The relationship between sphingosine-1-phosphate receptor 2 and epidermal growth factor in migration and invasion of oral squamous cell carcinoma.

Sphingosine-1-phosphate (S1P) is a lipid mediator and its binding to the S1P receptor 2 (S1PR2) is reported to regulate cytoskeletal organization. Epidermal growth factor (EGF) has been shown to induce migration and invasion in tumour cells. Since binding of S1P to S1PR2 and EGF to the EGF receptors exhibit some overlapping functionality, this study aimed to determine whether S1PR2 was involved in EGF-induced migration and invasion of oral squamous cell carcinoma (OSCC) lines and to identify any potential crosstalk between the two pathways. Migration was investigated using the scratch wound assay while invasion was studied using the transwell invasion and multicellular tumour spheroid (MCTS) assays. Activity of Rac1, a RhoGTPase, was measured using G-LISA (small GTPase activation assays) while S1P production was indirectly measured via the expression of sphingosine kinase (Sphk). S1PR2 inhibition with 10 µM JTE013 reduced EGF-induced migration, invasion and Rac1 activity, however, stimulation of S1PR2 with 10 µM CYM5478 did not enhance the effect of EGF on migration, invasion or Rac1 activity. The data demonstrated a crosstalk between EGF/EGFR and S1P/S1PR2 pathways at the metabolic level. S1PR2 was not involved in EGF production, but EGF promoted S1P production through the upregulation of Sphk1. In conclusion, OSCC lines could not migrate and invade without S1PR2 regulation, even with EGF stimulation. EGF also activated S1PR2 by stimulating S1P production via Sphk1. The potential for S1PR2 to control cellular motility may lead to promising treatments for OSCC patients and potentially prevent or reduce metastasis.

Salivary E-cadherin as a biomarker for diagnosis and predicting grade of periodontitis.

OBJECTIVES: To determine the abilities of salivary E-cadherin to differentiate between periodontal health and periodontitis and to discriminate grades of periodontitis. BACKGROUND: E-cadherin is the main protein responsible for maintaining the integrity of epithelial-barrier function. Disintegration of this protein is one of the events associated with the destructive forms of periodontal disease leading to increase concentration of E-cadherin in the oral biofluids. MATERIALS AND METHODS: A total of 63 patients with periodontitis (case) and 35 periodontally healthy subjects (control) were included. For each patient, periodontal parameters including bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded. Concentration of salivary E-cadherin was determined by ELISA. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to determine the diagnostic potentials of E-cadherin. RESULTS: Level of salivary E-cadherin was significantly higher in periodontitis cases than controls. The ROC analysis showed that salivary E-cadherin exhibits excellent sensitivity and specificity (AUC 1.000) to differentiate periodontal health from periodontitis with a cutoff concentration equal to 1.325 ng/mL. The AUCs of E-cadherin to differentiate grade A from grade B and C periodontitis were 0.731 (cutoff point = 1.754 ng/mL) and 0.746 (cutoff point = 1.722 ng/mL), respectively. However, the AUC of salivary E-cadherin to differentiate grade B from grade C periodontitis was lower (0.541). Additionally, BOP and PPD were significantly and positively correlated with the concentration of salivary E-cadherin. CONCLUSION: Salivary E-cadherin exhibited excellent sensitivity and specificity to differentiate periodontitis from a healthy periodontium. The level of accuracy of E-cadherin was also sufficient to recognize grade A periodontitis from grade B and C periodontitis.

Gingival tissue samples from periodontitis patients demonstrate epithelial-mesenchymal transition phenotype.

