Water fluoridation in Australia: A systematic review.

Water fluoridation is considered a safe and effective public health strategy to improve oral health. This review aimed to systematically summarize the available evidence of water fluoridation in Australia, focusing on the history, health impacts, cost effectiveness, challenges, and limitations. A systematic search was conducted on the Ovid Medline, Web of Science, Scopus, ProQuest Central, Cinahl, and Informit databases to identify literature on water fluoridation in Australia. A grey literature search and backward snowballing were used to capture additional literature. Primary studies, reviews, letters, and opinion papers were included in the quantitative analysis and summarized based on the year of publication and geographical location. The data were extracted from primary studies and summarized under three subheadings: history, community health impacts and the limitations and challenges. Water fluoridation in Australia was first implemented in 1953 in Tasmania. Most states and territories in Australia embraced water fluoridation by 1977 and currently, 89% of the Australian population has access to fluoridated drinking water. Studies report that water fluoridation has reduced dental caries by 26-44% in children, teenagers, and adults, benefiting everyone regardless of age, income, or access to dental care. It has been recognized as a cost-effective intervention to prevent dental caries, especially in rural and low-income areas. Water fluoridation as a public health measure has faced challenges, including political and public opposition, implementation and maintenance costs, access and equity, communication and education, and ethical concerns. Variations in research activities on water fluoridation across Australian states and territories over the last seven decades can be due to several factors, including the time of implementation, funding, and support. Ongoing monitoring and research to review and update optimal fluoride levels in drinking water in Australia is warranted to ensure sustainable benefits on oral health while preventing any adverse impacts.

Perceptions and attitudes of dental practitioners towards impacts of Covid 19 pandemic on clinical dentistry: a cross-sectional study.

BACKGROUND: The COVID-19 pandemic challenged all healthcare providers including dental practitioners. This cross-sectional study aimed to investigate the dental practitioners' perceptions and attitudes towards the impacts of COVID-19 on their professional practice, career decision and patient care. METHODS: Data was collected from dental practitioners registered in New South Wales (NSW), Australia using an online survey. RESULTS AND CONCLUSION: Responses received from 206 dental practitioners revealed their perceptions and attitudes towards COVID-19 infection risk, clinical guidelines, and measures adopted to deliver patient care. Majority of participants perceived the risk of infection in dentistry was higher compared with other health professionals. Most dental practices have followed guidelines received from professional associations and adopted multiple measures such as providing hand sanitizer, social distancing, and risk screen, to ensure safe delivery of oral health care. Over 80% of dental practitioners raised concerns on patients' accessibility to dental care during the pandemic. Despite tele-dentistry was introduced, almost half of the participants did not recognize tele-dentistry as an effective alternative. Moreover, negative impacts of COVID-19 pandemic on dental practitioner's professional career have been reported, including lower practice safety, reduction in working hours and income. Noteworthy, one quarter of participants even considered changing their practice environment, moving sectors or even leaving their career in dentistry. However, majority of the dental practitioners are willing to stay in their current practice environment and continue their career in dentistry. Our observations demonstrate the systematic disruption to dental practice faced in Australia due to the COVID-19 pandemic. Providing dental practitioners with timely educational training and support is important to minimise negative impacts of the challenges and to optimise dental care.

INTRACANAL CRYOTHERAPY MAY REDUCE POSTOPERATIVE ENDODONTIC PAIN.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Effectiveness of Intracanal Cryotherapy in Root Canal Therapy: A Systematic Review and Meta-analysis of Randomized Clinical Trials. Durre Sadaf, Muhammad Zubair Ahmad, Igho J Onakpoya, J Endod. 2020 Dec;46(12):1811-1823.e1. SOURCE OF FUNDING: The authors did not claim any funding support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

