Letter to editor

Application of Laser Blue Light With a Wavelength of 405 nm in the Treatment of Patients With the Virus COVID-19

Ehsan Kamani, Mohammadreza Razaghi

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 361-362

Dear Editor,

Scientists are concerned about a new virus that has infected tens of thousands of people and killed more than 2,000. The virus, which emerged in the Chinese city of Wuhan in December, is a coronavirus and belongs to the same family as the pathogen that causes severe acute respiratory syndrome, or SARS. It causes a respiratory illness called COVID-19, which can spread from person to person.[1] Laser and Virus Fatma Vatansever Together with their research team in the year 2013 they came to this conclusion by testing on viruses and pathogens UVC, blue light, PDI have been shown to be effective in inactivating pathogens without harm [2].Research on the use of lasers in viral mortality is not widespread, but with a few studies, the effectiveness of laser blue light and LEDs in eliminating the virus can now be studied. Diem ThoHo, with his research team studying 400 nm blue light, concluded thatThe results of this study provide the first evidence that 405-nm LED light has antiviral activity [3]. there are some wavelengths that can decrease microorganisms directly, such as blue, ultraviolet, or violet wavelengths. We can increase these effects by possibly combining this method with another method known as antimicrobial photodynamic therapy (aPDT).  According to mechanisms mentioned earlier, we are referring to the capabilities of PBM and photodynamic therapy. The best use is a combination of both methods, as mentioned earlier. The present treatments are focused on virus removal, tissue oxygenation, and reduction or inhibition of cytokine storm caused by severe inflammation. With a combination of these two methods, we can achieve these goals with minimal interference with pharmaceutical methods and battle this disease with biophysical agen [4]. The Blue Laser: Blue laser light of different wavelengths has been reported to have positive effects on our immune system. Can be used for anti-microbial photodynamic therapy  (for bacterial, viral and parasitic diseases) [5]. Based on past studies and the effectiveness of low-power laser light, we can use venous laser light in this method intravenously, but it should be noted that using blue light in a venous form is more cautious. Therefore, the use of this method should be all factors such as: Age, gender, weight, specific disease, and laser duration were considered so that we could do this properly.The wavelength used will be 405 nanometers with a power of 1.5 to 2 milliwatts, which due to the high energy of this wavelength should not exceed the mentioned power, and the duration of laser radiation according to the factors from 10 to 20 minutes in 10 sessions. There will be a day in between The goal is to reduce inflammation of the lungs and increase the amount of nitric oxygen that will increase the body's immunity and improve oxygen delivery to the blood and tissues.

Review Article

A Review of Low-Level Laser Therapy for Spinal Cord Injury: Challenges And Safety

Saeed Vafaei-Nezhad, Mahnaz Pour Hassan, Mohsen Noroozian, Abbas Aliaghaei, Atefe Shirazi Tehrani, Hojjat-allah Abbaszadeh, Shahrokh Khoshsirat

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 363-368

Introduction: Damage to the spinal cord is a central nervous system disorder that results in direct damage to neural cells (axons, cell bodies) and glia, followed by autonomic, motor and sensory impairments. Inflammatory response after this injury can contribute to secondary tissue damage that leads to further behavioral and functional disorders. Inflammation is a complex process, which occurs after an injury. If this progressive process is not well controlled can lead to additional damage to the spinal cord which is preventing neural improvement and regeneration and, which ultimately will not provide good clinical consequences. Inflammation in the injured spinal cord is a physiological response that causes the death of glial and neuronal cells. The reduction of the initial inflammatory process after damage to the spinal cord is one of the important therapeutic strategies. It has been proposed that low-level laser (LLL) therapy, as a noninvasive manner, can modulate inflammatory processes, which leads to a significant improvement in neurological symptoms after spinal cord injury (SCI).
Methods: A comprehensive review was performed on SCI, the etiologies, and treatment methods using the keywords spinal cord injury, low-level laser, and inflammation in valid medical databases such as Google Scholar, PubMed, and Elsevier (76 articles). Among the collected papers, articles that were most relevant to the purposes of the study were selected and studied.
Results: LLL therapy was able to reduce inflammation and also attenuate neuronal damage after spinal cord damage.
Conclusion: In conclusion, the present study illustrates that LLL therapy has positive effects on improving functional recovery and regulating the inflammatory function in the SCI.

