Browsing by Author "Cronshaw, Mark"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Open Access Current Concepts of Laser–Oral Tissue Interaction.(MDPI, 2020-06-28) Parker, Steven; Anagnostaki, Eugenia; Mylona, Valina; Cronshaw, Mark; Lynch, Edward; Grootveld, MartinFundamental to the adjunctive use of laser photonic energy for delivering therapy and tissue management, is the ability of the incident energy to be absorbed by target tissues. The aim of this review is to examine the differential performance of the separate components of oral hard and soft tissues when exposed to laser photonic irradiance of variable wavelengths and power values. Through an examination of peer-reviewed published data and materials, the interaction of laser photonic energy and target tissues are explored in detail. Varying laser wavelength emissions relative to anatomical structures explores the ability to optimise laser–tissue interactions, and also identifies possible risk scenarios as they apply to adjacent non-target structures. The concepts and practical aspects of laser photonic energy interactions with target oral tissues are clearly demonstrated. Emphasis was placed on optimising the minimum level of laser power delivery in order to achieve a desired tissue effect, whilst minimising the risk or outcome of collateral tissue damage.Item Embargo The Influence of Delivery Power Losses and Full Operating Parametry on the Effectiveness of Diode Visible – Near Infra-red (445 - 1064nm) Laser Therapy in Dentistry – A Multi-Center Investigation(Springer, 2022-01-14) Parker, Steven; Cronshaw, Mark; Grootveld, Martin; Anagnostaki, Eugenia; Mylona, Valina; Chala, Marianna; George, Roy; Walsh, LaurenceThe development of protocols for laser-assisted therapy demands strict compliance with comprehensive operating parametry. The purpose of this investigation was to examine the accuracy of correlation between laser control panel and fibre emission power values in a selection of diode dental lasers. Through retrospective analysis using successive systematic review and meta-analysis, it is clear that there is inconsistency in the details, and possible inaccuracies in laser power applied and associated computed data. Through a multi-centre investigation, 38 semi-conductor (“diode”) dental laser units were chosen, with emission wavelengths ranging from 445 to 1064 nm. Each unit had been recently serviced according to manufacturer’s recommendations, and delivery fibre assembly checked for patency and correct alignment with the parent laser unit. Subject to the output capacity of each laser, four average power values were chosen using the laser control panel—100 mW, 500 mW, 1.0 W, and 2.0 W. Using a calibrated power meter, the post-fbre emission power value was measured, and a percentage power loss calculated. For each emission, a series of six measurements were made and analysed to investigate sources of power losses along the delivery fibre, and to evaluate the precision of power loss determinations. Statistical analysis of a dataset comprising % deviations from power setting levels was performed using a factorial ANOVA model, and this demonstrated very highly significant differences between devices tested and emission power levels applied (p<10–142 and<10–52 respectively). The devices emission power interaction effect was also markedly significant (p<10–66), and this confirmed that differences observed in these deviations for each prior power setting parameter were dependent on the device employed for delivery. Power losses were found to be negatively related to power settings applied. Significant differences have emerged to recommend the need to standardize a minimum set of parameters that should form the basis of comparative research into laser–tissue interactions, both in vitro and in vivo.Item Open Access Laser-Assisted aPDT Protocols in Randomized Controlled Clinical Trials in Dentistry: A Systematic Review(MDPI, 2020-09-22) Mylona, Valina; Anagnostaki, Eugenia; Parker, Steven; Cronshaw, Mark; Lynch, Edward; Grootveld, MartinBackground: Antimicrobial photodynamic therapy (aPDT) has been proposed as an effective alternative method for the adjunctive treatment of all classes of oral infections. The multifactorial nature of its mechanism of action correlates with various influencing factors, involving parameters concerning both the photosensitizer and the light delivery system. This study aims to critically evaluate the recorded parameters of aPDT applications that use lasers as the light source in randomized clinical trials in dentistry. Methods: PubMedandCochrane search engineswere used to identifyhuman clinical trials of aPDT therapy in dentistry. After applying specific keywords, additional filters, inclusion and exclusion criteria, the initial number of 7744 articles was reduced to 38. Results: Almost one-half of the articles presented incomplete parameters, whilst the others had different protocols, even with the same photosensitizer and for the same field of application. Conclusions: No safe recommendation for aPDT protocols can be extrapolated for clinical use. Further research investigations should be performed with clear protocols, so that standardization for their potential dental applications can be achieved.Item Metadata only Photobiomodulation and Oral Mucositis: A Systematic Review(MDPI, 2020-08-05) Cronshaw, Mark; Parker, Steven; Anagnostaki, Eugenia; Mylona, Valina; Lynch, Edward; Grootveld, MartinOral mucositis (OM) is a debilitating complication of chemotherapy, and head and neck radiotherapy. In an effort to offer the best possible advice within the limitations of published research, a systematic review with an extended discussion and commentary on dosimetry and dose delivery is presented. Using keywords as listed, Pubmed, Google Scholar and Cochrane databases were searched during a period extending from 1995 to 2019. A total of 782 abstracts were identified. A total of 50 papers were analysed, and of these, 29 satisfied criteria required for systematic review in accordance