BUCCAL INFILTRATION WITH 4% ARTICAINE MAY BE AN ALTERNATIVE OPTION TO INFERIOR ALVEOLAR NERVE BLOCK WITH 2% LIDOCAINE FOR PULP THERAPY IN PRIMARY MANDIBULAR MOLARS.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Can 4% Articaine Buccal Infiltration Replace Inferior Alveolar Nerve Block (IANB) with 2% Xylocaine for Pulp Therapy in Primary Mandibular Molars? A Systematic Review. Sunny P Tirupathi, Srinitya Rajasekhar, Mayuri Ganesh, Abhishek Vamshi, David Tyro, Int J Clin Pediatr Dent. 2021;14(3):420-425. SOURCE OF FUNDING: The authors did not state any funding support. TYPE OF STUDY/DESIGN: Systematic review.

Chlorhexidine and Sodium Hypochlorite Provide Similar Antimicrobial Effect in Root Canal Disinfection.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Ruksakiet K, Hanák L, Farkas N, Hegyi P, Sadaeng W, Czumbel LM, Sang-Ngoen T, Garami A, Mikó A, Varga G, Lohinai Z. Antimicrobial Efficacy of Chlorhexidine and Sodium Hypochlorite in Root Canal Disinfection: A Systematic Review and Meta-analysis of Randomized Controlled Trials. J Endod. 2020 Aug;46(8):1032-1041.e7. doi: 10.1016/j.joen.2020.05.002. Epub 2020 May 12. PMID: 32413440. SOURCE OF FUNDING: The Hungarian Human Resources Development Operational Program, the Higher Education Excellence Program of the Hungarian Ministry of Human Capacities to the Therapy Research Module of Semmelweis University, National Research, Development and Innovation Office, Hungarian Scientific Research Fund and the Economic Development and Innovation Operative Programme Grant. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

Formation of biofilms from new pipelines at both ends of the drinking water distribution system and comparison of disinfection by-products formation potential.

The gradual updating of the water supply network is one of the crucial ways to ensure the safety of drinking water all over the world. The phenomenon and regularity of the biological risk and chemical risk of biofilms of the new pipes in drinking water distribution system (DWDS) is inadequate researched by now. In order to explore the biochemical risks of biofilms after new pipes are used, this paper studied the growth of biofilms, the content of disinfection by-products (DBPs) and the potential for disinfection by-products (DBPsFP) after 2-year use by establishing a pilot test platform at both ends of the DWDS in City S. The results showed that the total bacterial count in new pipelines was between 1.38 × 108-9.97 × 108/cm2; the DBPsFP at the front end and at the back end was subtly different. The overall DBPsFP of biofilms was the highest, followed by the ductile cast iron pipe and the galvanized pipe whereas the stainless steel pipe was the lowest. The HPC content of the 2-year-old pipe (1.68 × 105-7.09 × 106 CFU/cm2) was remarkably higher than that of the 1-year-old pipe (1.04 × 105-8.76 × 105 CFU/cm2), and the generation DBPsFP was about 50% higher. When a new pipeline was put into use in the urban drinking water distribution system, biofilms with certain biological hazards and risks of DBPs disinfection by-products would form in a short period of time.

Casein phosphopeptide combined with fluoride enhances the inhibitory effect on initial adhesion of Streptococcus mutans to the saliva-coated hydroxyapatite disc.