Evaluation of Efficacy of Low-Level Laser Therapy

Vahid Mansouri, Babak Arjmand, Mostafa Rezaei-Tavirani, Mohammadreza Razzaghi, Mohammad Rostami-Nejad, Mostafa Hamdieh

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 369-380

Introduction: Given the inconsistencies in the literature regarding laser performance in non-surgical treatments, this study investigated the available literature to determine the advantages and disadvantages of low-power lasers in treating non-surgical complications and diseases.
Methods: Authentic information from articles was extracted and evaluated to assess low-power laser performance for non-surgical treatments. A systematic search of studies on low-level laser therapy (LLLT) for non-surgical treatments was conducted mainly in PubMed and google scholar articles.
Results: Four categories of diseases, including brain-related diseases, skin-related diseases, cancers, and bone-related disorders, which were treated by LLLT were identified and introduced. The various types of LLLT regarding the studied diseases were discussed.
Conclusion: Positive aspects of LLLT versus a few disadvantages of its application imply more investigation to find better and efficient new methods.

Laser Acupuncture: 35 Years of Successful Application in Russia (Narrative Review)

Sergey Vladimirovich Moskvin, Lev Georgievich Agasarov

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 381-389

Introduction: Laser acupuncture is one of the low-level laser therapy (LLLT) methods, replacing the traditional technique of Chinese needle acupuncture. This article describes the main principles and parameters of laser acupuncture based on the analysis of 35 years of successful experience in applying the method in Russia.
Material and Methods: The search of the literature on laser acupuncture was made in the Russian Medical Library and the Russian State Library (1498 publications in Russian), and PubMed/ Medline (117 publications in English). 96 studies on laser acupuncture techniques were selected and a narrative review was conducted.
Results: The optimal parameters of the technique were worked out by Russian specialists in the the1970s, and are perfectly confirmed by the wide practice of clinical application. The literature the review showed that the most optimal parameters of laser acupuncture are wavelength - 635 nm (red spectrum), power - no more than 2-3 mW, the diameter of special nozzle attachment - not more than 1-1.5 mm, and exposure - 20-40 s (for corporal points) or 5-10 s (for auricular points). The impact on acupuncture points (APs) is carried out consistently in accordance with the recipe (protocol), with no more than 10-12 daily procedures.
Conclusion: Laser acupuncture is a very effective and reproducible technique to treat patients with different diseases. Any specialist can apply this method because of its simplicity, but using the most effective parameters.

Laser Therapy in Lumbar Disc Surgery : A Narrative Review

Behnam Hosseini, Farzad Allameh

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 390-394

Introduction: Low back pain is one of the most chronic debilitating conditions involving considerable loss of cash, work, and quality time. Lasers are utilized in different fields of drugs, providing unique advantages. They are useful and advantageous in treating lumbar disc disease. In this research, an attempt is made to examine the role and importance of different lasers in lumbar disc surgeries.
Methods: We conducted studies about laser therapy in lumbar disc surgery. Our primary search began with reviewing English-language citations from PubMed and Scopus between 1990 and 2019 using the keywords: (laser therapy) OR (lumbar disc AND disc surgery). The initial search yielded 97 articles. However, about 49 articles were selected and used in the present study.
Results: Based on the present study, it can be found that there are several methods of using lasers to treat lumbar disc surgery. These methods all have their strengths and weaknesses.
Conclusion: The development of laser lumbar disc surgery can be very helpful due to the reduction of surgical risks and the length of the patients’ hospital stay. However, the choice of method used for this type of surgery should be made according to the patient’s condition and based on the opinion of the treating physician.

Laser Treatment of Darier Disease: Report of Two Cases and Systematic Review of the Literature

Kathleen F O’Brien, Michelle A Fricke, Rhett A Kent, Cynthia Marie Carver DeKlotz

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 395-404

Introduction: Darier Disease (DD) is a chronic disease with high morbidity and limited treatment options. Laser efficacy in the treatment of DD remains understudied.
Methods: A literature search conducted between 07/21/2017 and 05/05/2018 identified all original cases of DD treated with laser therapy.
Results: Outcomes from 24 patients were reviewed, 22 patients were identified in the literature and 2 cases are included from our institution. Five types of lasers were identified [CO2 laser, Er:YAG laser, pulse dye laser [PDL], diode laser, erbium-doped fiber laser], with CO2 (46%) and PDL (42%) being the most common. Seventy-nine percent of patients were treated with more than one procedure (average, 3 procedures). The estimated body surface treated with each session ranged from 5%-50%. The most common adverse events came from CO2 and Er: YAG lasers and included dyspigmentation, pain, and post-laser erythema and edema. The time to response (mode, 1 month) was only reported in half of the studies.
Conclusion: Laser treatments appear to be a promising alternative to standardized therapies in DD.