OBJECTIVE: To determine the expression of key epithelial-mesenchymal transition (EMT) markers in gingival tissue samples collected from patients with periodontitis. BACKGROUND: Epithelial-mesenchymal transition is a process responsible for shifting epithelial-phenotype to mesenchymal-phenotype leading to loss of epithelial-barrier function. Thus, EMT could be involved as a pathogenic mechanism in periodontitis as both conditions share common promoters and signalling pathways. MATERIALS AND METHODS: Gingival tissue samples were collected from patients with periodontitis (case) and healthy periodontium (control). Periodontal parameters including bleeding on probing, probing pocket depth (PPD), and clinical attachment loss were recorded. Paraffinized tissue samples were processed and immunohistochemically stained to determine the expression of key EMT markers which included E-cadherin, ß-catenin, Snail1 and vimentin. RESULTS: The majority of cases (n = 65, 72.2%) were diagnosed with periodontitis stage 3 or 4, grade b or c vs 25 (27.8%) subjects with intact healthy periodontium. Discontinuity of epithelium was detected in up to 80.9% of periodontitis cases associated with reduced number of epithelial layers as compared to controls. Immunohistochemical expression of epithelial markers (E-cadherin and ß-catenin) was significantly downregulated in periodontitis patients as compared with controls. Periodontitis cases exhibited significant upregulation of Snail1 expression. Furthermore, cytoplasmic vimentin (66.2%) and nuclear ß-catenin (27.7%) were solely expressed in periodontally diseased tissues compared with control. Epithelial markers, E-cadherin and ß-catenin, were significantly negatively correlated with increasing PPD, while vimentin showed positive correlation with this parameter. CONCLUSION: There were marked downregulation of epithelial molecules and upregulation of mesenchymal markers in gingival tissues derived from periodontitis patients, suggesting expression of the EMT phenotype in the pathological epithelial lining of periodontal pockets.

Discovery, validation, and diagnostic ability of multiple protein-based biomarkers in saliva and gingival crevicular fluid to distinguish between health and periodontal diseases.

AIM: To discover and validate differential protein biomarker expression in saliva and gingival crevicular fluid (GCF) to discriminate objectively between periodontal health and plaque-induced periodontal disease states. MATERIALS AND METHODS: One-hundred and ninety participants were recruited from two centres (Birmingham and Newcastle upon Tyne, UK) comprising healthy, gingivitis, periodontitis, and edentulous donors. Samples from the Birmingham cohort were analysed by quantitative mass spectrometry proteomics for biomarker discovery. Shortlisted candidate proteins were then verified by enzyme-linked immunosorbent assay in both cohorts. Leave-one-out cross validation logistic regression analysis was used to identify the best performing biomarker panels. RESULTS: Ninety-five proteins were identified in both GCF and saliva samples, and 15 candidate proteins were selected based upon differences discovered between the donor groups. The best performing panels to distinguish between: health or gingivitis and periodontitis contained matrix metalloproteinase-9 (MMP9), S100A8, alpha-1-acid glycoprotein (A1AGP), pyruvate kinase, and age (area under the curve [AUC] 0.970); health and gingivitis contained MMP9, S100A8, A1AGP, and pyruvate kinase, but not age (AUC 0.768); and mild to moderate and advanced periodontitis contained MMP9, S100A8, A1AGP, pyruvate kinase, and age (AUC 0.789). CONCLUSIONS: Biomarker panels containing four proteins with and without age as a further parameter can distinguish between periodontal health and disease states.

Inflammasome dysregulation in human gingival fibroblasts in response to periodontal pathogens.

OBJECTIVE: Uncontrolled production of Interleukin-1ß (IL-1ß), a major proinflammatory cytokine, is associated with tissue destruction in periodontal disease. IL-1ß production is controlled by inflammasomes which are multiprotein regulatory complexes. The current study aimed to elucidate potential regulatory pathways by monitoring the effects of periodontal pathogens Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg) on inflammasomes and their regulators in human gingival fibroblasts (HGFs) in vitro. METHODS: HGFs were exposed to Fn and Pg alone or in combination for 24 hr at a multiplicity of infection of 100, ±30 min exposure with 5 mM adenosine triphosphate (ATP) incubation. Gene expression of NLRP3 and AIM2, inflammasome regulatory proteins POP1, CARD16 and TRIM16, and inflammasome components ASC and CASPASE 1, and IL-1ß, were evaluated by RT-PCR. Pro- and mature IL-1ß levels were monitored intracellularly by immunocytochemistry and extracellularly by ELISA. RESULTS: Fn + ATP significantly upregulated NLRP3, AIM2, IL-1ß, ASC, and CASPASE 1; however, it downregulated POP1 and TRIM16. Pg + ATP downregulated NLRP3, ASC, POP1, but upregulated IL-1ß and CARD16. Pg + Fn+ATP significantly upregulated AIM2, IL-1ß and CARD16, and downregulated POP1, TRIM16, and CASPASE 1. Pg + ATP exposure significantly increased pro- and mature IL-1ß production. CONCLUSION: Bacterial exposure with ATP may deregulate IL-1ß by dysregulating inflammasomes and their regulators in HGFs.

