Fluorescent Molecular Rotors

Building humidity sensors possessing the features of diverse‐configuration compatibility, and capability of measurement of spatial and temporal humidity gradients is of great interest for highly integrated electronics and wearable monitoring systems. Herein, a visual sensing approach based on fluorescent imaging is presented, by assembling aggregation‐induced‐emission (AIE)‐active molecular rotors into a moisture‐captured network; the resulting AIE humidity sensors are compatible with diverse applications, having tunable geometries and desirable architectures. The invisible information of relative humidity (RH) is transformed into different fluorescence colors that enable direct observation by the naked eyes based on the twisted intramolecular charge‐transfer effect of the AIE‐active molecular rotors. The resulting AIE humidity sensors show excellent performance in terms of good sensitivity, precise quantitative measurement, high spatial–temporal resolution, and fast response/recovery time. Their multiscale applications, such as regional environmental RH detection, internal humidity mapping, and sensitive human‐body humidity sensing are demonstrated. The proposed humidity visualization strategy may provide a new insight to develop humidity sensors for various applications.     

Microstructure Design of Carbonaceous Fibers: A Promising Strategy toward High‐Performance Weaveable/Wearable Supercapacitors

Fiber‐based supercapacitors (FSCs) possess great potential as an ideal type of power source for future weaveable/wearable electronics and electronic‐textiles. The performance of FSCs is, without doubt, primarily determined by the properties of fibrous electrodes. Carbonaceous fibers, e.g., commercial carbon fibers, newly developed graphene fibers, and carbon nanotube fibers, are deemed as promising materials for weaveable/wearable supercapacitors owing to their exotic properties including high tensile strength and robustness, excellent electrical conductivity, good flexibility, and environmental stability. Nevertheless, bare carbonaceous fiber normally exhibits low capacitance originating from electric double‐layer capacitance, which remains unsatisfactory for efficiently powering wearable and portable devices. Numerous efforts have been devoted to tailoring fiber properties by hybridizing pseudocapacitive materials, and impressive progress has been achieved thus far. Herein, the microstructures of pristine carbonaceous fibers are introduced in detail, and the recent advances in rational nano/microstructure design of their hybrids, which provides the feasibility to achieve the synergistic interaction between conductive agents and pseudocapacitive nanomaterials but are normally overlooked, are comprehensively reviewed. Besides, the challenges in developing high‐performance fibrous electrodes are also elaborately discussed.     

牙齿图像识别技术在法庭科学中的应用

现代法庭科学中,人体特征识别主要采用下列四种技术：指纹识别、虹膜纹识别、DNA技术和牙齿形态识别。指纹载体是综合性有机物,虹膜是软组织,在重大灾难性案件中,他们极易毁坏,且我国尚未建立非犯罪人口档案库。DNA技术虽然鉴定精确,但成本高,检验周期较长,因此三种技术都有不足之处。相比之下在某些重大灾难性和刑事案件中牙齿形态鉴定法效果较好,本文对此作以介绍。     

Supercapacitive Iontronic Nanofabric Sensing

The study of wearable devices has become a popular research topic recently, where high‐sensitivity, noise proof sensing mechanisms with long‐term wearability play critical roles in a real‐world implementation, while the existing mechanical sensing technologies (i.e., resistive, capacitive, or piezoelectric) have yet offered a satisfactory solution to address them all. Here, we successfully introduced a flexible supercapacitive sensing modality to all‐fabric materials for wearable pressure and force sensing using an elastic ionic–electronic interface. Notably, an electrospun ionic fabric utilizing nanofibrous structures offers an extraordinarily high pressure‐to‐capacitance sensitivity (114 nF kPa^?1), which is at least 1000 times higher than any existing capacitive sensors and one order of magnitude higher than the previously reported ionic devices, with a pressure resolution of 2.4 Pa, achieving high levels of noise immunity and signal stability for wearable applications. In addition, its fabrication process is fully compatible with existing industrial manufacturing and can lead to cost‐effective production for its utility in emerging wearable uses in a foreseeable future.     

Digital Image Analysis Assisted Microradiography—Measurement of Mineral Content of Caries Lesions in Teeth

This study investigated the feasibility of using a digital image analysis system to process the information contained in microradiographs of tooth sections that included dental caries lesions. The results show that by using an aluminum step wedge to provide a range of thickness standards and a sound area of the sample as an internal reference, data on tooth mineral content as a function of the location can be obtained with an estimated error of less than 5% relative to the mineral content of sound area. This microradiographic technique allows the response of tooth samples to a remineralization treatment to be quantitatively measured and statistically analyzed.     

牙齿形态图像的记录与鉴定

在现代法庭科学中，人体特征识别主要采用下列四种技术：指纹识别、虹膜纹识别、DNA技术和牙齿形态识别。指纹载体是综合性有机物，虹膜是软组织，在重大灾难性案件中，他们极易毁坏，且我国尚未建立非犯罪人口档案库。DNA技术虽然鉴定精确，但成本高，检验周期较长，因此三种技术都有不足之处。相比之下牙齿形态鉴定法效果较好，本文对此作详细介绍。     

Tailored Heterojunction Active Sites for Oxygen Electrocatalyst Promotion in Zinc-Air Batteries

Rechargeable zinc-air batteries (ZABs) are promising energy storage systems due to their low-cost and safety. However, the working principle of ZABs is based on oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), which display sluggish kinetic and low stability. Herein, this work proposes a novel method to design a heterogeneous CoP/CoO electrocatalyst on mesopore nanobox carbon/carbon nanotube (CoP/CoO@MNC-CNT) that enriched active sites and synergistic effect. Moreover, the well-defined heterointerfaces could lower the energy barrier for intermediate species adsorption and promote OER and ORR electrochemical performances. The CoP/CoO@MNC-CNT electrocatalyst presents a high half-wave potential of 0.838 V for ORR and a small overpotential of 270 mV for OER. The ZABs-based CoP/CoO@MNC-CNT air-cathode shows an open-circuit voltage of 1.409 V, the long-term cycle life of 500 h with a small voltage difference change of 7.7%. Additionally, the flexible ZABs exhibit highly mechanical stability, demonstrating their application potential in wearable electronic devices.