Original Article

Effect of a Combination of Photodynamic Therapy and Chitosan on Streptococcus mutans (An In Vitro Study)

Armin Mirfasihi, Beheshteh Malekafzali, Hosna Ebrahimi zadeh, Khashayar Sanjari, Maziar Mir

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 405-410

Introduction: This study aimed to assess the effect of photodynamic therapy (PDT) and chitosan separately and in combination with Streptococcus mutans.
Materials and Methods: This in vitro experimental study evaluated 216 microbial samples in 6 groups. First, 5 μL of 0.5 McFarland standard suspension of S. mutans was added to each well of an ELISA microplate; 100 μL of Mueller Hinton broth was also added to each well; 180 wells contained S. mutans suspension while 36 wells were devoid of bacteria. Group 1 served as the negative control and had no bacteria. Group 2 served as the positive control and S. mutans in the positive control wells did not undergo any intervention. In groups 3 and 4, PDT with a 50 mW low-level laser was performed for 30 and 40 seconds respectively. In group 5, 3 mg/mL of chitosan (100 μL) was used. In group 6, 3 mg/mL (100 μL) of chitosan was used in combination with PDT (50 mW laser for 30 seconds). The laser was irradiated under aseptic conditions at a 660 nm wavelength with 50 mW power. Data were analyzed using one-way ANOVA and Tukey’s test.
Results: PDT combined with chitosan showed maximum bactericidal effect followed by PDT for 40 seconds and chitosan groups (P < 0.05). PDT for 30 seconds showed a minimum bactericidal effect (P < 0.05). All pairwise comparisons revealed significant differences (P < 0.001).
Conclusion: Chitosan and PDT alone can be used to decrease the S. mutans count. However, their combined use has a greater bactericidal effect on S. mutans.

Shear Bond Strength of the Metal Bracket to Zirconium Ceramic Restoration Treated by the Nd: YAG Laser and Other Methods: An In Vitro Microscopic Study

Hadi Mokhtarpur, Maliheh Nafisifard, Sepideh Dadgar, Ardavan Etemadi, Nasim Chiniforush, Farhad Sobouti

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 411-416

Introduction: Providing reliable bonding of the bracket base and the zirconia surface is required to apply orthodontic force. The purpose of this scientific experiment was to evaluate the efficacy of three different methods of surface preparation for Zirconia, including surface roughening, sandblasting and the Nd: YAG laser, in the shear bond strength (SBS) of the orthodontic brackets.
Methods: Fifty-four discs of zirconia were divided into three groups of 18: A) Hydrofluoric acid etching, B) sandblasting, and C) Nd: irradiation using the power of 1.5 W for 10 seconds. After bonding the brackets, the samples were slowly thermo-cycled (1000 times) for 24 hours. The SBS test was performed by a universal testing machine at a head speed of 0.5 mm/min. The adhesive remnant index (ARI) was scored at a magnification of 10 in the stereo microscope. All data were collected and analyzed using the variance, Kruskal-Wallis, Tukey, Don, and Weibull tests (α = 0.05).
Results: The HF acid etching group (6.11± 0.94 MPa) had the highest SBS, which was followed by the laser group (6 ± 0.61 MPa) and the sandblast group (3.1080 ± 0.82 MPa). There was a significant statistical difference between the laser and HF groups and the sandblast group (P < 0.05) and no significant difference between the HF group and the laser group (P = 0.03).
Conclusion: Based on the obtained bond strength, the Nd: YAG laser with a power of 1.5 W could be a substitute treatment method for the HF acid-etching.

Cavity Disinfection With a 445 nm Diode Laser Within the Scope of Restorative Therapy – A Pilot Study

Inés Lusche, Cornelius Dirk, Matthias Frentzen, Joerg Meister

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 417-426

Introduction: Cavity disinfection is necessary to prevent a progressive infection of the crown dentin and pulp. Increasing intolerance and resistance to antiseptics and antibiotics as well as the controversy over the effects of those on the dental hard tissue and composite have prompted the investigation of alternative treatment options. The objective of this pilot study is to evaluate the antibacterial potential of a diode laser with a wavelength of 445 nm in the cavity preparation using the bacterium Streptococcus salivarius associated with caries in conjunction with the characteristics and influences of dentin on light transmission.
Methods: The bactericidal effect of the laser irradiation was determined in culture experiments by using caries-free human dentin samples on bacteria-inoculated agar. For this, dentin discs (horizontally cut coronal dentin) of 500 μm and 1000 μm thicknesses were produced and irradiated with the laser with irradiation parameters of 0.7-1 W in a cw-mode and exposure times of between 5-30 s. Based on the different sample thicknesses, the penetration depth effect of the irradiation was ascertained after the subsequent incubation of the bacteria-inoculated agar. Additional influential parameters on the irradiation transmission were investigated, including surface moisture, tooth color as well as the presence of a smear layer on the dentin surface.
Results: The optical transmission values of the laser radiation for dentin were significantly dependent on the sample thickness (P = 0.006) as well as its moisture content (P = 0.013) and were independent of the presence of a smear layer. There was a 40% reduction in bacteria after the radiography of the 500-μm-thick dentin samples, which was shown as the lowest laser dose (443 J/cm2).
Conclusion: These findings indicate that the diode laser with light emission at a wavelength of 445 nm is interesting for the supportive cavity disinfection within the scope of caries therapy and show potential for clinical applications.