Photobiomodulation of mineralisation in mesenchymal stem cells.

Mesenchymal stem cells (MSCs) and photobiomodulation (PBM) both offer significant therapeutic potential in regenerative medicine. MSCs have the ability to self-renew and differentiate; giving rise to multiple cellular and tissue lineages that are utilised in repair and regeneration of damaged tissues. PBM utilises light energy delivered at a range of wavelengths to promote wound healing. The positive effects of light on MSC proliferation are well documented; and recently, several studies have determined the outcomes of PBM on mineralised tissue differentiation in MSC populations. As PBM effects are biphasic, it is important to understand the underlying cellular regulatory mechanisms, as well as, provide accurate details of the irradiation conditions, to optimise and standardise outcomes. This review article focuses on the use of red, near-infra-red (R/NIR) and blue wavelengths to promote the mineralisation potential of MSCs; and also reports on the possible molecular mechanisms which underpin transduction of these effects. A variety of potential photon absorbers have been identified which are reported to mediate the signalling mechanisms, including respiratory chain enzymes, flavins, and cryptochromes. Studies report that R/NIR and blue light stimulate MSC differentiation by enhancing respiratory chain activity and increasing reactive oxygen species levels; however, currently, there are considerable variations between irradiation parameters reported. We conclude that due to its non-invasive properties, PBM may, following optimisation, provide an efficient therapeutic approach to clinically support MSC-mediated hard tissue repair. However, to optimise application, further studies are required to identify appropriate light delivery parameters, as well as elucidate the photo-signalling mechanisms involved.

Professional regulation for Australasian genetic counselors.

As a result of the ongoing global expansion of genetic counseling, the need to formalize a system of professional regulation for genetic counselors was identified in Australasia. In June 2017, under the auspices of the Human Genetics Society of Australasia (HGSA), a working party was convened. The purpose of the working party was to provide strategic leadership for the profession of Australasian genetic counselors with a goal to formalize a national regulatory framework for genetic counselors across both Australian and New Zealand jurisdictions. This was ultimately achieved in Australia through full membership with the National Alliance of Self-Regulating Health Professions (NASRHP) while the profession of genetic counseling in New Zealand is utilizing this framework to establish their regulation pathway. Regulation has a number of implications for genetic counselors, their employers, and the wider community, with the primary purpose of regulation being protection of the public from harm. This paper details the process of formalizing self-regulation for genetic counselors in Australasia, by defining professional regulation; outlining the purpose of regulation and the status of regulation for genetic counselors in Australasia and internationally, as well as health professionals more broadly; exploring the challenges of establishing regulation in Australasia; and the next steps for regulation in Australasia. Through detailing this process, the intention is to provide a framework to support genetic counseling colleagues internationally as well as other health professions in Australasia to explore and achieve regulation through their respective jurisdiction.

Inflammasomes and their regulation in periodontal disease: A review.

Interleukin-1ß (IL-1ß), which is secreted by host tissues leading to periodontal tissue inflammation, is a major pro-inflammatory cytokine in the pathogenesis of periodontal disease. The conversion of pro-IL-1ß into its biologically active form is controlled by multiprotein complexes named as inflammasomes, which are key regulator of host defense mechanisms and inflammasome involved diseases, including the periodontal diseases. Inflammasomes are regulated by different proteins and processes, including pyrin domain (PYD)-only proteins (POPs), CARD-only proteins (COPs), tripartite motif family proteins (TRIMs), autophagy, and interferons. A review of in vitro, in vivo, and clinical data from these publications revealed that several inflammasomes including (NOD)-like receptor (NLR) pyrin domain-containing 3 (NLRP3) and absent in melanoma 2 (AIM2) have been found to be involved in periodontal disease pathogenesis. To the best of our knowledge, the current article provides the first review of the literature focusing on studies that evaluated both inflammasomes and their regulators in periodontal disease. An upregulation for inflammasomes and a downregulation of inflammasome regulator proteins including POPs, COPs, and TRIMs have been reported in periodontal disease. Although interferons (types I and II) and autophagy have been found to be involved in periodontal disease, their possible role in inflammasome activation has not evaluated yet. Modulating the excessive inflammatory response by the use of inflammasome regulators may have potential in the management of periodontal disease.