BACKGROUND: Recent preventive strategies for dental caries focus on targeting the mechanisms underlying biofilm formation, including the inhibition of bacterial adhesion. A promising approach to prevent bacterial adhesion is to modify the composition of acquired salivary pellicle. This in vitro study investigated the effect and possible underlying mechanism of pellicle modification by casein phosphopeptide (CPP) on Streptococcus mutans (S. mutans) initial adhesion, and the impact of fluoride on the efficacy of CPP. METHODS: The salivary pellicle-coated hydroxyapatite (s-HA) discs were treated with phosphate buffered saline (negative control), heat-inactivated 2.5% CPP (heat-inactivated CPP), 2.5% CPP (CPP) or 2.5% CPP supplemented with 900 ppm fluoride (CPP + F). After cultivation of S. mutans for 30 min and 2 h, the adherent bacteria were visualized by scanning electron microscopy (SEM) and quantitatively evaluated using the plate count method. Confocal laser scanning microscopy (CLSM) was used to evaluate the proportions of total and dead S. mutans. The concentrations of total, free, and bound calcium and fluoride in the CPP and fluoride-doped CPP solutions were determined. The water contact angle and zeta potential of s-HA with and without modification were measured. The data were statistically analyzed using one-way ANOVA followed by a Turkey post hoc multiple comparison test. RESULTS: Compared to the negative control group, the amount of adherent S. mutans significantly reduced in the CPP and CPP + F groups, and was lowest in the CPP + F group. CLSM analysis showed that there was no statistically significant difference in the proportion of dead S. mutans between the four groups. Water contact angle and zeta potential of s-HA surface significantly decreased in the CPP and CPP + F groups as compared to the negative control group, and both were lowest in the CPP + F group. CONCLUSIONS: Pellicle modification by CPP inhibited S. mutans initial adhesion to s-HA, possibly by reducing hydrophobicity and negative charge of the s-HA surface, and incorporating fluoride into CPP further enhanced the anti-adhesion effect.

Corticosteroids Can Be Effective in Reducing Postoperative Endodontic Pain.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Efficacy of Corticosteroids on Postoperative Endodontic Pain: A Systemic Review and Meta-analysis. Shamszadeh S, Shirvani A, Eghbal MJ, Asgary S. J Endod 2018;44(7):1057-1065. SOURCE OF FUNDING: The authors' own institution, Shahid Beheshti University of Medical Sciences. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Polar Side Chain Effects on the Thermoelectric Properties of Benzo[1,2-b:4,5-b']Dithiophene-Based Conjugated Polymers.

The molecular structure of polymers has a great influence on their thermoelectric properties; however, the relationship between the molecular structure of a polymer and its thermoelectric properties remains unclear. In this work, two benzo[1,2-b:4,5-b']dithiophene (BDT)-based conjugated polymers are designed and synthesized, which contain alkyl side chains or polar side chains. The effects of the polymer side chain on the physicochemical properties are systematically investigated, especially the thermoelectric performance of the polymers after doping with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane. It is found that the BDT-based conjugated polymer with polar side chains exhibits good miscibility with the dopants, leading to higher thermoelectric properties than those of the polymer with alkyl side chains. This work can serve as a reference for the future design of high-performance organic thermoelectric polymers.

Impact of big data on oral health outcomes.

Biomedical big data amasses from different sources such as electronic health records, health research, wearable devices and social media. Recent advances in data capturing, storage and analysis techniques have facilitated conversion of a wealth of knowledge in biomedical big data into evidence-based actionable plans to enhance population health and well-being. The delay in reaping the benefits of biomedical big data in dentistry is mainly due to the slow adoption of electronic health record systems, unstructured clinical records, tattered communication between data silos and perceiving oral health as a separate entity from general health. Recent recognition of the complex interplay between oral and general health has acknowledged the power of oral health big data to glean new insights on disease prevention and management. This review paper summarizes recent advances, limitations and challenges in biomedical big data in health care with emphasis on oral health and discusses the potential future applications of oral health big data to improve the quality and efficiency of personalized health care.

Effect of interleukin-1ß on ghrelin receptor in periodontal cells.