The Long-term Effects of Percutaneous Laser Disc Decompression (PLDD) Treatment on Lumbar Disc Protrusion: A 2-Year Follow-up

Masoud Hashemi, Mani Falsafi, Mohammad Reza Razzaghi, Payman Dadkhah, Mehrdad Taheri, Mohammad Hossein Delshad, Alireza Zali

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 427-432

Introduction: Nowadays many physicians have focused their attention on using low invasive methods for the treatment of disc protrusion. Thus, the current study was carried out to evaluate the effect and therapeutic outcomes of clinical percutaneous laser disc decompression (PLDD) in the treatment of chronic low back pain caused by disc protrusion during a two-year follow-up.
Methods: This historical cohort study was conducted on 40 patients, who were suffering from chronic low back pain caused by disc protrusion diagnosed, and referred to the pain clinic of Akhtar Hospital from March to August 2016 were treated with PLDD and were followed up for at least two years after performing PLDD (from 2018 to 2019). All the information has been extracted using medical records and patient interviews. The severity of pain was measured by the Numeric Rating Scale (NRS), and the Oswestry disability index (ODI) was measured before and two years after the treatment.
Results: The most common sites for two-level PLDD were L4-S1 and L3-L5, and the most common sites for one-level PLDD were L5-S1 and L4-L5. Overall, the levels of pain and functional disability two years after PLDD showed significant improvements (P = 0.0001). The results revealed no statistically significant differences in NRS and ODI scores between the two groups of men and women two years after PLDD (P > 0.05). Furthermore, they indicated no statistically significant differences in NRS and ODI scores between the different disc protrusion levels two years after PLDD (P > 0.05).
Conclusion: It seems that the PLDD is a low-invasive, safe, and effective method that can be used in patients with chronic low back pain caused by a disc protrusion. Therefore, it can be considered as a suitable choice in treating patients with chronic low back pain caused by a disc protrusion

Computational Biology Analysis of COVID-19 Receptor-Binding Domains: A Target Site for Indocyanine Green Through Antimicrobial Photodynamic Therapy

Maryam Pourhajibagher, Abbas Bahador

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 433-441

Introduction: The receptor-binding domain (RBD) in SARS-CoV-2 binds strongly to angiotensin-converting enzyme 2 (ACE2) receptors and causes coronavirus disease 2019 (COVID-19). Antimicrobial photodynamic therapy (aPDT) is a well-established treatment option for the treatment of several viral infections. This in silico study was conducted to target the RBD of SARS-CoV-2 as a target site for aPDT.
Methods: SARS-CoV-2-RBD was selected as a novel target for indocyanine green (ICG) as a photosensitizer during aPDT to exploit its molecular modeling, hierarchical nature of protein structure, and physico-chemical properties using several bioinformatic tools. The binding mode of the RBD to ICG was assessed via protein-ligand docking.
Results: The results of a computational biology analysis revealed that SARS-CoV-2-RBD has 223 amino acids with a molecular weight of 25098.40 Da. RBD is most similar to 6W41 with an E-value of 4e-167, an identity of 100%, and a query cover of 100%. The aliphatic index of the RBD protein sequences was 71.61, suggesting that the protein is stable in a broad spectrum of temperatures. The predicted structure of RBD showed that it is a protein with a positive charge and a random coil structure (69.51%). Four ligands were modeled in this entry, including one N-acetyl-D-glucosamine (NAG), one glycerol (GOL), and two sulfate ions (SO4), to which ICG desires to bind in the molecular docking analysis.
Conclusion: Molecular modeling and simulation analysis showed that SARS-CoV-2-RBD could be a substrate for binding to ICG during aPDT to control the spread of COVID-19.

Efficacy of Er,Cr Laser incision Corticotomy in Rapid Maxillary Canine Retraction: A Split-Mouth Randomized Clinical Trial

Majid Mahmoudzadeh, Banafshe Poormoradi, Sara Alijani, Maryam Farhadian, Azadeh Kazemisaleh

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 442-449

Introduction: This study sought to evaluate the efficacy of lasercision corticotomy for the acceleration of the canine movement. Our secondary objectives were assessing the canine rotation, the rate of anchorage control, the level of pain, and the gingival index (GI).
Methods: Twelve orthodontic patients (9 females and 3 males) referring to the School of Dentistry and one dental clinic from May 2019 to September 2019 participated in this split-mouth randomized clinical trial. The allocation of the test and control sides was performed by flipping a coin. The mean age of patients was 18.91±3.87 years (range 15-30 years). The treatment plan included maxillary first premolar extraction. Following the initial leveling and alignment phase, an initial impression was made. Corticotomy was carried out with the erbium, chromium-doped yttrium scandium gallium garnet (Er, Cr: YSGG) laser (3.5 W, 30 Hz, 40% air, 80% water) in one maxillary quadrant (the laser side). Canine retraction was immediately initiated following surgery using nickel-titanium closed-coil springs with 150 g force. The impression was repeated 1 month after the onset of retraction. The casts were scanned, and the distance between the canine cusp tip and the rugae line was measured to quantify the amount of anteroposterior canine movement. The molar anchorage control was also evaluated by measuring the distance between the mesial contact of the permanent first molar and the rugae line. Gingival health was evaluated using the GI. The modified McGill pain questionnaire was used to assess the level of patients’ pain.
Results: Lasercision corticotomy accelerated canine retraction with no adverse effect on gingival health. Anchorage loss in the posterior teeth and pain scores were not significantly different between the control and laser sides.
Conclusion: Laser corticotomy can effectively accelerate canine retraction with no complications or discomfort for the patients.