Under the spotlight: mechanisms of photobiomodulation concentrating on blue and green light.

Photobiomodulation (PBM) describes the application of light at wavelengths ranging from 400-1100 nm to promote tissue healing, reduce inflammation and promote analgesia. Traditionally, red and near-infra red (NIR) light have been used therapeutically, however recent studies indicate that other wavelengths within the visible spectrum could prove beneficial including blue and green light. This review aims to evaluate the literature surrounding the potential therapeutic effects of PBM with particular emphasis on the effects of blue and green light. In particular focus is on the possible primary and secondary molecular mechanisms of PBM and also evaluation of the potential effective parameters for application both in vitro and in vivo. Studies have reported that PBM affects an array of molecular targets, including chromophores such as signalling molecules containing flavins and porphyrins as well as components of the electron transport chain. However, secondary mechanisms tend to converge on pathways induced by increases in reactive oxygen species (ROS) production. Systematic evaluation of the literature indicated 72% of publications reported beneficial effects of blue light and 75% reported therapeutic effects of green light. However, of the publications evaluating the effects of green light, reporting of treatment parameters was uneven with 41% failing to report irradiance (mW cm-2) and 44% failing to report radiant exposure (J cm-2). This review highlights the potential of PBM to exert broad effects on a range of different chromophores within the body, dependent upon the wavelength of light applied. Emphasis still remains on the need to report exposure and treatment parameters, as this will enable direct comparison between different studies and hence enable the determination of the full potential of PBM.

Modulation of Neutrophil Extracellular Trap and Reactive Oxygen Species Release by Periodontal Bacteria.

Oral bacteria are the main trigger for the development of periodontitis, and some species are known to modulate neutrophil function. This study aimed to explore the release of neutrophil extracellular traps (NETs), associated antimicrobial proteins, and reactive oxygen species (ROS) in response to periodontal bacteria, as well as the underlying pathways. Isolated peripheral blood neutrophils were stimulated with 19 periodontal bacteria. NET and ROS release, as well as the expression of NET-bound antimicrobial proteins, elastase, myeloperoxidase, and cathepsin G, in response to these species was measured using fluorescence-based assays. NET and ROS release was monitored after the addition of NADP (NADPH) oxidase pathway modulators and inhibitors of Toll-like receptors (TLRs). Moreover, bacterial entrapment by NETs was visualized microscopically, and bacterial killing was assessed by bacterial culture. Certain microorganisms, e.g., Veillonella parvula and Streptococcus gordonii, stimulated higher levels of ROS and NET release than others. NETs were found to entrap, but not kill, all periodontal bacteria tested. NADPH oxidase pathway modulators decreased ROS production but not NET production in response to the bacteria. Interestingly, TLR inhibitors did not impact ROS and NET release. These data suggest that the variability in the neutrophil response toward different bacteria may contribute to the pathogenesis of periodontal diseases by mechanisms such as bacterial avoidance of host responses and activation of neutrophils. Moreover, our results indicate that bacterium-stimulated NET release may arise in part via NADPH oxidase-independent mechanisms. The role of TLR signaling in bacterium-induced ROS and NET release needs to be further elucidated.

Periodontitis prevalence and serum antibody reactivity to periodontal bacteria in primary Sjögren's syndrome: a pilot study.

AIMS: The aims of this study were as follows: (i) To assess the prevalence of periodontitis among patients with primary Sjögren's syndrome (pSS) and comparator groups of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). (ii) To perform a pilot study to compare serum antibody responses to 10 oral/periodontal bacteria in these patient groups and a historical comparator group of patients with periodontitis. MATERIALS AND METHODS: Standard clinical periodontal assessments were performed on 39 pSS, 36 RA and 23 OA patients and "In-house" antibody ELISAs for serum antibodies against 10 oral/periodontal bacteria were performed in these groups. RESULTS: Forty-six percent of the pSS group, 64% of the RA group and 48% of the OA group had moderate/severe periodontitis. These frequencies did not reach statistical significance between groups. Raised antibody levels to Prevotella denticola were found in the pSS, RA and periodontitis groups compared to the OA group. Significant between group differences were seen for Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Campylobacter showae. None of these differences were specifically associated with pSS. CONCLUSION: This study showed no increase in periodontitis in pSS patients. Although the P. denticola data are of interest, identifying bacterial triggering factors for pSS will likely require alternative strategies including modern techniques such as microbiome analysis.