OBJECTIVES: Periodontopathogens induce immunoinflammatory responses characterized by the release of inflammatory mediators, e.g., interleukin (IL)-1ß, IL-6, and IL-8. Ghrelin (GHRL) is an appetite hormone which mediates its effect via the functional receptor GHS-R1a. This study was to examine the effect of an inflammatory insult on GHS-R1a in human periodontal cells. MATERIALS AND METHODS: Periodontal ligament (PDL) cells and gingival fibroblasts (HGFs) were exposed to IL-1ß in the presence and absence of GHRL. Cells were also pre-incubated with specific inhibitors of NF-κB or MEK1/MEK2 signaling. Gene expression of GHS-R1a and proinflammatory mediators was assessed by real-time PCR, GHS-R1 protein level by immunocytochemistry, and NF-κB nuclear translocation by immunofluorescence. RESULTS: IL-1ß increased significantly the GHS-R1a expression in both cell types in a dose-dependent manner. The stimulatory effect of IL-1ß involved the NF-κB and MAPK pathways. Exposure of cells to IL-1ß also resulted in an increased production of GHS-R1 protein in both cell types. Furthermore, GHRL counteracted significantly the stimulatory actions of IL-1ß on IL-6 and IL-8 in PDL cells. CONCLUSIONS: This study demonstrates for the first time that IL-1ß upregulates the functional ghrelin receptor in periodontal fibroblastic cells. Moreover, these results further support the assumption that the GHRL/GHS-R system exerts anti-inflammatory effects. Therefore, the upregulation of ghrelin receptor in periodontal cells in response to an inflammatory stimulus may represent a negative feedback mechanism to attenuate the initial inflammatory process in periodontal diseases. CLINICAL RELEVANCE: The anti-inflammatory GHRL/GHS-R system may serve as a promising target for the prevention and therapy of periodontal diseases.

Periodontitis May Be Associated With Chronic Kidney Disease, but Evidence on Causal Association Is Limited.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: The directional and nondirectional associations of periodontitis with chronic kidney disease: A systematic review and meta-analysis of observational studies. Zhao D, Khawaja AT, Jin L, Li K-Y, Tonetti M, Pelekos G. J Perio Res 2018; 53(5):682-704. SOURCE OF FUNDING: The authors' own institution, University of Hong Kong. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Side-Chain Effects on the Thermoelectric Properties of Fluorene-Based Copolymers.

Three conjugated polymers with alkyl chains of different lengths are designed and synthesized, and their structure-property relationship as organic thermoelectric materials is systematically elucidated. All three polymers show similar photophysical properties, thermal properties, and mechanical properties; however, their thermoelectric performance is influenced by the length of their side chains. The length of the alkyl chain significantly influences the electrical conductivity of the conjugated polymers, and polymers with a short alkyl chain exhibit better conductivity than those with a long alkyl chain. The length of the alkyl chain has little effect on the Seebeck coefficient. Only a slight increase in the Seebeck coefficient is observed with the increasing length of the alkyl chain. The purpose of this study is to provide comprehensive insight into fine-tuning the thermoelectric properties of conjugated polymers as a function of side-chain engineering, thereby providing a novel perspective into the design of high-performance thermoelectric conjugated polymers.

Regulation of Ghrelin Receptor by Periodontal Bacteria In Vitro and In Vivo.

Ghrelin plays a major role in obesity-related diseases which have been shown to be associated with periodontitis. This study sought to analyze the expression of the functional receptor for ghrelin (GHS-R1a) in periodontal cells and tissues under microbial conditions in vitro and in vivo. The GHS-R1a expression in human periodontal cells challenged with the periodontopathogen Fusobacterium nucleatum, in gingival biopsies from periodontally healthy and diseased individuals, and from rats with and without ligature-induced periodontitis was analyzed by real-time PCR, immunocytochemistry, and immunofluorescence. F. nucleatum induced an initial upregulation and subsequent downregulation of GHS-R1a in periodontal cells. In rat experimental periodontitis, the GHS-R1a expression at periodontitis sites was increased during the early stage of periodontitis, but significantly reduced afterwards, when compared with healthy sites. In human gingival biopsies, periodontally diseased sites showed a significantly lower GHS-R1a expression than the healthy sites. The expression of the functional ghrelin receptor in periodontal cells and tissues is modulated by periodontal bacteria. Due to the downregulation of the functional ghrelin receptor by long-term exposure to periodontal bacteria, the anti-inflammatory actions of ghrelin may be diminished in chronic periodontal infections, which could lead to an enhanced periodontal inflammation and tissue destruction.