with an optimized PRISMA statement. Clinical outcome as reported was subject to analysis with respect to time of intervention, incidence and severity of oral mucositis, and pain amelioration, and a comprehensive combined univariate and multivariate statistical analysis of the methods employed was performed. Recommendations are made with respect to the timing of the intervention. Moreover, there is an extended discussion available on the treatment care rationale of photobiomodulation (PBM), and its adjunctive association with OM. In conclusion, early prophylactic application offers clear advantages in clinical management. The many studies and associated variables and covariables assessed here revealed a choice of delivery techniques, associated wavelengths and many further indices to consider with regard to the accomplishment of optical parameters. It is therefore our recommendation that clinicians use PBM as a therapy with a full and proper understanding and training in order to optimise the clinical effects achievable.Item Open Access Photobiomodulation Delivery Parameters in Dentistry: An Evidence based Approach.(Mary Ann Liebert Inc, 2022-01-13) Parker, Steven; Cronshaw, Mark; Grootveld, MartinNotwithstanding around 50 years of continued research, and with an ascending level of current research submissions, there is at present no agreed methodology and process to adopted treatment protocols. Dosimetry at target tissue level is, however, largely agreed, and more recent proposals have promoted the concept of a multiphasic dose–response to clinical outcomes [1]. Higher dosimetry appears to be the most effective for analgesia, and a lower dose bracket for the growth-promoting and optimal tissue healing benefits associated with tissue regeneration and the resolution of inflammation [2–6]. There is, however, no agreement with respect to wavelengths adopted, spectral emission modes, optical beam spatial profiles, and the optical surface spot size, together with the inter-relationship of these variables to optimize therapy outcome. Further, energy delivery to subsurface targets has proven to be a significant challenge, with the requirement for the operator to deliver a meaningful photonic dose to target through overlying anisotropic multiple layers of variable tissue types [7–9]. However, despite the many difficulties that have been encountered by researchers and clinicians alike, there is considerable interest in harnessing the proven benefits of photobiomodulation (PBM) as a therapy. This has led the authors to consider broadly and as widely as possible within the prior published evidence base factors that can more consistently lead to reduced operator errors and a higher level of research and clinical endeavor outcomes. For the purpose of this study, the authors considered that a prime objective in maintaining the sustainability of evidence-based data is to mandate a full description of laser operating parameters, both those concerning control panel running parameters and computed data relating to photonic dose. In this regard, the authors conducted an audit of published randomized clinical trial (RCT)-level articles that formed the basis of five recent systematic reviews. Within a total of 141 published articles, a selection of criteria that contributed to a ‘‘risk of bias’’ determination was examined. From this, it is asserted that the high level of absence of some basic values of photonic energy delivery renders cause for concern regarding the scientific rigor of conclusions obtained in such studies.Item Metadata only Photobiomodulation Dose Parameters in Dentistry: A Systematic Review and Meta-Analysis(MDPI, 2020-10-06) Cronshaw, Mark; Parker, Steven; Anagnostaki, Eugenia; Mylona, Valina; Lynch, Edward; Grootveld, MartinObjective: This systematic review and meta-analysis of published randomized controlled trials examines a possible relationship between optical spot size at surface tissue, irradiance, radiant exposure, total energy delivered, operator technique and reported clinical outcomes. Background: Clinical photobiomodulation (PBM) therapy has achieved a high level of evidence-based acceptance in the mitigation of oral mucositis associated with cancer radiotherapy and chemotherapy, and supportive clinical research in relation to orthodontic tooth movement, oral medical conditions, including burning mouth syndrome, xerostomia and lichen planus. Inconsistent outcomes have been reported not withstanding a substantial body of primary supportive research from clinical, in vitro and animal studies. Materials and Methods: PubMed, Cochrane Database of Reviews and Google Scholar search engines were applied to identify human clinical trials of PBM therapy in clinical dentistry. A total of 766 articles between February 2009 and June 2020 were identified and following a full text evaluation, 38 papers with sufficient data to permit analyses are included in this investigation. Results: Following a detailed assessment of potential factors that may have an influence in clinical outcome, a clear trend is apparent associating optical spot size to a positive or negative effect. Furthermore, there is a clear difference in the reported results in relation to total energy applied, delivery techniques and optical parameters, which merits further investigation. Factorial statistical analyses identified an association between smaller optical surface applications and an overall lower level of reported clinical success in treating superficial and deeper targets, and correspondingly sub-surface larger target tissues were found to be more responsive to therapy by use of a larger optical surface spot size. Moreover, use of multiple small diameter probe applications was found to provide inconsistent results. Conclusions: Many factors can confound clinical success including variations in anatomy, site location, clinical condition and subject individuality. To achieve higher levels of predictable outcome, a mature appreciation of these factors, plus an expanded understanding of