The dark art of light measurement: accurate radiometry for low-level light therapy.

Lasers and light-emitting diodes are used for a range of biomedical applications with many studies reporting their beneficial effects. However, three main concerns exist regarding much of the low-level light therapy (LLLT) or photobiomodulation literature; (1) incomplete, inaccurate and unverified irradiation parameters, (2) miscalculation of 'dose,' and (3) the misuse of appropriate light property terminology. The aim of this systematic review was to assess where, and to what extent, these inadequacies exist and to provide an overview of 'best practice' in light measurement methods and importance of correct light measurement. A review of recent relevant literature was performed in PubMed using the terms LLLT and photobiomodulation (March 2014-March 2015) to investigate the contemporary information available in LLLT and photobiomodulation literature in terms of reporting light properties and irradiation parameters. A total of 74 articles formed the basis of this systematic review. Although most articles reported beneficial effects following LLLT, the majority contained no information in terms of how light was measured (73%) and relied on manufacturer-stated values. For all papers reviewed, missing information for specific light parameters included wavelength (3%), light source type (8%), power (41%), pulse frequency (52%), beam area (40%), irradiance (43%), exposure time (16%), radiant energy (74%) and fluence (16%). Frequent use of incorrect terminology was also observed within the reviewed literature. A poor understanding of photophysics is evident as a significant number of papers neglected to report or misreported important radiometric data. These errors affect repeatability and reliability of studies shared between scientists, manufacturers and clinicians and could degrade efficacy of patient treatments. Researchers need a physicist or appropriately skilled engineer on the team, and manuscript reviewers should reject papers that do not report beam measurement methods and all ten key parameters: wavelength, power, irradiation time, beam area (at the skin or culture surface; this is not necessarily the same size as the aperture), radiant energy, radiant exposure, pulse parameters, number of treatments, interval between treatments and anatomical location. Inclusion of these parameters will improve the information available to compare and contrast study outcomes and improve repeatability, reliability of studies.

The autoantibody repertoire in periodontitis: a role in the induction of autoimmunity to citrullinated proteins in rheumatoid arthritis?

BACKGROUND: Studies suggest that periodontitis may be a risk factor for rheumatoid arthritis (RA). The purpose of this study was to determine whether periodontitis is associated with autoantibodies characteristic of RA. METHODS: Serum samples were tested for anti-cyclic citrullinated peptide (CCP), anti-mutated citrullinated vimentin (MCV), anti-citrullinated α-enolase peptide-1 (CEP-1), anti-citrullinated vimentin (cit-vim), anti-citrullinated fibrinogen (cit-fib) and their uncitrullinated forms anti-CParg (negative control for anti-CCP), anti-arginine-containing α-enolase peptide-1 (REP-1), anti-vimentin and anti-fibrinogen antibodies in patients with and without periodontitis, none of whom had RA. RESULTS: Periodontitis, compared with non-periodontitis, was associated with a normal frequency of anti-CCP and anti-MCV (∼1%) but a higher frequency of positive anti-CEP-1 (12% vs 3%; p=0.02) and its uncitrullinated form anti-REP-1 (16% vs 2%; p<0.001). Positive antibodies against uncitrullinated fibrinogen and CParg were also more common among those with periodontitis compared to non-periodontitis patients (26% vs 3%; p<0.001, and 9% vs 3%; p=0.06). After adjusting for confounders, patients with periodontitis had 43% (p=0.03), 71% (p=0.002) and 114% (p<0.001) higher anti-CEP-1, anti-REP-1 and anti-fibrinogen titres, compared with non-periodontitis. Non-smokers with periodontitis, compared with non-periodontitis, had significantly higher titres of anti-CEP-1 (103%, p<0.001), anti-REP-1 (91%, p=0.001), anti-vimentin (87%, p=0.002), and anti-fibrinogen (124%, p<0.001), independent of confounders, confirming that the autoantibody response in periodontitis was not due to smoking. CONCLUSIONS: We have shown that the antibody response in periodontitis is predominantly directed to the uncitrullinated peptides of the RA autoantigens examined in this study. We propose that this loss of tolerance could then lead to epitope spreading to citrullinated epitopes as the autoimmune response in periodontitis evolves into that of presymptomatic RA.