Effect of Laser Irradiance and Fluoride Varnish on Demineralization around Dental Composite Restorations

Sara Valizadeh, Maryam Rahimi Khub, Nasim Chiniforush, Mohammad-Javad Kharazifard, Sedighe Sadat Hashemikamangar

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 450-455

Introduction: This study aimed to assess the effects of CO2 and erbium-doped yttrium aluminum garnet (Er:YAG) lasers with and without fluoride varnish on demineralization around composite restorations.
Methods: This in vitro experimental study evaluated 96 extracted human premolars. After preparation and restoration of class V cavities in the buccal surface of the teeth with composite resin, they were randomly divided into 8 groups of control, CO2 laser (L1), CO2 laser-NaF (L1F), NaF-CO2 laser (FL1), Er:YAG laser (L2), Er:YAG laser-NaF (L2F), NaF-Er:YAG laser (FL2) and NaF (F). The entire surface of the teeth, except for the restored cavity in the buccal surface and 1 mm around the margin, was coated with two layers of nail varnish. The teeth then underwent pH cycling for 10 days (3 hours in demineralizing solution and 21 hours in remineralizing solution) to artificially induce demineralization. The amount of calcium and phosphorous released into the cariogenic solution was quantified using atomic absorption spectroscopy and spectrophotometry. The Vickers hardness tester was used to measure the hardness of the tooth structure adjacent to composite restoration. Data were analyzed using one-way ANOVA and Tukey’s test.
Results: The four groups of L1F, FL1, FL2 and L2F showed minimum loss of calcium and phosphorous ions, and the mean hardness of FL1 and FL2 groups was higher than that of other groups.
Conclusion: The CO2 and Er:YAG lasers alone have no significant effect on the resistance of tooth structure to cariogenic solution. However, they can exert a synergistic effect when used along with NaF varnish. Fluoride varnish applied prior to laser irradiation confers further resistance to the tooth structure and positively affects its hardness.

Effect of Low-level Laser Therapy and Platelet-rich Fibrin on the Treatment of Intra-bony Defects

Devi Bala Raja Thalaimalai, Dhayanand John Victor, Ponnudurai Samuel Ganana Prakash, Sangeetha Subramaniam, Priyanka K Cholan

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 456-463

Introduction: Attempts to regenerate the periodontal osseous defect, which is lost as a result of periodontal disease, require the tapping of the innate healing potential of periodontium through appropriately designed therapeutic strategies. A multitude of grafted and non-grafted approaches have been used in the management of Intra-bony defects. However, they do not provide predictable periodontal regeneration. The aim of this study was to evaluate the combined effect of low-level laser therapy (LLLT) and platelet-rich fibrin (PRF), in site modulated intra-bony defects (decortication), which were accessed using a simplified papilla preservation flap (SPPF), on the clinical and radiographic outcomes of periodontal disease.
Methods: A total of 30 patients with intra-bony defects were recruited for the study and randomly distributed in two groups (n=15). Test group sites were accessed with SPPF and the defects received intra-marrow Penetration (IMP) following debridement and were irradiated with a low-level laser followed by PRF grafting and suturing done. The control group defects were accessed with SPPF and grafted with PRF before being secured by sutures. The plaque and bleeding score, PPD, CAL, and the position of the gingival margin with radiographic defect depth were recorded and analyzed at baseline and six months post-intervention using the student’s t-test and Wilcoxon signed-rank test.
Results: The test group showed a clinically relevant increase in mean PPD reduction, CAL gain, and radiographic bone fill (3.6 ± 1.35 mm, 3.26 ± 1.16 mm, and 2.44 ± 1.24 mm) compared to the control group (2.93 ±1.1 mm, 2.267 ± 1.33 mm and 1.26 ± 0.99 mm) six months post-intervention. However, intergroup comparison between the test and control groups did not show any statistically significant difference.
Conclusion: These results highlight that test protocol had greater amelioration of the effects of periodontal disease and all the investigated clinical and radiographic parameters showed considerable improvement from baseline to 6 months within the test and control group, but intergroup comparison between the test and control groups did not show any statistically significant difference, indicating statistical equivalence between the test and control protocol.