Mineralising and antibacterial effects of modified calcium phosphate treatment on human root cementum.

BACKGROUND: Aging population will lead to the increase of incidence of root caries globally. The clinical management of root caries is challenging due to the difficulty in moisture isolation. The root caries is caused by the release of organic acids from cariogenic bacteria which results in the dissolution of cementum and dentin of the root. The purpose of this study is to study the efficacy of modified saturated calcium phosphate solution (CaP) supplement with zinc (Zn(2+)) and/or fluoride (F(-)) in providing root cementum surfaces less susceptible to acid dissolution and bacterial colonization. METHODS: Human root cementum sections from extracted premolars were treated with three modified calcium phosphate solutions (M/A-CaPs) respectively: (A) CaP-F/Zn, supplemented with F(-) and Zn(2+); (B) CaP-F, supplemented with F(-) only; (C) CaP-Zn, supplemented with Zn(2+) only. The surface characteristics of treated cementum sections were investigated using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR). Following the acid attack and Streptococcus mutans challenge, M/A-CaPs treated cementum surfaces were analysed using inductive coupled plasma (ICP) and SEM respectively. RESULTS: Compared with the control group, M/A-CaPs treated cementum presented significant improvements in resistance to acid dissolution and bacterial colonization. Among M/A-CaPs, the CaP-F/Zn treated cementum surfaces released the lowest amount of Ca(2+) ions (2.11 ± 0.51 ppm) upon acid challenge (n = 3, p < 0.01) and also presented the most significant inhibiting effect against the colonization of S. mutans (n = 180, p < 0.05). CONCLUSIONS: Saturated calcium phosphate solution CaP supplemented with both F(-) and Zn(2+) could be applied as an effective coating material providing acid resistance and antibacterial property on cementum surfaces. The modified calcium phosphate-based solution could be a new treatment strategy to prevent the development of root caries and arrest the further progression of root caries.

Redox poly(ethylene glycol)-b-poly(L-lactide) micelles containing diselenide bonds for effective drug delivery.

Bioreducible polymers have appeared as the ideal drug carriers for tumor therapy due to their properties of high stability in extracellular circulation and rapid drug release in intracellular reducing environment. Recently, the diselenide bond has emerged as a new reduction-sensitive linkage. In this work, the amphiphilic poly(ethylene glycol)-b-poly(L-lactide) containing diselenide bond has been synthesized and used to load anti-tumor drug, docetaxel (DTX), to form the redox micelles. It was found that the redox micelles showed a rapid response to glutataione (GSH), which resulted in a fast release of DTX in the presence of GSH. In contrast, <40 % of DTX was released from the micelles within 72 h under the normal condition (absence of GSH). The DTX-loaded redox micelles showed the significant inhibition effect to MCF-7 cells, and the cytotoxicity was dependent on the intracellular GSH concentrations. Moreover, considering the potentially clinical applications of the micelles through intravenous injection, the blood compatibility was also studied by the hemolysis analysis, activated partial thromboplastin time, prothrombin time and thromboelastography assays. These results confirmed that the redox micelles showed good blood safety, suggesting a potential application in tumor therapy.

Sequence-independent processing site of the C-terminal domain (CTD) influences maturation of the RgpB protease from Porphyromonas gingivalis.