Evaluation of the role of mitofusin-1 and mitofusin-2 in periodontal disease.

BACKGROUND: Mitochondria and endoplasmic reticulum are key cellular organelles and create contact sites (mitochondria-endoplasmic reticulum contact [MERC]), which plays a major role in calcium metabolism, apoptotic processes, and inflammation. Previously, proteins that have been associated with these MERC contact sites mitofusin-1 (MFN1) and mitofusin-2 (MFN2) have been found to be downregulated in periodontal disease in vitro. Therefore, the aim of the current study was to evaluate MFN1 and MFN2 in gingival crevicular fluid (GCF) of patients with periodontal disease compared with healthy controls clinically. METHODS: A total of 48 participants were divided into three groups including periodontally healthy (n = 16), patients with gingivitis (n = 16), and patients with stage 3 grade B periodontitis (n = 16). GCF levels of MFN1, MFN2, calcium (Ca), caspase-1, and tumor necrosis factor-alpha (TNF-α) were determined via enzyme-linked immunosorbent assay (ELISA). Results were calculated as total amount and concentration. RESULTS: MFN1 levels (total amount) were significantly higher in patients with periodontitis and gingivitis when compared with healthy controls (p < 0.05). However, concentration levels of MFN1, MFN2, Ca, caspase-1, TNF-α significantly decreased in periodontal disease groups compared with healthy controls (p < 0.05). A positive correlation was detected among all evaluated markers (p < 0.05). CONCLUSION: The MERC protein MFN1 may have a role in the pathogenesis of periodontal disease due to its increase in GCF of patients with periodontitis and gingivitis.

Exposure to blue light reduces antimicrobial resistant Pseudomonas aeruginosa isolated from dog ear infections.

Introduction: Pseudomonas aeruginosa is a leading cause of canine otitis externa. Enrofloxacin is often applied topically to treat this condition, although recalcitrant and recurring infections are common. There is evidence that exposure to blue light (400-470 nm) has a bactericidal effect on P. aeruginosa and other microorganisms. Methods: In the present study, we tested the biocidal effect of blue light (375-450 nm), alone or in combination with enrofloxacin, against six isolates of P. aeruginosa from dogs with otitis externa (5 of which were resistant to enrofloxacin). Results: Treatment of planktonic cell cultures with blue light resulted in significant (p < 0.5) reductions in Colony Forming Units (CFU) for all seven strains tested, in some cases below the limit of detection. The greatest bactericidal effect was observed following exposure to light at 405 nm wavelength (p < 0.05). Exposure to blue light for 20 min usually resulted in a greater reduction in Pseudomonas aeruginosa than enrofloxacin treatment, and combination treatment typically resulted in the largest reductions in CFU. Analysis of the genome sequences of these strains established that enrofloxacin resistance was likely the result of a S466F substitution in GyrB. However, there was no clear association between genotype and susceptibility to blue light treatment. Discussion: These results suggest that blue light treatment, particularly at 405 nm wavelength, and especially in combination with enrofloxacin therapy, could be an effective treatment for otherwise recalcitrant canine otitis externa caused by Pseudomonas aeruginosa. It may also provide a way of extending the usefulness of enrofloxacin therapy which would otherwise be ineffective as a sole therapeutic agent.

Ceramic conversion treated titanium implant abutments with gold for enhanced antimicrobial activity.