Effect of an Er,Cr:YSGG Laser on the Debonding of Lithium Disilicate Veneers With Four Different Thicknesses

Hernán Giraldo, Juliana Castaño Gómez, Angela Natalia López Guerrero, Johanna Muñoz Fernández

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 464-468

Introduction: The objective of this study was to compare in vitro the resistance and type of failure in the debonding of lithium disilicate veneers with four different thicknesses using an erbium chromium yttrium-scandium gallium-garnet (Er, Cr: YSGG) laser.
Methods: Sixty-eight bovine teeth were used to bond round lithium disilicate veneers with a 6-millimeter diameter and four different thicknesses: group 1 (0.4 mm), group 2 (0.8 mm), group 3 (1.2 mm), and group 4 (1.6 mm). Each sample was irradiated with an Er, Cr: YSGG laser with 4 W of power and a frequency of 50 Hz, during 60 seconds, scanning concentrically. The energy density per pulse or fluency applied was 5.33 J/cm2 for the four groups. The samples were subjected to a force in a universal testing machine and then observed under a microscope to determine the type of failure. Data were statistically analyzed with the non-parametric Kruskal-Wallis test.
Results: The tendency in the results revealed that the thicker veneers showed more resistance to the debonding process. The debonding strength for group 3 was the highest (5.62 MPa), followed by group 4 (5.20 MPa), then group 2 (0.85 MPa), and finally group 1 (0.0 MPa). The most frequent type of failure was a cohesive failure in cement (CC) for all groups, with 73.53% (P ≤ 0.083).
Conclusion: Er, Cr: YSGG laser irradiation influences the debonding of lithium disilicate veneers with different thicknesses: the smaller thickness showed the greater debonding. The thickness of veneers was not associated with the type of failure.

Photobiomodulation Therapy in the Proliferation and Differentiation of Human Umbilical Cord Mesenchymal Stem Cells: An In Vitro Study

Jéssica Meirinhos Miranda, José Alcides Almeida de Arruda, Lara Marques Magalhães Moreno, Wyndly Daniel Cardoso Gaião, Sinval Vinícius Barbosa do Nascimento, Eduardo Vinícius de Souza Silva, Márcia Bezerra da Silva, Cláudio Gabriel Rodrigues, Diana Santana de Albuquerque, Rodivan Braz, Antonio Luiz Barbosa Pinheiro, Marleny Elizabeth Marquez de Martinez Gerbi

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 469-474

Introduction: Since photobiomodulation therapy (PBMT) favors in vitro mesenchymal stem cell (MSC) preconditioning before MSC transplantation, increasing the proliferation of these cells without molecular injuries by conserving their characteristics, in the present in vitro study we analyzed the effect of PBMT on the proliferation and osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).
Methods: Irradiation with an InGaAIP Laser (660 nm, 10 mW, 2.5 J/cm2, 0.08 cm2 spot size, and 10 s) was carried out. The cells were divided into four groups: CONTROL [cells grown in Dulbecco’s Modified Eagle Medium (DMEM)], OSTEO (cells grown in an osteogenic medium); PBMT (cells grown in DMEM+PBMT), and OSTEO+PBMT (cells grown in an osteogenic medium-plus PBMT). The cell proliferation curve was obtained over periods of 24, 48 and 72 hours using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Osteogenic differentiation was analyzed by the formation of calcium nodules over periods of 7, 14 and 21 days. Morphometric analysis was performed to quantify the total area of nodular calcification.
Results: The highest cell proliferation and cell differentiation occurred in the OSTEO+PBMT group, followed by the PBMT, OSTEO, and CONTROL groups respectively, at the observed times (P < 0.05).
Conclusion: PBMT enhanced the osteogenic proliferation and the differentiation of hUCMSCs during the periods tested, without causing damage to the cells and preserving their specific characteristics, a fact that may represent an innovative pretreatment in the application of stem cells.

Phototherapy With LED as an Effective Treatment for Chemotherapy-Induced Oral Mucositis in Hamsters

Luana Campos, Claudia Carrara Cotomacio, Victor Elias Arana-Chavez, Alyne Simões

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 475-480

Introduction: Oral mucositis (OM) has been considered one of the most feared collateral effects of oncological treatments. Some therapies have been used, such as light-emitting diode (LED), with promising results, but with no sufficient evidence in the literature.
Objective: Our study aimed to evaluate, by clinical and histological analysis, the effect of LED on the treatment of chemotherapy-induced OM (CIOM) in an animal model.
Methods: Twenty male hamsters were equally distributed to two groups: control (C), which received anesthesia and CIOM induction; and LED (L), which received anesthesia, CIOM induction, and LED treatment (635 nm, 120 mW, 0.48 J). The clinical analysis was performed through two specific scales for OM analysis on days 5, 7 and 10 of the experiment. In addition, the injured area of all hamsters check pouch mucosa was removed and processed for histological analysis on the last experimental day.
Results: After statistical analysis, group L showed less severity of OM when compared with the C group (P < 0.05); beyond that, both healed completely on day 10.
Conclusion: Our results suggested that the phototherapy with LED had a positive effect on accelerating repair, reducing the severity of CIOM.