The Gram-negative periodontal pathogen Porphyromonas gingivalis produces a family of outer membrane-anchored proteases, the gingipains, shown to play an essential role in virulence of the organism. The C-terminal domain (CTD) of gingipains and other secreted proteins is known to be the targeting signal for maturation and translocation of the protein through the outer membrane. The CTD is subsequently cleaved during the secretion process. Multiple alignment of various CTDs failed to define a consensus sequence at the putative CTD processing site. Using mutagenesis, we were able to show that cleavage at the site is not dependent on a specific residue and that recognition of the site is independent of local sequence. Interestingly, length of the junction between the CTD and adjacent Ig-like subdomain has a critical influence on post-translational glycan modification of the protein, whereby insertion of additional residues immediately N-terminal to the cleavage site results in failure of glycan modification and release of soluble protease into the culture medium. Various hypotheses are presented to explain these phenomena. Knowledge of the role CTDs play in maturation of gingipains has broader application for understanding maturation of CTD homologues expressed by bacteria of the Bacteriodetes phylum.

Low-temperature strain-sensitive sensor based on cellulose-based ionic conductive hydrogels with moldable and self-healing properties.

Bioelectronics based on high-performance conductive ionic hydrogels, which can create novel technological interfaces with the human body, have attracted significant interest from both academia and industry. However, it is still a challenge to fabricate hydrogel sensor with integration of good mechanical properties, fast self-healing ability and flexible strain sensitivity below 0 °C. In this paper, we present a moldable, self-healing and adhesive cellulose-based ionic conductive hydrogel with strain-sensitivity, which was prepared by forming dual-crosslinked networks using poly(vinyl alcohol) (PVA) with borax, calcium chloride (CaCl2), zinc chloride (ZnCl2) and 2,2,6,6-tetramethylpiperidine-1-oxyl oxidized cellulose nanofibril (TCNF). The hydrogel exhibited fast self-healing within 10 s, moderate modulus of 5.13 kPa, high elongation rate of 1500 % and excellent adhesion behavior on various substrates. Due to multiple hydrogen bonding and the presence of CaCl2 and ZnCl2, the hydrogel presented a reduced freezing point as low as -41.1 °C, which enabled its application as a low-temperature strain sensor. The proposed hydrogel provides a simple and facile method for fabricating multi-functional hydrogels that can be used as suitable strain sensors for applications such as wearable electronic sensor, soft robotics and electronic skins in a wide temperature range.

Chitosan/bacterial cellulose films incorporated with tea polyphenol nanoliposomes for silver carp preservation.

This study aimed to develop chitosan/bacterial cellulose-based films loaded with tea polyphenol-loaded chitosan coated nanoliposomes (CS-TP-lip) as an active agent for food preservation. The effects of the CS-TP-lip on the physicochemical properties of composite films were systematically evaluated. The CS-TP-lip exhibited spherical shapes with an average particle size of about 300 nm. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses suggested high compatibility between the CS-TP-lip and film matrix through intermolecular interactions. Furthermore, due to the CS-TP-lip's presence, the elongation at break and thermal stability of the films could be enhanced to reach 75.14 ± 1.2 % and 395.33 °C, respectively, and the stability of tea polyphenol could be increased to prolong its functioning time. The films were successfully used as packaging materials for fish fillet preservation. Therefore, the developed nanocomposite films exhibit great promise as a new generation of biodegradable, sustainable, and bioactive film for food preservation.

Lateral growth of cylinders.

The precise control of the shape, size and microstructure of nanomaterials is of high interest in chemistry and material sciences. However, living lateral growth of cylinders is still very challenging. Herein, we propose a crystallization-driven fusion-induced particle assembly (CD-FIPA) strategy to prepare cylinders with growing diameters by the controlled fusion of spherical micelles self-assembled from an amphiphilic homopolymer. The spherical micelles are heated upon glass transition temperature (Tg) to break the metastable state to induce the aggregation and fusion of the amorphous micelles to form crystalline cylinders. With the addition of extra spherical micelles, these micelles can attach onto and fuse with the cylinders, showing the living character of the lateral growth of cylinders. Computer simulations and mathematical calculations are preformed to reveal the total energy changes of the nanostructures during the self-assembly and CD-FIPA process. Overall, we demonstrated a CD-FIPA concept for preparing cylinders with growing diameters.