INTRODUCTION: Peri-implantitis is an inflammatory process around dental implants that is characterised by bone loss that may jeopardize the long-term survival of osseo integrated dental implants. The aim of this study was to create a surface coating on titanium abutments that possesses cellular adhesion and anti-microbial properties as a post-implant placement strategy for patients at risk of peri-implantitis. MATERIALS AND METHODSMETHODS: Titanium alloy Grade V stubs were coated with gold particles and then subjected to ceramic conversion treatment (CCT) at 620 °C for 3, 8 and 80 h. The surface characteristics and chemistry were assessed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. The leaching profile was investigated by inductively coupled plasma mass spectroscopy (ICP-MS) for all groups after 7, 14 and 28 days in contact with distilled water. A scratch test was conducted to assess the adhesion of the gold coating to the underlying titanium discs. Two bacterial species (Staphylococcus aureus (SA) & Fusobacterium nucleatum (FN)) were used to assess the antibacterial behaviour of the coated discs using a direct attachment assay test. The potential changes in surface chemistry by the bacterial species were investigated by grazing angle XRD. RESULTS: The gold pre-coated titanium discs exhibited good stability of the coating especially after immersion in distilled water and after bacterial colonisation as evident by XRD analysis. Good surface adhesion of the coating was demonstrated for gold treated discs after scratch test analysis, especially titanium, following a 3-hour (3 H) ceramic conversion treatment. All coated discs exhibited significantly improved antimicrobial properties against both tested bacterial species compared to untreated titanium discs. CONCLUSIONS: Ceramic conversion treated titanium with a pre-deposited gold layer showed improved antimicrobial properties against both SA and FN species than untreated Ti-C discs. Scratch test analysis showed good adherence properties of the coated discs the oxide layer formed is firmly adherent to the underlying titanium substrate, suggesting that this approach may have clinical efficacy for coating implant abutments.

Changes in Oral Health and Dental Esthetic in Smokers Switching to Combustion-Free Nicotine Alternatives: Protocol for a Multicenter and Prospective Randomized Controlled Trial.

BACKGROUND: Although the detrimental effects of conventional combustible cigarettes on oral health and dental esthetics are well known, there is limited information about the long-term impact of combustion-free nicotine alternatives (C-F NA) such as e-cigarettes or heated tobacco products. OBJECTIVE: This multicenter, prospective, 3-parallel-arm randomized controlled trial will investigate whether switching from combustible cigarettes to C-F NA will lead to measurable improvements in oral health parameters and dental esthetics over 18 months in adult smokers with limited gum disease. METHODS: Regular smokers not intending to quit and without clinical signs of periodontitis will be randomly assigned (1:4 ratio) to either standard of care with brief cessation advice (control group; arm A) or C-F NA use (intervention group; arm B). The study will also include a reference group of never smokers (reference group; arm C). The primary end point is the change in the Modified Gingival Index (MGI) score from baseline between the control arm (arm A) and the intervention arm (arm B) at the 18-month follow-up. In addition, the study will analyze the within- and between-group (arms A, B, and C) changes in MGI assessment, plaque imaging, dental shade quantitation, tooth stain scores, and oral health-related quality of life questionnaires measured at each study time point. All participants will attend a total of 7 clinic visits: screening, enrollment, and randomization (visit 0); baseline visit-day 14 (visit 1); day 90 (visit 2); day 180 (visit 3); day 360 (visit 4); and day 540 (visit 5). This multicenter study will be conducted in 4 dental clinics in 4 countries. The statistical analysis will involve descriptive statistics for continuous and categorical data. Primary end points will undergo tests for normality and, based on distribution, either a 2-sided t test or Mann-Whitney U test. Linear mixed model with random factors center and study arms by center will also be applied. Secondary end points, including MGI assessment and quality of life, will be subjected to similar tests and comparisons. Only if one value of the parameter MGI is missing after day 1, the last available observation will be carried forward. The analysis will be performed on the substituted data. Secondary parameters will not have missing value replacement. RESULTS: Participant recruitment began in October 2021, and enrollment was completed in June 2023. Results will be reported in 2025. CONCLUSIONS: This will be the first study to provide key insights into oral health benefits or risks associated with using C-F NA in smokers who are seeking alternatives to cigarette smoking. TRIAL REGISTRATION: ClinicalTrials.gov NCT04649645; https://clinicaltrials.gov/ct2/show/NCT04649645. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53222.