Low-Level Laser Therapy for Diabetic Dermopathy in Patients With Type 2 Diabetes: A Placebo-Controlled Pilot Study

Nermeen Mohamed Abdelhalim, Walid Kamal Abdelbasset, Bader Ali Alqahtani, Ahmed Fathy Samhan

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 481-485

Introduction: Diabetic dermopathy (DD) is the most common cutaneous diabetes marker. Few studies have targeted DD using low-level laser therapy (LLLT). This pilot study aimed to evaluate the effect of LLLT on DD in patients with type 2 diabetes (T2D).
Methods: 12 patients with T2D (9 men, 3 women) and bilateral DD were enrolled in this placebo-controlled pilot study, and their ages ranged 50-65 years. One side was subjected to LLLT, three sessions weekly for one month (LLLT side), while the other side received the same treatment protocol with a laser device switched off as a placebo (placebo side). All patients were instructed to receive skincare for both sides, such as debridement, antibiotic creams, and dressings with betadine solution. The diameter of DD lesion and the cutaneous blood flow of the knees and ankles sites were assessed before and after one month at the end of the intervention.
Results: At the baseline, no significant differences existed between LLLT and placebo sides in the DD and skin blood flow at the knee and ankle sites (P > 0.05). Post-intervention, a significant improvement occurred in DD diameter and the skin blood flow of the knee and ankle sites in the LLLT side (P < 0.05), while the placebo side showed a significant improvement only in DD diameter (P < 0.05) and non-significant changes in skin blood flow (P > 0.05). Comparing both sides, all measures significantly favored LLLT.
Conclusion: The findings of this study indicate that LLLT has beneficial effects on decreasing DD in T2D patients. Also, it was approved that the short term of LLLT is a safe modality to control DD in T2D patients.

Microshear Bond Strength of Composite Resin to Enamel Treated With Titanium Tetrafluoride and the Carbon Dioxide Laser (10.6 μm): An In Vitro Study

Narges Panahandeh, Mohadese Azarsina, Niyayesh Ostad Hossein, Reza Fekrazad

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 486-490

Introduction: The present study aims to assess the microshear bond strength (μSBS) of composite to enamel treated with titanium tetrafluoride (TiF4) and CO2 laser irradiation.
Methods: Fifteen human molars were sectioned and their enamel surfaces were abraded. The sections were randomly assigned to 5 groups (n = 15): (CO); control group, (AP); treated with 1.23% acidulated phosphate fluoride (APF) for 4 minutes, (Ti); 4% TiF4 for 1 minute, (L+AP); CO2 laser irradiation (10.6 μm wavelength, 1 W peak power, 10 ms pulse duration, 500 ms repetition time, 0.2 mm beam spot size at the tissue level, 2 cm distance of handpiece tip to tissue surface (DSE, South Cores) followed by 1.23% APF, and (L+ Ti); 10.6μm CO2 laser irradiation followed by 4% TiF4 for one minute. Using Tygon tubes, Z250 (3M/ESPE) composite was bonded to the surface of the samples. The μSBS of the composite to enamel was measured using a microtensile testing machine after 500 thermal cycles. The data were analyzed by one-way ANOVA and the Tukey HSD test (P < 0.05).
Results: The mean μSBS was 20.66, 20.21, 13.44, 23.01, and 10.16 MPa in CO, AP, Ti, L+AP, and L+Ti groups respectively. Significant differences were observed between CO and Ti (P = 0.026) and also CO and L+ Ti (P < 0.0001).
Conclusion: The application of TiF4 per se and after CO2 laser irradiation on enamel decreased the μSBS of the composite to enamel; on the other hand, APF alone and after laser irradiation did not have any adverse effect on the μSBS of the composite to the enamel.

