Assessing periodontal health and the British Society of Periodontology implementation of the New Classification of Periodontal Diseases 2017

Periodontal disease is a highly prevalent, chronic, inflammatory condition which is a major contributor to tooth loss and poor oral health-related quality of life. For the vast majority of patients, the disease is entirely preventable/manageable often aided by input from dental health professionals. As dental health professionals, understanding the periodontal disease process, the risk factors associated with it, standardized ways of detecting, diagnosing and monitoring the disease, along with the special tests needed to aid this process are essential skills for successful disease management. This article summarizes the need for assessing periodontal disease including key aspects of detection, a brief history of periodontal disease classification and the new classification. The paper goes on to discuss the British Society of Periodontology implementation plan of new classification and how this can be utilized for use in general dental practice. CPD/Clinical Relevance: This paper introduces the practitioner to the 2017 Classification of Periodontal Disease along with how this is implemented in general dental practice. The paper provides useful cases for practice as well as flowcharts to aid diagnosis

Pilot performance and workload whilst using an angle of attack system

Loss of control in flight is the primary category of fatal accidents within all sectors of aviation and failure to maintain adequate airspeed – leading to a stall - is often cited as a causal factor. Stalls occur when the critical angle of the aircraft is exceeded for a given airspeed. Using airspeed as an indicator of the potential to stall is an unreliable proxy. Systems that measure the angle of attack have been routinely used by military aircraft for over 50 years however rigorous academic research with respect to their effectiveness has been limited. Using a fixed-base flight simulator fitted with a simulated, commercially available angle of attack system, 20 pilots performed normal and emergency procedures during the circuit/pattern in a light aircraft. Experimental results have shown that pilot performance was improved when angle of attack was displayed in the cockpit for normal and emergency procedures during the approach phase of flight in the pattern/circuit. In relation to pilot workload, results indicated that during the approach phase of flight, there was a moderate but tolerable increase in pilot workload. The use of such a display may assist pilots to maintain the aircraft within the optimum range and hence reduce occurrences of unstable approaches. Overall, fewer stall events were observed when angle of attack was displayed and appropriate pilot decisions made during emergencies. These results provide a new perspective on pilot workload and aviation safety

Differential responses of myoblasts and myotubes to photobiomodulation are associated with mitochondrial number

Objective Photobiomodulation (PBM) is the application of light to promote tissue healing. Current indications suggest PBM induces its beneficial effects in vivo through upregulation of mitochondrial activity. However, how mitochondrial content influences such PBM responses have yet to be evaluated. Hence, the current study assessed the biological response of cells to PBM with varying mitochondrial contents. Methods DNA was isolated from myoblasts and myotubes (differentiated myoblasts), and mitochondrial DNA (mtDNA) was amplified and quantified using a microplate assay. Cells were seeded in 96‐wellplates, incubated overnight and subsequently irradiated using a light‐emitting diode array (400, 450, 525, 660, 740, 810, 830 and white light, 24 mW/cm2, 30‐240 seconds, 0.72‐5.76J/cm2). The effects of PBM on markers of mitochondrial activity including reactive‐oxygen‐species and real‐time mitochondrial respiration (Seahorse XFe96) assays were assessed 8 hours post‐irradiation. Datasets were analysed using general linear model followed by one‐way analysis of variance (and post hoc‐Tukey tests); P = 0.05). Results Myotubes exhibited mtDNA levels 86% greater than myoblasts (P < 0.001). Irradiation of myotubes at 400, 450 or 810 nm induced 53%, 29% and 47% increases (relative to non‐irradiated control) in maximal respiratory rates, respectively (P < 0.001). Conversely, irradiation of myoblasts at 400 or 450 nm had no significant effect on maximal respiratory rates. Conclusion This study suggests that mitochondrial content may influence cellular responses to PBM and as such explain the variability of PBM responses seen in the literature

Sulforaphane restores cellular glutathione levels and reduces chronic periodontitis neutrophil hyperactivity in vitro

The production of high levels of reactive oxygen species by neutrophils is associated with the local and systemic destructive phenotype found in the chronic inflammatory disease periodontitis. In the present study, we investigated the ability of sulforaphane (SFN) to restore cellular glutathione levels and reduce the hyperactivity of circulating neutrophils associated with chronic periodontitis. Using differentiated HL60 cells as a neutrophil model, here we show that generation of extracellular O2 . - by the nicotinamide adenine dinucleotide (NADPH) oxidase complex is increased by intracellular glutathione depletion. This may be attributed to the upregulation of thiol regulated acid sphingomyelinase driven lipid raft formation. Intracellular glutathione was also lower in primary neutrophils from periodontitis patients and, consistent with our previous findings, patients neutrophils were hyper-reactive to stimuli. The activity of nuclear factor erythroid-2-related factor 2 (Nrf2), a master regulator of the antioxidant response, is impaired in circulating neutrophils from chronic periodontitis patients. Although patients' neutrophils exhibit a low reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio and a higher total Nrf2 level, the DNA-binding activity of nuclear Nrf2 remained unchanged relative to healthy controls and had reduced expression of glutamate cysteine ligase catalytic (GCLC), and modifier (GCLM) subunit mRNAs, compared to periodontally healthy subjects neutrophils. Pre-treatment with SFN increased expression of GCLC and GCM, improved intracellular GSH/GSSG ratios and reduced agonist-activated extracellular O2 . - production in both dHL60 and primary neutrophils from patients with periodontitis and controls. These findings suggest that a deficiency in Nrf2-dependent pathways may underpin susceptibility to hyper-reactivity in circulating primary neutrophils during chronic periodontitis. © 2013 Dias et al