Photobiomodulation in Acute Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

Photobiomodulation (PBM) is a therapeutic modality that has gained increasing interest in neuroscience applications, including acute traumatic brain injury (TBI). Its proposed mechanisms for therapeutic effect when delivered to the injured brain include antiapoptotic and anti-inflammatory effects. This systematic review summarizes the available evidence for the value of PBM in improving outcomes in acute TBI and presents a meta-analysis of the pre-clinical evidence for neurological severity score (NSS) and lesion size in animal models of TBI. A systematic review of the literature was performed, with searches and data extraction performed independently in duplicate by two authors. Eighteen published articles were identified for inclusion: seventeen pre-clinical studies of in vivo animal models and one clinical study in human patients. The available human study supports safety and feasibility of PBM in acute moderate TBI. For pre-clinical studies, meta-analysis for NSS and lesion size were found to favor intervention versus control. Subgroup analysis based on PBM parameter variables for these outcomes was performed. Favorable parameters were identified as: wavelengths in the region of 665 nm and 810 nm; time to first administration of PBM ≤4 h; total number of daily treatments ≤3. No differences were identified between pulsed and continuous wave modes or energy delivery. Mechanistic substudies within included in vivo studies are presented and were found to support hypotheses of antiapoptotic, anti-inflammatory, and pro-proliferative effects, and a modulation of cellular metabolism. This systematic review provides substantial meta-analysis evidence of the benefits of PBM on functional and histological outcomes of TBI in in vivo mammalian models. Study design and PBM parameters should be closely considered for future human clinical studies.

Neutrophil superoxide production in the presence of cigarette smoke extract, nicotine and cotinine.

AIM: To determine the effect of cigarette smoke extract, nicotine and cotinine on lucigenin-detectable neutrophil superoxide production. MATERIALS & METHODS: Neutrophils from periodontally healthy individuals were treated with aqueous smoke extract, nicotine and cotinine, prior to stimulation or at the same time as stimulation with Fusobacterium nucleatum, IgG-opsonized Staphylococcus aureus and Escherichia coli Lipopolysaccharide (LPS). Superoxide generation was determined by lucigenin chemiluminescence. RESULTS: Smoke extract induced superoxide release from neutrophils (p <0.0001) in a dose-dependent manner. By contrast, superoxide generation by neutrophils in response to pathologically relevant stimuli was inhibited by pre-treatment with smoke extract (p <0.01). This inhibition did not require the continued presence of the extract. A similar reduction in stimulated superoxide production by smoke extract was detected when neutrophils were simultaneously exposed to the extract and stimuli. Nicotine and cotinine (0-10 µg/ml) had no effect on superoxide release from unstimulated or stimulated neutrophils. CONCLUSIONS: Stable water-soluble components of cigarette smoke directly induce superoxide generation by otherwise unstimulated neutrophils, but reduce superoxide responses of cells to pathologically relevant stimuli. These data suggest potential neutrophil-mediated mechanisms by which smoking may initiate and maintain oxidative stress at periodontally healthy sites and participate in disease progression, by reducing innate immune responses.

Adjunctive daily supplementation with encapsulated fruit, vegetable and berry juice powder concentrates and clinical periodontal outcomes: a double-blind RCT.

AIM: A double-blind randomized controlled trial to determine whether dietary supplementation with fruit/vegetable/berry juice powder concentrates, simultaneously with non-surgical periodontal therapy, improved 2-month treatment outcomes. METHODS: Volunteers with chronic periodontitis were randomly assigned to one of three groups: fruit/vegetable (FV), fruit/vegetable/berry (FVB) or placebo. Supplements were taken daily during non-surgical debridement and maintenance and outcomes assessed at 2, 5 and 8 months after completion. Primary outcomes were mean probing pocket depth (PPD), clinical attachment gain, % sites bleeding on probing (% BOP) at 2 months. Adherence and plasma ß-carotene were determined. RESULTS: Sixty-one nutritionally replete (by serum biochemistry) volunteers enrolled and 60 (n = 20 per arm) completed the 2-month review. Clinical outcomes improved in all groups at 2 months, with additional improvement in PPD versus placebo for FV (p < 0.03). Gingival crevicular fluid volumes diminished more in supplement groups than placebo (FVB; p < 0.05) at 2 months, but not at later times. The % BOP (5 months) and cumulative plaque scores (8 months) were lowered more in the FV group (p < 0.05). CONCLUSIONS: Adjunctive juice powder concentrates appear to improve initial pocket depth reductions in nutritionally replete patients, where plasma micronutrient bioavailability is attainable. Definitive multicentre studies in untreated and treated patients are required to ascertain the clinical significance of such changes.