Assessment of the Photobiomodulation Effect of a Blue Diode Laser on the Proliferation and Migration of Cultured Human Gingival Fibroblast Cells: A Preliminary In Vitro Study

Ardavan Etemadi, Soheil Taghavi Namin, Mahshid Hodjat, Emad Kosarieh, Neda Hakimiha

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 491-496

Introduction: Photobiomodulation therapy (PBM) is emerging as an effective strategy for the management of wound healing. The application of red and near infra-red light sources in laser therapy has been the subject of most researches in recent literature. Considering the lack of sufficient evidence in assessing the blue light in PBM, we aimed to investigate the photobiomodulation effect of a blue diode laser on the proliferation and migration of cultured human gingival fibroblast cells as a preliminary in vitro study.
Methods: Human gingival fibroblast cells were irradiated with a blue diode laser at a 445 nm wavelength. Irradiation was done using three different powers of 200 mW (irradiation times of 5, 10,15, and 20 seconds); 300 mW (irradiation times of 5, 10, and 15 seconds); and 400 mW (irradiation times of 5 and 10 seconds). The fibroblast cells without laser exposure were considered as control. After 24 hours of incubation, the MTT assay and the wound scratch test were performed on the cells to investigate the biomodulation effect of the blue laser on the proliferation and migration of the cells respectively. The results were analyzed by one-way ANOVA and a post-hoc Tukey test with a P value <0.05 as a statistical significance level.
Results: PBM with blue diode laser at power densities of 400 mW/cm2 with irradiation times of 10 and 15 seconds corresponding to energy densities of 4 and 6 J/cm2 exerted the statistically significant positive effect on both proliferation and migration of gingival fibroblast cells.
Conclusion: Considering the encouraging findings of this study, PBM with blue diode laser can promote proliferation and migration of human gingival fibroblasts, the key cells involved in the process of oral wound healing.

Case Report

Medication-Related Osteonecrosis of the Jaw and Low-Level Laser Therapy as Adjuvant Treatment: A Case Report

Amanda Azevedo Torres, Beatriz Leal de Freitas, Patrick Parry Carneiro, André Luca Araujo de Sousa, Maria Ângela Arêa Leão Ferraz, Jean de Pinho Mendes, André Luiz Ferreira Costa, Antonione Santos Bezerra Pinto

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 497-499

Introduction: Medication-related osteonecrosis of the jaw (MRONJ) occurs by the use of a drug that has osteonecrosis as one of its side effects.
Case Report: We describe a case of a 48-year-old oncological patient who had brain and bone metastasis due to breast cancer and was medicated with bisphosphonates (BPs). She presented cavities, and after an incorrect exodontia, the lesion evolved into jaw osteonecrosis. Then she did a sequestrectomy and was treated using laser therapy. Radiological and clinical features are also described.
Conclusion: In a case like this, we notice how necessary is a complete evaluation of the oncological patient before some procedures and laser therapy as an effective ally in the management.

Case Series

CO2 Laser Treatment in Idiopathic Scrotal Calcinosis: A Case Series

Giovanni Cannarozzo, Luigi Bennardo, Francesca Negosanti, Steven Paul Nisticò

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 500-501

Background: Idiopathic scrotal calcinosis (ISC) is a benign and uncommon condition characterized by the presence of multiple and calcified nodules of the scrotum without disorders in the calcium/phosphorous metabolism. The condition is usually asymptomatic. Various treatments are available. Surgery is the traditional treatment for ISC, as it allows a histopathological exam. However, newer treatments, such as ablative lasers, have been proposed with very good results.
Methods: In this article, we report our experience in the treatment of ISC with a CO2 laser. Five patients affected by ISC were enrolled for CO2 laser treatment.
Results: All patients had excellent healing. Four patients reported minimal scarring. No bleeding was reported after the procedure. Two patients reported itching and were treated with oral antibiotics and antihistamine drugs.
Conclusion: The CO2 super pulsed laser is a fast and effective way to treat ISC and may be an alternative to traditional surgery in this condition.

Excision of different oral benign exophitic lesions with diode laser: A clinical Case Series

Narges Gholizadeh, Jamile beygom Taheri, Zahara Namazi, Fatemeh Mashhadiabbas, Sedigheh Bakhtiari, Arezoo Rahimzamani, Mohammad Asnaashari

Journal of Lasers in Medical Sciences, Vol. 11 No. 4 (2020), 3 October 2020, Page 502-508

Introduction: Lasers are becoming the standard of care for many dental procedures, and are being introduced as a high-tech instrument. They are also becoming more routine in dentistry through the advent of office-based lasers, which are also simple to use within the oral cavity. Many studies have shown the competencies of laser technology for the management of benign oral lesions as these techniques allow for painless and bloodless oral surgery.
Cases Report: Nine patients attending the Department of oral and maxillofacial Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran, underwent laser outpatient procedures for the surgical removal of a wide range of benign oral lesions. Regarding the history, present illnesses and clinical figures of all reported cases, the clinician ensured that the lesions were benign and after taking informed consent from every patient, he did complete the excision of lesions with diode lasers. Following the injection of local anesthesia, an 810 nm diode laser was applied for the excisional biopsy of oral lesions. The specimens were sent for histopathological evaluations and the patients were assessed on intraoperative and postoperative complications. The patients were followed up for postoperative complications at one week and 2 weeks post-treatment.
Conclusions: According to our findings, a diode laser can be a choice for the outpatient treatment of oral mucosal benign lesions as this technique provides the painless and almost bloodless treatment.