laser parametry, tissue volume and target depth to deliver an adequate dose within current recommended guidelines, is essential.Item Metadata only Photothermal Effects of High-Energy Photobiomodulation Therapies: An In Vitro Investigation(MDPI, 2023-06-04) Cronshaw, Mark; Parker, Steven; Grootveld, Martin; Lynch, EdwardThe purpose of this study was to investigate photothermal aspects of photobiomodulation therapies (PBMT) in vitro to assist in the development of safe clinical parameters with respect to higher-power devices with large surface applicators. Laser wavelengths in the range of 650 nm–1064 nm were investigated using a thermal camera. Thermographic measures of surface and sub-surface temperature variations of similar lean porcine muscle tissue samples were recorded for a series of calibrated experiments. A thermal comparison was then made between Flat-top and Gaussian beam spatial distribution devices. Outcome data were subjected to statistical analysis using an ANOVA model. Results acquired at similar parameters of irradiance indicated that the application of the 980 nm wavelength was associated with the highest rise in temperature, which decreased with other wavelengths in the order 980 > 1064 ≈ 650 >>> 810 nm (p < 5 × 10−20). All wavelengths assessed were associated with a significant temperature increase, and with the exception of 810 nm, all exceeded the threshold of a 6 °C rise within the prescribed parameter limits. Optical scanning by movement of the applied source over a relevant area was found to offer effective mitigation of these temperature increases. An extended discussion is presented, analysing the clinical significance of the study outcomes. Recommendations are made within the limits of this in vitro study in order to assist future clinical investigations.Item Embargo Systematic review of post-surgical laser-assisted oral soft tissue outcomes using surgical wavelengths outside the 650–1350 nm optical window.(Mary Ann Liebert Inc, 2020-10-07) Parker, Steven; Anagnostaki, Eugenia; Mylona, Valina; Cronshaw, Mark; Lynch, Edward; Grootveld, MartinObjective: To explore via systematic review the validation of uneventful post-surgical healing, associated with shorter and longer laser wavelength applications in minor oral surgery procedures. Methods: From April 28 to May 11, 2020, PubMed, Cochrane Database of Systemic Reviews, and Google Scholar search engines were applied to identify human clinical trials of photobiomodulation (PBM) therapy in clinical dentistry. The searches were carried out with reference to (1) dental laser wavelengths shorter than 650 nm; (2) wavelengths localized within the 2780-2940 nm; and (3) the 9300-10,600 nm range. Selected articles were further assessed by three independent reviewers for strict compliance with PRISMA guidelines and modified Cochrane Risk of Bias to determine eligibility. Results: Using selection filters of randomized clinical trials, moderate/low risk of bias, and the applied period, and following PRISMA guidelines, 25 articles were selected and examined. A risk of bias was completed, where 11 out of 25 publications were classified as low risk of bias, and 14 out of 25 were classified as medium risk status. In total, 6 out of 13 (46% of) studies comparing the examined laser wavelengths with scalpel-based treatment showed positive results, whereas 6 out of 13 (46%) showed no difference, and only 1 out of 13 (7.7%) presented a negative outcome. In addition, 5 out of 6 (83% of) studies comparing the examined laser wavelengths with other diodes (808-980 nm) showed positive results, whereas 1 out of 6 (17%) had negative outcomes. Conclusions: A detailed and blinded examination of published studies has been undertaken, applying strict criteria to demonstrate research outcome data, which suggests positive or at worst neutral comparatives when a given laser wavelength system is used against an alternative control therapy. As such, substantiated evidence for laser surgery in delivering uneventful healing and analgesic effects, as an expression of a PBM-like (quasi-PBM) influence, has been shown.Item Open Access Unleashing the Hidden Potential: The Dynamic Duo of Antimicrobial Photodynamic Therapy and Photobiomodulation: A Spectrophotometric Study(MDPI, 2023-06-28) Mylona, Valina; Anagnostaki, Eugenia; Petrakis, Stylianos; Kosma, Kyriaki; Parker, Steven; Cronshaw, Mark; Papadogiannis, Nektarios; Grootveld, MartinBackground: Despite intensive research, the ideal protocol applied to maximize the overall benefits of antimicrobial photodynamic therapy (aPDT) remains unexplored. Evidence exists that following aPDT, the diffused light beyond the photosensitizer can exert a secondary therapeutic effect known as photobiomodulation (PBM), which stimulates the healing of the surrounding tissues. Therefore, the aim of this study was to examine the attenuation properties of five different photosen- sitizers activated by their corresponding laser wavelengths. Methods: The illumination of various concentrations of chosen photosensitizers, curcumin, methylene blue, toluidine blue, indocyanine green and a methylene blue derivative, irradiated by their respective laser wavelengths (445 nm, 635 nm, 660 nm and 808 nm) was explored via a spectrophotometric analysis. The onward transmitted light intensities for each combination of a photosensitizer and laser wavelength were assessed. The attenuation percentages observed were statistically evaluated using an analysis-of-variance (ANOVA) model. A Tukey’s post hoc test was performed to determine the significance of differences between individual group mean values. Results: With the exception of toluidine blue illuminated by an 808 nm laser, which showed the lowest intensity loss, all the other photosensitizers presented an attenuation range of 63% to 99%. Conclusions: At appropriate concentrations, all the examined photosensitizers may allow the passage of sufficient wavelength-dependent light transmission. Calculated fluences are proposed to achieve secondary, beneficial PBM effects.